Zoom optical system, optical apparatus, imaging apparatus and method for manufacturing the zoom optical system

TECHNICAL FIELD

The present invention relates to a zoom optical system, an optical apparatus and an imaging apparatus including the same, and a method for manufacturing the zoom optical system.

TECHNICAL BACKGROUND

Conventionally, zoom optical systems suitable for photographic cameras, electronic still cameras, video cameras and the like have been proposed (for example, see Patent literature 1).

PRIOR ARTS LIST
Patent Document

Patent literature 1: Japanese Laid-Open Patent Publication No. H4-293007(A)

Unfortunately, according to the conventional zoom optical system, reduction in the weight of a focusing lens group is insufficient.

SUMMARY OF THE INVENTION

A zoom optical system according to the present invention comprises, in order from an object: a front lens group having a positive refractive power; an M1 lens group having a negative refractive power; an M2 lens group having a positive refractive power; an RN lens group having a negative refractive power; and a subsequent lens group, wherein upon zooming, a distance between the front lens group and the M1 lens group changes, a distance between the M1 lens group and the M2 lens group changes, and a distance between the M2 lens group and the RN lens group changes, and upon focusing from an infinite distant object to a short distant object, the RN lens group moves.

An optical apparatus according to the present invention comprises the zoom optical system.

An imaging apparatus according to the present invention comprises: the zoom optical system; and an imaging unit that takes an image formed by the zoom optical system.

A method according to the present invention for manufacturing a zoom optical system comprising, in order from an object, a front lens group having a positive refractive power, an M1 lens group having a negative refractive power, an M2 lens group having a positive refractive power, an RN lens group having a negative refractive power, and a subsequent lens group, comprises achieving an arrangement where upon zooming, a distance between the front lens group and the M1 lens group changes, a distance between the M1 lens group and the M2 lens group changes, and a distance between the M2 lens group and the RN lens group changes, wherein upon focusing from an infinite distant object to a short distant object, the RN lens group moves, the subsequent lens group comprises, in order from the object, a lens having a negative refractive power and a lens having a positive refractive power, and a following conditional expression is satisfied,

0.70<(−fN)/fP<2.00

- where
- fN: a focal length of a lens having a strongest negative refractive power in the subsequent lens group, and
- fP: a focal length of a lens having a strongest positive refractive power in the subsequent lens group.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a lens configuration of a zoom optical system according to a first example of this embodiment;

FIG. 2A is graphs showing various aberrations of the zoom optical system according to the first example upon focusing on infinity in the wide-angle end state, and FIG. 2B is graphs showing meridional lateral aberrations (coma aberrations) when blur correction is applied to a rotational blur by 0.30°;

FIG. 3 is graphs showing various aberrations of the zoom optical system according to the first example upon focusing on infinity in the intermediate focal length state;

FIG. 4A is graphs showing various aberrations of the zoom optical system according to the first example upon focusing on infinity in the telephoto end state, and FIG. 4B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°;

FIGS. 5A, 5B and 5C are graphs showing various aberrations of the zoom optical system according to the first example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIG. 6 shows a lens configuration of a zoom optical system according to a second example of this embodiment;

FIG. 7A is graphs showing various aberrations of the zoom optical system according to the second example upon focusing on infinity in the wide-angle end state, and FIG. 7B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°;

FIG. 8 is graphs showing various aberrations of the zoom optical system according to the second example upon focusing on infinity in the intermediate focal length state;

FIG. 9A is graphs showing various aberrations of the zoom optical system according to the second example upon focusing on infinity in the telephoto end state, and FIG. 9B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°;

FIGS. 10A, 10B and 10C are graphs showing various aberrations of the zoom optical system according to the second example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIG. 11 shows a lens configuration of a zoom optical system according to a third example of this embodiment;

FIG. 12A is graphs showing various aberrations of the zoom optical system according to the third example upon focusing on infinity in the wide-angle end state, and FIG. 12B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°;

FIG. 13 is graphs showing various aberrations of the zoom optical system according to the third example upon focusing on infinity in the intermediate focal length state;

FIG. 14A is graphs showing various aberrations of the zoom optical system according to the third example upon focusing on infinity in the telephoto end state, and FIG. 14B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°;

FIGS. 15A, 15B and 15C are graphs showing various aberrations of the zoom optical system according to the third example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIG. 16 shows a lens configuration of a zoom optical system according to a fourth example of this embodiment;

FIG. 17A is graphs showing various aberrations of the zoom optical system according to the fourth example upon focusing on infinity in the wide-angle end state, and FIG. 17B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°;

FIG. 18 is graphs showing various aberrations of the zoom optical system according to the fourth example upon focusing on infinity in the intermediate focal length state;

FIG. 19A is graphs showing various aberrations of the zoom optical system according to the fourth example upon focusing on infinity in the telephoto end state, and FIG. 19B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°;

FIGS. 20A, 20B and 20C are graphs showing various aberrations of the zoom optical system according to the fourth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIG. 21 shows a lens configuration of a zoom optical system according to a fifth example of this embodiment;

FIG. 22A is graphs showing various aberrations of the zoom optical system according to the fifth example upon focusing on infinity in the wide-angle end state, and FIG. 22B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°;

FIG. 23 is graphs showing various aberrations of the zoom optical system according to the fifth example upon focusing on infinity in the intermediate focal length state;

FIG. 24A is graphs showing various aberrations of the zoom optical system according to the fifth example upon focusing on infinity in the telephoto end state, and FIG. 24B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°;

FIGS. 25A, 25B and 25C are graphs showing various aberrations of the zoom optical system according to the fifth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIG. 26 shows a lens configuration of a zoom optical system according to a sixth example of this embodiment;

FIG. 27A is graphs showing various aberrations of the zoom optical system according to the sixth example upon focusing on infinity in the wide-angle end state, and FIG. 27B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°;

FIG. 28 is graphs showing various aberrations of the zoom optical system according to the sixth example upon focusing on infinity in the intermediate focal length state;

FIG. 29A is graphs showing various aberrations of the zoom optical system according to the sixth example upon focusing on infinity in the telephoto end state, and FIG. 29B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°;

FIGS. 30A, 30B and 30C are graphs showing various aberrations of the zoom optical system according to the sixth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIG. 31 shows a lens configuration of a zoom optical system according to a seventh example of this embodiment;

FIG. 32A is graphs showing various aberrations of the zoom optical system according to the seventh example upon focusing on infinity in the wide-angle end state, and FIG. 32B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°;

FIG. 33 is graphs showing various aberrations of the zoom optical system according to the seventh example upon focusing on infinity in the intermediate focal length state;

FIG. 34A is graphs showing various aberrations of the zoom optical system according to the seventh example upon focusing on infinity in the telephoto end state, and FIG. 34B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°;

FIGS. 35A, 35B and 35C are graphs showing various aberrations of the zoom optical system according to the seventh example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIG. 36 shows a lens configuration of a zoom optical system according to an eighth example of this embodiment;

FIG. 37A is graphs showing various aberrations of the zoom optical system according to the eighth example upon focusing on infinity in the wide-angle end state, and FIG. 37B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°;

FIG. 38 is graphs showing various aberrations of the zoom optical system according to the eighth example upon focusing on infinity in the intermediate focal length state;

FIG. 39A is graphs showing various aberrations of the zoom optical system according to the eighth example upon focusing on infinity in the telephoto end state, and FIG. 39B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°;

FIGS. 40A, 40B and 40C are graphs showing various aberrations of the zoom optical system according to the eighth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIG. 41 shows a lens configuration of a zoom optical system according to a ninth example of this embodiment;

FIG. 42A is graphs showing various aberrations of the zoom optical system according to the ninth example upon focusing on infinity in the wide-angle end state, and FIG. 42B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°;

FIG. 43 is graphs showing various aberrations of the zoom optical system according to the ninth example upon focusing on infinity in the intermediate focal length state;

FIG. 44A is graphs showing various aberrations of the zoom optical system according to the ninth example upon focusing on infinity in the telephoto end state, and FIG. 44B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°;

FIGS. 45A, 45B and 45C are graphs showing various aberrations of the zoom optical system according to the ninth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIG. 46 shows a lens configuration of a zoom optical system according to a tenth example of this embodiment;

FIG. 47A is graphs showing various aberrations of the zoom optical system according to the tenth example upon focusing on infinity in the wide-angle end state, and FIG. 47B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°;

FIG. 48 is graphs showing various aberrations of the zoom optical system according to the tenth example upon focusing on infinity in the intermediate focal length state;

FIG. 49A is graphs showing various aberrations of the zoom optical system according to the tenth example upon focusing on infinity in the telephoto end state, and FIG. 49B is graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°;

FIGS. 50A, 50B and 50C are graphs showing various aberrations of the zoom optical system according to the tenth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIG. 51 shows a lens configuration of a zoom optical system according to an eleventh example of this embodiment;

FIGS. 52A, 52B and 52C are graphs showing various aberrations of the zoom optical system according to the eleventh example upon focusing on infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIGS. 53A, 53B and 53C are graphs showing various aberrations of the zoom optical system according to the eleventh example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIG. 54 shows a lens configuration of a zoom optical system according to a twelfth example of this embodiment;

FIGS. 56A, 56B and 56C are graphs showing various aberrations of the zoom optical system according to the twelfth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIG. 57 shows a lens configuration of a zoom optical system according to a thirteenth example of this embodiment;

FIGS. 59A, 59B and 59C are graphs showing various aberrations of the zoom optical system according to the thirteenth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively;

FIG. 60 shows a configuration of a camera including the zoom optical system according to this embodiment; and

FIG. 61 is a flowchart showing a method for manufacturing the zoom optical system according to this embodiment.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, a zoom optical system, an optical apparatus, and an imaging apparatus of this embodiment are described with reference to the drawings. As shown in FIG. 1, a zoom optical system ZL(1) as an example of a zoom optical system (zoom lens) ZL according to this embodiment comprises, in order from an object: a front lens group GFS having a positive refractive power; an M1 lens group GM1 having a negative refractive power; an M2 lens group GM2 having a positive refractive power; an RN lens group GRN having a negative refractive power; and a subsequent lens group GRS, wherein upon zooming, a distance between the front lens group GFS and the M1 lens group GM1 changes, a distance between the M1 lens group GM1 and the M2 lens group GM2 changes, and a distance between the M2 lens group GM2 and the RN lens group GRN changes, and upon focusing from an infinite distant object to a short distant object, the RN lens group GRN moves.

The zoom optical system ZL according to this embodiment may be a zoom optical system ZL(2) shown in FIG. 6, a zoom optical system ZL(3) shown in FIG. 11, a zoom optical system ZL(4) shown in FIG. 16, a zoom optical system ZL(5) shown in FIG. 21, a zoom optical system ZL(6) shown in FIG. 26, a zoom optical system ZL(7) shown in FIG. 31, a zoom optical system ZL(8) shown in FIG. 36, a zoom optical system ZL(9) shown in FIG. 41, a zoom optical system ZL(10) shown in FIG. 46, a zoom optical system ZL(11) shown in FIG. 51, a zoom optical system ZL(12) shown in FIG. 54, or a zoom optical system ZL(13) shown in FIG. 57.

The zoom optical system of this embodiment includes at least five lens groups, and changes the distances between lens groups upon zooming from the wide-angle end state to the telephoto end state, thereby allowing favorable aberration correction upon zooming to be facilitated. Focusing with the RN lens group GRN can reduce the size and weight of the lens group for zooming. The optical apparatus, the imaging apparatus, and the method for manufacturing the zoom optical system according to this embodiment can also achieve analogous advantageous effects.

In this embodiment, the subsequent lens group GRS may comprise, in order from the object: a lens having a negative refractive power; and a lens having a positive refractive power. Accordingly, various aberrations including the coma aberration can be effectively corrected.

Furthermore, preferably, in the zoom optical system, a following conditional expression (1) is satisfied,

0.70<(−fN)/fP<2.00 (1)

- where
- fN: a focal length of a lens having a strongest negative refractive power in the subsequent lens group GRS, and
- fP: a focal length of a lens having a strongest positive refractive power in the subsequent lens group GRS.

The conditional expression (1) described above defines the ratio of the focal length of the lens that is nearer to the image in the subsequent lens group GRS and has the strongest negative refractive power to the focal length of the lens that is nearer to the image in the subsequent lens group GRS and has the strongest positive refractive power. By satisfying the conditional expression (1), various aberrations including the coma aberration can be effectively corrected.

If the corresponding value of the conditional expression (1) exceeds the upper limit value, the refractive power of the lens that is nearer to the image in the focusing lens group and has a positive refractive power becomes strong, and the coma aberration occurs excessively. Setting of the upper limit value of the conditional expression (1) to 1.90 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable that the upper limit value of the conditional expression (1) be 1.80.

If the corresponding value of the conditional expression (1) falls below the lower limit value, the refractive power of the lens that is nearer to the image in the focusing lens group and has a negative refractive power becomes strong, and the coma aberration is excessively corrected. Setting of the lower limit value of the conditional expression (1) to 0.80 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable that the lower limit value of the conditional expression (1) be 0.90.

In this embodiment, preferably, upon zooming from a wide-angle end state to a telephoto end state, the front lens group GFS moves toward the object. Accordingly, the entire length of the lens at the wide-angle end state can be reduced, which facilitates reduction in the size of the zoom optical system.

In this embodiment, preferably, the RN lens group GRN comprises: at least one lens having a positive refractive power; and at least one lens having a negative refractive power.

In this embodiment, preferably, the zoom optical system satisfies a following conditional expression (2),

0.15<(−fTM1)/f1<0.35 (2)

- where
- fTM1: a focal length of the M1 lens group GM1 in a telephoto end state, and
- f1: a focal length of the front lens group GFS.

The conditional expression (2) defines the ratio of the focal length of the M1 lens group GM1 to the focal length of the front lens group GFS in the telephoto end state. By satisfying the conditional expression (2), various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end can be suppressed.

If the corresponding value of the conditional expression (2) exceeds the upper limit value, the refractive power of the front lens group GFS becomes strong, and it is difficult to correct various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end. Setting of the upper limit value of the conditional expression (2) to 0.33 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable that the upper limit value of the conditional expression (2) be 0.31.

If the corresponding value of the conditional expression (2) falls below the lower limit value, the refractive power of the M1 lens group GM1 becomes strong, and it is difficult to suppress variation in various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end. Setting of the lower limit value of the conditional expression (2) to 0.16 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable that the lower limit value of the conditional expression (2) be 0.17.

In this embodiment, preferably, the zoom optical system satisfies a following conditional expression (3),

0.20<fTM2/f1<0.40 (3)

- where
- fTM2: a focal length of the M2 lens group GM2 in a telephoto end state, and
- f1: a focal length of the front lens group GFS.

The conditional expression (3) defines the ratio of the focal length of the M2 lens group GM2 to the focal length of the front lens group GFS in the telephoto end state. By satisfying the conditional expression (3), various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end can be suppressed.

If the corresponding value of the conditional expression (3) exceeds the upper limit value, the refractive power of the front lens group GFS becomes strong, and it is difficult to correct various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end. Setting of the upper limit value of the conditional expression (3) to 0.37 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable that the upper limit value of the conditional expression (3) be 0.34.

If the corresponding value of the conditional expression (3) falls below the lower limit value, the refractive power of the M2 lens group GM2 becomes strong, and it is difficult to suppress variation in various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end. Setting of the lower limit value of the conditional expression (3) to 0.22 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable that the lower limit value of the conditional expression (3) be 0.24.

In this embodiment, preferably, the system further comprises a negative meniscus lens that has a concave surface facing the object, and is adjacent to an image side of the RN lens group GRN. Accordingly, various aberrations including the coma aberration can be effectively corrected.

In this embodiment, preferably, the zoom optical system satisfies a following conditional expression (4),

1.80<f1/fw<3.50 (4)

- where
- f1: a focal length of the front lens group GFS, and
- fw: a focal length of the zoom optical system in a wide-angle end state.

The conditional expression (4) defines the ratio of the focal length of the front lens group GFS to the focal length of the zoom optical system in the wide-angle end state. By satisfying the conditional expression (4), the size of the lens barrel can be prevented from increasing, and various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end can be suppressed.

If the corresponding value of the conditional expression (4) exceeds the upper limit value, the refractive power of the front lens group GFS becomes weak, and the size of lens barrel increases. Setting of the upper limit value of the conditional expression (4) to 3.30 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable to set the upper limit value of the conditional expression (4) to 3.10.

If the corresponding value of the conditional expression (4) falls below the lower limit value, the refractive power of the front lens group GFS becomes strong, and it is difficult to correct various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end. Setting of the lower limit value of the conditional expression (4) to 1.90 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable to set the lower limit value of the conditional expression (4) to 2.00, and it is more preferable to set the lower limit value of the conditional expression (4) to 2.10.

In this embodiment, preferably, the zoom optical system satisfies a following conditional expression (5),

3.70<f1/(−fTM1)<5.00 (5)

- where
- f1: a focal length of the front lens group GFS, and
- fTM1: a focal length of the M1 lens group GM1 in a telephoto end state.

The conditional expression (5) defines the ratio of the focal length of the front lens group GFS to the focal length of the M1 lens group GM1. By satisfying the conditional expression (5), various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end can be suppressed.

If the corresponding value of the conditional expression (5) exceeds the upper limit value, the refractive power of the M1 lens group GM1 becomes strong, and it is difficult to suppress variation in various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end. Setting of the upper limit value of the conditional expression (5) to 4.90 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable to set the upper limit value of the conditional expression (5) to 4.80.

If the corresponding value of the conditional expression (5) falls below the lower limit value, the refractive power of the front lens group GFS becomes strong, and it is difficult to correct various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end. Setting of the lower limit value of the conditional expression (5) to 3.90 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable to set the lower limit value of the conditional expression (5) to 3.95.

In this embodiment, preferably, the zoom optical system satisfies a following conditional expression (6),

3.20<f1/fTM2<5.00 (6)

- where
- f1: a focal length of the front lens group GFS, and
- fTM2: a focal length of the M2 lens group GM2 in a telephoto end state.

The conditional expression (6) defines the ratio of the focal length of the front lens group GFS to the focal length of the M2 lens group GM2. By satisfying the conditional expression (6), various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end can be suppressed.

If the corresponding value of the conditional expression (6) exceeds the upper limit value, the refractive power of the M2 lens group GM2 becomes strong, and it is difficult to suppress variation in various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end. Setting of the upper limit value of the conditional expression (6) to 4.80 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable to set the upper limit value of the conditional expression (6) to 4.60.

If the corresponding value of the conditional expression (6) falls below the lower limit value, the refractive power of the front lens group GFS becomes strong, and it is difficult to correct various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end. Setting of the lower limit value of the conditional expression (6) to 3.40 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable to set the lower limit value of the conditional expression (6) to 3.60.

In this embodiment, preferably, upon zooming, a lens group nearest to the object in the M1 lens group GM1 is fixed with respect to an image surface. Accordingly, degradation in performance due to manufacturing errors is suppressed, which can secure mass-productivity.

In this embodiment, preferably, the M2 lens group GM2 comprises a vibration-proof lens group movable in a direction orthogonal to an optical axis to correct an imaging position displacement due to a camera shake or the like. Such arrangement of the vibration-proof lens group in the M2 lens group GM2 can effectively suppress degradation in performance upon blur correction.

In this embodiment, preferably, the vibration-proof lens group consists of, in order from the object: a lens having a negative refractive power; and a lens having a positive refractive power. Accordingly, degradation in performance upon blur correction can be effectively suppressed.

In this embodiment, preferably, the zoom optical system satisfies a following conditional expression (7),

1.00<nvrN/nvrP<1.25 (7)

- where
- nvrN: a refractive index of the lens having the negative refractive power in the vibration-proof lens group, and
- nvrP: a refractive index of the lens having the positive refractive power in the vibration-proof lens group.

The conditional expression (7) defines the ratio of the refractive index of the lens that is in the vibration-proof lens group provided in the M2 lens group GM2 and has a negative refractive power to the refractive index of the lens that is in the vibration-proof lens group and has a positive refractive power. By satisfying the conditional expression (7), degradation in performance upon blur correction can be effectively suppressed.

If the corresponding value of the conditional expression (7) exceeds the upper limit value, the refractive index of the lens that is in the vibration-proof lens group and has a positive refractive power decreases, the decentering coma aberration caused upon blur correction excessively occurs, and it becomes difficult to correct the aberration. Setting of the upper limit value of the conditional expression (7) to 1.22 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable that the upper limit value of the conditional expression (7) be 1.20.

If the corresponding value of the conditional expression (7) is in this range, the refractive index of the lens that is in the vibration-proof lens group and has a negative refractive power is appropriate, and the decentering coma aberration upon blur correction is favorably corrected, which is preferable. Setting of the lower limit value of the conditional expression (7) to 1.03 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable that the lower limit value of the conditional expression (7) be 1.05.

In this embodiment, preferably, the zoom optical system satisfies a following conditional expression (8),

0.30<νvrN/νvrP<0.90 (8)

- where
- νvrN: an Abbe number of the lens having the negative refractive power in the vibration-proof lens group, and
- νvrP: an Abbe number of the lens having the positive refractive power in the vibration-proof lens group.

The conditional expression (8) defines the ratio of the Abbe number of the lens that is in the vibration-proof lens group and has a negative refractive power to the Abbe number of the lens that is in the vibration-proof lens group and has a positive refractive power. By satisfying the conditional expression (8), degradation in performance upon blur correction can be effectively suppressed.

If the corresponding value of the conditional expression (8) is in this range, the Abbe number of the lens that is in the vibration-proof lens group and has a positive refractive power is appropriate, and the chromatic aberration caused upon blur correction is favorably corrected, which is preferable. Setting of the upper limit value of the conditional expression (8) to 0.85 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable that the upper limit value of the conditional expression (8) be 0.80.

If the corresponding value of the conditional expression (8) falls below the lower limit value, the Abbe number of the lens that is in the vibration-proof lens group and has a negative refractive power decreases, and it becomes difficult to correct the chromatic aberration caused upon blur correction. Setting of the lower limit value of the conditional expression (8) to 0.35 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable that the lower limit value of the conditional expression (8) be 0.40.

In this embodiment, preferably, the M1 lens group GM1 also comprises a vibration-proof lens group movable in a direction orthogonal to an optical axis to correct an imaging position displacement due to a camera shake or the like. In this case, preferably, the vibration-proof lens group consists of, in order from the object: a lens having a negative refractive power; and a lens having a positive refractive power.

In this embodiment, preferably, the zoom optical system satisfies a following conditional expression (9),

0.80<nvrN/nvrP<1.00 (9)

- where
- nvrN: a refractive index of the lens having the negative refractive power in the vibration-proof lens group, and
- nvrP: a refractive index of the lens having the positive refractive power in the vibration-proof lens group.

The conditional expression (9) defines the ratio of the refractive index of the lens that is in the vibration-proof lens group provided in the M1 lens group GM1 and has a negative refractive power to the refractive index of the lens that is in the vibration-proof lens group provided in the M1 lens group GM1 and has a positive refractive power. By satisfying the conditional expression (9), degradation in performance upon blur correction can be effectively suppressed.

If the corresponding value of the conditional expression (9) exceeds the upper limit value, the refractive index of the lens that is in the vibration-proof lens group provided in the M1 lens group GM1 and has a positive refractive power decreases, and it becomes difficult to correct the decentering coma aberration caused upon blur correction. Setting of the upper limit value of the conditional expression (9) to 0.98 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable to set the upper limit value of the conditional expression (9) to 0.96.

If the corresponding value of the conditional expression (9) falls below the lower limit value, the refractive index of the lens that is in the vibration-proof lens group provided in the M1 lens group GM1 and has a negative refractive power decreases, and it becomes difficult to correct the decentering coma aberration caused upon blur correction. Setting of the lower limit value of the conditional expression (9) to 0.82 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable to set the lower limit value of the conditional expression (9) to 0.84.

In this embodiment, preferably, the zoom optical system satisfies a following conditional expression (10),

1.20<νvrN/νvrP<2.40 (10)

- where
- νvrN: an Abbe number of the lens having the negative refractive power in the vibration-proof lens group, and
- νvrP: an Abbe number of the lens having the positive refractive power in the vibration-proof lens group.

The conditional expression (10) defines the ratio of the Abbe number of the lens that is in the vibration-proof lens group provided in the M1 lens group GM1 and has a negative refractive power to the Abbe number of the lens that is in the vibration-proof lens group provided in the M1 lens group GM1 and has a positive refractive power. By satisfying the conditional expression (10), degradation in performance upon blur correction can be effectively suppressed.

If the corresponding value of the conditional expression (10) exceeds the upper limit value, the Abbe number of the lens that is in the vibration-proof lens group provided in the M1 lens group GM1 and has a positive refractive power significantly decreases. Accordingly, it becomes difficult to correct the chromatic aberration caused upon blur correction. Setting of the upper limit value of the conditional expression (10) to 2.30 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable to set the upper limit value of the conditional expression (10) to 2.20.

If the corresponding value of the conditional expression (10) falls below the lower limit value, the Abbe number of the lens that is in the vibration-proof lens group provided in the M1 lens group GM1 and has a negative refractive power significantly decreases. Accordingly, it becomes difficult to correct the chromatic aberration caused upon blur correction. Setting of the lower limit value of the conditional expression (10) to 1.30 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable to set the lower limit value of the conditional expression (10) to 1.40.

In this embodiment, preferably, the subsequent lens group GRS comprises a lens having a positive refractive power. Accordingly, various aberrations including the coma aberration can be effectively corrected.

In this case, preferably, the zoom optical system satisfies a following conditional expression (2),

0.15<(−fTM1)/f1<0.35 (2)

Note that the conditional expression (2) is the same as described above. The details are as described above.

Also in this case, if the corresponding value of the conditional expression (2) exceeds the upper limit value, the refractive power of the front lens group GFS becomes strong, and it is difficult to correct various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end. Setting of the upper limit value of the conditional expression (2) to 0.33 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable that the upper limit value of the conditional expression (2) be 0.31.

In the case described above, preferably, the zoom optical system satisfies a following conditional expression (3),

0.20<fTM2/f1<0.40 (3)

The conditional expression (3) is the same as described above. The details are as described above.

Also in this case, if the corresponding value of the conditional expression (3) exceeds the upper limit value, the refractive power of the front lens group GFS becomes strong, and it is difficult to correct various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end. Setting of the upper limit value of the conditional expression (3) to 0.37 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable that the upper limit value of the conditional expression (3) be 0.34.

In the case described above, preferably, the zoom optical system satisfies a following conditional expression (4),

1.80<f1/fw<3.50 (4)

The conditional expression (4) is the same as described above. The details are as described above.

Also in this case, if the corresponding value of the conditional expression (4) exceeds the upper limit value, the refractive power of the front lens group GFS becomes weak, and the size of lens barrel increases. Setting of the upper limit value of the conditional expression (4) to 3.30 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable to set the upper limit value of the conditional expression (4) to 3.10.

Furthermore, in the case described above, preferably, the zoom optical system satisfies a following conditional expression (5),

3.70<f1/(−fTM1)<5.00 (5)

The conditional expression (5) is the same as described above. The details are as described above.

Also in this case, if the corresponding value of the conditional expression (5) exceeds the upper limit value, the refractive power of the M1 lens group GM1 becomes strong, and it is difficult to suppress variation in various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end. Setting of the upper limit value of the conditional expression (5) to 4.90 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable to set the upper limit value of the conditional expression (5) to 4.80.

Furthermore, in the case described above, preferably, the zoom optical system satisfies a following conditional expression (6),

3.20<f1/fTM2<5.00 (6)

The conditional expression (6) is the same as described above. The details are as described above.

Also in this case, if the corresponding value of the conditional expression (6) exceeds the upper limit value, the refractive power of the M2 lens group GM2 becomes strong, and it is difficult to suppress variation in various aberrations including the spherical aberration upon zooming from the wide-angle end to the telephoto end. Setting of the upper limit value of the conditional expression (6) to 4.80 can more securely achieve the advantageous effects of this embodiment. To further secure the advantageous effects of this embodiment, it is preferable to set the upper limit value of the conditional expression (6) to 4.60.

An optical apparatus and an imaging apparatus according to this embodiment comprise the zoom optical system having the configuration described above. As a specific example, a camera (corresponding to the imaging apparatus of the invention of the present application) including the aforementioned zoom optical system ZL is described with reference to FIG. 60. As shown in FIG. 60, this camera 1 has a lens assembly configuration including a replaceable imaging lens 2. The zoom optical system having the configuration described above is provided in the imaging lens 2. That is, the imaging lens 2 corresponds to the optical apparatus of the invention of the present application. The camera 1 is a digital camera. Light from an object (subject), not shown, is collected by the imaging lens 2, and reaches an imaging element 3. Accordingly, the light from the subject is imaged by the imaging element 3, and recorded as a subject image in a memory, not shown. As described above, a photographer can take an image of the subject through the camera 1. Note that this camera may be a mirrorless camera, or a single-lens reflex type camera including a quick return mirror.

According to the configuration described above, the camera 1 mounted with the zoom optical system ZL described above in the imaging lens 2 can achieve high-speed AF and silence during AF without increasing the size of the lens barrel by reducing the size and weight of the focusing lens group. Furthermore, variation of aberrations upon zooming from the wide-angle end state to the telephoto end state, and variation of aberrations upon focusing from an infinite distant object to a short distant object can be favorably suppressed, and a favorable optical performance can be achieved.

Subsequently, referring to FIG. 61, an overview of a method for manufacturing the aforementioned zoom optical system ZL is described. First, arrange, in order from an object, a front lens group GFS having a positive refractive power, an M1 lens group GM1 having a negative refractive power, an M2 lens group GM2 having a positive refractive power, an RN lens group GRN having a negative refractive power, and a subsequent lens group GRS (step ST1). Then, achieve a configuration such that upon zooming, a distance between the front lens group GFS and the M1 lens group GM1 changes, a distance between the M1 lens group GM1 and the M2 lens group GM2 changes, and a distance between the M2 lens group GM2 and the RN lens group GRN changes, (step ST2). In this case, achieve a configuration such that upon focusing from an infinite distant object to a short distant object, the RN lens group GRN moves (step ST3), and configure the subsequent lens group GRS to include, in order from the object, a lens having a negative refractive power, and a lens having a positive refractive power (step ST4). Furthermore, arrange each lens so as to satisfy a predetermined conditional expression (step ST5).

EXAMPLES

Hereinafter, zoom optical systems (zoom lens) ZL according to the examples of this embodiment are described with reference to the drawings. FIGS. 1, 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 54 and 57 are sectional views showing the configurations and refractive power distributions of the zoom optical systems ZL {ZL(1) to ZL(13)} according to first to thirteenth examples. At lower parts of the sectional views of the zoom optical systems ZL(1) to ZL(13), the movement direction of each lens group along the optical axis during zooming from the wide-angle end state (W) to the telephoto end state (T) is indicated by a corresponding arrow. Furthermore, the movement direction during focusing the focusing group GRN from infinity to a short distant object is indicated by an arrow accompanied by characters “FOCUSING.”

FIGS. 1, 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 54 and 57 show each lens group by a combination of a symbol G and a numeral or alphabet(s), and show each lens by a combination of a symbol L and a numeral. In this case, to prevent the types and numbers of symbols and numerals from increasing and being complicated, the lens groups and the like are indicated using the combinations of symbols and numerals independently on an example-by-example basis. Accordingly, even though the same combinations of symbols and numerals are used among the examples, the combinations do not mean the same configurations.

Tables 1 to 13 are hereinafter shown below. Tables 1 to 13 are tables representing various data in the first to thirteenth examples. In each example, d-line (wavelength 587.562 nm) and g-line (wavelength 435.835 nm) are selected as calculation targets of aberration characteristics.

In [Lens data] tables, the surface number denotes the order of optical surfaces from the object along a light beam traveling direction, R denotes the radius of curvature (a surface whose center of curvature is nearer to the image is assumed to have a positive value) of each optical surface, D denotes the surface distance, which is the distance on the optical axis from each optical surface to the next optical surface (or the image surface), nd denotes the refractive index of the material of an optical element for the d-line, and νd denotes the Abbe number of the material of an optical element with reference to the d-line. The object surface denotes the surface of an object. “∞” of the radius of curvature indicates a flat surface or an aperture. (Stop S) indicates an aperture stop S. The image surface indicates an image surface I. The description of the air refractive index nd=1.00000 is omitted.

In [Various data] tables, f denotes the focal length of the entire zoom lens, FNO denotes the f-number, 2ω denotes the angle of view (represented in units of ° (degree); ω denotes the half angle of view), and Ymax denotes the maximum image height. TL denotes the distance obtained by adding BF to the distance on the optical axis from the lens forefront surface to the lens last surface upon focusing on infinity. BF denotes the distance (back focus) on the optical axis from the lens last surface to the image surface I upon focusing on infinity. Note that these values are represented for zooming states of the wide-angle end (W), the intermediate focal length (M), and the telephoto end (T).

[Variable distance data] tables show the surface distances at surface numbers (e.g., surface numbers 5, 13, 25 and 29 in First Example) to which the surface distance of “Variable” in the table representing [Lens data] correspond. This shows the surface distances in the zooming states of the wide-angle end (W), the intermediate focal length (M) and the telephoto end (T) upon focusing on infinity and a short distant object.

[Lens group data] tables show the starting surfaces (the surfaces nearest to the object) and the focal lengths of the first to fifth lens groups (or the sixth lens group).

[Conditional expression corresponding value] tables show values corresponding to the conditional expressions (1) to (10) described above. Here, not all the examples necessarily correspond to all the conditional expressions. Accordingly, the values of the corresponding conditional expressions in each example are shown.

Hereinafter, for all the data values, the listed focal length f, radius of curvature R, surface distance D, other lengths and the like are typically represented in “mm” if not otherwise specified. However, the optical system can exert equivalent optical performances even if being proportionally magnified or proportionally reduced. Consequently, the representation is not limited thereto.

The above descriptions of the tables are common to all the examples. Hereinafter, redundant description is omitted.

First Example

The first example is described with reference to FIG. 1 and Table 1. FIG. 1 shows a lens configuration of a zoom optical system according to the first example of this embodiment. The zoom optical system ZL(1) according to this example consists of, in order from the object: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a positive refractive power; a fourth lens group G4 having a negative refractive power; and a fifth lens group G5 having a positive refractive power. The sign (+) or (−) assigned to each lens group symbol indicates the refractive power of the corresponding lens group. This similarly applies to all the following examples.

In relation to the embodiment described above, in this configuration, the first lens group G1 corresponds to the front lens group GFS, the second lens group G2 corresponds to the M1 lens group GM1, the third lens group G3 corresponds to the M2 lens group GM2, the fourth lens group G4 corresponds to the RN lens group GRN, and the fifth lens group G5 corresponds to the subsequent lens group GRS.

The first lens group G1 consists of, in order from the object: a positive convexo-planar lens L11 having a convex surface facing the object; and a positive cemented lens consisting of a negative meniscus lens L12 having a convex surface facing the object, and a positive meniscus lens L13 having a convex surface facing the object.

The second lens group G2 consists of, in order from the object: a negative meniscus lens L21 having a convex surface facing the object; a positive biconvex lens L22; a negative biconcave lens L23; and a negative meniscus lens L24 having a concave surface facing the object.

The third lens group G3 consists of, in order from the object: a positive cemented lens consisting of a negative meniscus lens L31 having a convex surface facing the object, and a positive biconvex lens L32; a positive cemented lens consisting of a positive biconvex lens L33, and a negative biconcave lens L34; an aperture stop S; a negative cemented lens consisting of a negative meniscus lens L35 having a convex surface facing the object, and a positive biconvex lens L36; and a positive biconvex lens L37.

The fourth lens group G4 consists of, in order from the object: a positive meniscus lens L41 having a concave surface facing the object; and a negative biconcave lens L42.

The fifth lens group G5 consists of, in order from the object: a negative meniscus lens L51 having a concave surface facing the object; and a positive biconvex lens L52.

In the optical system according to this example, focusing from a long distant object to a short distant object is performed by moving the fourth lens group G4 in the image surface direction.

The zoom optical system according to this example corrects the imaging position displacement due to a camera shake or the like (vibration proof) by moving the positive cemented lens that consists of the negative meniscus lens L31 having the convex surface facing the object and the positive biconvex lens L32 and is included in the third lens group G3 (M2 lens group GM2), in a direction orthogonal to the optical axis.

To correct a rotational blur with an angle θ at a lens having the focal length f of the entire system and a vibration proof coefficient K (the ratio of the amount of image movement on the image forming surface to the amount of movement of the movable lens group upon blur correction), the movable lens group for blur correction may be moved in a direction orthogonal to the optical axis by (f·tan θ)/K. At the wide-angle end in the first example, the vibration proof coefficient is 1.65, and the focal length is 72.1 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.30° is 0.23 mm. In the telephoto end state in the first example, the vibration proof coefficient is 2.10, and the focal length is 292.0 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.20° is 0.49 mm.

The following Table 1 lists the values of data on the optical system according to this example. In Table 1, f denotes the focal length, and BF denotes the back focus.

TABLE 1

First Example

[Lens data]

Surface No.
R
D
nd
νd

Object surface
∞

1
109.4870
4.600
1.48749
70.31

2
∞
0.200

3
101.1800
1.800
1.62004
36.40

4
49.8109
7.200
1.49700
81.61

5
385.8166
Variable

6
176.0187
1.700
1.69680
55.52

7
31.3680
5.150

8
32.6087
5.500
1.78472
25.64

9
−129.7634
1.447

10
−415.4105
1.300
1.77250
49.62

11
34.3083
4.300

12
−33.1502
1.200
1.85026
32.35

13
−203.5644
Variable

14
70.9040
1.200
1.80100
34.92

15
30.2785
5.900
1.64000
60.20

16
−70.1396
1.500

17
34.0885
6.000
1.48749
70.31

18
−42.6106
1.300
1.80610
40.97

19
401.2557
2.700

20
∞
14.110

(Stop S)

21
350.0000
1.200
1.83400
37.18

22
30.1592
4.800
1.51680
63.88

23
−94.9908
0.200

24
66.3243
2.800
1.80100
34.92

25
−132.5118
Variable

26
−92.0997
2.200
1.80518
25.45

27
−44.0090
6.500

28
−36.9702
1.000
1.77250
49.62

29
68.3346
Variable

30
−24.5000
1.400
1.62004
36.40

31
−41.1519
0.200

32
106.0000
3.800
1.67003
47.14

33
−106.0000
BF

Image surface
∞

[Various data]

Zooming ratio 4.05

W
M
T

f
72.1
100.0
292.0

FNO
4.49
4.86
5.88

2ω
33.96
24.48
8.44

Ymax
21.60
21.60
21.60

TL
190.13
205.07
245.82

BF
39.12
46.45
67.12

[Variable distance data]

W
M
T

W
M
T
Short
Short
Short

Infinity
Infinity
Infinity
distance
distance
distance

d5
6.204
21.150
61.895
6.204
21.150
61.895

d13
30.000
22.666
2.000
30.000
22.666
2.000

d25
2.180
3.742
3.895
2.837
4.562
5.614

d29
21.418
19.856
19.703
20.761
19.036
17.984

[Lens group data]

Group
Starting surface
f

G1
1
145.319

G2
6
−29.546

G3
14
38.298

G4
26
−48.034

G5
30
324.470

[Conditional expression corresponding value]

(1)
(−fN)/fP = 1.266

(2)
(−fTM1)/f1 = 0.203

(3)
fTM2/f1 = 0.264

(4)
f1/fw = 2.016

(5)
f1/(−fTM1) = 4.918

(6)
f−/fTM2 = 3.794

(7)
nvrN/nvrP = 1.098

(8)
νvrN/νvrP = 0.580

FIGS. 2A and 2B are graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the first example upon focusing on infinity in the wide-angle end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°, respectively. FIG. 3 is graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the first example upon focusing on infinity in the intermediate focal length state. FIGS. 4A and 4B are graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the first example upon focusing on infinity in the telephoto end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°, respectively. FIGS. 5A, 5B and 5C are graphs showing various aberrations of the zoom optical system according to the first example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.

In the aberration graphs of FIGS. 2 to 5, FNO denotes the f-number, NA denotes the numerical aperture, and Y denotes the image height. Note that the spherical aberration graph shows the value of the f-number or the numerical aperture corresponding to the maximum aperture. The astigmatism graph and the distortion graph show the maximum value of the image height. The coma aberration graph shows the value of each image height. d denotes the d-line (λ=587.6 nm), and g denotes the g-line (λ=435.8 nm). In the astigmatism graph, solid lines indicate sagittal image surfaces, and broken lines indicate meridional image surfaces. Note that symbols analogous to those in this example are used also in the aberration graphs in the following examples.

The graphs showing various aberrations show that the zoom optical system according to this example favorably corrects the various aberrations and has excellent image forming performances from the wide-angle end state to the telephoto end state, and further has excellent image forming performances also upon focusing on a short distant object.

Second Example

FIG. 6 shows a lens configuration of a zoom optical system according to the second example of the present application. The zoom optical system according to this example consists of, in order from the object: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a negative refractive power; a fourth lens group G4 having a positive refractive power; a fifth lens group G5 having a negative refractive power; and a sixth lens group G6 having a positive refractive power.

In relation to the embodiment described above, in this configuration, the first lens group G1 corresponds to the front lens group GFS, the second lens group G2 and the third lens group G3 correspond to the M1 lens group GM1, the fourth lens group G4 corresponds to the M2 lens group GM2, the fifth lens group G5 corresponds to the RN lens group GRN, and the sixth lens group G6 corresponds to the subsequent lens group GRS.

The second lens group G2 consists of, in order from the object: a negative meniscus lens L21 having a convex surface facing the object; a positive biconvex lens L22; and a negative biconcave lens L23.

The third lens group G3 consists of a negative meniscus lens L31 having a concave surface facing the object.

The fourth lens group G4 consists of, in order from the object: a positive cemented lens consisting of a negative meniscus lens L41 having a convex surface facing the object, and a positive biconvex lens L42; a positive cemented lens consisting of a positive biconvex lens L43, and a negative biconcave lens L44; an aperture stop S; a negative cemented lens consisting of a negative meniscus lens L45 having a convex surface facing the object, and a positive biconvex lens L46; and a positive biconvex lens L47.

The fifth lens group G5 consists of, in order from the object: a positive meniscus lens L51 having a concave surface facing the object; and a negative biconcave lens L52.

The sixth lens group G6 consists of, in order from the object: a negative meniscus lens L61 having a concave surface facing the object; and a positive biconvex lens L62.

In the optical system according to this example, focusing from a long distant object to a short distant object is performed by moving the fifth lens group G5 in the image surface direction. The imaging position displacement due to a camera shake or the like is corrected by moving the positive cemented lens that consists of the negative meniscus lens L41 having the convex surface facing the object and the positive biconvex lens L42 and is included in the fourth lens group G4 (M2 lens group GM2), in a direction orthogonal to the optical axis.

Note that to correct a rotational blur with an angle θ at a lens having the focal length f of the entire system and a vibration proof coefficient K (the ratio of the amount of image movement on the image forming surface to the amount of movement of the movable lens group upon blur correction), the movable lens group for blur correction is moved in a direction orthogonal to the optical axis by (f·tan θ)/K. At the wide-angle end in the second example, the vibration proof coefficient is 1.66, and the focal length is 72.1 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.30° is 0.23 mm. In the telephoto end state in the second example, the vibration proof coefficient is 2.10, and the focal length is 292.0 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.20° is 0.49 mm.

The following Table 2 lists the values of data on the optical system according to this example.

TABLE 2

Second Example

[Lens data]

Surface No.
R
D
nd
νd

Object surface
∞

1
107.5723
4.600
1.48749
70.32

2
∞
0.200

3
96.9007
1.800
1.62004
36.40

4
47.8324
7.200
1.49700
81.61

5
361.3792
Variable

6
139.8663
1.700
1.69680
55.52

7
33.7621
6.806

8
33.5312
5.500
1.78472
25.64

9
−139.8348
0.637

10
−492.0620
1.300
1.80400
46.60

11
35.1115
Variable

12
−34.6163
1.200
1.83400
37.18

13
−377.1306
Variable

14
74.8969
1.200
1.80100
34.92

15
31.6202
5.900
1.64000
60.19

16
−69.0444
1.500

17
34.2668
6.000
1.48749
70.32

18
−42.8334
1.300
1.80610
40.97

19
434.9585
2.700

20
∞
14.312

(Stop S)

21
350.0000
1.200
1.83400
37.18

22
30.4007
4.800
1.51680
63.88

23
−98.0361
0.200

24
68.9306
2.800
1.80100
34.92

25
−129.3404
Variable

26
−90.5065
2.200
1.80518
25.45

27
−44.1796
6.500

28
−37.6907
1.000
1.77250
49.62

29
68.3000
Variable

30
−24.5545
1.400
1.62004
36.40

31
−41.7070
0.200

32
106.0000
3.800
1.67003
47.14

33
−106.0000
BF

Image surface
∞

[Various data]

Zooming ratio 4.05

W
M
T

f
72.1
100.0
292.0

FNO
4.53
4.89
5.88

2ω
33.98
24.48
8.44

Ymax
21.60
21.60
21.60

TL
190.82
206.02
245.82

BF
39.12
46.27
66.46

[Variable distance data]

W
M
T

W
M
T
Short
Short
Short

Infinity
Infinity
Infinity
distance
distance
distance

d5
2.861
18.057
57.861
2.861
18.057
57.861

d11
5.727
5.812
6.883
5.727
5.812
6.883

d13
30.500
23.259
2.000
30.500
23.259
2.000

d25
2.246
3.634
3.634
2.888
4.436
5.329

d29
22.411
21.023
21.023
21.770
20.221
19.329

[Lens group data]

Group
Starting surface
f

G1
1
141.867

G2
6
−104.910

G3
12
−45.774

G4
14
38.681

G5
26
−48.266

G6
30
340.779

[Conditional expression corresponding value]

(1)
(−fN)/fP = 1.248

(2)
(−fTM1)/f1 = 0.208

(3)
fTM2/f1 = 0.273

(4)
f1/fw = 1.968

(5)
f1/(−fTM1) = 4.804

(6)
f1/fTM2 = 3.668

(7)
nvrN/nvrP = 1.098

(8)
νvrN/νvrP = 0.580

FIGS. 7A and 7B are graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the second example upon focusing on infinity in the wide-angle end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°, respectively. FIG. 8 is graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the second example upon focusing on infinity in the intermediate focal length state. FIGS. 9A and 9B are graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the second example upon focusing on infinity in the telephoto end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°, respectively. FIGS. 10A, 10B and 10C are graphs showing various aberrations of the zoom optical system according to the second example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.

Third Example

FIG. 11 shows a lens configuration of a zoom optical system according to the third example of the present application. The zoom optical system according to this example consists of, in order from the object: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a positive refractive power; a fourth lens group G4 having a positive refractive power; a fifth lens group G5 having a negative refractive power; and a sixth lens group G6 having a positive refractive power.

In relation to the embodiment described above, in this configuration, the first lens group G1 corresponds to the front lens group GFS, the second lens group G2 corresponds to the M1 lens group GM1, the third lens group G3 and the fourth lens group G4 correspond to the M2 lens group GM2, the fifth lens group G5 corresponds to the RN lens group GRN, and the sixth lens group G6 corresponds to the subsequent lens group GRS.

The fourth lens group G4 consists of, in order from the object: a negative cemented lens consisting of a negative meniscus lens L41 having a convex surface facing the object, and a positive biconvex lens L42; and a positive biconvex lens L43.

The fifth lens group G5 consists of, in order from the object: a positive meniscus lens L51 having a concave surface facing the object; and a negative biconcave lens L52.

The sixth lens group G6 consists of, in order from the object: a negative meniscus lens L61 having a concave surface facing the object; and a positive biconvex lens L62.

In the optical system according to this example, focusing from a long distant object to a short distant object is performed by moving the fifth lens group G5 in the image surface direction. The imaging position displacement due to a camera shake or the like is corrected by moving the positive cemented lens that consists of the negative meniscus lens L31 having the convex surface facing the object and the positive biconvex lens L32 and is included in the third lens group G3 (M2 lens group GM2), in a direction orthogonal to the optical axis.

Note that to correct a rotational blur with an angle θ at a lens having the focal length f of the entire system and a vibration proof coefficient K (the ratio of the amount of image movement on the image forming surface to the amount of movement of the movable lens group upon blur correction), the movable lens group for blur correction is moved in a direction orthogonal to the optical axis by (f·tan θ)/K. At the wide-angle end in the third example, the vibration proof coefficient is 1.65, and the focal length is 72.1 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.30° is 0.23 mm. In the telephoto end state in the third example, the vibration proof coefficient is 2.10, and the focal length is 292.0 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.20° is 0.49 mm.

The following Table 3 lists the values of data on the optical system according to this example.

TABLE 3

Third Example

[Lens data]

Surface No.
R
D
nd
νd

Object surface
∞

1
106.7563
4.600
1.48749
70.32

2
∞
0.200

3
99.4635
1.800
1.62004
36.40

4
49.2336
7.200
1.49700
81.61

5
332.7367
Variable

6
152.3830
1.700
1.69680
55.52

7
31.0229
5.695

8
32.0867
5.500
1.78472
25.64

9
−139.5695
1.399

10
−403.4713
1.300
1.77250
49.62

11
33.8214
4.300

12
−34.0003
1.200
1.85026
32.35

13
−235.0206
Variable

14
69.3622
1.200
1.80100
34.92

15
29.8420
5.900
1.64000
60.19

16
−71.2277
1.500

17
34.4997
6.000
1.48749
70.32

18
−43.1246
1.300
1.80610
40.97

19
382.2412
2.700

20
∞
Variable

(Stop S)

21
350.0000
1.200
1.83400
37.18

22
30.6178
4.800
1.51680
63.88

23
−88.2508
0.200

24
66.4312
2.800
1.80100
34.92

25
−142.7832
Variable

26
−93.6206
2.200
1.80518
25.45

27
−44.3477
6.500

28
−37.1859
1.000
1.77250
49.62

29
68.3000
Variable

30
−24.9508
1.400
1.62004
36.40

31
−42.7086
0.200

32
106.0000
3.800
1.67003
47.14

33
−106.0000
BF

Image surface
∞

[Various data]

Zooming ratio 4.05

W
M
T

f
72.1
100.0
292.0

FNO
4.49
4.85
5.88

2ω
33.98
24.48
8.44

Ymax
21.60
21.60
21.60

TL
190.26
205.79
245.82

BF
39.12
46.10
67.12

[Variable distance data]

W
M
T

W
M
T
Short
Short
Short

Infinity
Infinity
Infinity
distance
distance
distance

d5
5.981
21.510
61.535
5.981
21.510
61.535

d13
30.000
23.014
2.000
30.000
23.014
2.000

d20
14.365
14.107
14.196
14.365
14.107
14.196

d25
2.202
3.476
3.676
2.867
4.301
5.396

d29
21.004
19.988
19.700
20.339
19.163
17.979

[Lens group data]

Group
Starting surface
f

G1
1
145.335

G2
6
−29.607

G3
14
48.974

G4
21
62.364

G5
26
−48.296

G6
30
336.791

[Conditional expression corresponding value]

(1)
(−fN)/fP = 1.253

(2)
(−fTM1)/f1 = 0.204

(3)
fTM2/f1 = 0.264

(4)
f1/fw = 2.016

(5)
f1/(−fTM1) = 4.909

(6)
f1/fTM2 = 3.786

(7)
nvrN/nvrP = 1.098

(8)
νvrN/νvrP = 0.580

FIGS. 12A and 12B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the third example upon focusing on infinity in the wide-angle end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°, respectively. FIG. 13 is graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the third example upon focusing on infinity in the intermediate focal length state. FIGS. 14A and 14B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the third example upon focusing on infinity in the telephoto end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°, respectively. FIGS. 15A, 15B and 15C are graphs showing various aberrations of the zoom optical system according to the third example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.

Fourth Example

FIG. 16 shows a lens configuration of a zoom optical system according to the fourth example of the present application. The zoom optical system according to this example consists of, in order from the object: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a positive refractive power; a fourth lens group G4 having a negative refractive power; and a fifth lens group G5 having a positive refractive power.

The fourth lens group G4 consists of, in order from the object: a positive meniscus lens L41 having a concave surface facing the object; and a negative biconcave lens L42.

The fifth lens group G5 consists of, in order from the object: a negative meniscus lens L51 having a concave surface facing the object; a positive biconvex lens L52; and a positive meniscus lens L53 having a convex surface facing the object.

In the optical system according to this example, focusing from a long distant object to a short distant object is performed by moving the fourth lens group G4 in the image surface direction. The imaging position displacement due to a camera shake or the like is corrected by moving the positive cemented lens that consists of the negative meniscus lens L31 having the convex surface facing the object and the positive biconvex lens L32 and is included in the third lens group G3 (M2 lens group GM2), in a direction orthogonal to the optical axis.

Note that to correct a rotational blur with an angle θ at a lens having the focal length f of the entire system and a vibration proof coefficient K (the ratio of the amount of image movement on the image forming surface to the amount of movement of the movable lens group upon blur correction), the movable lens group for blur correction is moved in a direction orthogonal to the optical axis by (f·tan θ)/K. At the wide-angle end in the fourth example, the vibration proof coefficient is 1.65, and the focal length is 72.1 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.30° is 0.23 mm. In the telephoto end state in the fourth example, the vibration proof coefficient is 2.10, and the focal length is 292.0 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.20° is 0.49 mm.

The following Table 4 lists the values of data on the optical system according to this example.

TABLE 4

Fourth Example

[Lens data]

Surface No.
R
D
nd
νd

Object surface
∞

1
109.5099
4.600
1.48749
70.32

2
∞
0.200

3
101.8486
1.800
1.62004
36.40

4
49.8873
7.200
1.49700
81.61

5
403.0130
Variable

6
166.1577
1.700
1.69680
55.52

7
31.1882
3.953

8
32.0256
5.500
1.78472
25.64

9
−139.5816
1.553

10
−767.2482
1.300
1.77250
49.62

11
33.9202
4.300

12
−32.8351
1.200
1.85026
32.35

13
−256.2484
Variable

14
69.5902
1.200
1.80100
34.92

15
29.9877
5.900
1.64000
60.19

16
−70.0411
1.500

17
36.2271
6.000
1.48749
70.32

18
−39.9358
1.300
1.80610
40.97

19
820.8027
2.700

20
∞
14.092

(Stop S)

21
427.1813
1.200
1.83400
37.18

22
31.7606
4.800
1.51680
63.88

23
−89.4727
0.200

24
73.5865
2.800
1.80100
34.92

25
−110.0493
Variable

26
−83.7398
2.200
1.80518
25.45

27
−42.9999
6.500

28
−36.8594
1.000
1.77250
49.62

29
73.0622
Variable

30
−26.0662
1.400
1.62004
36.4

31
−40.4068
0.200

32
143.0444
3.035
1.67003
47.14

33
−220.8402
0.200

34
100.4330
2.145
1.79002
47.32

35
170.3325
BF

Image surface
∞

[Various data]

Zooming ratio 4.05

W
M
T

f
72.1
100.0
292.0

FNO
4.48
4.85
5.87

2ω
33.94
24.44
8.42

Ymax
21.60
21.60
21.60

TL
190.21
205.27
245.82

BF
39.12
46.37
67.13

[Variable distance data]

W
M
T

W
M
T
Short
Short
Short

Infinity
Infinity
Infinity
distance
distance
distance

d5
5.892
20.953
61.502
5.892
20.953
61.502

d13
30.000
22.752
2.000
30.000
22.752
2.000

d25
2.212
3.707
3.900
2.864
4.521
5.606

d29
21.306
19.811
19.618
20.654
18.997
17.912

[Lens group data]

Group
Starting surface
f

G1
1
145.022

G2
6
−29.562

G3
14
38.233

G4
26
−48.257

G5
30
318.066

[Conditional expression corresponding value]

(1)
(−fN)/fP = 0.947

(2)
(−fTM1)/f1 = 0.204

(3)
fTM2/f1 = 0.264

(4)
f1/fw = 2.011

(5)
f1/(−fTM1) = 4.906

(6)
f1/fTM2 = 3.793

(7)
nvrN/nvrP = 1.098

(8)
νvrN/νvrP = 0.580

FIGS. 17A and 17B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the fourth example upon focusing on infinity in the wide-angle end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°, respectively. FIG. 18 is graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the fourth example upon focusing on infinity in the intermediate focal length state. FIGS. 19A and 19B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the fourth example upon focusing on infinity in the telephoto end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°, respectively. FIGS. 20A, 20B and 20C are graphs showing various aberrations of the zoom optical system according to the fourth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.

Fifth Example

The fifth example is described with reference to FIGS. 21 to 25 and Table 5. FIG. 21 shows a lens configuration of a zoom optical system according to the fifth example of this embodiment. The zoom optical system ZL(5) according to the fifth example consists of, in order from the object: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a positive refractive power; a fourth lens group G4 having a negative refractive power; and a fifth lens group G5 having a positive refractive power. Upon zooming from the wide-angle end state (W) to the telephoto end state (T), the first to fifth lens groups G1 to G5 move in the directions indicated by the respective arrows in FIG. 21.

The first lens group G1 consists of, in order from the object: a positive meniscus lens L11 having a convex surface facing the object; and a positive cemented lens consisting of a negative meniscus lens L12 having a convex surface facing the object, and a positive biconvex lens L13.

The second lens group G2 consists of, in order from the object: a negative meniscus lens L21 having a convex surface facing the object; a positive biconvex lens L22; a negative biconcave lens L23; and a negative cemented lens consisting of a negative biconcave lens L24, and a positive meniscus lens L25 having a convex surface facing the object.

The third lens group G3 consists of, in order from the object: a positive biconvex lens L31; a positive cemented lens consisting of a positive biconvex lens L32 and a negative biconcave lens L33; an aperture stop S; a positive cemented lens consisting of a negative meniscus lens L34 having a convex surface facing the object, and a positive biconvex lens L35; and a positive biconvex lens L36.

The fourth lens group G4 consists of, in order from the object: a positive meniscus lens L41 having a concave surface facing the object; and a negative biconcave lens L42.

The fifth lens group G5 consists of, in order from the object: a negative meniscus lens L51 having a concave surface facing the object; and a positive meniscus lens L52 having a convex surface facing the object. An image surface I is disposed to the image side of the fifth lens group G5.

In the zoom optical system ZL(5) according to the fifth example, the entire fourth lens group G4 constitutes the focusing lens group, and focusing from a long distant object to a short distant object is performed by moving the entire fourth lens group G4 in the image surface direction. In the zoom optical system ZL(5) according to the fifth example, the negative cemented lens, which consists of the negative lens L24 and the positive meniscus lens L25 and is included in the second lens group G2 (M1 lens group GM1), constitutes the vibration-proof lens group movable in a direction perpendicular to the optical axis, and corrects the imaging position displacement (image blur on the image surface I) due to a camera shake or the like.

Note that to correct a rotational blur with an angle θ at a lens having the focal length f of the entire system and a vibration proof coefficient K (the ratio of the amount of image movement on the image forming surface to the amount of movement of the movable lens group upon blur correction), the movable lens group for blur correction is moved in a direction orthogonal to the optical axis by (f·tan θ)/K. In the wide-angle end state in the fifth example, the vibration proof coefficient is 0.97, and the focal length is 72.1 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.30° is 0.39 mm. In the telephoto end state in the fifth example, the vibration proof coefficient is 2.01, and the focal length is 292.0 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.20° is 0.51 mm.

The following Table 5 lists the values of data on the optical system according to the fifth example.

TABLE 5

Fifth Example

[Lens data]

Surface No.
R
D
nd
νd

Object surface
∞

1
121.1094
4.980
1.48749
70.31

2
474.6427
0.200

3
104.9110
1.700
1.83400
37.18

4
63.9583
9.069
1.49700
81.73

5
−1816.1542
Variable

6
153.9285
1.000
1.83400
37.18

7
37.0130
9.180

8
41.8122
5.321
1.80518
25.45

9
−148.0087
1.552

10
−153.0936
1.000
1.90366
31.27

11
74.4958
4.888

12
−65.0702
1.000
1.69680
55.52

13
35.9839
3.310
1.83400
37.18

14
121.5659
Variable

15
85.1793
3.534
1.80400
46.60

16
−101.3301
0.200

17
38.9890
5.033
1.49700
81.73

18
−62.2191
1.200
1.95000
29.37

19
378.6744
1.198

20
∞
19.885

(Stop S)

21
44.8832
1.200
1.85026
32.35

22
20.5002
4.485
1.51680
63.88

23
−586.4581
0.200

24
64.4878
2.563
1.62004
36.40

25
−357.2881
Variable

26
−801.6030
2.383
1.80518
25.45

27
−50.3151
1.298

28
−57.1873
1.000
1.77250
49.62

29
26.1668
Variable

30
−21.0000
1.300
1.77250
49.62

31
−28.8136
0.200

32
58.9647
3.137
1.62004
36.40

33
524.5289
BF

Image surface
∞

[Various data]

Zooming ratio 4.05

W
M
T

f
72.1
99.9
292.0

FNO
4.57
4.79
5.88

2ω
33.24
23.82
8.24

Ymax
21.60
21.60
21.60

TL
191.32
204.14
241.16

BF
38.52
42.04
60.52

[Variable distance data]

W
M
T

W
M
T
Short
Short
Short

Infinity
Infinity
Infinity
distance
distance
distance

d5
2.000
22.163
69.630
2.000
22.163
69.630

d14
41.783
30.929
2.000
41.783
30.929
2.000

d25
2.000
3.259
2.000
2.462
3.867
3.166

d29
14.999
13.740
14.999
14.538
13.133
13.833

[Lens group data]

Group
Starting surface
f

G1
1
167.635

G2
6
39.933

G3
15
37.727

G4
26
−36.765

G5
30
2825.740

[Conditional expression corresponding value]

(1)
(−fN)/fP = 1.011

(2)
(−fTM1)/f1 = 0.238

(3)
fTM2/f1 = 0.225

(4)
f1/fw = 2.325

(5)
f1/(−fTM1) = 4.198

(6)
f1/fTM2 = 4.443

(9)
nvrN/nvrP = 0.925

(10)
νvrN/νvrP = 1.493

FIGS. 22A and 22B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the fifth example upon focusing on infinity in the wide-angle end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°, respectively. FIG. 23 is graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the fifth example upon focusing on infinity in the intermediate focal length state. FIGS. 24A and 24B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the fifth example upon focusing on infinity in the telephoto end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°, respectively. FIGS. 25A, 25B and 25C are graphs showing various aberrations of the zoom optical system according to the fifth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.

The graphs showing various aberrations show that the zoom optical system according to fifth example favorably corrects the various aberrations and has excellent image forming performances from the wide-angle end state to the telephoto end state, and further has excellent image forming performances also upon focusing on a short distant object.

Sixth Example

The sixth example is described with reference to FIGS. 26 to 30 and Table 6. FIG. 26 shows a lens configuration of a zoom optical system according to the sixth example of this embodiment. The zoom optical system ZL(6) according to the sixth example consists of, in order from the object: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a positive refractive power; a fourth lens group G4 having a negative refractive power; and a fifth lens group G5 having a negative refractive power. Upon zooming from the wide-angle end state (W) to the telephoto end state (T), the first to fifth lens groups G1 to G5 move in the directions indicated by the respective arrows in FIG. 26.

The second lens group G2 consists of, in order from the object: a negative meniscus lens L21 having a convex surface facing the object; a positive cemented lens consisting of a positive biconvex lens L22 and a negative biconcave lens L23; and a negative cemented lens consisting of a negative biconcave lens L24, and a positive meniscus lens L25 having a convex surface facing the object.

The third lens group G3 consists of, in order from the object: a positive biconvex lens L31; a positive cemented lens consisting of a positive biconvex lens L32 and a negative biconcave lens L33; an aperture stop S; a negative cemented lens consisting of a negative meniscus lens L34 having a convex surface facing the object, and a positive meniscus lens L35 having a convex surface facing the object; and a positive biconvex lens L36.

The fourth lens group G4 consists of, in order from the object: a positive meniscus lens L41 having a concave surface facing the object; and a negative biconcave lens L42.

In the zoom optical system ZL(6) according to the sixth example, the entire fourth lens group G4 constitutes the focusing lens group, and focusing from a long distant object to a short distant object is performed by moving the entire fourth lens group G4 in the image surface direction. In the zoom optical system ZL(6) according to the sixth example, the negative cemented lens, which consists of the negative lens L24 and the positive meniscus lens L25 and is included in the second lens group G2 (M1 lens group GM1), constitutes the vibration-proof lens group movable in a direction perpendicular to the optical axis, and corrects the imaging position displacement (image blur on the image surface I) due to a camera shake or the like.

Note that to correct a rotational blur with an angle θ at a lens having the focal length f of the entire system and a vibration proof coefficient K (the ratio of the amount of image movement on the image forming surface to the amount of movement of the movable lens group upon blur correction), the movable lens group for blur correction is moved in a direction orthogonal to the optical axis by (f·tan θ)/K. In the wide-angle end state in the sixth example, the vibration proof coefficient is 0.93, and the focal length is 72.1 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.30° is 0.41 mm. In the telephoto end state in the sixth example, the vibration proof coefficient is 1.90, and the focal length is 292.0 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.20° is 0.54 mm.

The following Table 6 lists the values of data on the optical system according to the sixth example.

TABLE 6

Sixth Example

[Lens data]

Surface No.
R
D
nd
νd

Object surface
∞

1
114.5391
5.639
1.48749
70.31

2
663.8041
0.200

3
103.9783
1.700
1.83400
37.18

4
62.4686
8.805
1.49700
81.73

5
−43979.1830
Variable

6
146.6152
1.000
1.77250
49.62

7
35.8241
11.693

8
37.5245
4.696
1.68893
31.16

9
−254.6834
1.000
1.83400
37.18

10
64.6045
5.066

11
−60.5874
1.000
1.56883
56.00

12
39.1203
2.952
1.75520
27.57

13
93.1442
Variable

14
92.3597
3.688
1.80400
46.60

15
−87.7395
0.200

16
36.8528
5.291
1.49700
81.73

17
−63.3187
1.200
1.95000
29.37

18
264.8384
1.289

19
∞
19.911

(Stop S)

20
52.0583
1.200
1.85026
32.35

21
20.7485
3.983
1.51680
63.88

22
439.3463
0.200

23
64.0215
2.788
1.62004
36.40

24
−130.2911
Variable

25
−343.5287
2.371
1.80518
25.45

26
−47.6881
1.474

27
−51.9782
1.000
1.77250
49.62

28
29.6298
Variable

29
−21.0360
1.300
1.60300
65.44

30
−30.1613
0.200

31
64.8879
2.981
1.57501
41.51

32
614.9077
BF

Image surface
∞

[Various data]

Zooming ratio 4.05

W
M
T

f
72.1
99.9
292.0

FNO
4.59
4.76
5.87

2ω
33.22
23.72
8.22

Ymax
21.60
21.60
21.60

TL
191.32
205.16
240.15

BF
38.52
41.03
60.02

[Variable distance data]

W
M
T

W
M
T
Short
Short
Short

Infinity
Infinity
Infinity
distance
distance
distance

d5
2.000
23.304
67.717
2.000
23.304
67.717

d13
40.383
30.413
2.000
40.383
30.413
2.000

d24
2.000
3.305
2.001
2.487
3.962
3.248

d28
15.588
14.284
15.587
15.101
13.626
14.340

[Lens group data]

Group
Starting surface
f

G1
1
161.728

G2
6
−38.469

G3
14
38.469

G4
25
−39.083

G5
29
−12107.081

[Conditional expression corresponding value]

(1)
(−fN)/fP = 0.968

(2)
(−fTM1)/f1 = 0.238

(3)
fTM2/f1 = 0.238

(4)
f1/fw = 2.243

(5)
f1/(−fTM1) = 4.204

(6)
f1/fTM2 = 4.204

(9)
nvrN/nvrP = 0.894

(10)
νvrN/νvrP = 2.031

FIGS. 27A and 27B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the sixth example upon focusing on infinity in the wide-angle end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°, respectively. FIG. 28 is graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the sixth example upon focusing on infinity in the intermediate focal length state. FIGS. 29A and 29B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the sixth example upon focusing on infinity in the telephoto end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°, respectively. FIGS. 30A, 30B and 30C are graphs showing various aberrations of the zoom optical system according to the sixth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.

The graphs showing various aberrations show that the zoom optical system according to sixth example favorably corrects the various aberrations and has excellent image forming performances from the wide-angle end state to the telephoto end state, and further has excellent image forming performances also upon focusing on a short distant object.

Seventh Example

The seventh example is described with reference to FIGS. 31 to 35 and Table 7. FIG. 31 shows a lens configuration of a zoom optical system according to the seventh example of this embodiment. The zoom optical system ZL(7) according to the seventh example consists of, in order from the object: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a positive refractive power; a fourth lens group G4 having a negative refractive power; and a fifth lens group G5 having a positive refractive power. Upon zooming from the wide-angle end state (W) to the telephoto end state (T), the first to fifth lens groups G1 to G5 move in the directions indicated by the respective arrows in FIG. 31.

The first lens group G1 consists of, in order from the object: a positive biconvex lens L11; and a positive cemented lens consisting of a negative meniscus lens L12 having a convex surface facing the object, and a positive biconvex lens L13.

The third lens group G3 consists of, in order from the object: a positive biconvex lens L31; a positive cemented lens consisting of a positive biconvex lens L32 and a negative biconcave lens L33; an aperture stop S; and a positive cemented lens consisting of a negative meniscus lens L34 having a convex surface facing the object, and a positive biconvex lens L35.

The fourth lens group G4 consists of, in order from the object: a positive meniscus lens L41 having a concave surface facing the object; and a negative biconcave lens L42.

The fifth lens group G5 consists of, in order from the object: a negative meniscus lens L51 having a concave surface facing the object; and a positive biconvex lens L52. An image surface I is disposed to the image side of the fifth lens group G5.

In the zoom optical system ZL(7) according to the seventh example, the entire fourth lens group G4 constitutes the focusing lens group, and focusing from a long distant object to a short distant object is performed by moving the entire fourth lens group G4 in the image surface direction. In the zoom optical system ZL(7) according to the seventh example, the negative cemented lens, which consists of the negative lens L24 and the positive meniscus lens L25 and is included in the second lens group G2 (M1 lens group GM1), constitutes the vibration-proof lens group movable in a direction perpendicular to the optical axis, and corrects the imaging position displacement (image blur on the image surface I) due to a camera shake or the like.

Note that to correct a rotational blur with an angle θ at a lens having the focal length f of the entire system and a vibration proof coefficient K (the ratio of the amount of image movement on the image forming surface to the amount of movement of the movable lens group upon blur correction), the movable lens group for blur correction is moved in a direction orthogonal to the optical axis by (f·tan θ)/K. In the wide-angle end state in the seventh example, the vibration proof coefficient is 0.96, and the focal length is 72.1 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.30° is 0.39 mm. In the telephoto end state in the seventh example, the vibration proof coefficient is 2.00, and the focal length is 292.0 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.20° is 0.51 mm.

The following Table 7 lists the values of data on the optical system according to the seventh example.

TABLE 7

Seventh Example

[Lens data]

Surface No.
R
D
nd
νd

Object surface
∞

1
268.8673
3.827
1.48749
70.31

2
−1922.6559
0.200

3
111.5860
1.700
1.62004
36.40

4
61.6123
8.761
1.49700
81.73

5
−1745.4439
Variable

6
124.2629
1.000
1.77250
49.62

7
34.3759
7.147

8
35.3149
5.189
1.60342
38.03

9
−190.5775
1.000
1.77250
49.62

10
75.4448
4.904

11
−65.2960
1.000
1.67003
47.14

12
37.2634
3.301
1.80518
25.45

13
119.9726
Variable

14
80.9765
3.968
1.77250
49.62

15
−78.4621
0.200

16
33.2120
5.701
1.49700
81.73

17
−56.7466
1.200
1.85026
32.35

18
108.8392
1.685

19
∞
18.569

(Stop S)

20
40.1917
1.200
1.85026
32.35

21
18.3878
4.752
1.54814
45.79

22
−98.0255
Variable

23
−121.4042
2.367
1.75520
27.57

24
−36.6433
2.111

25
−37.5895
1.000
1.77250
49.62

26
35.8631
Variable

27
−21.0000
1.300
1.60311
60.69

28
−30.2149
0.200

29
95.7916
3.938
1.67003
47.14

30
−115.9256
BF

Image surface
∞

[Various data]

Zooming ratio 4.05

W
M
T

f
72.1
99.9
292.0

ENO
4.61
4.79
5.87

2ω
33.52
23.90
8.28

Ymax
21.60
21.60
21.60

TL
191.32
207.98
243.25

BF
38.52
41.37
61.52

[Variable distance data]

W
M
T

W
M
T
Short
Short
Short

Infinity
Infinity
Infinity
distance
distance
distance

d5
2.000
25.429
72.273
2.000
25.429
72.273

d13
43.342
33.718
2.000
43.342
33.718
2.000

d22
2.000
3.210
3.710
2.512
3.900
5.147

d26
19.235
18.025
17.525
18.723
17.335
16.088

[Lens group data]

Group
Starting surface
f

G1
1
169.647

G2
6
−39.988

G3
14
38.817

G4
23
−37.515

G5
27
207.702

[Conditional expression corresponding value]

(1)
(−fN)/fP = 1.529

(2)
(−fTM1)/f1 = 0.236

(3)
fTM2/f1 = 0.229

(4)
f1/fw = 2.353

(5)
f1/(−fTM1) = 4.242

(6)
f1/fTM2 = 4.370

(9)
nvrN/nvrP = 0.925

(10)
νvrN/νvrP = 1.852

FIGS. 32A and 32B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the seventh example upon focusing on infinity in the wide-angle end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°, respectively. FIG. 33 is graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the seventh example upon focusing on infinity in the intermediate focal length state. FIGS. 34A and 34B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the seventh example upon focusing on infinity in the telephoto end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°, respectively. FIGS. 35A, 35B and 35C are graphs showing various aberrations of the zoom optical system according to the seventh example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.

The graphs showing various aberrations show that the zoom optical system according to seventh example favorably corrects the various aberrations and has excellent image forming performances from the wide-angle end state to the telephoto end state, and further has excellent image forming performances also upon focusing on a short distant object.

Eighth Example

The eighth example is described with reference to FIGS. 36 to 40 and Table 8. FIG. 36 shows a lens configuration of a zoom optical system according to the eighth example of this embodiment. The zoom optical system ZL(8) according to the eighth example consists of, in order from the object: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a positive refractive power; a fourth lens group G4 having a negative refractive power; and a fifth lens group G5 having a positive refractive power. Upon zooming from the wide-angle end state (W) to the telephoto end state (T), the first to fifth lens groups G1 to G5 move in the directions indicated by the respective arrows in FIG. 36.

The third lens group G3 consists of, in order from the object: a positive biconvex lens L31; a positive cemented lens consisting of a positive biconvex lens L32 and a negative biconcave lens L33; an aperture stop S; and a positive cemented lens consisting of a negative meniscus lens L34 having a convex surface facing the object, and a positive biconvex lens L35.

The fourth lens group G4 consists of, in order from the object: a positive meniscus lens L41 having a concave surface facing the object; and a negative biconcave lens L42.

The fifth lens group G5 consists of: a negative meniscus lens L51 having a concave surface facing the object; and a positive biconvex lens L52. An image surface I is disposed to the image side of the fifth lens group G5.

In the zoom optical system ZL(8) according to the eighth example, the positive meniscus lens L41 and the negative lens L42 in the fourth lens group G4 constitute the focusing lens group, and focusing from a long distant object to a short distant object is performed by moving the positive meniscus lens L41 and the negative lens L42 in the fourth lens group G4 in the image surface direction. In the zoom optical system ZL(8) according to the eighth example, the negative cemented lens, which consists of the negative lens L24 and the positive meniscus lens L25 and is included in the second lens group G2 (M1 lens group GM1), constitutes the vibration-proof lens group movable in a direction perpendicular to the optical axis, and corrects the imaging position displacement (image blur on the image surface I) due to a camera shake or the like.

Note that to correct a rotational blur with an angle θ at a lens having the focal length f of the entire system and a vibration proof coefficient K (the ratio of the amount of image movement on the image forming surface to the amount of movement of the movable lens group upon blur correction), the movable lens group for blur correction is moved in a direction orthogonal to the optical axis by (f·tan θ)/K. In the wide-angle end state in the eighth example, the vibration proof coefficient is 1.05, and the focal length is 72.1 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.30° is 0.36 mm. In the telephoto end state in the eighth example, the vibration proof coefficient is 2.20, and the focal length is 292.0 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.20° is 0.46 mm.

The following Table 8 lists the values of data on the optical system according to the eighth example.

TABLE 8

Eighth Example

[Lens data]

Surface No.
R
D
nd
νd

Object surface
∞

1
384.8872
4.307
1.48749
70.31

2
−459.3665
0.200

3
108.5471
1.700
1.62004
36.40

4
59.1633
8.722
1.49700
81.73

5
−3828.8091
Variable

6
116.0785
1.000
1.77250
49.62

7
33.3782
6.789

8
34.8547
5.123
1.64769
33.73

9
−166.2311
1.000
1.80400
46.60

10
68.6485
5.021

11
−58.3172
1.000
1.66755
41.87

12
33.1524
3.543
1.80518
25.45

13
108.5224
Variable

14
80.6236
4.111
1.77250
49.62

15
−73.7947
0.200

16
32.8485
5.846
1.49700
81.73

17
−53.4390
1.200
1.85026
32.35

18
100.1735
1.748

19
∞
17.032

(Stop S)

20
45.6071
1.200
1.80100
34.92

21
18.9488
5.048
1.54814
45.79

22
−90.5382
Variable

23
−106.0821
2.387
1.72825
28.38

24
−35.2284
2.066

25
−36.8890
1.000
1.77250
49.62

26
46.9619
Variable

27
−21.5153
1.300
1.60311
60.69

28
−31.7338
0.200

29
126.4587
3.612
1.77250
49.62

30
−132.9868
BF

Image surface
∞

[Various data]

Zooming ratio 4.05

W
M
T

f
72.1
99.9
292.0

FNO
4.60
4.77
5.88

2ω
33.56
23.82
8.26

Ymax
21.60
21.60
21.60

TL
192.32
210.67
244.12

BF
38.52
40.08
57.94

[Variable distance data]

W
M
T

W
M
T
Short
Short
Short

Infinity
Infinity
Infinity
distance
distance
distance

d5
2.000
25.713
69.580
2.000
25.713
69.580

d13
40.783
32.701
2.000
40.783
32.701
2.000

d22
2.000
3.163
5.584
2.559
3.917
7.234

d26
23.661
23.661
23.661
23.103
22.908
22.012

[Lens group data]

Group
Starting surface
f

G1
1
164.404

G2
6
−37.386

G3
14
38.634

G4
23
−43.744

G5
27
272.771

[Conditional expression corresponding value]

(1)
(−fN)/fP = 1.378

(2)
(−fTM1)/f1 = 0.227

(3)
fTM2/f1 = 0.235

(4)
f1/fw = 2.280

(5)
f1/(−fTM1) = 4.397

(6)
f1/fTM2 = 4.255

(9)
nvrN/nvrP = 0.924

(10)
νvrN/νvrP = 1.645

FIGS. 37A and 37B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the eighth example upon focusing on infinity in the wide-angle end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°, respectively. FIG. 38 is graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the eighth example upon focusing on infinity in the intermediate focal length state. FIGS. 39A and 39B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the eighth example upon focusing on infinity in the telephoto end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°, respectively. FIGS. 40A, 40B and 40C are graphs showing various aberrations of the zoom optical system according to the eighth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.

The graphs showing various aberrations show that the zoom optical system according to eighth example favorably corrects the various aberrations and has excellent image forming performances from the wide-angle end state to the telephoto end state, and further has excellent image forming performances also upon focusing on a short distant object.

Ninth Example

The ninth example is described with reference to FIGS. 41 to 45 and Table 9. FIG. 41 shows a lens configuration of a zoom optical system according to the ninth example of this embodiment. The zoom optical system ZL(9) according to the ninth example consists of, in order from the object: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a positive refractive power; a fourth lens group G4 having a negative refractive power; and a fifth lens group G5 having a positive refractive power. Upon zooming from the wide-angle end state (W) to the telephoto end state (T), the first to fifth lens groups G1 to G5 move in the directions indicated by the respective arrows in FIG. 41.

The second lens group G2 consists of, in order from the object: a negative meniscus lens L21 having a convex surface facing the object; a positive meniscus lens L22 having a convex surface facing the object; and a negative cemented lens consisting of a negative biconcave lens L23, and a positive meniscus lens L24 having a convex surface facing the object.

The third lens group G3 consists of, in order from the object: a positive biconvex lens L31; a positive cemented lens consisting of a positive biconvex lens L32 and a negative biconcave lens L33; an aperture stop S; and a positive cemented lens consisting of a negative meniscus lens L34 having a convex surface facing the object, and a positive biconvex lens L35.

The fourth lens group G4 consists of, in order from the object: a positive meniscus lens L41 having a concave surface facing the object; and a negative biconcave lens L42.

In the zoom optical system ZL(9) according to the ninth example, the entire fourth lens group G4 constitutes the focusing lens group, and focusing from a long distant object to a short distant object is performed by moving the entire fourth lens group G4 in the image surface direction. In the zoom optical system ZL(9) according to the ninth example, the negative cemented lens, which consists of the negative lens L23 and the positive meniscus lens L24 and is included in the second lens group G2 (M1 lens group GM1), constitutes the vibration-proof lens group movable in a direction perpendicular to the optical axis, and corrects the imaging position displacement (image blur on the image surface I) due to a camera shake or the like.

Note that to correct a rotational blur with an angle θ at a lens having the focal length f of the entire system and a vibration proof coefficient K (the ratio of the amount of image movement on the image forming surface to the amount of movement of the movable lens group upon blur correction), the movable lens group for blur correction is moved in a direction orthogonal to the optical axis by (f·tan θ)/K. In the wide-angle end state in the ninth example, the vibration proof coefficient is 1.02, and the focal length is 72.1 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.30° is 0.37 mm. In the telephoto end state in the ninth example, the vibration proof coefficient is 2.10, and the focal length is 292.0 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.20° is 0.49 mm.

The following Table 9 lists the values of data on the optical system according to the ninth example.

TABLE 9

Ninth Example

[Lens data]

Surface No.
R
D
nd
νd

Object surface
∞

1
494.4763
3.486
1.48749
70.31

2
−654.7200
0.200

3
104.3848
1.700
1.62004
36.40

4
60.0944
8.673
1.49700
81.73

5
−2277.9468
Variable

6
131.3496
1.300
1.80400
46.60

7
35.6812
7.900

8
36.7192
2.871
1.68893
31.16

9
62.4101
4.726

10
−66.4912
1.000
1.70000
48.11

11
36.3174
3.414
1.80518
25.45

12
127.2974
Variable

13
90.0733
3.862
1.80400
46.60

14
−78.6804
0.200

15
33.8033
5.583
1.49700
81.73

16
−57.6791
1.200
1.85026
32.35

17
101.7237
1.726

18
∞
19.598

(Stop S)

19
49.9975
1.200
1.85026
32.35

20
20.1023
4.713
1.54814
45.79

21
−72.4003
Variable

22
−158.4470
2.458
1.71736
29.57

23
−37.7406
1.732

24
−39.9149
1.000
1.77250
49.62

25
43.7406
Variable

26
−22.3495
1.300
1.69680
55.52

27
−32.8093
0.200

28
139.7659
3.301
1.80610
40.97

29
−141.5832
BF

Image surface
∞

[Various data]

Zooming ratio 4.05

W
M
T

f
72.1
99.9
292.0

FNO
4.68
4.85
5.88

2ω
33.48
23.86
8.26

Ymax
21.60
21.60
21.60

TL
192.32
208.96
243.67

BF
38.32
41.06
60.32

[Variable distance data]

W
M
T

W
M
T
Short
Short
Short

Infinity
Infinity
Infinity
distance
distance
distance

d5
2.000
26.074
74.834
2.000
26.074
77.834

d12
45.487
35.318
2.000
45.487
35.318
2.000

d21
2.000
3.315
2.845
2.597
4.123
4.511

d25
21.171
19.856
20.326
20.574
19.048
18.660

[Lens group data]

Group
Starting surface
f

G1
1
171.348

G2
6
−41.929

G3
13
40.969

G4
22
−45.959

G5
26
423.598

[Conditional expression corresponding value]

(1)
(−fN)/fP = 1.209

(2)
(−fTM1)/f1 = 0.245

(3)
fTM2/f1 = 0.239

(4)
f1/fw = 2.377

(5)
f1/(−fTM1) = 4.087

(6)
f1/fTM2 = 4.182

(9)
nvrN/nvrP = 0.942

(10)
νvrN/νvrP = 1.890

FIGS. 42A and 42B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the ninth example upon focusing on infinity in the wide-angle end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°, respectively. FIG. 43 is graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the ninth example upon focusing on infinity in the intermediate focal length state. FIGS. 44A and 44B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the ninth example upon focusing on infinity in the telephoto end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°, respectively. FIGS. 45A, 45B and 45C are graphs showing various aberrations of the zoom optical system according to the ninth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.

The graphs showing various aberrations show that the zoom optical system according to ninth example favorably corrects the various aberrations and has excellent image forming performances from the wide-angle end state to the telephoto end state, and further has excellent image forming performances also upon focusing on a short distant object.

Tenth Example

The tenth example is described with reference to FIGS. 46 to 50 and Table 10. FIG. 46 shows a lens configuration of a zoom optical system according to the tenth example of this embodiment. The zoom optical system ZL(10) according to the tenth example consists of, in order from the object: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a positive refractive power; a fourth lens group G4 having a negative refractive power; and a fifth lens group G5 having a positive refractive power. Upon zooming from the wide-angle end state (W) to the telephoto end state (T), the first to fifth lens groups G1 to G5 move in the directions indicated by the respective arrows in FIG. 46.

The first lens group G1 consists of, in order from the object: a positive cemented lens consisting of a negative meniscus lens L11 having a convex surface facing the object, and a positive biconvex lens L12; and a positive meniscus lens L13 having a convex surface facing the object.

The second lens group G2 consists of, in order from the object: a positive biconvex lens L21; a negative biconcave lens L22; a positive meniscus lens L23 having a convex surface facing the object; and a negative cemented lens consisting of a negative biconcave lens L24, and a positive meniscus lens L25 having a convex surface facing the object.

The third lens group G3 consists of, in order from the object: a positive biconvex lens L31; a positive cemented lens consisting of a positive biconvex lens L32 and a negative biconcave lens L33; an aperture stop S; and a positive cemented lens consisting of a negative meniscus lens L34 having a convex surface facing the object, and a positive biconvex lens L35.

The fourth lens group G4 consists of, in order from the object: a positive biconvex lens L41; and a negative biconcave lens L42.

In the zoom optical system ZL(10) according to the tenth example, the entire fourth lens group G4 constitutes the focusing lens group, and focusing from a long distant object to a short distant object is performed by moving the entire fourth lens group G4 in the image surface direction. In the zoom optical system ZL(10) according to the tenth example, the negative cemented lens, which consists of the negative lens L24 and the positive meniscus lens L25 and is included in the second lens group G2 (M1 lens group GM1), constitutes the vibration-proof lens group movable in a direction perpendicular to the optical axis, and corrects the imaging position displacement (image blur on the image surface I) due to a camera shake or the like.

Note that to correct a rotational blur with an angle θ at a lens having the focal length f of the entire system and a vibration proof coefficient K (the ratio of the amount of image movement on the image forming surface to the amount of movement of the movable lens group upon blur correction), the movable lens group for blur correction is moved in a direction orthogonal to the optical axis by (f·tan θ)/K. In the wide-angle end state in the tenth example, the vibration proof coefficient is 1.01, and the focal length is 72.1 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.30° is 0.37 mm. In the telephoto end state in the tenth example, the vibration proof coefficient is 2.10, and the focal length is 292.0 mm. Accordingly, the amount of movement of the vibration-proof lens group to correct a rotational blur by 0.20° is 0.49 mm.

The following Table 10 lists the values of data on the optical system according to the tenth example.

TABLE 10

Tenth Example

[Lens data]

Surface No.
R
D
nd
νd

Object surface
∞

1
139.3408
1.700
1.64769
33.73

2
77.5654
9.455
1.49700
81.73

3
−496.0322
0.200

4
144.5249
3.734
1.48749
70.31

5
357.2933
Variable

6
142.3498
3.303
1.84666
23.80

7
−361.0297
1.824

8
−451.3220
1.300
1.83400
37.18

9
33.3045
7.193

10
35.8308
3.147
1.71736
29.57

11
69.2532
4.718

12
−63.1663
1.000
1.66755
41.87

13
34.7105
3.239
1.80518
25.45

14
102.2323
Variable

15
73.7312
3.697
1.77250
49.62

16
−95.2978
0.200

17
33.5557
5.512
1.49700
81.73

18
−68.5312
1.200
1.90366
31.27

19
129.3820
1.534

20
∞
17.193

(Stop S)

21
40.0826
1.200
1.85026
32.35

22
17.3868
5.268
1.56732
42.58

23
−141.3282
Variable

24
297.2824
2.624
1.64769
33.73

25
−42.2438
0.835

26
−48.9103
1.000
1.77250
49.62

27
31.0082
Variable

28
−22.3095
1.300
1.69680
55.52

29
−31.0148
0.200

30
73.8865
3.135
1.80100
34.92

31
3043.5154
BF

Image surface
∞

[Various data]

Zooming ratio 4.05

W
M
T

f
72.1
100.0
292.0

FNO
4.65
4.93
5.88

2ω
33.24
23.86
8.28

Ymax
21.60
21.60
21.60

TL
192.32
206.35
244.34

BF
38.32
42.77
60.32

[Variable distance data]

W
M
T

W
M
T
Short
Short
Short

Infinity
Infinity
Infinity
distance
distance
distance

d5
2.000
22.642
74.835
2.000
22.642
74.835

d14
44.818
33.757
2.000
44.818
33.757
2.000

d23
2.000
3.329
2.024
2.604
4.116
3.661

d27
19.472
18.143
19.448
18.869
17.356
17.812

[Lens group data]

Group
Starting surface
f

G1
1
176.000

G2
6
−42.283

G3
15
38.971

G4
24
−44.470

G5
28
381.600

[Conditional expression corresponding value]

(1)
(−fN)/fP = 1.286

(2)
(−fTM1)/f1 = 0.240

(3)
fTM2/f1 = 0.221

(4)
f1/fw = 2.441

(5)
f1/(−fTM1) = 4.162

(6)
f1/fTM2 = 4.516

(9)
nvrN/nvrP = 0.924

(10)
νvrN/νvrP = 1.645

FIGS. 47A and 47B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the tenth example upon focusing on infinity in the wide-angle end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.30°, respectively. FIG. 48 is graphs showing various aberrations of the zoom optical system having the vibration-proof function according to the tenth example upon focusing on infinity in the intermediate focal length state. FIGS. 49A and 49B are graphs showing various aberrations of the zoom optical system having a vibration-proof function according to the tenth example upon focusing on infinity in the telephoto end state, and graphs showing meridional lateral aberrations when blur correction is applied to a rotational blur by 0.20°, respectively. FIGS. 50A, 50B and 50C are graphs showing various aberrations of the zoom optical system according to the tenth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively.

The graphs showing various aberrations show that the zoom optical system according to tenth example favorably corrects the various aberrations and has excellent image forming performances from the wide-angle end state to the telephoto end state, and further has excellent image forming performances also upon focusing on a short distant object.

Eleventh Example

The eleventh example is described with reference to FIGS. 51, 52 and 53 and Table 11. FIG. 51 shows a lens configuration of a zoom optical system according to the eleventh example of this embodiment. The zoom optical system ZL(11) according to the eleventh example consists of, in order from the object: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a positive refractive power; a fourth lens group G4 having a negative refractive power; and a fifth lens group G5 having a positive refractive power. An aperture stop S is provided in the third lens group G3. An image surface I is provided to face the image surface side of the fifth lens group G5.

The second lens group G2 consists of, in order from the object: a negative cemented lens consisting of a negative biconcave lens L21, and a positive meniscus lens L22 having a convex surface facing the object; and a negative biconcave lens L23.

The third lens group G3 consists of, in order from the object: a positive biconvex lens L31; an aperture stop S; a positive cemented lens consisting of a positive biconvex lens L32 and a negative biconcave lens L33; a positive cemented lens consisting of a negative meniscus lens L34 having a convex surface facing the object, and a positive biconvex lens L35; and a positive meniscus lens L36 having a convex surface facing the object.

The fourth lens group G4 consists of a negative cemented lens consisting of a positive meniscus lens L41 having a concave surface facing the object, and a negative biconcave lens L42.

The fifth lens group G5 consists of a positive biconvex lens L51.

In the optical system according to the eleventh example, focusing from a long distant object to a short distant object is performed by moving the fourth lens group G4 (RN lens group GRN) in the image surface direction. Preferably, the second lens group G2 (M1 lens group GM1) constitutes the vibration-proof lens group having displacement components in the optical axis and a direction perpendicular to the optical axis, and performs image blur correction (vibration proof, and camera shake correction) on the image surface I.

The following Table 11 lists the values of data on the optical system according to the eleventh example.

TABLE 11

Eleventh Example

[Lens data]

Surface No.
R
D
nd
νd

Object surface
∞

1
91.1552
6.167
1.51680
63.88

2
−844.6033
0.204

3
92.5357
1.500
1.64769
33.73

4
45.6802
6.598
1.48749
70.31

5
154.0927
Variable

6
−211.4795
1.000
1.69680
55.52

7
22.5821
3.677
1.80518
25.45

8
60.3602
2.652

9
−46.9021
1.000
1.77250
49.62

10
299.7358
Variable

11
48.8916
3.796
1.69680
55.52

12
−131.4333
1.000

13
∞
1.000

(Stop S)

14
39.8799
4.932
1.69680
55.52

15
−49.6069
1.000
1.85026
32.35

16
72.3703
8.805

17
57.3477
1.000
1.80100
34.92

18
18.1075
6.038
1.48749
70.31

19
−116.1586
0.200

20
26.5494
3.513
1.62004
36.40

21
96.5593
Variable

22
−119.7021
3.510
1.74950
35.25

23
−16.6839
1.000
1.69680
55.52

24
25.6230
Variable

25
124.9308
2.143
1.48749
70.31

26
−480.8453
BF

Image surface
∞

[Various data]

Zooming ratio 4.12

W
M
T

f
71.4
100.0
294.0

FNO
4.56
4.26
5.89

2ω
22.82
16.04
5.46

Ymax
14.25
14.25
14.25

TL
159.32
185.24
219.32

BF
45.32
39.43
70.09

[Variable distance data]

W
M
T

W
M
T
Short
Short
Short

Infinity
Infinity
Infinity
distance
distance
distance

d5
2.881
37.560
65.654
2.881
37.560
65.654

d10
29.543
26.683
2.000
29.543
26.683
2.000

d21
5.002
5.002
5.002
5.295
5.470
5.772

d24
15.836
15.836
15.836
15.543
15.368
15.066

[Lens group data]

Group
Starting surface
f

G1
1
146.976

G2
6
−31.771

G3
11
30.544

G4
22
−32.594

G5
25
203.039

[Conditional expression corresponding value]

(2)
(−fTM1)/f1 = 0.216

(3)
fTM2/f1 = 0.208

(4)
f1/fw = 2.058

(5)
f1/(−fTM1) = 4.626

(6)
f1/fTM2 = 4.809

Twelfth Example

The twelfth example is described with reference to FIGS. 54, 55 and 56 and Table 12. FIG. 54 shows a lens configuration of a zoom optical system according to the twelfth example of this embodiment. The zoom optical system ZL(12) according to the twelfth example consists of, in order from the object: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a positive refractive power; a fourth lens group G4 having a negative refractive power; and a fifth lens group G5 having a positive refractive power.

The fourth lens group G4 consists of a negative cemented lens consisting of a positive meniscus lens L41 having a concave surface facing the object, and a negative biconcave lens L42.

The fifth lens group G5 consists of a positive meniscus lens L51 having a convex surface facing the object.

In the optical system according to the twelfth example, focusing from a long distant object to a short distant object is performed by moving the fourth lens group G4 in the image surface direction. In this example, preferably, the second lens group G2 (M1 lens group GM1) constitutes the vibration-proof lens group having displacement components in the optical axis and a direction perpendicular to the optical axis, and performs image blur correction (vibration proof, and camera shake correction) on the image surface I.

The following Table 12 lists the values of data on the optical system according to the twelfth example.

TABLE 12

Twelfth Example

[Lens data]

Surface No.
R
D
nd
νd

Object surface
∞

1
100.0120
5.590
1.51680
63.88

2
−356.7115
0.200

3
87.0822
1.500
1.62004
36.40

4
36.8924
7.184
1.51680
63.88

5
131.1594
Variable

6
−122.1413
1.000
1.69680
55.52

7
20.4910
3.496
1.80518
25.45

8
49.8357
2.470

9
−48.8699
1.000
1.77250
49.62

10
8360.2394
Variable

11
56.6713
3.785
1.58913
61.22

12
−64.2309
0.200

13
35.4309
4.669
1.48749
70.31

14
−48.4394
1.000
1.80100
34.92

15
159.7328
1.860

16
∞
16.684

(Stop S)

17
57.8297
1.000
1.80100
34.92

18
19.6163
4.946
1.48749
70.31

19
−96.4204
0.200

20
27.1066
2.717
1.62004
36.40

21
65.2029
Variable

22
−157.1131
3.395
1.64769
33.73

23
−22.3553
1.000
1.56883
56.00

24
25.0407
Variable

25
46.5745
2.500
1.62004
36.40

26
60.0000

Image surface
∞

[Various data]

Zooming ratio 4.29

W
M
T

f
68.6
100.0
294.0

ENO
4.69
4.72
6.10

2ω
23.74
16.04
5.46

Ymax
14.25
14.25
14.25

TL
164.32
184.76
221.32

BF
38.52
38.73
64.73

[Variable distance data]

W
M
T

W
M
T
Short
Short
Short

Infinity
Infinity
Infinity
distance
distance
distance

d5
4.964
31.058
63.669
4.964
31.058
63.669

d10
29.909
24.050
2.000
29.909
24.050
2.000

d21
3.666
4.368
2.697
4.068
4.962
3.755

d24
20.866
20.163
21.834
20.464
19.569
20.776

[Lens group data]

Group
Starting surface
f

G1
1
137.939

G2
6
−30.083

G3
11
34.644

G4
22
−42.585

G5
25
313.363

[Conditional expression corresponding value]

(2)
(−fTM1)/f1 = 0.218

(3)
fTM2/f1 = 0.251

(4)
f1/fw = 2.011

(5)
f1/(−fTM1) = 4.585

(6)
f1/fTM2 = 3.982

FIGS. 55A, 55B and 55C are graphs showing various aberrations of the zoom optical system according to the twelfth example upon focusing on infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. FIGS. 56A, 56B and 56C are graphs showing various aberrations of the zoom optical system according to the twelfth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. The graphs showing various aberrations show that the zoom optical system according to this example favorably corrects the various aberrations and has excellent image forming performances from the wide-angle end state to the telephoto end state, and further has excellent image forming performances also upon focusing on a short distant object.

Thirteenth Example

The thirteenth example is described with reference to FIGS. 57, 58 and 59 and Table 13. FIG. 57 shows a lens configuration of a zoom optical system according to the thirteenth example of this embodiment. The zoom optical system ZL(13) according to the thirteenth example consists of, in order from the object: a first lens group G1 having a positive refractive power; a second lens group G2 having a negative refractive power; a third lens group G3 having a positive refractive power; a fourth lens group G4 having a negative refractive power; and a fifth lens group G5 having a positive refractive power.

The fourth lens group G4 consists of: a negative cemented lens consisting of a positive meniscus lens L41 having a concave surface facing the object, and a negative biconcave lens L42; and a negative meniscus lens L43 having a convex surface facing the object.

The fifth lens group G5 consists of a positive meniscus lens L51 having a convex surface facing the object.

In the optical system according to the thirteenth example, focusing from a long distant object to a short distant object is performed by moving the fourth lens group G4 in the image surface direction. In this example, preferably, the second lens group G2 (M1 lens group GM1) constitutes the vibration-proof lens group having displacement components in the optical axis and a direction perpendicular to the optical axis, and performs image blur correction (vibration proof, and camera shake correction) on the image surface I.

The following Table 13 lists the values of data on the optical system according to the thirteenth example.

TABLE 13

Thirteenth Example

[Lens data]

Surface No.
R
D
nd
νd

Object surface
∞

1
102.5193
5.542
1.51680
63.88

2
−366.1796
0.200

3
90.4094
1.500
1.62004
36.40

4
37.8518
7.229
1.51680
63.88

5
144.7539
Variable

6
−163.5053
1.000
1.69680
55.52

7
20.5835
3.475
1.80518
25.45

8
48.1602
2.598

9
−47.4086
1.000
1.77250
49.62

10
4634.3570
Variable

11
57.6094
3.843
1.58913
61.22

12
−66.7307
0.200

13
36.4629
4.709
1.48749
70.31

14
−48.7603
1.000
1.80100
34.92

15
206.1449
1.786

16
∞
16.497

(Stop S)

17
55.1101
1.000
1.80100
34.92

18
19.3181
4.785
1.48749
70.31

19
−100.3387
0.200

20
26.0254
2.707
1.62004
36.40

21
57.5286
Variable

22
−201.9970
3.376
1.64769
33.73

23
−22.7237
1.000
1.56883
56.00

24
29.2295
1.172

25
34.9681
1.000
1.79952
42.09

26
26.1166
Variable

27
39.9439
2.135
1.62004
36.40

28
60.0000
BF

Image surface
∞

[Various data]

Zooming ratio 4.28

W
M
T

f
68.7
100.0
294.0

FNO
4.70
4.73
6.06

2ω
23.74
16.08
5.48

Ymax
14.25
14.25
14.25

TL
164.32
184.47
221.32

BF
38.52
38.72
64.52

[Variable distance data]

W
M
T

W
M
T
Short
Short
Short

Infinity
Infinity
Infinity
distance
distance
distance

d5
4.000
30.052
63.492
4.000
30.052
63.492

d10
30.492
24.393
2.000
30.492
24.393
2.000

d21
3.686
4.454
2.923
4.052
4.994
3.907

d26
19.668
18.899
20.430
19.301
18.359
19.446

[Lens group data]

Group
Starting surface
f

G1
1
138.289

G2
6
−30.436

G3
11
34.256

G4
22
−36.764

G5
27
185.180

[Conditional expression corresponding value]

(2)
(−fTM1)/f1 = 0.220

(3)
fTM2/f1 = 0.248

(4)
f1/fw = 2.013

(5)
f1/(−fTM1) = 4.544

(6)
f1/fTM2 = 4.037

FIGS. 58A, 58B and 58C are graphs showing various aberrations of the zoom optical system according to the thirteenth example upon focusing on infinity in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. FIGS. 59A, 59B and 59C are graphs showing various aberrations of the zoom optical system according to the thirteenth example upon focusing on a short distant object in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. The graphs showing various aberrations show that the zoom optical system according to this example favorably corrects the various aberrations and has excellent image forming performances from the wide-angle end state to the telephoto end state, and further has excellent image forming performances also upon focusing on a short distant object.

According to each of the examples described above, reduction in size and weight of the focusing lens group can achieve high-speed AF and silence during AF without increasing the size of the lens barrel, and the zoom optical system can be achieved that favorably suppresses variation of aberrations upon zooming from the wide-angle end state to the telephoto end state, and variation of aberrations upon focusing from an infinite distant object to a short distant object.

Here, each of the examples described above represents a specific example of the invention of the present application. The invention of the present application is not limited thereto.

Note that the following details can be appropriately adopted in a range without impairing the optical performance of the zoom optical system of the present application.

The five-group configurations and the six-group configurations have been described as the numeric examples of the zoom optical systems of the present application. However, the present application is not limited thereto. Zoom optical systems having other group configurations (for example, seven-group ones and the like) can also be configured. Specifically, a zoom optical system having a configuration where a lens or a lens group is added to the zoom optical system of the present application at a position nearest to the object or to the image surface may be configured. Note that the lens group indicates a portion that has at least one lens and is separated by air distances varying upon zooming.

The lens surfaces of the lenses constituting the zoom optical system of the present application may be spherical surfaces, plane surfaces, or aspherical surfaces. A case where the lens surface is a spherical surface or a plane surface facilitates lens processing and assembly adjustment, and can prevent the optical performance from being reduced owing to the errors in lens processing or assembly adjustment. Consequently, the case is preferable. It is also preferable because reduction in depiction performance is small even when the image surface deviates. In a case where the lens surface is an aspherical surface, the surface may be an aspherical surface made by a grinding process, a glass mold aspherical surface made by forming glass into an aspherical shape with a mold, or a composite type aspherical surface made by forming resin provided on the glass surface into an aspherical shape. The lens surface may be a diffractive surface. The lens may be a gradient index lens (GRIN lens) or a plastic lens.

An antireflection film having a high transmissivity over a wide wavelength range may be applied to the lens surfaces of the lenses constituting the zoom optical system of the present application. This reduces flares and ghosts, and can achieve a high optical performance having a high contrast.

According to the configurations described above, this camera 1 mounted with the zoom optical system according to the first example as the imaging lens 2 can achieve high-speed AF and silence during AF without increasing the size of the lens barrel, by reducing the size and weight of the focusing lens group, can favorably suppresses variation of aberrations upon zooming from the wide-angle end state to the telephoto end state, and variation of aberrations upon focusing from an infinite distant object to a short distant object, and can achieve a favorable optical performance. Note that possible configurations of cameras mounted with the zoom optical systems according to the second to seventh examples described above as the imaging lens 2 can also exert the advantageous effects analogous to those of the camera 1 described above.

EXPLANATION OF NUMERALS AND CHARACTERS

G1
First lens group
G2
Second lens group

G3
Third lens group
G4
Fourth lens group

G5
Fifth lens group
GFS
Front lens group

GM1
M1 lens group
GM2
M2 lens group

GRN
RN lens group
GRS
Subsequent lens group

I
Image surface
S
Aperture stop

Number	Name	Date	Kind
5847882	Nakayama	Dec 1998	A
6392816	Hamano	May 2002	B1
8891173	Hagiwara	Nov 2014	B2
20090251781	Adachi et al.	Oct 2009	A1
20090290232	Hagiwara	Nov 2009	A1
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59-147314	Aug 1984	JP
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2012-113285	Jun 2012	JP
2013-195749	Sep 2013	JP
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Zoom optical system, optical apparatus, imaging apparatus and method for manufacturing the zoom optical system

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Non-Patent Literature Citations (9)

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Entry
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