Compact folded lenses with large apertures

Information

  • Patent Grant
  • 10948696
  • Patent Number
    10,948,696
  • Date Filed
    Sunday, July 22, 2018
    5 years ago
  • Date Issued
    Tuesday, March 16, 2021
    3 years ago
Abstract
Lens assemblies comprising, from an object side to an image side, a positive first lens element L1 with a first optical axis and a first lens width W1, a light folding element, a negative second lens element L2 and a plurality of additional lens elements L3-LN with a common second optical axis, and an image sensor having a sensor diagonal length (SDL), wherein the light folding element is configured to fold light from the first optical axis to the second optical axis, wherein the folded lens has an optical height OH, wherein SDL/OH>0.7 and wherein OH/W1<1.1.
Description
FIELD

Embodiments disclosed herein relate to optical lenses, and more particularly, to folded optical lenses.


BACKGROUND

Cameras with folded optics (or simply “folded camera modules” or “folded cameras”) are known. In particular, such folded camera modules have been proposed for incorporation in electronic mobile devices such as cellphones or smartphones, e.g. as part of a multiple-camera structure that comprises two or more lens modules, where at least one of the lens modules is “folded”. One example is a two-camera structure (also referred to as “dual-camera” or “dual-aperture camera”) that may include one or two folded camera modules.


In a folded camera module structure, an optical path folding element (referred to hereinafter as “OPFE”), e.g. a prism or a mirror, is added to tilt the light propagation direction from a first direction (e.g. the direction perpendicular to the phone back surface) to a second direction (e.g. parallel to the phone back surface). If the folded camera module is part of a dual-aperture camera, this provides a folded optical path through one lens module (normally a “Tele” lens module). Such a camera is referred to herein as folded-lens dual-aperture camera or dual-aperture camera with folded lens.


As the dimensions of mobile devices (and in particular the thickness of devices such as smartphones) are being constantly reduced, compact camera dimensions are becoming an increasingly limiting factor on device thickness. Therefore, camera dimensions and in particular folded camera heights and lengths need to be further reduced.


SUMMARY

The presently disclosed subject matter includes various designs of folded cameras with designs of folded lenses that have large camera aperture area, reduced optical height, and that can support an image sensor with a large diagonal size relative to an optical height and in which most lens elements have circular apertures.


In this specification, the known in the art term “total track length” (TTL), which is shown and marked in the figures, is a property of a lens and includes (i.e. is a sum of) two parts TTL1 and TTL2 (see e.g. in FIGS. 1B and 2B): a first part measured along a first optical axis from a light entrance surface of a first lens element to a prism reflective surface, and a second part measured along a second optical axis from the prism reflective surface to an image sensor (e.g. CCD or CMOS sensor). In general, the angle between the first and second optical axes is a 90° angle, however in some examples of other angles, the value of the angle may be less than or greater than 90°. In the examples provided below, the TTL is measured when the lens is focused to infinity and includes a window (e.g. IR filter) positioned between the last lens element and the image sensor, as specified in the design values.


In this specification, the term “total lens length” (TLL), which is shown and marked in e.g. FIG. 1B, is a property of a lens defined as the distance along the second optical axis direction between an image plane at the image sensor and the furthest vertex of the first optical element. TLL is measured when the lens is focused to infinity and includes a window (e.g. IR filter) positioned between the last lens element and the image sensor, as specified in the design values.


In this specification the known in the art term “back focal length” (BFL), which is shown and marked in e.g. FIG. 1B, is a property of a lens, which defined as the distance along the second optical axis direction between the image plane and the closest point of the last optical element to the image.


In this specification, the known in the art term “effective focal length” (EFL) is a property of a lens which has its regular meaning. EFL is defined as to be equal to the focal length of a single lens element having an equal magnification power as the entire lens (that has a few lens elements).


In this specification, “lens surface aperture” refers to the shape and size of a maximum optically useable lens element surface, i.e. all the surface with a sag defined by a lens formula. “Lens element apertures” or “lens apertures” refer to front and back surfaces of the lens. “Camera aperture” or “lens assembly aperture” refers to the lens aperture of the first lens element object side surface that is open to incoming light rays.


In this specification, each lens is designed for an image sensor having a sensor diagonal length (SDL) given in mm. SDL/2 is half of the sensor diagonal length. All sensors having SDL specified may be used with the combination of the given lens examples disclosed herein, e.g. sensors having 3:4 or 9:16 or 1:2 width-to-height ratio, etc.


In various exemplary embodiments, there are provided folded lens assemblies comprising, from an object side to an image side: a positive first lens element L1 with a first optical axis and a first lens width W1, a light folding element, a negative second lens element L2 and a plurality of additional lens elements L3-LN with a common second optical axis, and an image sensor having a sensor diagonal length SDL, wherein the light folding element is configured to fold light from the first optical axis to the second optical axis, wherein each folded lens assembly has an optical height OH, wherein SDL/OH>0.7 and wherein OH/W1<1.1.


In an embodiment, SDL/OH>1.


In an embodiment, OH/W1<1. In an embodiment, OH/W1<0.95.


In an embodiment, BFL/TTL>0.2. In an embodiment, BFL/TTL>0.35.


In an embodiment, the first lens element has a length A1 such that OH/A1<1.4. In an embodiment, OH/A1<1.1.


In an embodiment, the second lens element L2 may have circular aperture.


In an embodiment, a lens assembly includes at least two air gaps between lens elements that comply with the condition STD<0.020, where STD is a normalized gap standard deviation and rnorm is a minimum value of half a gap between adjacent surfaces LiS2 and Li+1S1. In an embodiment with at least two air gaps, STD<0.010.


In an embodiment, a lens assembly includes at least three air gaps between lens elements that comply with the condition STD<0.035. In an embodiment with at least three air gaps, STD<0.015.


In an embodiment, a lens assembly includes at least four air gaps between lens elements that comply with the condition STD<0.050. In an embodiment with at least four air gaps, STD<0.025


In some embodiments, a lens assembly includes, from the object side to the image side five lens elements, with a first element having positive refractive power, a second lens having negative refractive power and any one of the other elements having either positive or negative refractive power. For example, the power sign sequence of the lens elements may be PNPPN or PNPNP, where P refers to a positive lens element power and N refers to a negative lens element power.


In an embodiment, a lens assembly includes at least one air gap between lens elements that complies with the conditions STD<0.01 and OA_Gap/TTL<1/80, where OA_Gap is an on-axis gap. In an embodiment, STD<0.01 and OA_Gap/TTL<1/65.


In some embodiments, the first and second lens elements and a third lens element have respective Abbe numbers larger than 50, smaller than 30 and larger than 50.


In some embodiments, the second lens element and a third lens element have together a negative effective focal length.


In some embodiments, the first lens element has a focal length f1 and f1/EFL<0.7. In an embodiment, f1/EFL<0.6. In an embodiment, the second lens element has a focal length f2 and |f2/f1|<1. In an embodiment, |f2/f1|<0.7.


In some embodiments, lens elements L2 to LN have circular apertures.


In some embodiments, TTL/EFL<1.1.


In an embodiment, the apertures of the first lens element are cut along the second optical axis.


In an embodiment, TLL/EFL<1.


In various exemplary designs, the optical powers of the first two lens elements L1 and L2 are significant contributors to the lens system low OH/W1 and TTL/EFL ratios. This is achieved by the low (<0.6) f1/EFL ratio and also the low (<1) absolute value of the f2/f1 ratio. The high (>50) and low (<30) Abby numbers of respectively L1 and L2 also contribute to reduce the lens system chromatic aberration. The L3 to LN lens elements contribute manly to reduction of aberrations (e.g. spherical, distortion, field curvature, etc.). The close proximity or small gaps between lens elements that results in a large (>0.2) BFL/TTL ratio contributes to the lens system supporting a large SDL/OH ratio.





BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting examples of embodiments disclosed herein are described below with reference to figures attached hereto that are listed following this paragraph. Identical structures, elements or parts that appear in more than one figure are generally labeled with a same numeral in all the figures in which they appear. The drawings and descriptions are meant to illuminate and clarify embodiments disclosed herein and should not be considered limiting in any way. In the drawings:



FIG. 1A shows a first embodiment of a folded camera, comprising an optical lens assembly disclosed herein in an isometric view;



FIG. 1B shows the camera of FIG. 1A from a side view;



FIG. 1C shows the camera of FIG. 1A from a top view;



FIG. 1D shows the camera of FIG. 1A with light ray tracing from an object to an image sensor;



FIG. 1E shows the camera of FIG. 1A in a housing;



FIG. 1F shows a side cut of the camera of FIG. 1E;



FIG. 2A shows a second embodiment of a folded camera, comprising an optical lens assembly, disclosed herein in an isometric view;



FIG. 2B shows the folded camera of FIG. 2A from a side view;



FIG. 2C shows the folded camera of FIG. 2A from a top view;



FIG. 2D shows the camera of FIG. 2A with light ray tracing from an object to an image sensor;



FIG. 3 shows a third exemplary embodiment of a folded camera with light ray tracing from an object to an image sensor;



FIG. 4 shows a fourth exemplary embodiment of a folded camera with light ray tracing from an object to an image sensor;



FIG. 5 shows a fifth exemplary embodiment of a folded camera with light ray tracing from an object to an image sensor;



FIG. 6 shows a sixth exemplary embodiment of a folded camera with light ray tracing from an object to an image sensor;



FIG. 7 shows a seventh exemplary embodiment of a folded camera with light ray tracing from an object to an image sensor.





DETAILED DESCRIPTION


FIGS. 1A-1C show a first exemplary embodiment (also referred to as “Example 1”) of a folded camera disclosed herein and numbered 100. FIG. 1A shows embodiment 100 in an isometric view, FIG. 1B shows embodiment 100 in a side view and FIG. 1C shows embodiment 100 in a top view. The element numbers in FIG. 1A apply also to FIGS. 1B and 1C.


Folded camera 100 comprises a folded lens assembly (also simply referred to as “folded lens”) 102 and an image sensor 106. Optionally, camera 100 may comprise a window (e.g. glass window) 114 that may serve for example as a dust cover for the image sensor and/or to filter infra-red (IR) light and prevent the IR light from reaching image sensor 106. In an embodiment, folded lens assembly 102 comprises, in order from an object side to an image side, a first lens element L1, a light folding element (exemplarily a prism) 104, and a plurality of lens elements L2 . . . LN. In total, lens assembly 102 includes a plurality of N lens elements, for example (as in this embodiment) five lens elements marked L1, L2, L3, L4 and L5. In other embodiments, a lens assembly may include another number of elements, for example N=4, 6 or 7, wherein the design principles disclosed herein with respect to five lens elements can be maintained with other (e.g. greater) number of lens elements. In general, Li will mark the ith lens element of any lens, where “i” is an integer between 1 and N. Each lens element Li has an optical axis. Lens element L1 has an optical axis (also referred to as “first optical axis”) 108. Lens elements L2 . . . LN have a common optical axis (also referred to as “second optical axis”) 110. Prism 104 folds light arriving from an object or scene 116 and passing through lens element L1 along a first optical path substantially parallel to first optical axis 108, to a second optical path substantially parallel to second optical axis 110 toward image sensor 106. Prism 104 has a light entering surface (or “plane”) 104a, a light exiting surface (plane) 104b and a light folding surface (plane) 104c. First optical axis 108 and second optical axis 110 intersect on plane 104c. In an example, prism light exiting surface 104b is smaller than prism light entering surface 104a, i.e. the diameter of light exiting surface 104b is smaller than the diameter of light entering surface 104a. This feature allows the prism to be lower (have lower height) than the case of equal diameter of light entering and exiting surfaces. Thus, the optical height (OH, see FIG. 1B and definition below) of lens 102 can be reduced. According to some examples described herein, the ratio between the prism light exiting surface and the prism light entering surface dimensions can be less than 1.00.


Each lens element Li has a respective focal length given in Table 1 for all lens elements of all examples in this specification. Each lens element L1 has a respective height Hi measured along the direction of the first optical axis, see e.g. FIG. 1F.


Each lens element Li has a respective front surface LiS1 and a respective rear surface LiS2 where “i” is an integer between 1 and N. As used herein, the term “front surface” of each lens element refers to the surface of a lens element located closer to the entrance of the camera (camera object side) and the term “rear surface” refers to the surface of a lens element located closer to the image sensor (camera image side). The front surface and/or the rear surface can be in some cases aspherical. The front surface and/or the rear surface can be in some cases spherical. These options are, however, not limiting. Lens elements L1 to LN may be made from various materials, for example plastic or glass. Some lens elements may be made of different materials than other lens elements.


In the case of camera 100, L1S2 is the same surface as the prism light entering surface 104a. However, in other cases there can be an air gap between the two surfaces (not shown). In the case of camera 100, L1 and the prism are made as two parts which are fixedly attached (e.g. glued) to each other. In other cases, they may be made as one part, e.g. by taking a prism and polishing its entrance surface to have optical power and serve as a lens. The optical design of the lens for such a case (L1 and prism as one part) may be identical to the design of lens 102, in which L1S2 which has no optical power. In camera 100, L1 and the prism are made of the same material. In other embodiments, they may be made of different materials.


L1 has two surfaces (L1S1, L1S2), having two apertures that include two cuts (facets) 112a and 112b. Therefore, lens element L1 is referred to as a “cut lens”. The cuts enable the lens assembly to be lower and/or shorter, as shown in the drawings. The cuts in L1 allow shortening the prism entrance surface and thereby the shortening of TLL. The shortening of the prism entrance surface also allows lowering of the prism exit surface and thereby the lowering of the optical height.


The aperture of L1S1 is referred to herein as a “cut aperture”. As illustrated by way of example in FIG. 1B, the length of L1 (denoted A1) is measured along the second optical axis direction, between cuts 112a and 112b. As further illustrated by a way of example in FIG. 1C, the width of L1 (denoted W1) is measured along a direction perpendicular to both directions of the first and second optical axes. A1 and W1 are likewise applied to all other examples provided herein.


Detailed optical data of camera 100 (Example 1) and of lens assembly 102 are given in Tables 2-4. R is the radius of curvature of a surface and T is the distance from the surface to the next surface along an optical axis. D is the optical diameter of the surface. D/2 expresses a “semi-diameter” or half of the diameter. The units of R, T, D, A and W are in millimeters (mm). Nd and Vd are respectively the refraction index and Abbe number of the lens element material residing between the surface and the next surface. “Offset” in various Tables (given in mm) is the displacement from the optical axis, information required for reconstructing a prism in optical design software. “Type” in Table 1 has the common meaning well known in the art. Surface types are defined in Tables 2 and the coefficients for the surfaces are in Table 3:

    • Standard Surfaces;
    • Aspherical surfaces, which are defined using Eq. 1 and their details given in table 4:










S





A





G

=



c


r
2



1
+


1
-


(

1
+
k

)



c
2



r
2






+


α
1



r
2


+


α
2



r
4


+


a
3



r
6


+


a
4



r
8


+


α
5



r

1

0



+


a
6



r

1

2



+


α
7



r

1

4








(

Eq
.




1

)








where r is the distance of a point in the optical surface from (and perpendicular to) the relevant optical axis (first or second), k is the conic coefficient, c=1/R, and α are coefficients given in Table 4. In the equation above as applied to lens 102 in folded camera 100, coefficients α1 and α4 to α7 are zero Note that, for any aspheric surface, the maximum value of r (“max r”) is the semi-diameter (D/2) of the respective surface.

    • A “stop”, i.e. a surface that can block a portion of the light from reaching the image sensor, as known in the art. Stops are common in optical design. A stop may help to reduce stray light and improve optical quality of the image. The position of the stop surface in lens 102 (between the prism and L2) is exemplary. In other embodiments, one or more stops may be located between other elements or even before L1. Yet other embodiments may not include a “stop”.
    • The reflective surface of the prism, also commonly known as a “mirror”.


In this specification, “height” of a part, an element, or of a group of parts or elements is defined as a distance in the direction of the first optical axis (Y direction in an exemplary coordinate system) between the lowermost point of the part/element/group and the upper-most point of the part/element/group. The term “upper” or “top” refers to a section of any part/element/group that is closer to and facing an imaged (photographed) object (e.g. object 116) along Y relative to other sections of the same part/element or group. The term “lower” or “bottom” refers to a section of any part/element/group that is farthest from and facing away from an imaged object along Y relative to other sections of the same part/element or group. For example, as seen in FIG. 2B, the height of L5 is the distance from a bottom-most part 118a of L5 to a top-most part 118b of L5 along the Y direction. The optical height (OH) of folded lens 102 (marked in FIG. 1B) is defined as the distance from the lowest of the bottom-most part of any of lens elements L2 . . . LN and prism 104 to the top-most part of lens element L1. For example, the optical height of folded lens 102 is measured from the bottom-most part of lens L5, as this lens has the largest diameter. In this specification, fi will denote the focal length of lens element Li. According to some examples, the following relationships holds: |f1|>|f3|>|f2|. According to some examples, the following relationships holds: |f3|>|f1|>|f2|. According to some examples, |f3|>|f2|>|f1|.


A known definition of F-number (F #) of a lens is the ratio of the lens effective focal length (EFL) to the diameter of the entrance pupil (d).


In this application, in some cases the entrance pupil is not circular. In such cases, d is replaced by an “equivalent” circular entrance pupil diameter of de given by:










d
e

=



4
·
entrance






pupil





area


/


π






(

Eq
.




2

)








and then










F





£

=


E





F





L


d
e






(

Eq
.




3

)







In this specification, a “gap” or an “air gap” refers to the space between consecutive lens elements. In the case of lens elements 1 and 2, it refers to the air space between the prism exit surface and the first surface of lens 2.


A number of functions and constants per gap are defined:

    • 1. A “Gapi(r)” function, (where i is the lens element number and r is the same variable used in Eq. 1) is:
      • a) for i=1: Gap1(r)=SAG(r) of L2S1+(the distance along the second optical axis between the prism exit surface and L2S1);
      • b) for i>1: Gapi(r)=SAG(r) of Li+1S1+(the distance along the second optical axis between LiS2 and Li+1S1)−SAG(r) of LiS2;
      • c) for r=0, an “on-axis gap” (OA_Gap) is defined as Gapi(r=0);
    • 2. A “gap average” (AVG) constant is given by:










A





V






G
i


=


1
N






j
=
0

N




Gap
i



(


j
·

r
norm


N

)








(

Eq
.




4

)








where j is a discrete variable that runs from 0 to N, where N is an integer >10, and where rnorm is the minimum value D/2 of surfaces {LiS2, Li+1Si}.

    • 3. A normalized gap standard deviation (STDi) constant is given by:










S





T






D
i


=


1

r

n

o

r

m







1
N






j
=
0

N




(



Gap
i



(


j
·

r

n

o

r

m



N

)


-

A





V






G
i



)

2









(

Eq
.




5

)








where rnorm is the minimum value D/2 of surfaces {LiS2, Li+1S1}, N is an integer >10, and AVGi is defined as in (Eq. 4).
















TABLE 1






Ex 1
Ex 2
Ex 3
Ex 4
Ex 5
Ex 6
Ex 7






















F#
2.73
2.63
2.75
2.75
2.75
2.75
2.75


EFL [mm]
14.947
14.956
15.00
14.960
14.958
14.961
14.967


TTL [mm]
15.05
15.61
14.77
14.60
14.62
14.79
14.45


TLL [mm]
13.85
14.31
13.56
13.25
13.26
13.43
13.13


BFL [mm]
4.751
4.515
5.500
5.275
5.374
5.297
5.457


TTL/EFL
1.006
1.043
0.984
0.975
0.977
0.988
0.965


BFL/TTL
0.315
0.289
0.372
0.361
0.367
0.358
0.377


A1 [mm]
4.8
5.7
4.7
4.7
4.7
4.7
4.7


W1 [mm]
5.7
5.7
5.7
5.7
5.7
5.7
5.7


W1/TTL1
1.583
1.373
1.599
1.538
1.536
1.538
1.549


SDL [mm]
5.86
5.86
5.86
5.86
5.86
5.86
5.86


D(LNS2)/SDL
0.607
0.512
0.619
0.617
0.616
0.617
0.615


OH [mm]
5.38
6.05
5.37
5.51
5.51
5.51
5.48


OH/W1
0.943
1.061
0.942
0.967
0.968
0.967
0.962


OH/A1
1.120
1.061
1.142
1.173
1.174
1.173
1.167


SDL/OH
1.089
0.968
1.091
1.063
1.063
1.063
1.069


f1 [mm] 0.587 μm
8.87
9.66
8.72
9.38
9.36
8.94
9.13


f2 [mm] 0.587 μm
−5.20
−5.13
−5.86
−9.26
−8.68
−6.13
−7.17


f3 [mm] 0.587 μm
6.94
5.91
36.00
−6855.9
−8587.8
4.92
18.32


f4 [mm] 0.587 μm
6.38
6.03
7.40
8.70
−11.26
−14.95
−6.59


f5 [mm] 0.587 μm
−4.81
−4.32
−11.30
−10.76
8.17
−12.24
6.72


f1/EFL
0.593
0.646
0.581
0.627
0.626
0.598
0.610


|f2/f1 |
0.586
0.530
0.672
0.987
0.926
0.685
0.785


TTL/OA_Gap1
27.870
41.696
131.937
150.447
149.100
138.803
146.802


TTL/OA_Gap2
86.450
128.449
254.474
278.606
279.280
50.084
258.256


TTL/OA_Gap3
97.510
101.485
35.102
29.309
38.463
291.430
26.310


TTL/OA_Gap4
99.554
100.425
58.416
134.274
111.851
71.467
126.195


STD1
0.022
0.022
0.007
0.003
0.004
0.013
0.007


STD2
0.014
0.004
0.011
0.028
0.018
0.038
0.001


STD3
0.001
0.003
0.056
0.078
0.056
0.032
0.049


STD4
0.013
0.014
0.026
0.012
0.014
0.031
0.013









Example 1
















TABLE 2








R
T


A/2
W/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]
[mm]























S1
L1S1
Aspheric -Stop
4.326
1.200
1.487
70.405
2.400
2.850


S2
L1S2
Prism Entrance
Infinity
2.400
1.487
70.405
2.400
2.850


S3

Prism
Infinity
−2.400
1.487
70.405






Reflective face








S4
*
Prism Exit
Infinity
−0.540


2.100
2.850





*the prism exit surface includes a −0.3 mm offset.




















TABLE 3








R
T


D/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]






















S5
L2S1
Aspheric
7.502
−0.296
1.639
23.523
1.450


S6
L2S2
Aspheric
−6.089
−0.174


1.400


S7
L3S1
Aspheric
−5.811
−1.105
1.534
55.664
1.500


S8
L3S2
Aspheric
9.627
−0.154


1.500


S9
L4S1
Aspheric
10.940
−1.600
1.639
23.523
1.500


S10
L4S2
Aspheric
3.143
−0.151


1.700


S11
L5S1
Aspheric
2.344
−0.273
1.534
55.664
1.700


S12
L5S2
Aspheric
27.026
−4.151


1.800


S13

Standard
Infinity
−0.210
1.516
64.167
2.900


S14

Standard
Infinity
−0.400


2.950


S15

Standard
Infinity
0.000


3.030





















TABLE 4







#
k
α2
α3





















S1
−0.305
  6.77E−05
  3.27E−06



S5
15.881
−1.26E−02
−1.55E−02



S6
6.600
  1.35E−02
−5.89E−03



S7
−7.648
  2.29E−02
−4.61E−03



S8
26.734
  4.59E−02
−4.28E−03



S9
26.996
  4.53E−02
−1.64E−03



S10
−0.292
  1.60E−02
−5.36E−04



S11
−0.336
  8.70E−04
−1.26E−03



S12
3.075
−4.34E−03
  6.15E−04










According to one example, in camera 100, the length A1 (denoted in the figure as 128) of L1 is 4.80 mm, while its width W1 is 5.7 mm, the length being smaller than the width because of cuts 112a and 112b. TLL is 13.85 mm and EFL is 15 mm. TTL1 is 11.45 mm, TTL2 is 3.60 mm. TTL (i.e. TTL1+TTL2) is therefore 15.05 mm. The optical height OH is 5.38 mm. To further decrease OH, prism 104 can have a flat surface 104d parallel to light entering plane 104a and intersecting exit plane 104b and light folding plane 104c. The apertures of L1 are cut along the second optical axis 110. The apertures of L2, L3, L4 and L5 are circular. Note that in some embodiments, some of the apertures of L2, L3, L4 and L5 may also have cuts.


In lens 102, L1 is a positive (i.e. with positive refractive optical power) lens element. L2 is a negative (i.e. with negative refractive optical power) lens element. This holds true also for all other embodiments (i.e. Examples 2-7) disclosed herein. Lens elements L3 to Ln may have any sign. In example 100. L3 is positive, L4 is positive and L5 is negative. In other examples given here, L3 is positive, L4 is negative and L5 is positive. In yet other examples given here, L3 is negative, L4 is negative and L5 is positive. Given the description and values listed above, it is evident that the optical height (5.38 mm) is smaller than 1.2×A1 (4.80 mm)=5.76 mm, that the ratio TTL/EFL=1.0033 (smaller than 1.2 and even than 1.1) and that TLL/EFL<1. According to some examples (see below), TTL/EFL<1.



FIG. 1E shows a folded camera 100′ like camera 100 housed in a housing 127FIG. 1F shows a cut along a line A-A in FIG. 1E. Housing 127 may be used to protect optical elements from dust and mechanical damage. Housing 127 include an opening 128. Light can enter lens 102 through opening 128. In camera 100′, lens elements L2 to LN are housed in a lens barrel 150. Lens barrel 150 can be used for example for mechanical protection, to prevent unwanted light entering the lens, and for mechanical alignment of lens elements L2-LN. A height HC of camera 100′ is defined as the height from the lower most point of camera 100′ to the highest point of camera 100′. HC may be substantially equal to the optical height OH plus a “penalty” 140. Penalty 140 may be equal to the thickness of a bottom shield 125 (which is part of housing 127) and an air gap 144. Air gap 142 may be required for the actuation of lens 102 (see below). In an example, bottom shield 125 may be 50-150 μm thick and air gap 144 may be 50-150 μm wide. Thus, in some examples, HC may be equal to optical height OH plus 100 μm, or to OH plus 200 μm, or to OH plus 300 μm.


In addition to HC, in some cases, camera 100′ may have uneven height. That is, a section 132 of camera 100′ may have higher height than a section 134. In some example, section 132 may include lens element L1 and prism 104, while section 134 may include lens elements L2 to LN, and barrel 150. A lower part of camera 100′ (section 134) is referred as “camera shoulder”, and a shoulder height is marked HS. Height HS may be substantially equal to the height of barrel 150 (marked HB) plus a penalty 140 plus a penalty 146. Penalty 146 may be equal to the thickness of a top shield 126 (which is part of a housing 122) and an air gap 148. Air gap 148 may be required for the actuation of lens 102 (see below). In an example, top shield 126 may be 50-150 μm thick and air gap 148 may be 50-150 μm wide. Thus, in some examples, HS may be equal to the HB plus 250 μm, or to OH plus 300 μm, or OH plus 500 μm.


Housing 122 may further comprise an actuator that may move (actuate, shift) folded lens 102 for focusing (or auto focusing—“AF”) and optical image stabilization (OIS). Focusing may be performed by shifting lens 102 relative to image sensor 108 along second optical axis 110. OIS may be performed by shifting lens 102 along the two axes perpendicular to second optical axis 110.



FIGS. 2A-2C show a second exemplary embodiment (Example 2) of a folded camera disclosed herein and numbered 200. FIG. 2A shows embodiment 200 in an isometric view, FIG. 2B shows camera 200 in a side view and FIG. 2C shows camera 200 in a top view. All elements in cameras 100 and 200 are identical except for first lens element L1, which in this embodiment lacks cuts such as 112a and 112b. Therefore, the folded lens in camera 200 is marked 202 and is referred to as a “no cut lens”. Detailed optical data for the folded camera 200 and folded lens 202 is given in Tables 1 and 5-7.


Example 2
















TABLE 5








R
T


A/2
W/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]
[mm]























S1
L1S1
Aspheric
4.712
1.300
1.48749
70.4058
2.850
2.850


S2
L1S2
Prism Entrance
Infinity
2.850
1.48749
70.4058
2.850
2.850


S3

Prism
Infinity
−2.850
1.48749
70.4058






Reflective face








S4
*
Prism Exit
Infinity
−0.169


2.360
2.850





*the prism exit surface includes a −0.495 mm offset.




















TABLE 6








R
T


D/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]






















S5

Standard - Stop
Infinity
−0.206


1.455


S6
L2S1
Aspheric
7.821
−0.296
1.6397
23.523
1.436


S7
L2S2
Aspheric
−5.750
−0.122


1.407


S8
L3S1
Aspheric
−4.660
−1.120
1.5348
55.664
1.425


S9
L3S2
Aspheric
9.045
−0.154


1.465


S10
L4S1
Aspheric
12.330
−1.600
1.6397
23.523
1.412


S11
L4S2
Aspheric
3.090
−0.155


1.550


S12
L5S1
Aspheric
2.329
−0.273
1.5348
55.664
1.484


S13
L5S2
Aspheric
−350.821
−3.905


1.507


S14

Standard
Infinity
−0.210
1.5168
64.2
2.930


S15

Standard
Infinity
−0.400


2.930


S16

Standard
Infinity
0.000


3.030





















TABLE 7







#
k
α2
α3





















S1
−0.361
  9.14E−05
  3.24E−06



S6
18.000
−1.09E−02
−1.72E−03



S7
2.173
  1.72E−02
−7.95E−03



S8
−4.968
  2.36E−02
−6.40E−03



S9
22.508
  4.42E−02
−4.56E−03



S10
19.512
  4.90E−02
−2.09E−03



S11
−0.257
  1.90E−02
−1.20E−03



S12
−0.219
  4.04E−03
−2.14E−03



S13
91.000
−2.45E−03
  4.74E−04










In folded camera 200, A1 and W1 are 5.70 mm (i.e. in camera 200, L1 is circular). TLL is 14.31 mm and EFL is 15 mm, TTL1 is 11.46 mm, TTL2 is 4.15 mm (i.e., the total TTL=15.61 mm) and OH is 6.05 mm. As in folded camera 100, the prism can have a flat surface parallel to the light entering plane and intersecting the light exiting plane and the light folding plane. In the example shown according to FIG. 2, the apertures of all lens elements are circular.


Given the description and values listed above, it is evident that the optical height (6.05 mm) is smaller than 1.2×A1 (5.70 mm)=6.84 mm, and smaller even than 1.1×A1 (=6.27 mm). The ratio TTL/EFL=1.0407, i.e. smaller than 1.2 and even smaller than 1.1. Also, TLL/EFL<1.



FIG. 3 shows a third exemplary embodiment of a folded camera numbered 300 (“Example 3”) with a lens 302 and light ray tracing from an object to the image sensor. Detailed optical data for the folded camera 300 and folded lens 302 is given in Tables 1 and 8-10. All elements in camera 300 except lens 302 are identical with elements in cameras 100 and 200.


Example 3
















TABLE 8








R
T


A/2
W/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]
[mm]























S1

Standard - STOP
Infinity
−0.905


2.350
2.850


S2
L1S1
Aspheric
4.611
1.214
1.528
76.975
2.350
2.850


S3
L1S2
Prism Entrance
Infinity
2.350
1.528
76.975
2.350
2.850


S4

Prism
Infinity
−2.350
1.528
76.975






Reflective face








S5
*
Prism Exit
Infinity
−0.112


2.100
2.850





*the prism exit surface includes a −0.265 mm offset.




















TABLE 9








R
T


D/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]






















S6
L2S1
Aspheric
20.118
−0.441
1.651
21.513
1.815


S7
L2S2
Aspheric
−4.758
−0.058


1.718


S8
L3S1
Aspheric
−3.508
−0.902
1.535
56.115
1.736


S9
L3S2
Aspheric
−3.904
−0.421


1.658


S10
L4S1
Aspheric
−8.924
−0.925
1.651
21.513
1.652


S11
L4S2
Aspheric
10.049
−0.253


1.754


S12
L5S1
Aspheric
3.985
−0.252
1.535
56.115
1.723


S13
L5S2
Aspheric
11.922
−4.790


1.815


S14

Standard
Infinity
−0.210
1.516
64.167
2.889


S15

Standard
Infinity
−0.500


2.919


S16

Standard
Infinity



3.030





















TABLE 10







#
K
α2
α3





















S2
−0.874
  8.10E−04
  1.91E−05



S6
−129.217
−2.12E−03
−2.70E−04



S7
0.203
  4.80E−03
−2.56E−03



S8
0.184
  1.64E−02
−3.58E−03



S9
1.622
  2.67E−02
−1.23E−03



S10
−22.269
  2.61E−02
  2.30E−03



S11
12.035
  2.21E−02
  9.77E−04



S12
1.931
  8.11E−03
  3.19E−04



S13
21.054
  3.37E−04
  3.10E−04










In folded camera 300 (Example 3 and Tables 8-10), A1 and W1 are respectively 4.7 mm and 5.7 mm (i.e. in camera 300, L1 is a cut lens). TLL is 13.56 mm and EFL is 15.00 mm, TTL1 is 3.564 mm, TTL2 is 11.206 mm (i.e., the total TTL=14.77 mm) and OH is 5.37 mm. As in folded camera 100 (surface 104d) or 200, the prism can have a flat surface parallel to the light entering plane and intersecting the light exiting plane and the light folding plane that contributes to the reducing of OH. Note that in Examples 3-7 (as well as in Example 1), the apertures of all lens elements except for L1 are circular. Note that in Example 2, all lens elements including L1 have circular apertures.


Given the description and values listed above, it is evident that the optical height (5.37 mm) is smaller than 1.2×A1 (4.7 mm)=5.64 mm. The ratio TTL/EFL=0.984, i.e. smaller than 1.2 and even smaller than 1.1 and even smaller than 1. Also, TLL/EFL<1.



FIG. 4 shows a fourth exemplary embodiment of a folded camera numbered 400 (Example 4) with a lens 402 and light ray tracing from an object to the image sensor. Detailed optical data for the folded camera 400 and folded lens 402 is given in Tables 1 and 11-13. All elements in camera 400 except lens 402 are identical with elements in cameras 100, 200 and 300.


Example 4
















TABLE 11








R
T


A/2
W/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]
[mm]























S1

Standard - STOP
Infinity
−1.057


2.350
2.850


S2
L1S1
Aspheric
4.073
1.355
1.433
95.232
2.350
2.850


S3
L1S2
Prism Entrance
Infinity
2.350
1.433
95.232
2.350
2.850


S4

Prism
Infinity
−2.350
1.433
95.232






Reflective face








S5
*
Prism Exit
Infinity
−0.097


2.080
2.850





*the prism exit surface includes a −0.270 mm offset.




















TABLE 12








R
T


D/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]






















S6
L2S1
Aspheric
31.776
−0.409
1.651
21.513
1.806


S7
L2S2
Aspheric
−7.479
−0.052


1.716


S8
L3S1
Aspheric
−3.567
−0.907
1.535
56.115
1.730


S9
L3S2
Aspheric
−3.247
−0.498


1.619


S10
L4S1
Aspheric
−14.616
−0.951
1.651
21.513
1.622


S11
L4S2
Aspheric
9.021
−0.109


1.750


S12
L5S1
Aspheric
4.476
−0.252
1.535
56.115
1.740


S13
L5S2
Aspheric
20.463
−4.566


1.806


S14

Standard
Infinity
−0.210
1.516
64.167
2.876


S15

Standard
Infinity
−0.500


2.907


S16

Standard
Infinity



3.030





















TABLE 13







#
K
α2
α3





















S2
−0.303
  7.31E−05
  1.71E−06



S6
96.549
−6.01E−03
−6.90E−06



S7
10.219
−5.99E−03
  3.20E−04



S8
−0.715
−1.72E−03
  1.80E−04



S9
−3.213
−3.61E−03
  9.19E−04



S10
−108.408
  1.13E−02
  3.97E−03



S11
−0.202
  6.62E−03
  3.68E−03



S12
3.281
−1.18E−02
  2.17E−03



S13
95.038
−2.74E−03
  4.32E−04










In folded camera 400 (Example 4 and Tables 11-13), A1 and W1 are respectively 4.7 and 5.7 mm. TLL is 13.25 mm and EFL is 14.96 mm, TTL1 is 3.705 mm, TTL2 is 10.895 mm (i.e., the total TTL=14.6 mm) and OH is 5.51 mm. As in folded camera 100 or 200, the prism can have a flat surface parallel to the light entering plane and intersecting the light exiting plane and the light folding plane. The apertures of all lens elements are circular.


Given the description and values listed above, it is evident that the optical height (5.51 mm) is smaller than 1.2×A1 (4.7 mm)=5.64 mm. The ratio TTL/EFL=0.975, i.e. smaller than 1.2 and even smaller than 1.1 and even smaller than 1. Also, TLL/EFL<1.



FIG. 5 shows a fifth exemplary embodiment of a folded camera numbered 500 (“Example 5”) with a lens 502 and light ray tracing from an object to the image sensor. Detailed optical data for the folded camera 500 and folded lens 502 is given in Tables 1 and 14-16. All elements in camera 500 except lens 502 are identical with elements in cameras 100, 200, 300 and 400.


Example 5
















TABLE 14








R
T


A/2
W/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]
[mm]























S1

Standard - STOP
Infinity
−1.065


2.350
2.850


S2
L1S1
Aspheric
4.062
1.359
1.433
95.232
2.350
2.850


S3
L1S2
Prism Entrance
Infinity
2.350
1.433
95.232
2.350
2.850


S4

Prism
Infinity
−2.350
1.433
95.232






Reflective face








S5
*
Prism Exit
Infinity
−0.098


2.080
2.850





*the prism exit surface includes a −0.27 mm offset.




















TABLE 15








R
T


D/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]






















S6
L2S1
Aspheric
52.828
−0.649
1.651
21.513
1.800


S7
L2S2
Aspheric
−6.365
−0.052


1.709


S8
L3S1
Aspheric
−3.970
−0.906
1.535
56.115
1.720


S9
L3S2
Aspheric
−3.651
−0.380


1.636


S10
L4S1
Aspheric
−7.218
−0.446
1.535
56.115
1.637


S11
L4S2
Aspheric
−3.214
−0.131


1.749


S12
L5S1
Aspheric
−4.056
−0.531
1.651
21.513
1.765


S13
L5S2
Aspheric
−16.194
−4.665


1.807


S14

Standard
Infinity
−0.210
1.516
64.167
2.883


S15

Standard
Infinity
−0.500


2.914


S16

Standard
Infinity



3.030





















TABLE 16







#
k
α2
α3





















S2
−0.225
−3.72E−05
−3.37E−06



S6
2.287
−1.24E−03
  1.30E−04



S7
3.112
−5.95E−03
  1.01E−03



S8
−0.731
−1.11E−03
  3.02E−04



S9
0.084
  2.12E−02
−1.55E−03



S10
−24.608
  2.74E−02
  7.22E−04



S11
−10.147
  8.67E−04
  1.15E−03



S12
−13.144
  3.59E−03
  1.08E−03



S13
−14.426
  1.64E−02
−1.25E−04










In folded camera 500 (Example 5 and Tables 14-16), A1 and W1 are respectively 4.7 and 5.7 mm. TLL is 13.26 mm and EFL is 14.958 mm, TTL1 is 3.709 mm, TTL2 is 10.911 mm (i.e., the total TTL=14.62 mm) and OH is 5.51 mm. As in folded camera 100 or 200, the prism can have a flat surface parallel to the light entering plane and intersecting the light exiting plane and the light folding plane. The apertures of all lens elements are circular.


Given the description and values listed above, it is evident that the optical height (5.51 mm) is smaller than 1.2×A1 (4.7 mm)=5.64 mm. The ratio TTL/EFL=0.977, i.e. smaller than 1.2 and even smaller than 1.1 and even smaller than 1. Also, TLL/EFL<1.



FIG. 6 shows a sixth exemplary embodiment of a folded camera numbered 600 (Example 6) with a lens 602 and light ray tracing from an object to the image sensor. Detailed optical data for the folded camera 600 and folded lens 602 is given in Tables 1 and 17-19. All elements in camera 600 except lens 602 are identical with elements in cameras 100, 200, 300, 400 and 500.


Example 6
















TABLE 17








R
T


A/2
W/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]
[mm]























S1

Standard - STOP
Infinity
−1.060


2.350
2.850


S2
L1S1
Aspheric
4.078
1.355
1.456
90.900
2.350
2.850


S3
L1S2
Prism Entrance
Infinity
2.350
1.456
90.900
2.350
2.850


S4

Prism
Infinity
−2.350
1.456
90.900






Reflective face








S5

Prism Exit
Infinity
−0.107


2.080
2.850





*the prism exit surface includes a −0.27 mm offset.




















TABLE 18








R
T


D/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]






















S6
L2S1
Aspheric
15.780
−0.670
1.651
21.513
1.767


S7
L2S2
Aspheric
−5.439
−0.295


1.653


S8
L3S1
Aspheric
−8.111
−0.907
1.651
21.513
1.653


S9
L3S2
Aspheric
5.073
−0.051


1.760


S10
L4S1
Aspheric
7.664
−0.953
1.651
21.513
1.789


S11
L4S2
Aspheric
37.777
−0.207


1.809


S12
L5S1
Aspheric
5.035
−0.250
1.535
56.115
1.809


S13
L5S2
Aspheric
22.129
−4.588


1.811


S14

Standard
Infinity
−0.210
1.516
64.167
2.864


S15

Standard
Infinity
−0.500


2.896


S16

Standard
Infinity



3.030





















TABLE 19







#
K
α2
α3





















S2
−0.283
  7.76E−05
  3.45E−06



S6
22.671
−1.94E−04
−1.43E−03



S7
6.703
  1.44E−02
  8.50E−05



S8
−31.425
  9.90E−03
  4.27E−03



S9
−35.446
−2.24E−02
  5.67E−03



S10
−112.063
−3.55E−02
  5.52E−03



S11
63.734
−1.41E−03
  2.85E−04



S12
2.909
−9.30E−03
−2.48E−03



S13
113.315
−6.41E−03
−1.64E−03










In folded camera 600 (Example 6 and Tables 17-19), A1 and W1 are respectively 4.7 and 5.7 mm. TLL is 13.43 mm and EFL is 14.961 mm, TTL1 is 3.705 mm, TTL2 is 11.085 mm (i.e., the total TTL=14.79 mm) and OH is 5.51 mm. As in folded camera 100 or 200, the prism can have a flat surface parallel to the light entering plane and intersecting the light exiting plane and the light folding plane. The apertures of all lens elements are circular.


Given the description and values listed above, it is evident that the optical height (5.51 mm) is smaller than 1.2×A1 (4.7 mm)=5.64 mm. The ratio TTL/EFL=0.988, i.e. smaller than 1.2 and even smaller than 1.1 and even smaller than 1. Also, TLL/EFL<1.



FIG. 7 shows a seventh exemplary embodiment of a folded camera numbered 700 (Example 7) with a lens 702 and light ray tracing from an object to the image sensor. Detailed optical data for the folded camera 700 and folded lens 702 is given in Tables 1 and 20-22. All elements in camera 700 except lens 702 are identical with elements in cameras 100, 200, 300, 400, 500 and 600.


Example 7
















TABLE 20








R
T


A/2
W/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]
[mm]























S1

Standard - STOP
Infinity
−1.024


2.350
2.850


S2
L1S1
Aspheric
4.166
1.328
1.433
95.232
2.350
2.850


S3
L1S2
Prism Entrance
Infinity
2.350
1.433
95.232
2.350
2.850


S4

Prism
Infinity
−2.350
1.433
95.232






Reflective face








S5

Prism Exit
Infinity
−0.098


2.080
2.850





*the prism exit surface includes a −0.27 mm offset.




















TABLE 21








R
T


D/2


#

Type
[mm]
[mm]
Nd
Vd
[mm]






















S6
L2S1
Aspheric
−25.077
−0.253
1.651
21.513
1.791


S7
L2S2
Aspheric
−3.922
−0.056


1.715


S8
L3S1
Aspheric
−4.023
−0.906
1.535
56.115
1.721


S9
L3S2
Aspheric
−6.284
−0.549


1.646


S10
L4S1
Aspheric
−7.945
−0.431
1.535
56.115
1.615


S11
L4S2
Aspheric
−2.399
−0.115


1.754


S12
L5S1
Aspheric
−3.472
−0.563
1.651
21.513
1.773


S13
L5S2
Aspheric
−15.725
−4.747


1.803


S14

Standard
Infinity
−0.210
1.516
4.167
2.877


S15

Standard
Infinity
−0.500


2.908


S16

Standard
Infinity



3.030





















TABLE 22







#
K
α2
α3









S2
−0.373
  1.69E−04
  7.56E−06



S6
−30.531
  5.01E−03
−1.01E−03



S7
−0.953
  4.25E−03
−1.57E−03



S8
−5.260
−3.33E−03
−1.47E−03



S9
−22.816
  1.13E−02
−1.86E−03



S10
−91.835
  4.26E−02
−8.24E−04



S11
−8.964
  7.03E−03
  2.50E−04



S12
−13.635
  4.43E−03
−2.45E−04



S13
−36.786
  2.05E−02
−2.06E−03










In folded camera 700 (Example 7 and Tables 20-22), A1 and W1 are respectively 4.7 and 5.7 mm. TLL is 13.13 mm and EFL is 14.967 mm, TTL1 is 3.678 mm, TTL2 is 10.772 mm (i.e., the total TTL=14.45 mm) and OH is 5.48 mm. As in other folded cameras, the prism can have a flat surface parallel to the light entering plane and intersecting the light exiting plane and the light folding plane. The apertures of all lens elements are circular.


Given the description and values listed above, it is evident that the optical height (5.48 mm) is smaller than 1.2×A1 (4.7 mm)=5.64 mm. The ratio TTL/EFL=0.965, i.e. smaller than 1.2 and even smaller than 1.1 and even smaller than 1. Also, TLL/EFL<1.


Table 23 summarizes the design characteristics and parameters as they appear in the examples listed above. These characteristics helps to achieve the goal of a compact folded lens with large lens assembly aperture:


“AA”: AA1≡BFL/TTL>0.2, AA2≡BFL/TTL>0.28, AA3≡BFL/TTL>0.35;


“BB”: BB1≡OH/A1<1.4, BB2≡OH/A1<1.2, BB3≡OH/A1<1.1;


“CC”: CC1≡OH/W1<1.1, CC2≡OH/W1<1.00, CC3≡OH/W1<0.95;


“DD”: At least two gaps that comply with DD1≡STD<0.020, DD2≡STD<0.015, DD3 ≡STD<0.010;


“EE”: At least 3 gaps that comply with EE1≡STD<0.035, EE2≡STD<0.025, EE3≡STD<0.015;


“FF”: At least 4 gaps that comply with FF1≡STD<0.050, FF2≡STD<0.035, FF3≡STD<0.025;


“GG”: GG1≡SDL/OH>0.7, GG2≡SDL/OH>0.85, GG3≡SDL/OH>1;


“HH”: a power sign sequence;


“II”: At least 1 gap that complies with II1≡STD<0.01 and OA_Gap/TTL<1/80, II2≡STD<0.015 and OA_Gap/TTL<1/65;


“JJ”: Abbe number sequence of lens element 1, 2 and 3 can be respectively larger than 50, smaller than 30 and larger than 50;


“KK”: Effective focal length of combined lens elements 2 and 3 is negative;


“LL”: LL1≡f1/EFL<0.7, LL2≡f1/EFL<0.6;


“MM”: MM1≡|f2/f1|<1, MM2≡|f2/f1|<0.7; and


“NN”: L2 to LN have circular apertures.


Table 23 indicates whether a parameter or a condition is fulfilled (symbol “✓”) or not fulfilled (symbol “x”) in each Example. The cited examples are brought in order to illustrate the principles of the disclosed subject matter and should not be construed as limiting. Other examples are also contemplated within the scope of the presently disclosed subject matter.
















TABLE 23





Example
EX1
EX2
EX3
EX4
EX5
EX6
EX7







AA1









AA2









AA3
x
x







BB1









BB2









BB3
x

x
x
x
x
x


CC1









CC2









CC3

x

x
x
x
x


DD1









DD2





x



DD3
x

x
x
x
x



EE1









EE2



x

x



EE3


x
x
x
x



FF1


x
x
x




FF2


x
x
x
x
x


FF3


x
x
x
x
x


GG1









GG2









GG3

x







HH
PNPPN
PNPPN
PNPPN
PNNPN
PNNNP
PNPNN
PNPNP


II1





x



II2









JJ









KK





x



LL1









LL2

x

x
x




MM1









MM2



x
x

x


NN
















While this disclosure describes a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of such embodiments may be made. In general, the disclosure is to be understood as not limited by the specific embodiments described herein, but only by the scope of the appended claims.


All references mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual reference was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present application.

Claims
  • 1. A folded lens assembly comprising: from an object side to an image side, a) a positive first lens element L1 with a first optical axis and a first lens width W1;b) a light folding element;c) a negative second lens element L2 and a plurality of additional lens elements L3-LN with a common second optical axis; andd) an image sensor having a sensor diagonal length (SDL), wherein the light folding element is configured to fold light from the first optical axis to the second optical axis, wherein the folded lens has an optical height OH, wherein SDL/OH>0.7 and wherein OH/W1<1.1.
  • 2. The folded lens assembly of claim 1, wherein SDL/OH>1.
  • 3. The folded lens assembly of claim 1, wherein OH/W1<0.95.
  • 4. The folded lens assembly of claim 1, wherein the lens assembly has a back focal length (BFL) and a total track length (TTL) and wherein BFL/TTL>0.2.
  • 5. The folded lens assembly of claim 1, wherein the lens assembly has a back focal length (BFL) and a total track length (TTL) and wherein BFL/TTL>0.35.
  • 6. The folded lens assembly of claim 1, wherein the first lens element has a length A1 and wherein OH/A1<1.4.
  • 7. The folded lens assembly of claim 1, wherein the first lens element has a length A1 and wherein OH/A1<1.1.
  • 8. The folded lens assembly of claim 1, wherein the lens assembly includes at least two air gaps between lens elements that comply with the condition STD<0.020, where STD is a normalized gap standard deviation and rnorm is a minimum value of half a gap between adjacent surfaces LiS2 and Li+1S1.
  • 9. The folded lens assembly of claim 1, wherein the lens assembly includes at least two air gaps between lens elements that comply with the condition STD<0.010, where STD is a normalized gap standard deviation and rnorm is a minimum value of half a gap between adjacent surfaces LiS2 and Li+1S1.
  • 10. The folded lens assembly of claim 1, wherein the lens assembly includes at least three air gaps between lens elements that comply with the condition STD<0.035, where STD is a normalized gap standard deviation and rnorm is a minimum value of half a gap between adjacent surfaces LiS2 and Li+1S1.
  • 11. The folded lens assembly of claim 1, wherein the lens assembly includes at least three air gaps between lens elements that comply with the condition STD<0.015, where STD is a normalized gap standard deviation and rnorm is a minimum value of half a gap between adjacent surfaces LiS2 and Li+1S1.
  • 12. The folded lens assembly of claim 1, wherein the lens assembly includes at least four air gaps between lens elements that comply with the condition STD<0.050, where STD is a normalized gap standard deviation and rnorm is a minimum value of half a gap between adjacent surfaces LiS2 and Li+1S1.
  • 13. The folded lens assembly of claim 1, wherein the lens assembly includes at least four air gaps between lens elements that comply with the condition STD<0.025, where STD is a normalized gap standard deviation and rnorm is a minimum value of half a gap between adjacent surfaces LiS2 and Li+1S1.
  • 14. The folded lens assembly of claim 1, wherein the lens assembly includes, from the object side to the image side five lens elements with any one of the following power sign sequence: PNPPN, PNNPN, PNNNP, PNPNN, and PNPNP.
  • 15. The folded lens assembly of claim 1, wherein the lens assembly includes at least one air gap between lens elements that complies with the conditions STD<0.01 and OA_Gap/TTL<1/80, where STD is a normalized gap standard deviation and OA_Gap is an on-axis gap.
  • 16. The folded lens assembly of claim 1, wherein the lens assembly includes at least one air gap between lens elements that complies with the conditions STD<0.01 and OA_Gap/TTL<1/65, where STD is a normalized gap standard deviation and OA_Gap is an on-axis gap.
  • 17. The folded lens assembly of claim 1, wherein the first and second lens elements and a third lens element have respective Abbe numbers larger than 50, smaller than 30 and larger than 50.
  • 18. The folded lens assembly of claim 1, wherein the second lens element and a third lens element have together a negative effective focal length.
  • 19. The folded lens assembly of claim 1, wherein the lens assembly has an effective focal length EFL, wherein the first lens element has a focal length f1 and wherein f1/EFL<0.7.
  • 20. The folded lens assembly of claim 1, wherein the lens assembly has an effective focal length EFL, wherein the first lens element has a focal length f1 and wherein f1/EFL<0.6.
  • 21. The folded lens assembly of claim 1, wherein the first lens element has a focal length f1, wherein the second lens element has a focal length f2 and wherein |f2/f1|<1.
  • 22. The folded lens assembly of claim 1, wherein the first lens element has a focal length f1, wherein the second lens element has a focal length f2 and wherein |f2/f1|<0.7.
  • 23. The folded lens assembly of claim 1, wherein L2 to LN have circular apertures.
  • 24. The folded lens assembly of claim 1, wherein the lens assembly has an effective focal length (EFL) and a total track length (TTL) and wherein TTL/EFL<1.1.
  • 25. The folded lens assembly of claim 1, wherein the apertures of the first lens element is cut along the second optical axis.
  • 26. The folded lens assembly of claim 1, wherein the lens assembly has an effective focal length EFL and a total lens element length (TLL), wherein the TLL/EFL<1.
  • 27. The folded lens assembly of claim 1, wherein the first lens element is made of glass and wherein the second lens element and the plurality of lens elements are made of plastic.
  • 28. The folded lens assembly of claim 1, wherein the all the lens elements are made of plastic.
CROSS REFERENCE TO RELATED APPLICATIONS

This application is a 371 application from international patent application No. PCT/IB2018/055450 filed Jul. 22, 2018, and claims the benefit of priority of U.S. Provisional patent application No. 62/535,926 filed Jul. 23, 2017, which is incorporated herein by reference in its entirety.

PCT Information
Filing Document Filing Date Country Kind
PCT/IB2018/055450 7/22/2018 WO 00
Publishing Document Publishing Date Country Kind
WO2019/021145 1/31/2019 WO A
US Referenced Citations (141)
Number Name Date Kind
2106752 Land Feb 1938 A
2354503 Cox Jul 1944 A
2378170 Aklin Jun 1945 A
2441093 Aklin May 1948 A
3388956 Eggert et al. Jun 1968 A
3524700 Eggert et al. Aug 1970 A
3558218 Grey Jan 1971 A
3709582 Walker Jan 1973 A
3864027 Harada Feb 1975 A
3942876 Betensky Mar 1976 A
4134645 Sugiyama et al. Jan 1979 A
4338001 Matsui Jul 1982 A
4465345 Yazawa Aug 1984 A
5000551 Shibayama Mar 1991 A
5969869 Hirai et al. Oct 1999 A
6147702 Smith Nov 2000 A
6169636 Kreitzer Jan 2001 B1
6654180 Ori Nov 2003 B2
7187504 Horiuchi Mar 2007 B2
7206136 Labaziewicz et al. Apr 2007 B2
7515351 Chen et al. Apr 2009 B2
7564635 Tang Jul 2009 B1
7630139 Souma Dec 2009 B2
7643225 Tsai Jan 2010 B1
7660049 Tang Feb 2010 B2
7684128 Tang Mar 2010 B2
7688523 Sano Mar 2010 B2
7692877 Tang et al. Apr 2010 B2
7697220 Iyama Apr 2010 B2
7738186 Chen et al. Jun 2010 B2
7777972 Chen et al. Aug 2010 B1
7813057 Lin Oct 2010 B2
7821724 Tang et al. Oct 2010 B2
7826149 Tang et al. Nov 2010 B2
7826151 Tsai Nov 2010 B2
7869142 Chen et al. Jan 2011 B2
7898747 Tang Mar 2011 B2
7916401 Chen et al. Mar 2011 B2
7918398 Li et al. Apr 2011 B2
7957075 Tang Jun 2011 B2
7957076 Tang Jun 2011 B2
7957079 Tang Jun 2011 B2
7961406 Tang et al. Jun 2011 B2
8000031 Tsai Aug 2011 B1
8004777 Souma Aug 2011 B2
8077400 Tang Dec 2011 B2
8149523 Ozaki Apr 2012 B2
8218253 Tang Jul 2012 B2
8228622 Tang Jul 2012 B2
8233224 Chen Jul 2012 B2
8253843 Lin Aug 2012 B2
8279537 Sato Oct 2012 B2
8363337 Tang et al. Jan 2013 B2
8395851 Tang et al. Mar 2013 B2
8400717 Chen et al. Mar 2013 B2
8451549 Yamanaka et al. May 2013 B2
8503107 Chen et al. Aug 2013 B2
8514502 Chen Aug 2013 B2
8570668 Takakubo et al. Oct 2013 B2
8718458 Okuda May 2014 B2
8780465 Chae Jul 2014 B2
8810923 Shinohara Aug 2014 B2
8854745 Chen Oct 2014 B1
8958164 Kwon et al. Feb 2015 B2
9185291 Shabtay et al. Nov 2015 B1
9229194 Yoneyama et al. Jan 2016 B2
9235036 Kato et al. Jan 2016 B2
9279957 Kanda et al. Mar 2016 B2
9438792 Nakada et al. Sep 2016 B2
9488802 Chen et al. Nov 2016 B2
9557627 Mercado Jan 2017 B2
9568712 Dror et al. Feb 2017 B2
9678310 Iwasaki et al. Jun 2017 B2
9817213 Mercado Nov 2017 B2
20020118471 Imoto Aug 2002 A1
20050041300 Oshima et al. Feb 2005 A1
20050062346 Sasaki Mar 2005 A1
20050128604 Kuba Jun 2005 A1
20050141103 Nishina Jun 2005 A1
20050168840 Obayashi et al. Aug 2005 A1
20050270667 Gurevich et al. Dec 2005 A1
20070229983 Saori Oct 2007 A1
20080056698 Lee et al. Mar 2008 A1
20080304161 Souma Dec 2008 A1
20090002839 Sato Jan 2009 A1
20090122423 Ark et al. May 2009 A1
20090141365 Jannard et al. Jun 2009 A1
20090208195 Hatakeyama Aug 2009 A1
20090225438 Kubota Sep 2009 A1
20100165476 Eguchi Jul 2010 A1
20100277813 Ito Nov 2010 A1
20110001838 Lee Jan 2011 A1
20110115965 Engelhardt et al. May 2011 A1
20110149119 Matsui Jun 2011 A1
20110157430 Hosoya et al. Jun 2011 A1
20110188121 Goring et al. Aug 2011 A1
20120069455 Lin et al. Mar 2012 A1
20120092777 Tochigi et al. Apr 2012 A1
20120105708 Hagiwara May 2012 A1
20120154929 Tsai et al. Jun 2012 A1
20120229920 Otsu et al. Sep 2012 A1
20120262806 Huang Oct 2012 A1
20130057971 Zhao et al. Mar 2013 A1
20130088788 You Apr 2013 A1
20130208178 Park Aug 2013 A1
20130279032 Suigetsu et al. Oct 2013 A1
20130286488 Chae Oct 2013 A1
20140022436 Kim et al. Jan 2014 A1
20140146216 Okumura May 2014 A1
20140204480 Jo et al. Jul 2014 A1
20140285907 Tang Sep 2014 A1
20140293453 Ogino et al. Oct 2014 A1
20140362274 Christie et al. Dec 2014 A1
20150116569 Mercado Apr 2015 A1
20150253543 Mercado Sep 2015 A1
20150253647 Mercado Sep 2015 A1
20150316748 Cheo Nov 2015 A1
20150373252 Georgiev Dec 2015 A1
20150373263 Georgiev et al. Dec 2015 A1
20160044250 Shabtay et al. Feb 2016 A1
20160062084 Chen et al. Mar 2016 A1
20160070088 Koguchi Mar 2016 A1
20160085089 Mercado Mar 2016 A1
20160187631 Choi et al. Jun 2016 A1
20160291295 Shabtay et al. Oct 2016 A1
20160306161 Harada et al. Oct 2016 A1
20160313537 Mercado Oct 2016 A1
20160341931 Liu et al. Nov 2016 A1
20160353008 Osborne Dec 2016 A1
20170102522 Jo Apr 2017 A1
20170115471 Shinohara Apr 2017 A1
20170160511 Kim et al. Jun 2017 A1
20170276912 Yao Sep 2017 A1
20170276913 Yao Sep 2017 A1
20170276914 Yao Sep 2017 A1
20180059365 Bone et al. Mar 2018 A1
20180217475 Goldenberg et al. Aug 2018 A1
20180224630 Lee et al. Aug 2018 A1
20190170965 Shabtay et al. Jun 2019 A1
20190331897 Lee Oct 2019 A1
20200026033 Mercado Jan 2020 A1
Foreign Referenced Citations (22)
Number Date Country
102193162 Sep 2011 CN
102147519 Jan 2013 CN
104297906 Jan 2015 CN
105467563 Apr 2016 CN
S54157620 Dec 1979 JP
S59121015 Jul 1984 JP
6165212 Apr 1986 JP
S6370211 Mar 1988 JP
406059195 Mar 1994 JP
2007133096 May 2007 JP
2007219199 Aug 2007 JP
2007306282 Nov 2007 JP
2010164841 Jul 2010 JP
2012203234 Oct 2012 JP
2013105049 May 2013 JP
2013106289 May 2013 JP
2014142542 Aug 2014 JP
20110115391 Oct 2011 KR
20140135909 May 2013 KR
20140023552 Feb 2014 KR
2013058111 Apr 2013 WO
2013063097 May 2013 WO
Non-Patent Literature Citations (8)
Entry
A compact and cost effective design for cell phone zoom lens, Chang et al., Sep. 2007, 8 pages.
Consumer Electronic Optics: How small a lens can be? The case of panomorph lenses, Thibault et al., Sep. 2014, 7 pages.
Optical design of camera optics for mobile phones, Steinich et al., 2012, pp. 51-58 (8 pages).
Modeling and measuring liquid crystal tunable lenses, Peter P. Clark, 2014, 7 pages.
Mobile Platform Optical Design, Peter P. Clark, 2014, 7 pages.
“Cheat sheet: how to understand f-stops”, Internet article, Digital Camera World, 2017.
Boye et al., “Ultrathin Optics for Low-Profile Innocuous Imager”, Sandia Report, 2009, pp. 56-56.
European Search Report in related EP patent application 18821980.2, dated Jul. 10, 2019. 4 pages.
Related Publications (1)
Number Date Country
20210048628 A1 Feb 2021 US
Provisional Applications (1)
Number Date Country
62535926 Jul 2017 US