This application claims the priority benefit of Japanese Patent Applications Ser. No. 2018-041754 filed on Mar. 8, 2018, the entire content of which is incorporated herein by reference.
The present disclosure relates to optical lens, in particular to a camera optical lens suitable for handheld devices such as smart phones and digital cameras and imaging devices.
In recent years, the demand for miniature camera lens is increasing day by day, but the photosensitive devices of general camera lens are no other than Charge Coupled Device (CCD) or Complementary metal-Oxide Semiconductor Sensor (CMOS sensor), and as the progress of the semiconductor manufacturing technology makes the pixel size of the photosensitive devices shrink, coupled with the current development trend of electronic products being that it should have excellent optical characteristics and high light flux and their shape should be small, miniature camera lens with good imaging quality therefor has become a mainstream in the market.
A typical related camera lens comprises six lenses, and from the object side to the image side, the camera lens comprises in sequence: a first lens having a positive refractive power, a second lens having a negative refractive power, a third lens having a positive refractive power, a fourth lens having a negative refractive power, a fifth lens having a positive refractive power, and a sixth lens having a negative refractive power.
However, the refractive index distribution of the first lens and the shape of the first lens and the fourth lens are insufficient, the luminance is not sufficient for Fno≥2.14. In other traditional camera lenses, although Fno≥2.15, but the luminance is also insufficient.
Many aspects of the exemplary embodiments can be better understood with reference to the following drawings. The components in the drawing are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure.
The present disclosure will hereinafter be described in detail with reference to several exemplary embodiments. To make the technical problems to be solved, technical solutions and beneficial effects of the present disclosure more apparent, the present disclosure is described in further detail together with the figure and the embodiments. It should be understood the specific embodiments described hereby is only to explain the disclosure, not intended to limit the disclosure.
As referring to
The first lens L1 has a positive refractive power, the second lens L2 has a negative refractive power, the third lens L3 has a positive refractive power, the fourth lens L4 has a negative refractive power, the fifth lens L5 has a positive refractive power, and the sixth lens L6 has a negative refractive power. In order to correct the aberration problem, the surface of the six lens should be designed to aspherical surface.
Here, the focal length of the whole camera optical lens LA is defined as f, the focal length of the first lens is defined as f1. The camera optical lens LA further satisfies the following condition: 1.00≤f1/f≤1.10 Condition 1.00≤f1/f≤1.10 fixes the positive refractive power of the first lens L1. If the lower limit of the set value is exceeded, although it benefits the ultra-thin development of lenses, but the positive refractive power of the first lens L1 will be too strong, problem like aberration is difficult to be corrected. On the contrary, if the upper limit of the set value is exceeded, the positive refractive power of the first lens L1 becomes too weak, it is then difficult to develop miniaturized lenses.
The curvature radius of the object side surface of the first lens L1 is defined as R1, the curvature radius of the image side surface of the first lens L1 is defined as R2. The following condition should be satisfied: −2.40≤(R1+R2)/(R1−R2)≤−1.90, by which, the shape of the first lens L1 is fixed, further, and when beyond this range, it is unfavorable for realization of high light flux (Fno), excellent optical characteristics and miniaturization.
The curvature radius of the object side surface of the fourth lens L4 is defined as R7, the curvature radius of the image side surface of the fourth lens L4 is defined as R8. The following condition should be satisfied: 11.40≤(R7+R8)/(R7−R8)≤16.00, by which, the shape of the fourth lens L4 is fixed, further, when beyond this range, it is unfavorable for realization of high light flux (Fno), excellent optical characteristics and miniaturization.
The second lens L2 has a negative refractive power and the fourth lens L4 has a negative refractive power. The focal length of the second lens L2 is f2, the focal length of the fourth lens L4 is f4. The following condition should be satisfied: 0.15≤f2/f4≤0.16. This condition fixes the ratio between the focal length of the second lens L2 and the focal length of the fourth lens L4. When beyond this range, it is unfavorable for realization of high light flux (Fno), excellent optical characteristics and miniaturization.
The sixth lens L6 has a negative refractive power. The focal length of the whole camera optical lens LA is f, the curvature radius of the object side surface of the sixth lens L6 is defined as R11. The following condition should be satisfied: 2.30≤R11/f≤2.50. This condition fixes the ratio between the curvature radius of the object side surface of the sixth lens L6 and the focal length of the whole camera optical lens LA. When beyond this range, it is unfavorable for realization of high light flux (Fno), excellent optical characteristics and miniaturization.
When the focal length of the camera optical lens LA of the present invention, the focal length of each lens, the refractive power of the related lens, and the curvature radius of the camera optical lens satisfy the above conditions, the camera optical lens LA has the advantage of high light flux (Fno), excellent optical characteristics and miniaturization.
In the following, an example will be used to describe the camera optical lens LA of the present invention. The symbols recorded in each example are as follows. The unit of distance, radius and center thickness is mm
f: The focal length of the camera lens;
f1: The focal length of the first lens;
f2: The focal length of the second lens;
f3: The focal length of the third lens;
f4: The focal length of the fourth lens;
f5: The focal length of the fifth lens;
f6: The focal length of the sixth lens;
Fno: F value;
2ω: Field;
S1: Aperture;
R: The curvature radius of the optical surface, the central curvature radius in case of lens;
R1: The curvature radius of the object side surface of the first lens L1;
R2: The curvature radius of the image side surface of the first lens L1;
R3: The curvature radius of the object side surface of the second lens L2;
R4: The curvature radius of the image side surface of the second lens L2;
R5: The curvature radius of the object side surface of the third lens L3;
R6: The curvature radius of the image side surface of the third lens L3;
R7: The curvature radius of the object side surface of the fourth lens L4;
R8: The curvature radius of the image side surface of the fourth lens L4;
R9: The curvature radius of the object side surface of the fifth lens L5;
R10: The curvature radius of the image side surface of the fifth lens L5;
R11: The curvature radius of the object side surface of the sixth lens L6;
R12: The curvature radius of the image side surface of the sixth lens L6;
R13: The curvature radius of the object side surface of the optical filter GF;
R14: The curvature radius of the image side surface of the optical filter GF;
d: The thickness on-axis of the lens and the distance on-axis between the lens;
d0: The distance on-axis from aperture S1 to the object side surface of the first lens L1;
d1: The thickness on-axis of the first lens L1;
d2: The distance on-axis from the image side surface of the first lens L1 to the object side surface of the second lens L2;
d3: The thickness on-axis of the second lens L2;
d4: The distance on-axis from the image side surface of the second lens L2 to the object side surface of the third lens L3;
d5: The thickness on-axis of the third lens L3;
d6: The distance on-axis from the image side surface of the third lens L3 to the object side surface of the fourth lens L4;
d7: The thickness on-axis of the fourth lens L4;
d8: The distance on-axis from the image side surface of the fourth lens L4 to the object side surface of the fifth lens L5;
d9: The thickness on-axis of the fifth lens L5;
d10: The distance on-axis from the image side surface of the fifth lens L5 to the object side surface of the sixth lens L6;
d11: The thickness on-axis of the sixth lens L6;
d12: The distance on-axis from the image side surface of the sixth lens L6 to the object side surface of the optical filter GF;
d13: The thickness on-axis of the optical filter GF;
d14: The distance on-axis from the image side surface to the image surface of the optical filter GF;
nd: The refractive power of the d line;
nd1: The refractive power of the d line of the first lens L1;
nd2: The refractive power of the d line of the second lens L2;
nd3: The refractive power of the d line of the third lens L3;
nd4: The refractive power of the d line of the fourth lens L4;
nd5: The refractive power of the d line of the fifth lens L5;
nd6: The refractive power of the d line of the sixth lens L6;
nd7: The refractive power of the d line of the optical filter GF;
vd: The abbe number;
v1: The abbe number of the first lens L1;
v2: The abbe number of the second lens L2;
v3: The abbe number of the third lens L3;
v4: The abbe number of the fourth lens L4;
v5: The abbe number of the fifth lens L5;
v6: The abbe number of the sixth lens L6;
v7: The abbe number of the optical filter GF.
IH: Image height;
TTL: Optical length (the distance on-axis from the object side surface of the first lens L1 to the image surface);
LB: The distance on-axis from the image side surface of the sixth lens L6 to the image surface (including the thickness of the glass plate GF);
y=(x2/R)/[1+{1−(k+1)(x2/R2)}1/2]+A4x4+A6x6+A8x8+A10x10+A12x12+A14x14+A16x16+A18x18+A20x20 (1)
Among them, K is a conic index, A4, A6, A8, A10, A12, A14, A16 A18, A20 are aspheric surface indexes.
For convenience, the aspheric surface of each lens surface uses the aspheric surfaces shown in the above condition (1). However, the present invention is not limited to the aspherical polynomials form shown in the condition (1).
Table 2 shows the aspherical surface data of the camera optical lens LA in the embodiment 1 of the present invention.
Table 7 shows the various values of the embodiments 1, 2, 3, and the values corresponding with the parameters which are already specified in the conditions.
As shown in Table 7, the first embodiment satisfies the various conditions.
Table 3 and table 4 show the design data of the camera optical lens 20 in embodiment 2 of the present invention.
Table 4 shows the aspherical surface data of each lens of the camera optical lens 20 in embodiment 2 of the present invention.
As shown in Table 7, the second embodiment satisfies the various conditions.
Table 5 and table 6 show the design data of the camera optical lens 30 in embodiment 3 of the present invention.
Table 6 shows the aspherical surface data of each lens of the camera optical lens 30 in embodiment 3 of the present invention.
As shown in Table 7, the third embodiment satisfies the various conditions.
Table 7 shows the various values of the embodiments 1, 2, 3, and the values corresponding with the parameters which satisfies the various conditions. In addition, the units of the various values shown in table 5 are 2ω (°) f (mm) f1 (mm) f2 (mm) f3 (mm) f4 (mm) f5 (mm) f6 (mm) TTL (mm) LB (mm) IH (mm).
It is to be understood, however, that even though numerous characteristics and advantages of the present exemplary embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms where the appended claims are expressed.
Number | Date | Country | Kind |
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2018-041754 | Mar 2018 | JP | national |