# Patent

## Title
Camera lens

## Abstract

A camera lens is disclosed. The camera lens includes five piece ultra-thin and wide angle lenses with excellent optical properties and with chromatic aberration sufficiently corrected as follows: a first lens with positive refractive power; a second lens with negative refractive power; a third lens with positive refractive power; a fourth lens with positive refractive power; a fifth lens with negative refractive power which are arranged sequentially from the object side. The camera lens is characterized in that it meets specified conditions.

## Background
FIELD OF THE INVENTION
The present invention relates to a camera lens, and more particularly to a camera lens very suitable for mobile phone camera module and WEB camera lens etc. equipped with high-pixel camera elements such as CCD, CMOS etc.
DESCRIPTION OF RELATED ART
In recent years, various camera devices equipped with camera elements such as CCD, CMOS are extensively popular. Along with development on camera lens toward miniaturization and high performance, ultra-thin and high-luminous flux (Fno) wide angle camera lenses with excellent optical properties are needed.
The technology related to a camera lens composed of five piece high-luminous flux (Fno) lenses with excellent optical properties is developed gradually. The camera lens mentioned in the proposal of Prior Reference Documents 1 and 2 is composed of five piece lenses which are arranged sequentially from object side as follows: a first lens with positive refractive power; a second lens with negative refractive power; a third lens with positive refractive power; a fourth lens with positive refractive power and a fifth lens with negative refractive power.
The camera lens disclosed in embodiment 1 ̃4 of the Prior Reference Document 1 is composed of above mentioned five piece lenses, but refractive power distribution of the first lens and the third lens is insufficient, therefore it is 2ω≧74.4 wide angle.
The camera lens disclosed in embodiments 1, 2 of the Prior Document 2 is composed of above mentioned five piece lenses, but refractive power distribution of the first lens and the third lens is insufficient, therefore it is 2ω≧78.4 wide angle.
PRIOR REFERENCE DOCUMENTS
[Prior Reference Document 1] Japan Patent Publication No. JP2016-020973.
[Prior Reference Document 2] Japan Patent No. JP2015-079175.
Therefore, it is necessary to provide a novel camera lens to solve the above-mentioned technical problem.



BRIEF DESCRIPTION OF THE DRAWINGS
Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
FIG. 1 is an illustrative structure of a camera lens LA of the present disclosure.
FIG. 2 is an illustrative structure of a camera lens LA in accordance with a first embodiment (Embodiment 1) of the present disclosure.
FIG. 3 is a Longitudinal Aberration diagram of the camera lens LA in the Embodiment 1.
FIG. 4 is a Lateral Color Aberration diagram of the camera lens LA in the Embodiment 1.
FIG. 5 is a Field Curvature Distortion of the camera lens LA in the Embodiment 1.
FIG. 6 is an illustrative structure of a camera lens LA in accordance with a second embodiment (Embodiment 2) of the present disclosure.
FIG. 7 is a Longitudinal Aberration diagram of the camera lens LA in the Embodiment 2.
FIG. 8 is the Lateral Color Aberration diagram of the camera lens LA in the Embodiment 2.
FIG. 9 is a Field Curvature Distortion of the camera lens LA in the Embodiment 2.



DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
The present invention will hereinafter be described in detail with reference to exemplary embodiments. To make the technical problems to be solved, technical solutions and beneficial effects of present disclosure more apparent, the present disclosure is described in further detail together with the figures and the embodiments. It should be understood the specific embodiments described hereby is only to explain this disclosure, not intended to limit this disclosure.
A camera lens LA in accordance with an embodiment of the present disclosure includes, in an order from an object side to an image side, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5. A glass plate GF is arranged between the fifth lens L5 and the imaging surface. And a glass cover or an optical filter having the function of filtering IR can serve as the glass plate GF. Moreover, it shall be OK if no glass plate GF is arranged between the fifth lens L5 and the image surface.
The first lens L1 has positive refractive power; the second lens L2 has negative refractive power; the third lens L3 has positive refractive power; the fourth lens L4 has positive refractive power; the fifth lens has negative refractive power. Moreover, the surfaces of the five lenses should be designed as the aspheric shape preferably in order to correct the aberration well.
The camera lens LA satisfies the following conditions (1) ̃(5):

0.40≦f1/f≦0.60  (1);

2.50≦f3/f≦5.50  (2);

−1.35≦(R1+R2)/(R1−R2)≦−0.75  (3);

−5.00≦(R5+R6)/(R5−R6)≦−1.70  (4);

0.10≦d5/f≦0.25  (5); where

f: overall focal distance of the camera lens;

f1: focal distance of the first lens L1;

f3: focal distance of the third lens L3;

R1: curvature radius of the first lens L1's object side surface;

R2: curvature radius of the first lens L1's image side surface;

R5: curvature radius of the third lens L3's object side surface;

R6: curvature radius of the third lens L3's image side surface;

d5: axial distance from the image side surface of the second lens L2 to the object side surface of the third lens L3;

The positive refractive power of the first lens L1 is specified in the condition (1). The development of narrow angle and small sized lens with excellent optical properties cannot be easily implemented outside the range of condition (1).
Therefore, numerical range of condition (1) should be set within the numerical range of the following condition (1-A) preferably,

0.47≦f1/f≦0.53  (1-A)

The positive refractive power of the third lens L3 is specified in the condition (2). The development of narrow angle and small sized lens with excellent optical properties cannot be easily implemented outside the range of condition (2).
Therefore, numerical range of condition (2) should be set within the numerical range of the following condition (2-A) preferably,

3.00≦f3/f≦4.50  (2-A)

The shape of the first lens L1 is specified in the condition (3). Moreover, the development of narrow angle, small sized and high luminous flux trend cannot be implemented easily outside the range of the condition (3).
Therefore, numerical range of condition (3) should be set within the numerical range of the following condition (3-A) preferably,

−1.20≦(R1+R2)/(R1−R2)≦−0.90  (3-A)

The shape of the third lens L3 is specified in the condition (4). Moreover, the development of narrow angle, small sized and high luminous flux trend cannot be implemented easily outside the range of the condition (4).
Therefore, numerical range of condition (4) should be set within the numerical range of the following condition (4-A) preferably,

−4.20≦(R5+R6)/(R5−R6)≦−2.00  (4-A)

Ratio of axial distance from the image side surface of the second lens L2 to the object side surface of the third lens L3 to overall focal distance of the camera lens is specified in condition (5). Moreover, the development of narrow angle, small sized and high luminous flux trend cannot be implemented easily outside the range of the condition (5).
Therefore, numerical range of condition (5) should be set within the numerical range of the following condition (5-A) preferably,

0.12≦d5/f≦0.20  (5-A)

The second lens L2 has negative refractive power and meets following conditions (6) ̃(7).

−1.00≦f2/f≦−0.50  (6);

0.05≦(R3+R4)/(R3−R4)≦1.80  (7); where,

f: overall focal distance of the camera lens;

f2: focal distance of the second lens L2;

R3: curvature radius of the second lens L2's object side surface;

R4: curvature radius of the second lens L2's image side surface.

Negative refractive power of the second lens L2 is specified in the condition (6). Moreover, the development of narrow angle, small sized chromatic aberration correction trend cannot be implemented easily outside the range of the condition (6).
Therefore, numerical range of condition (6) should be set within the numerical range of the following condition (6-A) preferably,

−0.85≦f2/f≦−0.70  (6-A)

Shape of the second lens L2 is specified in the condition (7). Moreover, the development of narrow angle, small sized chromatic aberration correction trend cannot be implemented easily outside the range of the condition (7).
Therefore, numerical range of condition (7) should be set within the numerical range of the following condition (7-A) preferably,

0.15≦(R3+R4)/(R3−R4)≦1.50  (7-A)

Because five lenses of camera Lens all have the stated formation and meet all the conditions, so it is possible to produce a camera lens which is composed of five narrow angle, small sized and high luminous flux lenses with excellent optional properties.
The camera lens LA of the invention shall be explained below by using the embodiments. Moreover, the symbols used in all embodiments are shown as follows. And mm shall be taken as the units of the distance, the radius and the center thickness.
f: overall focal distance of the camera lens LA
f1: focal distance of the first lens L1
f2: focal distance of the second lens L2
f3: focal distance of the third lens L3
f4: focal distance of the fourth lens L4
f5: focal distance of the fifth lens L5
Fno: F value
2ω: total angle of view
S1: aperture
R: curvature radius of optical surface, central curvature radius when the lens is involved
R1: curvature radius of the first lens L1's object side surface
R2: curvature radius of the first lens L1's image side surface
R3: curvature radius of the second lens L2's object side surface
R4: curvature radius of the second lens L2's image side surface
R5: curvature radius of the third lens L3's object side surface
R6: curvature radius of the third lens L3's image side surface
R7: curvature radius of the fourth lens L4's object side surface
R8: curvature radius of the fourth lens L4's image side surface
R9: curvature radius of the fifth lens L5's object side surface
R10: curvature radius of the fifth lens L5's image side surface
R11: curvature radius of the glass plate GF's object side surface
R12: curvature radius of the glass plate GF's image side surface
d: center thickness of lenses or the distance between lenses
d1: center thickness of the first lens L1
d2: axial distance from the image side surface of the first lens L1 to aperture S1
d3: axial distance from aperture S1 to the object side surface of the second lens L2
d4: center thickness of the second lens L2
d5: axial distance from the image side surface of the second lens L2 to the object side surface of the third lens L3
d6: center thickness of the third lens L3
d7: axial distance from the image side surface of the third lens L3 to the object side surface of the fourth lens L4
d8: center thickness of the fourth lens L4
d9: axial distance from the image side surface of the fourth lens L4 to the object side surface of the fifth lens L5
d10: center thickness of the fifth lens L5
d11: axial distance from the image side surface of the fifth lens L5 to the object side surface of glass plate GF
d12: center thickness of the glass plate GF
d13: axial distance from the image side surface to the imaging surface of the glass plate GF
nd: refractive power of line d
nd1: refractive power of line d of the first lens L1
nd2: refractive power of line d of the second lens L2
nd3: refractive power of line d of the third lens L3
nd4: refractive power of line d of the fourth lens L4
nd5: refractive power of line d of the fifth lens L5
nd6: refractive power of line d of the glass plate GF
νd: abbe number
ν1: abbe number of the first lens L1
ν2: abbe number of the second lens L2
ν3: abbe number of the third lens L3
ν4: abbe number of the fourth lens L4
ν5: abbe number of the fifth lens L5
ν6: abbe number of the glass plate GF
TTL: optical length (axial distance from object side surface to the imaging surface of the first lens L1)
LB: axial distance (including thickness of the glass plate GF) from the image side surface to the imaging surface of the fifth lens L5;
IH: image height

y=(x2/R)/[1+{1−(k+1)(x2/R2)}1/2]+A4×4+A6×6+A8×8+A10×10+A12×12+A14×14+A16×16  (8)

Wherein R indicates the curvature radius on the axle; k indicates the conic coefficient; and A4, A6, A8, A10, A12, A14 and A16 indicates the coefficients of the aspheric surface.
For convenience sake, the aspheric surface shown in the formula (8) shall be taken as the aspheric surfaces of all lens surfaces. However, the invention shall be not limited to the polynomial form of the aspheric surface shown in the formula (8).
Embodiment 1
The configuration structure diagram of the camera lens LA in the Embodiment 1 is shown in the FIG. 2. Moreover, the data including curvature radius R of the object side surfaces and the image side surfaces, center thicknesses of the lenses, the distances d among the lenses, refractive powers nd and abbe numbers v d of the lens L1-L5 in the Embodiment 1 are shown in the Table 1, wherein the camera lens LA is formed by the lens L1-L5; and the data including conic coefficients k and aspheric coefficients are shown in the Table 2.











TABLE 1






R
d
nd
v d






















R1
1.44481
d1 =
0.835
nd1
1.5441
v 1
56.12


R2
17.48576
d2 =
0.072






S1
∞
d3 =
0.020






R3
−7.09734
d4 =
0.263
nd2
1.6397
v 2
23.53


R4
4.87051
d5 =
0.734






R5
5.78938
d6 =
0.376
nd3
1.6397
v 3
23.53


R6
9.67745
d7 =
0.781






R7
−2.94553
d8 =
0.296
nd4
1.5441
v 4
56.12


R8
−1.73626
d9 =
0.137






R9
−4.16365
d10 =
0.386
nd5
1.5352
v 5
56.12


R10
3.48801
d11 =
0.480






R11
∞
d12 =
0.210
nd6
1.5168
v 6
64.17


R12
∞
d13 =
0.681


















TABLE 2








conic 




coefficient
aspheric coefficient
















k
A4
A6
A8
A10
A12
A14
A16


















R1
0.0000E+00
−9.9056E−03
  1.7320E−02
−3.7089E−02
  2.0440E−02
−5.9236E−03
−1.1716E−03
−2.6506E−03


R2
0.0000E+00
−1.2742E−02
−1.4148E−02
  4.1660E−02
−2.8941E−02
−9.1673E−03
−2.2014E−03
  4.6662E−03


R3
0.0000E+00
  6.6477E−02
  2.1231E−02
  1.1787E−02
  7.7874E−03
−1.5917E−05
−1.6090E−02
  6.4719E−03


R4
1.9324E+01
  7.8826E−02
  9.6185E−02
  7.1613E−03
−8.7187E−02
  6.2496E−02
2.6034E−01
−1.9100E−01


R5
0.0000E+00
−1.1425E−01
  4.5945E−02
−1.7252E−02
−1.5105E−03
  7.7271E−03
8.6326E−03
−4.9079E−03


R6
−1.5562E+02
−9.8873E−02
  7.5876E−03
−3.6662E−05
  9.3118E−03
−8.3140E−04
−2.1474E−03
  1.7449E−03


R7
2.6393E+00
−6.7119E−02
  8.6349E−03
−1.0282E−02
  8.3052E−04
−2.4019E−04
1.0425E−03
  2.8987E−04


R8
−7.1440E+00
−4.8313E−02
  5.7120E−02
−2.3140E−02
  4.2102E−03
−3.1899E−04
4.0395E−05
−2.2828E−05


R9
0.0000E+00
−7.1379E−03
  9.4934E−03
−2.3106E−05
−1.8930E−04
  4.6924E−06
−1.5084E−06
−6.6351E−07


R10
−4.6391E+01
−6.0296E−02
  1.2389E−02
−2.4801E−03
  2.5353E−04
  5.8060E−06
6.7000E−06
−8.1219E−07









The values in the embodiments 1 and 2 and the values corresponding to the parameters specified in the conditions (1)-(7) are shown in the subsequent Table 5.
The Embodiment 1 meets the conditions (1)-(7), as shown in Table 5.
See FIG. 3 for Longitudinal Aberration of the camera lens LA in the Embodiment 1, see FIG. 4 for Lateral Color Aberration of it, and see FIG. 5 for curvature of field and distortion of it. Further, the curvature of field S in the FIG. 5 is the one in the sagittal direction, and T is the one in the direction of meridian, as well as in the Embodiment 2. Moreover, Fno=2.04 2ω=49.8° TTL=5.271 of the camera lens LA in the Embodiment 1 as shown in FIGS. 3 ̃5, and the lens refers to small sized narrow angle amera lens having high luminous flux, wherein 2ω=80.0°, TTL/IH=1.498, Fno=5.271; therefore, it is no wonder that this lens has these excellent optical properties.
Embodiment 2
The configuration structure diagram of the camera lens LA in the Embodiment 2 is shown in the FIG. 6. Moreover, the curvature radius R of the object side surfaces and the image side surfaces, the center thicknesses of the lenses, the distances d among the lenses, the refractive powers nd and abbe numbers νd of the lens L1-L5 in the Embodiment 2 are shown in the Table 3, wherein the camera lens LA is formed by the lens L1-L5; and the conic coefficients k and aspheric coefficients are shown in the Table 4.











TABLE 3






R
d
nd
v d






















R1
1.45665
d1 =
0.795
nd1
1.5441
v 1
56.12


R2
20.20828
d2 =
0.084






S1
∞
d3 =
0.010






R3
−6.94912
d4 =
0.270
nd2
1.6397
v 2
23.53


R4
5.05558
d5 =
0.731






R5
5.47639
d6 =
0.353
nd3
1.6397
v 3
23.53


R6
9.15742
d7 =
0.785






R7
−2.96715
d8 =
0.271
nd4
1.5441
v 4
56.12


R8
−1.79592
d9 =
0.164






R9
−4.07080
d10 =
0.397
nd5
1.5352
v 5
56.12


R10
3.64468
d11 =
0.480






R11
∞
d12 =
0.210
nd6
1.5168
v 6
64.17


R12
∞
d13 =
0.709


















TABLE 4








conic coefficient
aspheric coefficient
















k
A4
A6
A8
A10
A12
A14
A16


















R1
0.0000E+00
−9.7008E−03
  1.5787E−02
−3.8311E−02
  1.9591E−02
−6.5932E−03
−1.8428E−03
−3.3024E−03


R2
0.0000E+00
−1.4393E−02
−1.6320E−02
  3.9329E−02
−3.0841E−02
−1.0357E−02
−2.3794E−03
5.6514E−03


R3
0.0000E+00
  6.8702E−02
  2.2779E−02
  1.2274E−02
  7.7577E−03
−1.3868E−04
−1.6127E−02
6.2107E−03


R4
1.9628E+01
  8.4666E−02
  9.1527E−02
  8.2794E−03
−8.0099E−02
  7.1036E−02
  2.6278E−01
−2.0509E−01


R5
0.0000E+00
−1.1933E−01
  4.2125E−02
−1.8877E−02
  5.1900E−03
  1.0955E−02
  7.7701E−03
−6.0687E−03


R6
−1.9390E+02
−9.8365E−02
  8.1776E−03
−8.9714E−04
  8.7486E−03
  5.8305E−04
−8.4776E−04
1.7725E−03


R7
2.6862E+00
−6.7498E−02
  1.0116E−02
−9.3849E−03
  1.4448E−03
  1.0830E−04
  1.0700E−03
1.6191E−04


R8
−8.0144E+00
−4.8653E−02
  5.7314E−02
−2.3041E−02
  4.2351E−03
−3.1294E−04
  3.7816E−05
−2.8020E−05


R9
0.0000E+00
−6.7045E−03
  9.6292E−03
  8.0907E−06
−2.0861E−04
−3.1911E−06
−2.1915E−06
1.9086E−07


R10
−4.9993E+01
−5.9319E−02
  1.2455E−02
−2.4746E−03
  2.5002E−04
  4.3677E−06
  6.2753E−06
−8.0878E−07









The Embodiment 2 meets the conditions (1)-(7), as shown in Table 5.
See FIG. 7 for Longitudinal Aberration of the camera lens LA in the Embodiment 2, see FIG. 8 for Lateral Color Aberration of it, and see FIG. 9 for curvature of field and distortion of it. Moreover, Fno=2.16 2ω=49.8° TTL=5.259 of the camera lens LA in the Embodiment 2 as shown in FIGS. 7 ̃9, and the lens refers to small sized narrow angle camera lens having high luminous flux, wherein 2ω=80.0°, TTL/IH=1.498, Fno=5.271; therefore, it is no wonder that this lens has these excellent optical properties.
The values in all embodiments and the values corresponding to the parameters specified in the conditions (1)-(7) are shown in the Table 5. Moreover, the units including 2ω(°), f(mm), f1(mm), f2(mm), f3(mm), f4(mm), f5(mm), TTL(mm), LB(mm) and IH(mm) are shown in the Table 5, respectively.










TABLE 5






Embodiment 1
Embodiment 2
Condition


















f1/f
0.516
0.516
1


f3/f
3.939
3.727
2


(R1 + R2)/(R1 − R2)
−1.180
−1.155
3


(R5 + R6)/(R5 − R6)
−3.978
−3.975
4


d5/f
0.133
0.133
5


f2/f
−0.812
−0.823
6


(R3 + R4)/(R3 − R4)
0.186
0.158
7


Fno
2.04
2.16



2ω
49.8
49.8



f
5.511
5.509



f1
2.843
2.843



f2
−4.477
−4.535



f3
21.708
20.530



f4
7.156
7.732



f5
−3.485
−3.530



TTL
5.271
5.259



LB
1.371
1.399



IH
2.619
2.619









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.

## Claims

1. A camera lens comprising, in an order from an object side to an image side:
a first lens with positive refractive power;
a second lens with negative refractive power;
a third lens with positive refractive power;
a fourth lens with positive refractive power;
a fifth lens with negative refractive power; wherein the camera lens satisfies the following conditions (1) ̃(5):


0.40≦f1/f≦0.60  (1);



2.50≦f3/f≦5.50  (2);



−1.35≦(R1+R2)/(R1−R2)≦−0.75  (3);



−5.00≦(R5+R6)/(R5−R6)≦−1.70  (4);



0.10≦d5/f≦0.25  (5); where,


f: overall focal distance of the camera lens;
f1: focal distance of the first lens;
f3: focal distance of the third lens;
R1: curvature radius of the first lens' object side surface;
R2: curvature radius of the first lens' image side surface;
R5: curvature radius of the third lens' object side surface;
R6: curvature radius of the third lens' image side surface;
d5: axial distance from the image side surface of the second lens to the object side surface of the third lens.

2. The camera lens as described in claim 1 further satisfying the following conditions (6) ̃(7):


−1.00≦f2/f≦−0.50  (6);



0.05≦(R3+R4)/(R3−R4)≦1.80  (7);

where,
f: overall focal distance of the camera lens;
f2: focal distance of the second lens;
R3: curvature radius of the second lens' object side surface;
R4: curvature radius of the second lens' image side surface.