# Patent

## Title
Imaging lens

## Abstract

An imaging lens includes, from an object-side to an image-side: an aperture stop, a first lens of positive refractive power with two convex surfaces along the optical axis of the imaging lens, a meniscus second lens of negative refractive power with a convex surface on the object-side, a meniscus third lens of positive refractive power with a convex surface on the image-side, a meniscus fourth lens of negative refractive power with a convex surface on the object-side. Specified conditions are satisfied in order to reduce aberrations and an Fno (focal ratio number) and enhance wide-angle view.

## Background
BACKGROUND
1. Technical Field
The disclosure relates to imaging lenses and, particularly, to a compact imaging lens which has fourth lenses, a reduced total length, a wide-angle view and a high brightness.
2. Description of Related Art
In recent years, an image pickup element, such as a CCD (Charge Coupled Device) or a CMOS (Complementary-Metal Oxide Semiconductor) is widely used. In order to obtain small-sized camera modules for use in thin devices, such as mobile phones, personal digital assistant (PDA), or webcams that can still capture quality images, zoom lens systems with high zoom ratio but short overall length are desired.
Factors affecting both the zoom ratio and the overall length of the imaging lens, such as, the number and state of lenses employed, the power distribution of the employed lenses, and the shape of each employed lens, complicates any attempts at increasing zoom ratios but shortening overall lengths of imaging lenses. Additional, when the field of view of the lens is greater than 60°, a number of lens groups must be used to correct aberrations and ensure image quality, which will increase the overall length of the imaging lens. For example, reducing the number of lenses can shorten the overall length of the imaging lens, but zoom ratio and wide-angle view will suffer, conversely, increasing the number of lenses can increase zoom ratio and wide-angle view, but increases overall length of the imaging lens.
Therefore, the demand is high to develop an imaging lens with a short overall length and an reliable optical performance that matches with image sensing chips having enhanced resolution.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the imaging lens of the present invention.
FIG. 2 is a schematic view of the imaging lens according to a first embodiment.
FIGS. 3 ̃4, 5A, 5B are graphs respectively showing spherical aberration, lateral color aberration, astigmatism and distortion of FIG. 1.
FIG. 6 is a schematic view of the imaging lens according to a second embodiment.
FIGS. 7 ̃8, 9A, 9B are graphs respectively showing spherical aberration, lateral color aberration, astigmatism and distortion of FIG. 5.
FIG. 10 is a schematic view of the imaging lens according to a third embodiment.
FIGS. 11 ̃12, 13A, 13B are graphs respectively showing spherical aberration, lateral color aberration, astigmatism and distortion of FIG. 9.
FIG. 14 is a schematic view of the imaging lens according to a fourth embodiment.
FIGS. 15 ̃16, 17A, 17B are graphs respectively showing spherical aberration, lateral color aberration, astigmatism and distortion of FIG. 13.
FIG. 18 is a schematic view of the imaging lens according to a fifth embodiment.
FIGS. 19 ̃20, 21A, 21B are graphs respectively showing spherical aberration, lateral color aberration, astigmatism and distortion of FIG. 17.
FIG. 22 is a schematic view of the imaging lens according to a sixth embodiment.
FIGS. 23 ̃24, 25A, 25B are graphs respectively showing spherical aberration, lateral color aberration, astigmatism and distortion of FIG. 21.
FIG. 26 is a schematic view of the imaging lens according to a seventh embodiment.
FIGS. 27 ̃28, 29A, 29B are graphs respectively showing spherical aberration, lateral color aberration, astigmatism and distortion of FIG. 25.
FIG. 30 is a schematic view of the imaging lens according to an eighth embodiment.
FIGS. 31 ̃32, 33A, 33B are graphs respectively showing spherical aberration, lateral color aberration, astigmatism and distortion of FIG. 29.
FIG. 34 is a schematic view of the imaging lens according to a ninth embodiment.
FIGS. 35 ̃36, 37A, 37B are graphs respectively showing spherical aberration, lateral color aberration, astigmatism and distortion of FIG. 33.
FIG. 38 is a schematic view of the imaging lens according to a tenth embodiment.
FIGS. 39 ̃40, 41A, 41B are graphs respectively showing spherical aberration, lateral color aberration, astigmatism and distortion of FIG. 37.
FIG. 42 is a schematic view of the imaging lens according to an eleventh embodiment.
FIGS. 43 ̃44, 45A, 45B are graphs respectively showing spherical aberration, lateral color aberration, astigmatism and distortion of FIG. 41.
FIG. 46 is a schematic view of the imaging lens according to a twelfth embodiment.
FIGS. 47 ̃48, 49A, 49B are graphs respectively showing spherical aberration, lateral color aberration, astigmatism and distortion of FIG. 45.



DETAILED DESCRIPTION
Embodiments of the disclosure will now be described in detail below, with reference to the accompanying drawings.
Referring to FIG. 1, an imaging lens LA of the present invention, includes, in this order from the object-side to the image-side of the imaging lens LA, an aperture stop S1, a first lens L1 of positive refraction power, a meniscus second lens L2 of negative refraction power, a meniscus third lens L3 of positive refraction power, a meniscus fourth lens L4 of positive refraction power, a color filter GF, and an image plane IMG. The aperture stop S1 is positioned on the object-side surface the first lens L1. The color filter GF is positioned between the fourth lens L4 and the image plane IMG. The color filter GF can select from glass plate, or IR cut-off filter or low-pass filter. In other embodiments, the color filter GF can't be installed between the fourth lens L4 and the image plane IMG, but installed on other positions.
The first lens L1 has two convex surfaces along the optical axis of the imaging lens LA, the second lens L2 has a convex surface on the object-side, the third lens L3 has a convex surface on the image-side, and the fourth lens L4 has a convex surface on the object-side. In the present embodiment, in order to obtain a minimize overall length of the imaging lens LA, the four lenses are designed a telephoto type structure with position, negative, position and negative refractive power. Furthermore, in order to correct aberrations, all surfaces of the first, second, third lenses are aspherical surface.
The imaging lens LA satisfies the following condition formulas:

0.50≦f1/f≦0.75;  (1)

5.20≦f/d1≦8.00;  (2)

12.00≦f/d6≦45.00;  (3)

−0.35≦≦R1/R2≦−0.20;  (4)

3.00≦R3/R4≦20.00;  (5)

Wherein: f is a focal length of the imaging lens LA; f1 is a focal length of the first lens L1; d1 is a center thickness of the first lens L1 on the optical axis of the imaging lens LA; d6 is a distance between the image-side surface of the third lens L3 and the object-side surface of the fourth lens L4 on the optical axis of imaging lens LA; R1 is a radius of curvature of the object-side surface of the first lens L1; R2 is a radius of curvature of the image-side surface of the first lens L1; R3 is a radius of curvature of the object-side surface of the second lens L2; R4 is a radius of curvature of the image-side surface of the second lens L2.
The first condition (1) is configured for controlling the positive refraction power of the first lens L1. That is to say, when the ratio of the first condition (1) is smaller than the lower limit of the first condition (1), although it can effectively reduce the total length, the distortion is changed over a large range. By contraries, when ratio of the first condition (1) is greater than the upper limit of the first condition (1), the compact configuration is difficultly realized. So, when the ratio is met within the first condition (1), it not only can effectively reduce a total length of the imaging lens LA, but also can obtain low distortion, good imaging quality and a compact configuration.
The fourth condition (2) is configured for controlling the ratio that is the focal length of the imaging lens LA, and the center thickness of the first lens L1. When the ratio is under the lower limit of the condition (2), the distance LB between the image-side surface of the fourth lens L4 and the image plane IMG is difficult to control. By contraries, when the ratio is beyond the upper limit of the first condition (2), the thickness of the periphery of the first lens L1 is difficultly realized.
The fourth condition (3) is configured for controlling the ratio that is the focal length of the imaging lens LA, and the distance between the image-side surface of the third lens L3 and the object-side surface of the fourth lens L4. When the ratio is under the lower limit of the condition (3), although it can effectively reduce the total length of the imaging lens LA, the distortion is changed too bigger. By contraries, when the ratio is beyond the upper limit of the first condition (3), the short overall length of the imaging lens is difficultly realized.
The third condition (4) is configured for adjusting the shape of the first lens L1. When it is not satisfied the condition (4), when the wide-angle is in 60° ̃70° range and FNo (focal ratio number)<2.6, it is difficult to correct the spherical aberration and the coma aberration in a short overall length of the imaging lens LA.
The third condition (5) is configured for adjusting the shape of the second lens L2. When it is not satisfied the condition (5), when the wide-angle is in 60°  ̃70° range and FNo (focal ratio number) is less than 2.6, it is difficult to control the refraction power of the second lens L2, and correct the coma aberration in a short overall length of the imaging lens LA.
To achieve the imaging lens LA with a short overall length and excellent optical performance, both the first lens L1 and the third lens L3 are positive refraction power. the imaging lens LA satisfies the following conditions:

1.00≦R5/R6≦3.00;  (6)

−1.30≦f2/f≦−0.95;  (7)

Wherein: R5 is a radius of curvature of the object-side surface of the third lens L3; R6 is a radius of curvature of the image-side surface of the third lens L3; f is a focal length of the imaging lens; f2 is a focal length of the second lens L2.

The sixth condition (6) is configured for adjusting the shape of the third lens L3. When it is not satisfied the sixth condition (6), when the wide-angle is in 60° ̃70° range and FNo (focal ratio number) is less than 2.6, it is difficult to control the refraction power of the third lens L3, and obtain a short overall length.
The seventh condition (7) is configured for controlling the negative refraction power of the second lens L2. When it is not satisfied the sixth condition (7), the negative refraction power of the second lens L2 is changed in a large range, which is difficult to correct the coma aberration.
In order to obtain a short overall length, both the first lens L1 and the third lens L3 are positive refraction powers. In the present embodiment, the positive refraction power of the third lens L3 is configured for controlling the positive refraction power of the first lens L1.
In order to obtain a good coma aberration, both the second lens L2 and the fourth lens L4 are negative refraction powers. In the present embodiment, the negative refraction power of the fourth lens L4 is configured for controlling the negative refraction power of the second lens L2.
In order to obtain low distortion, good imaging quality, the imaging lens LA satisfies the following conditions:

0.55≦f3/f≦0.80;  (8)

−1.00≦f4/f≦−0.50.  (9)

Wherein f is a focal length of the imaging lens; f3 is a focal length of the third lens L3; f4 is a focal length of the fourth lens L4.
The eighth condition (8) is configured for controlling the positive refraction power of the third lens L3. When it is not satisfied the eighth condition (8), the positive refraction power of the third lens L3 is changed in a large range, which is difficult to correct the coma aberration.
The ninth condition (9) is configured for controlling the negative refraction power of the fourth lens L4. When it is not satisfied the ninth condition (9), the negative refraction power of the fourth lens L4 is changed in a large range, which is difficult to correct the coma aberration.
In the above conditions, though the overall length of the imaging lens LA is reduced, brightness of FNo (focal ratio number) is maintained less than 2.6, wide-angle view is maintained within 60° ̃70° range, aberrations of the imaging lens LA are maintained within an acceptable range. That is, the imaging lens LA keeps chromatic aberrations at a minimum while reducing the total length of the imaging lens LA.
The first, second, third, and fourth lenses L1, L2, L3, L4 are made of glass or resin. When using of glass manufacturing the lens, it is preferred to select the glass that the transfer temperature below 400 degrees to improve the durability of the lens.
The resin can efficiently manufacture the lens with complicated configuration relative to the glass. When the resin used to manufacture the lens, it can select the resin according to the ASTMD542 method for the determination of refractive index of d light in 1.500 ̃1.670 range and wavelength in 450 nm  ̃600 nm range, and the light transmittance of 80% or more, the best in more than 85%, such as thermoplastic resin, thermosetting resin. Regardless of thermoplastic resin and thermosetting resin, the first, second, third, and fourth lenses L1, L2, L3, and L4 can be made of the same resin material or different materials. The material of the second lens L2 is different from that of the first lens L1. The manufacture method of the resin can select injection molding, compression molding or injection molding.
It is well known that the refractive index of the resin can be changed according to the different temperature. In order to suppress this changement, it is preferred to select the atomic resin with average particle size below 100 nm, best in 50 nm, such as silicon dioxide, acidification aluminum, acidification titanium as the manufacturing material of lens.
The first, second, third, and fourth lenses L1, L2, L3, L4 made of resin each define an edge portion at the periphery thereof, the shape of the edge portion has no special requirement except do not affect the optical performance of the lenses. It is viewed from the forming process of the lens, the thickness of the edge portion is preferably within the thickness of 70% ̃130% range of the periphery of the lens. The incident light onto the arch of the lens can cause ghosting and flash phenomenon. In this case, it can arrange emitter masks between the lenses to prevent incident light onto the arch according to what's needed.
Before the imaging lens LA is used in the lens modules, each surface of the lenses L1, L2, L3 can be coated a film such as anti-reflective film, an IR film or a surface hardening process. The lens modules with the imaging lens LA can be used in components such as digital cameras, WEB cameras, computers, cars.
Example diagrams of the imaging lens LA will be described below with reference to FIGS. 1-48B. It is to be understood that the disclosure is not limited to these examples. The following are symbols used in each exemplary embodiment.

    
    
        f: the focal length of the imaging 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;
        FNo: focal ratio number;
        2ω: field angle;
        S1: aperture stop;
        R: curvature radius of each optical surface, it is referred to the center curvature radius of the imaging lens;
        R1: curvature radius of the object-side surface of the first lens;
        R2: curvature radius of the image-side surface of the first lens;
        R3: curvature radius of the object-side surface of the second lens;
        R4: curvature radius of the image-side surface of the second lens;
        R5: curvature radius of the object-side surface of the third lens;
        R6: curvature radius of the image-side surface of the third lens;
        R7: curvature radius of the object-side surface of the fourth lens;
        R8: curvature radius of the image-side surface of the fourth lens;
        R9: curvature radius of the object-side surface of the color filter;
        R10: curvature radius of the image-side surface of the color filter;
        d: center thickness of each lens;
        d0: distance between the aperture stop and the object-side surface of the first lens;
        d1: center thickness of the first lens;
        d2: distance between the image-side surface of the first lens and the object-side surface of the second lens;
        d3: center thickness of the second lens;
        d4: distance between the image-side surface of the second lens and the object-side surface of the third lens;
        d5: center thickness of the third lens;
        d6: distance between the image-side surface of the third lens and object-side surface of the fourth lens;
        d7: center thickness of the fourth lens;
        d8: distance between the image-side surface of the fourth lens and the object-side surface of the color filter;
        d9: center thickness of the color filter;
        d10: distance between the image-side surface of the color filter and the image plane;
        nd: refractive index of d light (wavelength: 587.6 nm);
        n1: refractive index of d light in the first lens;
        n2: refractive index of d light in the second lens;
        n3: refractive index of d light in the third lens;
        n4: refractive index of d light in the fourth lens;
        n5: refractive index of d light in the color filter;
        vd: Abbe number of d light;
        v1: Abbe number of the first lens;
        v2: Abbe number of the second lens;
        v3: Abbe number of the third lens;
        v4: Abbe number of the fourth lens;
        v5: Abbe number of the color filter;
        TTL: distance between the object-side surface of the color filter and the image plane;
        LB: distance between the image-side surface of the fourth lens and the image plane (including the thickness of the color filter);
        IH: the height of the image.
    
    


Each surface of the first, second, third, and fourth lenses L1, L2, L3, L4 is aspherical surface. The aspherical surfaces are shaped according to the formula:

Y=(X2/R)/[1+{1−(K+1)(X2/R2)}]+A4X4+A6X6+A8X8+A10X10+A12X12  (10)

Wherein R is curvature radius on the optical axis of the imaging lens; k is conic constant; A4, A6, A8, A10, A12 all are aspheric constant; y is the optical axis of the light passing forward direction; x is an axis perpendicular to the optical axis. The aspheric surface of the lenses shaped according to the formula (10), but, not limited to shaped by the formula (10).

Tables 1-2 show a first specification of the first embodiment of the imaging lens LA.












TABLE 1







R
d
nd
vd























S1
∞
d0 =
0.000






R1
1.612
d1 =
0.584
n1
1.544
v1
56.1


R2
−6.718
d2 =
0.060


R3
34.776
d3 =
0.330
n2
1.640
v2
23.4


R4
2.369
d4 =
0.804


R5
−2.309
d5 =
0.586
n3
1.544
v3
56.1


R6
−0.845
d6 =
0.093


R7
3.264
d7 =
0.403
n4
1.544
v4
56.1


R8
0.858
d8 =
0.500


R9
∞
d9 =
0.300
n5
1.517
v5
64.17


R10
∞
d10 =
0.641



















TABLE 2









conic




constant
aspheric constant














k
A4
A6
A8
A10
A12

















R1
−8.7753E−01
2.3787E−03
−2.0823E−03
−3.2880E−02
−1.4124E−02
0.0000E+00


R2
−2.6049E+02
−4.5064E−02
−1.1565E−01
1.9068E−01
−7.3006E−02
0.0000E+00


R3
0.0000E+00
8.4680E−02
−3.1523E−01
5.0741E−01
−1.7976E−01
0.0000E+00


R4
4.6525E+00
2.9740E−02
−1.3924E−01
1.5978E−01
−4.2234E−02
0.0000E+00


R5
−1.1331E+00
2.3652E−02
−1.2280E−01
1.1539E−01
−7.3780E−02
2.6379E−02


R6
−3.9393E+00
−1.2801E−01
3.1006E−02
−3.6571E−03
2.0234E−02
−4.7615E−03


R7
5.1145E−01
−2.0880E−01
6.7472E−02
5.9491E−03
−8.0924E−03
1.2442E−03


R8
−6.0999E+00
−1.2662E−01
5.1293E−02
−1.6832E−02
3.4268E−03
−3.3912E−04









Referring to FIG. 2, an imaging lens LA according to a first embodiment is shown. FIGS. 3 ̃4, 5A, 5B, are graphs of aberrations (spherical aberration, lateral color aberration, astigmatism, and distortion) of the first specification of the first embodiment of the imaging lens LA. In FIGS. 3 and 4, curves are spherical aberration and lateral color aberration characteristic curves of F light (wavelength: 486.1 nm), d light (wavelength: 587.6 nm) and C light (wavelength: 656.3 nm) of the imaging lens LA. The spherical aberration of the first specification of the exemplary embodiment is from −0.1 mm to 0.1 mm, the lateral color aberration of the first specification of the exemplary embodiment is from −2 mm to 2 mm. As illustrated in FIG. 5A, the astigmatism is shown at the d light (wavelength: 588 nm) for both the sagittal image surface S and the tangential image surface T. The astigmatism of the first specification of the exemplary embodiment of the imaging lens LA is from −0.10 mm to 0.10 mm. In FIG. 5B, the distortion of the first specification of the exemplary embodiment of the imaging lens LA is from −2% to 2%.
In the first specification, not only the overall length of the imaging lens LA is reduced and the brightness is ensured (seen in Table 25, 2ω=65.0°, TTL=4.301 mm, FNo=2.4), but also aberrations of the imaging lens LA are favorably corrected. That is, the imaging lens LA keeps lateral color aberration at a minimum while maintaining the field angle in 60° ̃70° range, and reducing the total length of the imaging lens LA.
Tables 3-4 show a second specification of the second embodiment of the imaging lens LA.












TABLE 3







R
d
nd
vd























S1
∞
d0 =
0.000






R1
1.605
d1 =
0.586
n1
1.544
v1
56.1


R2
−6.534
d2 =
0.051


R3
38.164
d3 =
0.329
n2
1.640
v2
23.4


R4
2.366
d4 =
0.821


R5
−2.277
d5 =
0.568
n3
1.544
v3
56.1


R6
−0.846
d6 =
0.085


R7
3.636
d7 =
0.395
n4
1.544
v4
56.1


R8
0.857
d8 =
0.500


R9
∞
d9 =
0.300
n5
1.517
v5
64.17


R10
∞
d10 =
0.745



















TABLE 4









conic




constant
aspheric constant














k
A4
A6
A8
A10
A12

















R1
−8.9033E−01
1.9453E−03
−2.4431E−03
−3.2967E−02
−1.3737E−02
0.0000E+00


R2
−2.6636E+02
−4.5824E−02
−1.1583E−01
1.9050E−01
−7.3373E−02
0.0000E+00


R3
0.0000E+00
8.5633E−02
−3.1474E−01
5.0782E−01
−1.7919E−01
0.0000E+00


R4
4.6495E+00
2.5198E−02
−1.4030E−01
1.6078E−01
−4.0582E−02
0.0000E+00


R5
−9.2180E−01
2.1463E−02
−1.2391E−01
1.1371E−01
−7.6085E−02
2.0673E−02


R6
−4.0477E+00
−1.2639E−01
3.1258E−02
−3.9581E−03
1.9245E−02
−5.3830E−03


R7
4.6006E−01
−2.0905E−01
6.7416E−02
5.9291E−03
−8.0997E−03
1.2411E−03


R8
−6.3958E+00
−1.2650E−01
5.1304E−02
−1.6833E−02
3.4249E−03
−3.4017E−04









Referring to FIG. 6, an imaging lens LA according to a second embodiment is shown. FIGS. 7 ̃8, 9A, 9B, are graphs of aberrations (spherical aberration, lateral color aberration, astigmatism, and distortion) of the second specification of the second embodiment of the imaging lens LA. In FIGS. 7 and 8, curves are spherical aberration and lateral color aberration characteristic curves of F light (wavelength: 486.1 nm), d light (wavelength: 587.6 nm) and C light (wavelength: 656.3 nm) of the imaging lens LA. The spherical aberration of the second specification of the second embodiment is from −0.1 mm to 0.1 mm, the lateral color aberration of the second specification of the second embodiment is from −2 mm to 2 mm. As illustrated in FIG. 9A, the astigmatism is shown at the d light (wavelength: 588 nm) for both the sagittal image surface S and the tangential image surface T. The astigmatism of the second specification of the second embodiment of the imaging lens LA is from −0.10 mm to 0.10 mm. In FIG. 9B, the distortion of the second specification of the second embodiment of the imaging lens LA is from −2% to 2%.
In the second specification, not only the overall length of the imaging lens LA is reduced and the brightness is ensured (seen in Table 25, 2ω=62.2°, TTL=4.380 mm, FNo=2.4), but also aberrations of the imaging lens LA are favorably corrected. That is, the imaging lens LA keeps lateral color aberration at a minimum while maintaining the field angle in 60° ̃70° range, and reducing the total length of the imaging lens LA.
Tables 5-6 show a third specification of the third embodiment of the imaging lens LA.












TABLE 5







R
d
nd
vd























S1
∞
d0 =
0.000






R1
1.622
d1 =
0.657
n1
1.544
v1
56.1


R2
−5.899
d2 =
0.060


R3
42.323
d3 =
0.330
n2
1.640
v2
23.4


R4
2.351
d4 =
0.750


R5
−2.312
d5 =
0.605
n3
1.544
v3
56.1


R6
−0.847
d6 =
0.099


R7
3.569
d7 =
0.406
n4
1.544
v4
56.1


R8
0.858
d8 =
0.500


R9
∞
d9 =
0.300
n5
1.517
v5
64.17


R10
∞
d10 =
0.601



















TABLE 6









conic




constant
aspheric constant














k
A4
A6
A8
A10
A12

















R1
−8.6130E−01
2.8158E−03
−4.3287E−04
−3.2208E−02
−1.3428E−02
0.0000E+00


R2
−2.0423E+02
−5.1127E−02
−1.1561E−01
1.9288E−01
−7.1225E−02
0.0000E+00


R3
0.0000E+00
8.2588E−02
−3.1616E−01
5.0718E−01
−1.7875E−01
0.0000E+00


R4
4.5761E+00
2.6619E−02
−1.3618E−01
1.6316E−01
−4.2345E−02
0.0000E+00


R5
−1.0772E+00
2.3150E−02
−1.2204E−01
1.1094E−01
−7.5557E−02
2.5327E−02


R6
−3.9563E+00
−1.2785E−01
3.0552E−02
−4.5331E−03
1.9723E−02
−4.9585E−03


R7
5.5583E−01
−2.0862E−01
6.7544E−02
5.9718E−03
−8.0847E−03
1.2461E−03


R8
−6.1695E+00
−1.2704E−01
5.1197E−02
−1.6854E−02
3.4207E−03
−3.4154E−04









Referring to FIG. 10, an imaging lens LA according to a third embodiment is shown. FIGS. 11 ̃12, 13A, 13B, are graphs of aberrations (spherical aberration, lateral color aberration, astigmatism, and distortion) of the third specification of the third embodiment of the imaging lens LA. In FIGS. 11 and 12, curves are spherical aberration and lateral color aberration characteristic curves of F light (wavelength: 486.1 nm), d light (wavelength: 587.6 nm) and C light (wavelength: 656.3 nm) of the imaging lens LA. The spherical aberration of the third specification of the exemplary embodiment is from −0.1 mm to 0.1 mm, the lateral color aberration of the third specification of the exemplary embodiment is from −2 mm to 2 mm. As illustrated in FIG. 13A, the astigmatism is shown at the d light (wavelength: 588 nm) for both the sagittal image surface S and the tangential image surface T. The astigmatism of the third specification of the exemplary embodiment of the imaging lens LA is from −0.10 mm to 0.10 mm. In FIG. 13B, the distortion of the third specification of the exemplary embodiment of the imaging lens LA is from −2% to 2%.
In the third specification, not only the overall length of the imaging lens LA is reduced and the brightness is ensured (seen in Table 25, 2ω=64.7°, TTL=4.308 mm, FNo=2.4), but also aberrations of the imaging lens LA are favorably corrected. That is, the imaging lens LA keeps lateral color aberration at a minimum while maintaining the field angle in 60° ̃70° range, and reducing the total length of the imaging lens LA.
Tables 7-8 show a fourth specification of the fourth embodiment of the imaging lens LA.












TABLE 7







R
d
nd
vd























S1
∞
d0 =
0.000






R1
1.626
d1 =
0.538
n1
1.544
v1
56.1


R2
−6.686
d2 =
0.062


R3
37.750
d3 =
0.330
n2
1.640
v2
23.4


R4
2.352
d4 =
0.815


R5
−2.302
d5 =
0.579
n3
1.544
v3
56.1


R6
−0.845
d6 =
0.089


R7
3.307
d7 =
0.400
n4
1.544
v4
56.1


R8
0.856
d8 =
0.500


R9
∞
d9 =
0.300
n5
1.517
v5
64.17


R10
∞
d10 =
0.767



















TABLE 8









conic




constant
aspheric constant














k
A4
A6
A8
A10
A12

















R1
−9.8359E−01
−1.9080E−03
4.3815E−05
−2.8769E−02
−1.5456E−02
0.0000E+00


R2
−2.5340E+02
−3.4947E−02
−1.1484E−01
1.9457E−01
−5.7522E−02
0.0000E+00


R3
0.0000E+00
9.4463E−02
−30.843E−01
5.1106E−01
−1.7896E−01
0.0000E+00


R4
4.7265E+00
2.1808E−02
−1.4070E−01
1.5494E−01
−5.1885E−02
0.0000E+00


R5
−1.2740E+00
2.5030E−02
−1.2315E−01
1.1802E−01
−7.2206E−02
2.4283E−02


R6
−3.9432E+00
−1.2670E−01
3.1876E−02
−2.3804E−03
2.0614E−02
−4.3756E−03


R7
5.7300E−01
−2.0794E−01
6.7451E−02
5.9387E−03
−8.0558E−03
1.2636E−03


R8
−6.1907E+00
−1.2531E−01
5.1922E−02
−1.6766E−02
3.4315E−03
−3.4041E−04









Referring to FIG. 14, an imaging lens LA according to a fourth embodiment is shown. FIGS. 15 ̃16, 17A, 17B, are graphs of aberrations (spherical aberration, lateral color aberration, astigmatism, and distortion) of the fourth specification of the exemplary embodiment of the imaging lens LA. In FIGS. 15 and 16, curves are spherical aberration and lateral color aberration characteristic curves of F light (wavelength: 486.1 nm), d light (wavelength: 587.6 nm) and C light (wavelength: 656.3 nm) of the imaging lens LA. The spherical aberration of the fourth specification of the exemplary embodiment is from −0.1 mm to 0.1 mm, the lateral color aberration of the fourth specification of the exemplary embodiment is from −2 mm to 2 mm. As illustrated in FIG. 17A, the astigmatism is shown at the d light (wavelength: 588 nm) for both the sagittal image surface S and the tangential image surface T. The astigmatism of the fourth specification of the exemplary embodiment of the imaging lens LA is from −0.10 mm to 0.10 mm. In FIG. 17B, the distortion of the fourth specification of the exemplary embodiment of the imaging lens LA is from −2% to 2%.
In the fourth specification, not only the overall length of the imaging lens LA is reduced and the brightness is ensured (seen in Table 25, 2ω=63.1°, TTL=4.380 mm, FNo=2.4), but also aberrations of the imaging lens LA are favorably corrected. That is, the imaging lens LA keeps lateral color aberration at a minimum while maintaining the field angle in 60° ̃70° range, and reducing the total length of the imaging lens LA.
Tables 9-10 show a fifth specification of the fifth embodiment of the imaging lens LA.












TABLE 9







R
d
nd
vd























S1
∞
d0 =
0.000






R1
1.613
d1 =
0.593
n1
1.544
v1
56.1


R2
−5.992
d2 =
0.060


R3
43.507
d3 =
0.346
n2
1.640
v2
23.4


R4
2.352
d4 =
0.631


R5
−2.229
d5 =
0.548
n3
1.544
v3
56.1


R6
−0.840
d6 =
0.268


R7
3.907
d7 =
0.388
n4
1.544
v4
56.1


R8
0.856
d8 =
0.500


R9
∞
d9 =
0.300
n5
1.517
v5
64.17


R10
∞
d10 =
0.400



















TABLE 10









conic




constant
aspheric constant














k
A4
A6
A8
A10
A12
















R1
−8.0477E−01
4.3553E−03
−1.2756E−02
−3.6843E−02
−3.1766E−02
0.0000E+00


R2
−1.0847E+02
−5.8440E−02
−1.2761E−01
1.6705E−01
−1.0195E−01
0.0000E+00


R3
0.0000E+00
4.3374E−02
−3.2744E−01
5.0289E−01
−1.8573E−01
0.0000E+00


R4
4.1238E+00
1.5815E−02
−1.6029E−01
1.6373E−01
−4.0825E−02
0.0000E+00


R5
−3.2239E+00
4.2801E−02
−1.2917E−01
1.1601E−01
−7.9895E−02
1.5579E−02


R6
−3.9619E+00
−1.1650E−01
3.6285E−02
−2.1487E−03
2.2420E−02
−3.8709E−03


R7
5.9931E−01
−2.0823E−01
6.7769E−02
5.8513E−03
−8.1083E−03
1.2720E−03


R8
−6.2852E+00
−1.3091E−01
5.1653E−02
−1.6715E−02
3.2510E−03
−3.1093E−04









Referring to FIG. 18, an imaging lens LA according to a fifth embodiment is shown. FIGS. 19 ̃20, 21A, 21B, are graphs of aberrations (spherical aberration, lateral color aberration, astigmatism, and distortion) of the fifth specification of the exemplary embodiment of the imaging lens LA. In FIGS. 19 and 20, curves are spherical aberration and lateral color aberration characteristic curves of F light (wavelength: 486.1 nm), d light (wavelength: 587.6 nm) and C light (wavelength: 656.3 nm) of the imaging lens LA. The spherical aberration of the fifth specification of the exemplary embodiment is from −0.1 mm to 0.1 mm, the lateral color aberration of the first specification of the exemplary embodiment is from −2 mm to 2 mm. As illustrated in FIG. 21A, the astigmatism is shown at the d light (wavelength: 588 nm) for both the sagittal image surface S and the tangential image surface T. The astigmatism of the fifth specification of the exemplary embodiment of the imaging lens LA is from −0.10 mm to 0.10 mm. In FIG. 21B, the distortion of the fifth specification of the exemplary embodiment of the imaging lens LA is from −2% to 2%.
In the fifth specification, not only the overall length of the imaging lens LA is reduced and the brightness is ensured (seen in Table 25, 2ω=69.2°, TTL=4.034 mm, FNo=2.4), but also aberrations of the imaging lens LA are favorably corrected. That is, the imaging lens LA keeps lateral color aberration at a minimum while maintaining the field angle in 60° ̃70° range, and reducing the total length of the imaging lens LA.
Tables 11-12 show a sixth specification of the sixth embodiment of the imaging lens LA.












TABLE 11







R
d
nd
vd























S1
∞
d0 =
0.000






R1
1.699
d1 =
0.589
n1
1.544
v1
56.1


R2
−5.080
d2 =
0.059


R3
39.148
d3 =
0.329
n2
1.640
v2
23.4


R4
2.363
d4 =
0.806


R5
−2.298
d5 =
0.613
n3
1.544
v3
56.1


R6
−0.844
d6 =
0.091


R7
3.311
d7 =
0.402
n4
1.544
v4
56.1


R8
0.857
d8 =
0.500


R9
∞
d9 =
0.300
n5
1.517
v5
64.17


R10
∞
d10 =
0.648



















TABLE 12









conic




constant
aspheric constant














k
A4
A6
A8
A10
A12

















R1
−8.7548E−01
3.0313E−03
−9.7556E−03
−3.8332E−02
−1.7400E−02
0.0000E+00


R2
−1.4488E+02
−4.9158E−02
−1.1679E−01
1.8980E−01
−7.3604E−02
0.0000E+00


R3
0.0000E+00
−8.8917E−02
−3.1427E−01
5.0770E−01
−1.7957E−01
0.0000E+00


R4
4.6521E+00
2.3502E−02
−1.4596E−01
1.5667E−01
−4.2776E−02
0.0000E+00


R5
−1.1645E+00
2.3987E−02
−1.2274E−01
1.1474E−01
−7.3940E−02
2.6225E−02


R6
−3.9393E+00
−1.2765E−01
3.1131E−02
−3.6975E−03
2.0328E−02
−4.6742E−03


R7
5.1308E−01
−2.0881E−01
6.7479E−02
5.9541E−03
−8.0890E−03
1.2464E−03


R8
−6.3089E+00
−1.2651E−01
5.1323E−02
−1.6831E−02
3.4273E−03
−3.3895E−04









Referring to FIG. 22, an imaging lens LA according to a sixth embodiment is shown. FIGS. 23 ̃24, 25A, 25B, are graphs of aberrations (spherical aberration, lateral color aberration, astigmatism, and distortion) of the sixth specification of the exemplary embodiment of the imaging lens LA. In FIGS. 23 and 24, curves are spherical aberration and lateral color aberration characteristic curves of F light (wavelength: 486.1 nm), d light (wavelength: 587.6 nm) and C light (wavelength: 656.3 nm) of the imaging lens LA. The spherical aberration of the sixth specification of the exemplary embodiment is from −0.1 mm to 0.1 mm, the lateral color aberration of the first specification of the exemplary embodiment is from −2 mm to 2 mm. As illustrated in FIG. 25A, the astigmatism is shown at the d light (wavelength: 588 nm) for both the sagittal image surface S and the tangential image surface T. The astigmatism of the sixth specification of the exemplary embodiment of the imaging lens LA is from −0.15 mm to 0.15 mm. In FIG. 25B, the distortion of the sixth specification of the exemplary embodiment of the imaging lens LA is from −2% to 2%.
In the sixth specification, not only the overall length of the imaging lens LA is reduced and the brightness is ensured (seen in Table 25, 2ω=64.9°, TTL=4.337 mm, FNo=2.4), but also aberrations of the imaging lens LA are favorably corrected. That is, the imaging lens LA keeps lateral color aberration at a minimum while maintaining the field angle in 60° ̃70° range, and reducing the total length of the imaging lens LA.
Tables 13-14 show a seventh specification of the seventh embodiment of the imaging lens LA.












TABLE 13







R
d
nd
vd























S1
∞
d0 =
0.000






R1
1.680
d1 =
0.617
n1
1.544
v1
56.1


R2
−6.999
d2 =
0.040


R3
6.141
d3 =
0.300
n2
1.640
v2
23.4


R4
1.981
d4 =
0.925


R5
−2.186
d5 =
0.563
n3
1.544
v3
56.1


R6
−0.855
d6 =
0.113


R7
3.870
d7 =
0.379
n4
1.544
v4
56.1


R8
0.845
d8 =
0.500


R9
∞
d9 =
0.300
n5
1.517
v5
64.17


R10
∞
d10 =
0.613



















TABLE 14









conic




constant
aspheric constant














k
A4
A6
A8
A10
A12

















R1
−1.0791E+00
−1.0449E−02
−1.4728E−02
−8.1900E−02
−2.1841E−02
0.0000E+00


R2
−3.6219E+02
−1.0333E−01
−1.6554E−01
1.9559E−01
−1.1266E−01
0.0000E+00


R3
0.0000E+00
7.3115E−02
−3.4325E−01
4.4752E−01
−1.5114E−01
0.0000E+00


R4
2.2414E+00
4.6895E−02
−1.2397E−01
1.2864E−01
−3.7455E−02
0.0000E+00


R5
−8.2612E−01
1.9291E−02
−1.1704E−01
1.2465E−01
−6.8965E−02
1.1710E−02


R6
−4.2024E+00
−1.2047E−01
3.2870E−02
−3.2419E−03
2.0755E−02
−6.9888E−03


R7
7.1285E−01
−2.0864E−01
6.6366E−02
5.5455E−03
−8.1191E−03
1.1983E−03


R8
−6.3027E+00
−1.2492E−01
5.0391E−02
−1.7038E−02
3.5303E−03
−4.0044E−04









Referring to FIG. 26, an imaging lens LA according to a seventh embodiment is shown. FIGS. 27 ̃28, 29A, 29B, are graphs of aberrations (spherical aberration, lateral color aberration, astigmatism, and distortion) of the seventh specification of the exemplary embodiment of the imaging lens LA. In FIGS. 27 and 28, curves are spherical aberration and lateral color aberration characteristic curves of F light (wavelength: 486.1 nm), d light (wavelength: 587.6 nm) and C light (wavelength: 656.3 nm) of the imaging lens LA. The spherical aberration of the seventh specification of the exemplary embodiment is from −0.1 mm to 0.1 mm, the lateral color aberration of the first specification of the exemplary embodiment is from −2 mm to 2 mm. As illustrated in FIG. 29A, the astigmatism is shown at the d light (wavelength: 588 nm) for both the sagittal image surface S and the tangential image surface T. The astigmatism of the seventh specification of the exemplary embodiment of the imaging lens LA is from −0.10 mm to 0.10 mm. In FIG. 29B, the distortion of the seventh specification of the exemplary embodiment of the imaging lens LA is from −2% to 2%.
In the seventh specification, not only the overall length of the imaging lens LA is reduced and the brightness is ensured (seen in Table 25, 2ω=62.5°, TTL=4.350 mm, FNo=2.5), but also aberrations of the imaging lens LA are favorably corrected. That is, the imaging lens LA keeps lateral color aberration at a minimum while maintaining the field angle in 60° ̃70° range, and reducing the total length of the imaging lens LA.
Tables 15-16 show an eighth specification of the eighth embodiment of the imaging lens LA.












TABLE 15







R
d
nd
vd























S1
∞
d0 =
0.000






R1
1.656
d1 =
0.579
n1
1.544
v1
56.1


R2
−6.463
d2 =
0.059


R3
26.958
d3 =
0.329
n2
1.640
v2
23.4


R4
2.451
d4 =
0.820


R5
−2.532
d5 =
0.617
n3
1.544
v3
56.1


R6
−0.858
d6 =
0.084


R7
3.366
d7 =
0.386
n4
1.544
v4
56.1


R8
0.851
d8 =
0.500


R9
∞
d9 =
0.300
n5
1.517
v5
64.17


R10
∞
d10 =
0.641



















TABLE 16









conic




constant
aspheric constant














k
A4
A6
A8
A10
A12

















R1
−9.3193E−01
4.7424E−04
−8.7026E−03
−3.4025E−02
−1.4447E−02
0.0000E+00


R2
−2.4708E+02
−4.6403E−02
−1.2136E−01
1.8438E−01
−7.5827E−02
0.0000E+00


R3
0.0000E+00
8.4363E−02
−3.1733E−01
5.0411E−01
−1.8449E−01
0.0000E+00


R4
4.7195E+00
2.9598E−02
−1.4043E−01
1.5992E−01
−3.9558E−02
0.0000E+00


R5
−8.5414E−01
2.1107E−02
−1.2331E−01
1.1483E−01
−7.3989E−02
2.6098E−02


R6
−4.0378E+00
−1.2720E−01
3.1153E−02
−4.2270E−03
2.0204E−02
−4.7620E−03


R7
5.2724E−01
−2.0866E−01
6.7532E−02
5.9754E−03
−8.0801E−03
1.2502E−03


R8
−5.9896E+00
−1.2660E−01
5.1414E−02
−1.6818E−02
3.4291E−03
−3.3886E−04









Referring to FIG. 30, an imaging lens LA according to an eighth embodiment is shown. FIGS. 31 ̃32, 33A, 33B, are graphs of aberrations (spherical aberration, lateral color aberration, astigmatism, and distortion) of the eighth specification of the exemplary embodiment of the imaging lens LA. In FIGS. 31 and 32, curves are spherical aberration and lateral color aberration characteristic curves of F light (wavelength: 486.1 nm), d light (wavelength: 587.6 nm) and C light (wavelength: 656.3 nm) of the imaging lens LA. The spherical aberration of the eighth specification of the exemplary embodiment is from −0.1 mm to 0.1 mm, the lateral color aberration of the eighth specification of the exemplary embodiment is from −2 mm to 2 mm. As illustrated in FIG. 33A, the astigmatism is shown at the d light (wavelength: 588 nm) for both the sagittal image surface S and the tangential image surface T. The astigmatism of the eighth specification of the exemplary embodiment of the imaging lens LA is from −0.10 mm to 0.10 mm. In FIG. 33B, the distortion of the eighth specification of the exemplary embodiment of the imaging lens LA is from −2% to 2%.
In the eighth specification, not only the overall length of the imaging lens LA is reduced and the brightness is ensured (seen in Table 25, 2ω=65.0°, TTL=4.315 mm, FNo=2.4), but also aberrations of the imaging lens LA are favorably corrected. That is, the imaging lens LA keeps lateral color aberration at a minimum while maintaining the field angle in 60° ̃70° range, and reducing the total length of the imaging lens LA.
Tables 17-18 show a ninth specification of the ninth embodiment of the imaging lens LA.












TABLE 17







R
d
nd
vd























S1
∞
d0 =
0.030






R1
1.548
d1 =
0.674
n1
1.544
v1
56.1


R2
−6.055
d2 =
0.040


R3
38.941
d3 =
0.302
n2
1.640
v2
23.4


R4
2.291
d4 =
0.797


R5
−1.594
d5 =
0.445
n3
1.544
v3
56.1


R6
−0.839
d6 =
0.139


R7
2.917
d7 =
0.419
n4
1.544
v4
56.1


R8
0.857
d8 =
0.500


R9
∞
d9 =
0.300
n5
1.517
v5
64.17


R10
∞
d10 =
0.704



















TABLE 18









conic




constant
aspheric constant














k
A4
A6
A8
A10
A12

















R1
−7.6636E−01
7.9749E−03
−1.6769E−02
−4.1295E−02
−6.3517E−03
0.0000E+00


R2
−1.7524E+02
−5.8214E−02
−1.3106E−01
1.7969E−01
−8.3389E−02
0.0000E+00


R3
0.0000E+00
7.6879E−02
−3.1725E−01
4.9902E−01
−1.8295E−01
0.0000E+00


R4
4.1313E+00
2.6875E−02
−1.1494E−01
1.6270E−01
−1.8652E−02
0.0000E+00


R5
−1.0802E+00
2.7908E−02
−1.4132E−01
8.7801E−02
−5.7981E−02
−1.2891E−02


R6
−3.8769E+00
−1.1648E−01
2.3367E−02
−2.8178E−03
2.1470E−02
−3.5467E−03


R7
1.5755E−01
−2.1002E−01
6.8239E−02
5.9684E−03
−8.1117E−03
1.2773E−03


R8
−6.4516E+00
−1.2416E−01
5.1364E−02
−1.6675E−02
3.4708E−03
−3.3846E−04









Referring to FIG. 34, an imaging lens LA according to a ninth embodiment is shown. FIGS. 35 ̃36, 37A, 37B, are graphs of aberrations (spherical aberration, lateral color aberration, astigmatism, and distortion) of the ninth specification of the exemplary embodiment of the imaging lens LA. In FIGS. 35 and 36, curves are spherical aberration and lateral color aberration characteristic curves of F light (wavelength: 486.1 nm), d light (wavelength: 587.6 nm) and C light (wavelength: 656.3 nm) of the imaging lens LA. The spherical aberration of the ninth specification of the exemplary embodiment is from −0.1 mm to 0.1 mm, the lateral color aberration of the ninth specification of the exemplary embodiment is from −2 mm to 2 mm. As illustrated in FIG. 37A, the astigmatism is shown at the d light (wavelength: 588 nm) for both the sagittal image surface S and the tangential image surface T. The astigmatism of the ninth specification of the exemplary embodiment of the imaging lens LA is from −0.10 mm to 0.10 mm. In FIG. 37B, the distortion of the ninth specification of the exemplary embodiment of the imaging lens LA is from −2% to 2%.
In the ninth specification, not only the overall length of the imaging lens LA is reduced and the brightness is ensured (seen in Table 25, 2ω=60.5°, TTL=4.350 mm, FNo=2.5), but also aberrations of the imaging lens LA are favorably corrected. That is, the imaging lens LA keeps lateral color aberration at a minimum while maintaining the field angle in 60° ̃70° range, and reducing the total length of the imaging lens LA.
Tables 19-20 show a tenth specification of the ninth embodiment of the imaging lens LA.












TABLE 19







R
d
nd
vd























S1
∞
d0 =
0.000






R1
1.605
d1 =
0.591
n1
1.544
v1
56.1


R2
−6.488
d2 =
0.059


R3
32.195
d3 =
0.328
n2
1.640
v2
23.4


R4
2.382
d4 =
0.766


R5
−2.324
d5 =
0.708
n3
1.544
v3
56.1


R6
−0.831
d6 =
0.092


R7
3.935
d7 =
0.405
n4
1.544
v4
56.1


R8
0.853
d8 =
0.500


R9
∞
d9 =
0.300
n5
1.517
v5
64.17


R10
∞
d10 =
0.637



















TABLE 20









conic




constant
aspheric constant














k
A4
A6
A8
A10
A12

















R1
−1.0152E+00
−2.0664E−03
1.0595E−02
−3.7729E−02
−4.4990E−02
0.0000E+00


R2
−2.0958E+02
−4.5852E−02
−1.3148E−01
1.7762E−01
−7.9581E−02
0.0000E+00


R3
0.0000E+00
8.4766E−02
−3.1854E−01
5.0493E−01
−1.8427E−01
0.0000E+00


R4
4.7693E+00
2.9417E−02
−1.1800E−01
1.6274E−01
−6.1790E−02
0.0000E+00


R5
−1.2324E+00
2.4613E−02
−1.2733E−01
1.1343E−01
−7.2319E−02
2.7387E−02


R6
−3.9290E+00
−1.2841E−01
2.9907E−02
−4.2303E−03
1.9925E−02
−5.4126E−03


R7
7.0111E−01
−2.0809E−01
6.7684E−02
6.0232E−03
−8.0707E−03
1.2528E−03


R8
−6.4745E+00
−1.2755E−01
5.1535E−02
−1.6822E−02
3.4309E−03
−3.3817E−04









Referring to FIG. 38, an imaging lens LA according to a tenth embodiment is shown. FIGS. 39 ̃40, 41A, 41B, are graphs of aberrations (spherical aberration, lateral color aberration, astigmatism, and distortion) of the tenth specification of the exemplary embodiment of the imaging lens LA. In FIGS. 39 and 40, curves are spherical aberration and lateral color aberration characteristic curves of F light (wavelength: 486.1 nm), d light (wavelength: 587.6 nm) and C light (wavelength: 656.3 nm) of the imaging lens LA. The spherical aberration of the tenth specification of the exemplary embodiment is from −0.1 mm to 0.1 mm, the lateral color aberration of the tenth specification of the exemplary embodiment is from −2 mm to 2 mm. As illustrated in FIG. 41A, the astigmatism is shown at the d light (wavelength: 588 nm) for both the sagittal image surface S and the tangential image surface T. The astigmatism of the tenth specification of the exemplary embodiment of the imaging lens LA is from −0.15 mm to 0.15 mm. In FIG. 41B, the distortion of the tenth specification of the exemplary embodiment of the imaging lens LA is from −2% to 2%.
In the tenth specification, not only the overall length of the imaging lens LA is reduced and the brightness is ensured (seen in Table 25, 2ω=64.1°, TTL=4.386 mm, FNo=2.5), but also aberrations of the imaging lens LA are favorably corrected. That is, the imaging lens LA keeps lateral color aberration at a minimum while maintaining the field angle in 60° ̃70° range, and reducing the total length of the imaging lens LA.
Tables 21-22 show an eleventh specification of the eleventh embodiment of the imaging lens LA.












TABLE 21







R
d
nd
vd























S1
∞
d0 =
0.000






R1
1.592
d1 =
0.564
n1
1.544
v1
56.1


R2
−5.762
d2 =
0.053


R3
42.135
d3 =
0.316
n2
1.640
v2
23.4


R4
2.374
d4 =
0.767


R5
−2.179
d5 =
0.492
n3
1.544
v3
56.1


R6
−0.907
d6 =
0.110


R7
2.701
d7 =
0.441
n4
1.544
v4
56.1


R8
0.889
d8 =
0.500


R9
∞
d9 =
0.300
n5
1.517
v5
64.17


R10
∞
d10 =
0.530



















TABLE 22









conic




constant
aspheric constant














k
A4
A6
A8
A10
A12

















R1
−6.3815E−01
9.4466E−03
−7.3373E−03
−4.9611E−02
−2.8483E−02
0.0000E+00


R2
−1.7901E+02
−1.2458E−02
−9.2264E−02
7.2402E−02
−1.4473E−01
0.0000E+00


R3
0.0000E+00
9.1625E−02
−2.7859E−01
4.4349E−01
−2.8324E−01
0.0000E+00


R4
3.6841E+00
1.0454E−02
−1.5106E−01
2.9154E−01
−1.6937E−01
0.0000E+00


R5
−6.7099E−01
1.8272E−02
−1.2868E−01
1.1018E−01
−7.8183E−02
2.2703E−02


R6
−4.1203E+00
−1.2380E−01
3.3845E−02
−1.7766E−03
2.1553E−02
−3.7712E−03


R7
4.2483E−01
−2.0982E−01
6.7191E−02
5.8575E−03
−8.1374E−03
1.2226E−03


R8
−5.7083E+00
−1.2605E−01
5.1304E−02
−1.6844E−02
3.4223E−03
−3.4031E−04









Referring to FIG. 42, an imaging lens LA according to an eleventh embodiment is shown. FIGS. 43 ̃44, 45A, 45B, are graphs of aberrations (spherical aberration, lateral color aberration, astigmatism, and distortion) of the eleventh specification of the exemplary embodiment of the imaging lens LA. In FIGS. 43 and 44, curves are spherical aberration and lateral color aberration characteristic curves of F light (wavelength: 486.1 nm), d light (wavelength: 587.6 nm) and C light (wavelength: 656.3 nm) of the imaging lens LA. The spherical aberration of the eleventh specification of the exemplary embodiment is from −0.1 mm to 0.1 mm, the lateral color aberration of the first specification of the exemplary embodiment is from −2 mm to 2 mm. As illustrated in FIG. 45A, the astigmatism is shown at the d light (wavelength: 588 nm) for both the sagittal image surface S and the tangential image surface T. The astigmatism of the eleventh specification of the exemplary embodiment of the imaging lens LA is from −0.10 mm to 0.10 mm. In FIG. 45B, the distortion of the eleventh specification of the exemplary embodiment of the imaging lens LA is from −2% to 2%.
In the eleventh specification, not only the overall length of the imaging lens LA is reduced and the brightness is ensured (seen in Table 25, 2ω=68°, TTL=4.073 mm, FNo=2.5), but also aberrations of the imaging lens LA are favorably corrected. That is, the imaging lens LA keeps lateral color aberration at a minimum while maintaining the field angle in 60° ̃70° range, and reducing the total length of the imaging lens LA.
Tables 23-24 show an twelfth specification of the twelfth embodiment of the imaging lens LA.












TABLE 23







R
d
nd
vd























S1
∞
d0 =
0.000






R1
1.648
d1 =
0.583
n1
1.544
v1
56.1


R2
−6.507
d2 =
0.030


R3
20.210
d3 =
0.300
n2
1.640
v2
23.4


R4
2.526
d4 =
0.870


R5
−2.240
d5 =
0.597
n3
1.544
v3
56.1


R6
−0.844
d6 =
0.088


R7
4.308
d7 =
0.398
n4
1.544
v4
56.1


R8
0.851
d8 =
0.500


R9
∞
d9 =
0.300
n5
1.517
v5
64.17


R10
∞
d10 =
0.734



















TABLE 24









conic




constant
aspheric constant














k
A4
A6
A8
A10
A12

















R1
−9.7544E−01
−1.3042E−03
−9.8227E−03
−4.0077E−02
−1.9929E−02
0.0000E+00


R2
−2.0950E+02
−3.3050E−02
−1.3791E−01
1.7660E−01
−6.8432E−02
0.0000E+00


R3
3.1508E+02
8.8756E−02
−3.0811E−03
5.0591E−01
−1.9255E−01
0.0000E+00


R4
5.0623E+00
2.1923E−02
−1.1561E−01
1.4649E−01
−3.6099E−02
0.0000E+00


R5
−4.5399E−01
1.6173E−02
−1.2542E−01
1.0712E−01
−6.1141E−02
1.6195E−02


R6
−4.0379E+00
−1.2388E−01
3.2972E−02
−3.6453E−03
2.1179E−02
−4.5416E−03


R7
−1.3578E−01
−2.0780E−01
6.7717E−02
6.1746E−03
−7.9948E−03
1.2855E−03


R8
−6.2513E+00
−1.2672E−01
5.1567E−02
−1.6889E−02
3.3996E−03
−3.2307E−04









Referring to FIG. 46, an imaging lens LA according to a twelfth embodiment is shown. FIGS. 47 ̃48, 49A, 49B, are graphs of aberrations (spherical aberration, lateral color aberration, astigmatism, and distortion) of the twelfth specification of the exemplary embodiment of the imaging lens LA. In FIGS. 47 and 48, curves are spherical aberration and lateral color aberration characteristic curves of F light (wavelength: 486.1 nm), d light (wavelength: 587.6 nm) and C light (wavelength: 656.3 nm) of the imaging lens LA. The spherical aberration of the twelfth specification of the exemplary embodiment is from −0.1 mm to 0.1 mm, the lateral color aberration of the twelfth specification of the exemplary embodiment is from −2 mm to 2 mm. As illustrated in FIG. 49A, the astigmatism is shown at the d light (wavelength: 588 nm) for both the sagittal image surface S and the tangential image surface T. The astigmatism of the twelfth specification of the exemplary embodiment of the imaging lens LA is from −0.10 mm to 0.10 mm. In FIG. 49B, the distortion of the twelfth specification of the exemplary embodiment of the imaging lens LA is from −2% to 2%.
In the twelfth specification, not only the overall length of the imaging lens LA is reduced and the brightness is ensured (seen in Table 25, 2ω=61.4°, TTL=4.400 mm, FNo=2.5), but also aberrations of the imaging lens LA are favorably corrected. That is, the imaging lens LA keeps lateral color aberration at a minimum while maintaining the field angle in 60° ̃70° range, and reducing the total length of the imaging lens LA.
Table 25 shows every specification of the above embodiments, every numerical value is met with the conditions (1) ̃(9) shown above.





















TABLE 25







embodi-
embodi-
embodi-
embodi-
embodi-
embodi-
embodi-
embodi-
embodi-
embodiment
embodiment
embodiment




ment 1
ment 2
ment 3
ment 4
ment 5
ment 6
ment 7
ment 8
ment 9
10
11
12
remark





























f1/f
0.695
0.653
0.680
0.672
0.735
0.684
0.679
0.705
0.607
0.676
0.708
0.656
formula(1)


f/d1
6.038
6.353
5.400
6.799
5.513
5.993
6.096
6.093
5.717
6.071
5.902
6.489
formula(2)


f/d6
37.914
43.800
35.838
41.101
12.198
35.923
33.283
42.000
27.719
39.000
30.264
42.989
formula(3)


R1/R2
−0.240
−0.246
−0.275
−0.243
−0.269
−0.335
−0.240
−0.256
−0.256
−0.247
−0.276
−0.253
formula(4)


R3/R4
14.678
16.130
18.000
16.049
18.500
16.566
3.100
11.000
17.000
13.515
17.748
8.000
formula(5)


R5/R6
2.733
2.692
2.731
2.725
2.655
2.721
2.556
2.951
1.900
2.796
2.402
2.643
formula(6)


f2/f
−1.131
−1.062
−1.100
−1.075
−1.192
−1.117
−1.250
−1.200
−0.990
−1.125
−1.184
−1.200
formula(7)


f3/f
0.609
0.583
0.604
0.588
0.665
0.605
0.598
0.599
0.699
0.568
0.755
0.575
formula(8)


f4/f
−0.645
−0.583
−0.618
−0.616
−0.646
−0.639
−0.553
−0.628
−0.624
−0.585
−0.800
−0.537
formula(9)


Fno
2.40
2.40
2.40
2.45
2.40
2.40
2.50
2.40
2.50
2.50
2.50
2.50


2w
65.0
62.2
64.7
63.1
69.2
64.9
62.5
65.0
60.5
64.1
68.0
61.4


f
3.526
3.723
3.548
3.658
3.269
3.530
3.761
3.528
3.853
3.588
3.329
3.783


f1
2.450
2.430
2.413
2.460
2.403
2.415
2.554
2.486
2.340
2.427
2.356
2.480


f2
−3.988
−3.955
−3.902
−3.934
−3.897
−3.944
−4.701
−4.234
−3.815
−4.037
−3.943
−4.541


f3
2.146
2.170
2.143
2.152
2.174
2.136
2.248
2.112
2.695
2.038
2.514
2.177


f4
−2.273
−2.171
−2.193
−2.253
−2.111
−2.257
−2.080
−2.215
−2.404
−2.099
−2.663
−2.032


TTL
4.301
4.380
4.308
4.380
4.034
4.337
4.350
4.315
4.350
4.386
4.073
4.400


LB
1.441
1.545
1.206
1.567
1.200
1.448
1.413
1.441
1.413
1.437
1.330
1.534


IH
2.268
2.268
2.268
2.268
2.268
2.268
2.268
2.268
2.268
2.268
2.268
2.268









While certain embodiments have been described and exemplified above, various other embodiments will be apparent to those skilled in the art from the foregoing disclosure. The disclosure is not limited to the particular embodiments described and exemplified, and the embodiments are capable of considerable variation and modification without departure from the scope of the appended claims.

## Claims

1. An imaging lens, in the order from the object-side to the image-side of the imaging lens, comprising:
a first lens of positive refraction power, with two convex surfaces along the optical axis of the imaging lens;
a second lens of negative refraction power, with a convex surface on the object-side and having a meniscus shape;
a third lens of positive refraction power, with a convex surface on the image-side and having a meniscus shape;
a fourth lens of negative refraction power, with a convex surface on the object-side and having a meniscus shape;
wherein the imaging lens satisfies the following conditions:
0.50≦f1/f≦0.75; 5.20≦f/d1≦8.00; 12.00≦f/d6≦45.00; −0.35≦R1/R2≦−0.20; and 3.00≦R3/R4≦20.00;
Wherein: f is a focal length of the imaging lens; f1 is a focal length of the first lens; d1 is a center thickness of the first lens on the optical axis of the imaging lens; d6 is a distance between the image-side surface of the third lens and the object-side surface of the fourth lens on the optical axis of imaging lens; R1 is a radius of curvature of the object-side surface of the first lens; R2 is a radius of curvature of the image-side surface of the first lens; R3 is a radius of curvature of the object-side surface of the second lens; R4 is a radius of curvature of the image-side surface of the second lens.

2. The imaging lens of claim 1, further comprising an aperture stop, wherein the aperture stop is installed on the object-side surface of the first lens.

3. The lens system of claim 1, wherein following condition is satisfied: 1.00≦R5/R6≦3.00; wherein R5 is a radius of curvature of the object-side surface of the third lens; R6 is a radius of curvature of the image-side surface of the third lens.

4. The lens system of claim 1, wherein t following condition is satisfied: −1.30≦f2/f≦−0.95; wherein f is a focal length of the imaging lens; f2 is a focal length of the second lens.

5. The lens system of claim 1, wherein the following condition is satisfied: 0.55≦f3/f≦0.80; wherein f is a focal length of the imaging lens; f2 is a focal length of the third lens.

6. The lens system of claim 1, wherein the following condition is satisfied: −1.00≦f4/f≦−0.50; wherein f is a focal length of the imaging lens; f4 is a focal length of the fourth lens.