TWI603112B - Optical lens system with a wide field of view - Google Patents

Description

Wide-angle imaging lens set

The present invention relates to a wide-angle imaging lens set, and more particularly to a miniaturized four-piece wide-angle imaging lens set for use in electronic products.

With the rise of electronic products with photographic functions, the demand for optical systems is increasing. In the shooting, in order to obtain a wider shooting range, the angle of view of the lens is required to meet certain requirements, and thus the requirements for the angle and quality of the lens are becoming stricter. Usually, the angle of the lens (the field of view FOV) is designed to be 50 to 60 degrees. If the angle of the above design is exceeded, not only the aberration is large, but also the design of the lens is complicated. Conventional US 8335043, US 8576497 use 2 lens groups, 5-6 pieces to achieve a large angle purpose, but its distortion is too large, and such as US 8593737, US 8576497, US 8395853, although it can achieve a large angle purpose, However, the total length (TL) of the lens group is too long.

Therefore, how to develop a miniaturized wide-angle imaging lens set, which can be equipped with a lens used in a digital camera, a lens used in a network camera, or a mobile phone lens, etc., and has a larger angle of drawing and lowering The efficacy of aberrations to reduce the complexity of lens design is the motivation for the development of the present invention.

It is an object of the present invention to provide a wide-angle imaging lens set, and more particularly to a four-piece wide-angle imaging lens set that enhances the angle of view, has high resolution, short lens length, and small distortion.

In order to achieve the foregoing objective, a wide-angle imaging lens set according to the present invention includes, in order from the object side to the image side, an aperture; a first lens having a positive refractive power and an object side thereof The surface near-optical axis is convex, and the image side surface is convex at the near-optical axis, and at least one surface of the object-side surface and the image-side surface is aspherical; a second lens has a negative refractive power, and the object side surface is low-beam The shaft is concave, and at least one surface of the object side surface and the image side surface is aspherical; a third lens has a positive refractive power, and the image side surface is convex at the near optical axis, and the object side surface and the image side surface are at least One surface is aspherical; a fourth lens has a negative refractive power, and the object side surface is convex at the near optical axis, and at least one surface of the object side surface and the image side surface is aspherical, and the object side surface and the image side surface thereof At least one surface has at least one inflection point; wherein the focal length of the first lens is f1, the combined focal length of the second lens and the third lens is f23, and the following condition is satisfied: 0.4 < f1/f23 < 1.7.

When f1/f23 satisfies the above conditions, the wide-angle imaging lens group can significantly improve the resolution of the image while obtaining a wide angle of view (angle of view).

Preferably, the object side surface of the third lens has a concave surface at a near optical axis, and the image side surface has a convex surface at a near optical axis; the object side surface of the fourth lens has a convex surface and an image side surface near the optical axis. The area is concave.

Preferably, the focal length of the first lens is f1, the focal length of the second lens is f2, and the following condition is satisfied: -0.9 < f1/f2 < -0.3. Thereby, the refractive power arrangement of the first lens and the second lens is suitable, which is advantageous for obtaining a wide angle of view (angle of view) and reducing excessive increase of system aberration.

Preferably, the focal length of the second lens is f2, the focal length of the third lens is f3, and the following condition is satisfied: -4.2 < f2 / f3 < -1.3. Thereby, the arrangement of the refractive power of the second lens and the third lens is balanced, which contributes to the correction of the aberration and the reduction of the sensitivity.

Preferably, the focal length of the third lens is f3, the focal length of the fourth lens is f4, and the following condition is satisfied: -1.1 < f3 / f4 < -0.4. Thereby, it is advantageous to ensure a positive and negative telephoto structure formed by the third lens and the fourth lens, which can effectively reduce the total optical length of the system.

Preferably, the focal length of the first lens is f1, the focal length of the third lens is f3, and the following condition is satisfied: 0.7 < f1/f3 < 2.1. Thereby, the positive refractive power of the first lens is effectively distributed, and the sensitivity of the wide-angle imaging lens group is reduced.

Preferably, the focal length of the second lens is f2, the focal length of the fourth lens is f4, and the following condition is satisfied: 0.55 < f2 / f4 < 4.0. Therefore, the system's negative refractive power distribution is more suitable, which is beneficial to correct system aberrations to improve the imaging quality of the system.

Preferably, the combined focal length of the second lens and the third lens is f23, the focal length of the fourth lens is f4, and the following condition is satisfied: -1.3 < f23 / f4 < -0.6. Thereby, the wide-angle imaging lens group can significantly improve the resolution of the image while obtaining a wide angle of view (angle of view).

Preferably, the combined focal length of the first lens and the second lens is f12, and the combined focal length of the third lens and the fourth lens is f34, and the following condition is satisfied: 0.3 < f12 / f34 < 2.2. Thereby, it is advantageous to obtain a wide angle of view (angle of view) and to effectively correct the curvature of field.

Preferably, the overall focal length of the wide-angle imaging lens group is f, the distance from the object-side surface of the first lens to the imaging surface on the optical axis is TL, and the following condition is satisfied: 0.5 < f / TL < 0.8. Thereby, it is advantageous to obtain a wide angle of view (angle of view) and to facilitate the miniaturization of the wide-angle imaging lens group to be mounted on a thin electronic product.

Preferably, the maximum angle of view of the wide-angle imaging lens group is FOV and the following conditions are satisfied: 75 degrees < FOV < 95 degrees. Thereby, the wide-angle imaging lens set can have a suitable larger field of view.

Preferably, the thickness of the second lens on the optical axis is CT2, the thickness of the first lens on the optical axis is CT1, and the following condition is satisfied: 0.2<CT2/CT1<0.7. Thereby, the first lens and the second lens have an appropriate thickness, which makes injection molding easier.

Preferably, the distance between the first lens and the second lens on the optical axis is T12, the thickness of the second lens on the optical axis is CT2, and the following condition is satisfied: 0.05<T12/CT2<1.25. Thereby, the maximum angle of view of the wide-angle imaging lens group can be further increased.

Preferably, the image side surface has a radius of curvature R2, and the second lens has an object side surface radius of curvature R3 and satisfies the following condition: 0.01 < R2 / R3 < 4.3. Effectively reduce the spherical aberration and astigmatism of the wide-angle imaging lens group.

Preferably, the first lens has a dispersion coefficient of V1, the second lens has a dispersion coefficient of V2, and satisfies the following condition: 30<V1-V2<42. Thereby, the chromatic aberration of the wide-angle imaging lens group is effectively reduced.

The present invention has been described with reference to the preferred embodiments of the present invention and the accompanying drawings.

100, 200, 300, 400, 500, 600, 700, 800‧ ‧ aperture

110, 210, 310, 410, 510, 610, 710, 810 ‧ ‧ first lens

111, 211, 311, 411, 511, 611, 711, 811 ‧ ‧ ‧ side surface

112, 212, 312, 412, 512, 612, 712, 812‧‧‧ image side surface

120, 220, 320, 420, 520, 620, 720, 820‧‧‧ second lens

121, 221, 321, 421, 521, 621, 721, 821‧‧ ‧ side surfaces

122, 222, 322, 422, 522, 622, 722, 822 ‧ ‧ side surface

130, 230, 330, 430, 530, 630, 730, 830 ‧ ‧ third lens

131, 231, 331, 431, 531, 631, 731, 831 ‧ ‧ ‧ side surface

132, 232, 332, 432, 532, 632, 732, 832‧‧‧ side surface

140, 240, 340, 440, 540, 640, 740, 840 ‧ ‧ fourth lens

141, 241, 341, 441, 541, 641, 741, 841‧‧‧ ‧ side surfaces

142, 242, 342, 442, 542, 642, 742, 842 ‧ ‧ side surface

170, 270, 370, 470, 570, 670, 770, 870 ‧ ‧ infrared filter components

180, 280, 380, 480, 580, 680, 780, 880 ‧ ‧ imaging surface

190, 290, 390, 490, 590, 690, 790, 890‧‧‧ optical axis

f‧‧‧Focus of the wide-angle imaging lens set

Aperture value of Fno‧‧‧ wide-angle imaging lens set

Maximum field of view in the FOV‧‧‧ wide-angle imaging lens set

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

F12‧‧‧Combined focal length of the first lens and the second lens

F23‧‧‧Combined focal length of the second lens and the third lens

F34‧‧‧Combined focal length of the third lens and the fourth lens

R2‧‧‧ Image side surface radius of curvature of the first lens

R3‧‧‧ radius of curvature of the object side surface of the second lens

V1‧‧‧Dispersion coefficient of the first lens

V2‧‧‧Dispersion coefficient of the second lens

CT1‧‧‧ thickness of the first lens on the optical axis

CT2‧‧‧ thickness of the second lens on the optical axis

T12‧‧‧The distance between the first lens and the second lens on the optical axis

TL‧‧‧The distance from the object side surface of the first lens to the imaging surface on the optical axis

Fig. 1A is a schematic view showing a wide-angle imaging lens group of a first embodiment of the present invention.

1B is a spherical aberration, astigmatism, and distortion curve of the wide-angle imaging lens group of the first embodiment, from left to right.

2A is a schematic view of a wide-angle imaging lens set of a second embodiment of the present invention.

2B is a spherical aberration, astigmatism, and distortion curve of the wide-angle imaging lens group of the second embodiment, from left to right.

Fig. 3A is a schematic view showing a wide-angle imaging lens group of a third embodiment of the present invention.

3B is a spherical aberration, astigmatism, and distortion curve of the wide-angle imaging lens group of the third embodiment, from left to right.

4A is a schematic view of a wide-angle imaging lens set of a fourth embodiment of the present invention.

4B is a spherical aberration, astigmatism, and distortion curve of the wide-angle imaging lens group of the fourth embodiment, from left to right.

Fig. 5A is a schematic view showing a wide-angle imaging lens group of a fifth embodiment of the present invention.

Fig. 5B is a spherical aberration, astigmatism, and distortion curve of the wide-angle imaging lens group of the fifth embodiment, from left to right.

Fig. 6A is a schematic view showing a wide-angle imaging lens group of a sixth embodiment of the present invention.

Fig. 6B is a spherical aberration, astigmatism, and distortion curve of the wide-angle imaging lens group of the sixth embodiment, from left to right.

Fig. 7A is a schematic view showing a wide-angle imaging lens group of a seventh embodiment of the present invention.

Fig. 7B is a spherical aberration, astigmatism, and distortion curve of the wide-angle imaging lens group of the seventh embodiment, from left to right.

Fig. 8A is a schematic view showing a wide-angle imaging lens group of an eighth embodiment of the present invention.

Fig. 8B is a spherical aberration, astigmatism, and distortion curve of the wide-angle imaging lens group of the eighth embodiment, from left to right.

<First Embodiment>

1A and FIG. 1B, FIG. 1A is a schematic diagram of a wide-angle imaging lens group according to a first embodiment of the present invention, and FIG. 1B is a left-to-right spherical aberration of the wide-angle imaging lens group of the first embodiment. Astigmatic and distorted graphs. As can be seen from FIG. 1A, the wide-angle imaging lens assembly includes an aperture 100 and an optical group including the first lens 110, the second lens 120, the third lens 130, and the fourth lens 140 from the object side to the image side. , an infrared filter filter element 170, and an imaging surface 180, wherein the wide angle is There are four lenses with refractive power in the lens group. The aperture 100 is disposed between the image side surface 112 of the first lens 110 and the subject.

The first lens 110 has a positive refractive power and is made of a plastic material. The object side surface 111 is convex at the near optical axis 190, and the image side surface 112 is convex at the near optical axis 190, and the object side surface 111 and the image side are Surface 112 is aspherical.

The second lens 120 has a negative refractive power and is made of a plastic material. The object side surface 121 is a concave surface at the near optical axis 190, and the image side surface 122 is convex at the near optical axis 190, and the object side surface 121 and the image side are Surface 122 is aspherical.

The third lens 130 has a positive refractive power and is made of a plastic material. The object side surface 131 is concave at the near optical axis 190, and the image side surface 132 is convex at the near optical axis 190, and the object side surface 131 and the image side are The surfaces 132 are all aspherical.

The fourth lens 140 has a negative refractive power and is made of a plastic material. The object side surface 141 is convex at the near optical axis 190, and the image side surface 142 is concave at the near optical axis 190, and the object side surface 141 and the image side are The surface 142 is aspherical, and at least one surface of the object side surface 141 and the image side surface 142 has at least one inflection point.

The infrared filter element 170 is made of glass and disposed between the fourth lens 140 and the imaging surface 180 without affecting the focal length of the wide-angle imaging lens group.

The aspherical curve equations of the above lenses are expressed as follows:

Where z is the position value with reference to the surface apex at a position of height h in the direction of the optical axis 190; c is the curvature of the lens surface near the optical axis 190, and is the reciprocal of the radius of curvature (R) (c = 1/R) R is the radius of curvature of the lens surface near the optical axis 190, h is the vertical distance of the lens surface from the optical axis 190, k is a conic constant, and A, B, C, D, E, G, ... ...is a high-order aspheric coefficient.

In the wide-angle imaging lens group of the first embodiment, the focal length of the wide-angle imaging lens group is f, the aperture value (f-number) of the wide-angle imaging lens group is Fno, and the maximum angle of view (arrow angle) in the wide-angle imaging lens group is FOV. The values are as follows: f = 1.978 (mm); Fno = 2.0; and FOV = 88 (degrees).

In the wide-angle imaging lens group of the first embodiment, the composite focal length of the second lens 120 and the third lens 130 is f23, the focal length of the fourth lens 140 is f4, and the following condition is satisfied: f23/f4=-1.0061.

In the wide-angle imaging lens group of the first embodiment, the focal length of the first lens 110 is f1, the focal length of the second lens 120 is f2, and the following condition is satisfied: f1/f2 = -0.6443.

In the wide-angle imaging lens group of the first embodiment, the focal length of the second lens 120 is f2, the focal length of the third lens 130 is f3, and the following condition is satisfied: f2/f3=-2.2334.

In the wide-angle imaging lens group of the first embodiment, the focal length of the third lens 130 is f3, the focal length of the fourth lens 140 is f4, and the following condition is satisfied: f3/f4 = -0.8555.

In the wide-angle imaging lens group of the first embodiment, the focal length of the first lens 110 is f1, the focal length of the third lens 130 is f3, and the following condition is satisfied: f1/f3 = 1.4389.

In the wide-angle imaging lens group of the first embodiment, the focal length of the second lens 120 is f2, the focal length of the fourth lens 140 is f4, and the following condition is satisfied: f2/f4 = 1.9107.

In the wide-angle imaging lens group of the first embodiment, the focal length of the first lens 110 is f1, the combined focal length of the second lens 120 and the third lens 130 is f23, and the following condition is satisfied: f1/f23=1.2235.

In the wide-angle imaging lens group of the first embodiment, the composite focal length of the first lens 110 and the second lens 120 is f12, and the combined focal length of the third lens 130 and the fourth lens 140 is f34, and the following condition is satisfied: f12/ F34=1.0944.

In the wide-angle imaging lens group of the first embodiment, the overall focal length of the wide-angle imaging lens group is f, the distance from the object-side surface 111 to the imaging surface 180 of the first lens 110 on the optical axis 190 is TL, and the following conditions are satisfied. :f/TL=0.6571.

In the wide-angle imaging lens set of the first embodiment, the thickness of the second lens 120 on the optical axis 180 is CT2, the thickness of the first lens 110 on the optical axis 180 is CT1, and the following conditions are met: CT2/CT1= 0.3537.

In the wide-angle imaging lens set of the first embodiment, the distance between the first lens 110 and the second lens 120 on the optical axis 190 is T12, and the thickness of the second lens 120 on the optical axis 190 is CT2, and the following is satisfied. Condition: T12/CT2 = 1.1152.

In the wide-angle imaging lens group of the first embodiment, the image side surface 112 of the first lens 110 has a radius of curvature R2, and the object side surface 121 of the second lens 120 has a radius of curvature R3 and satisfies the following condition: R2/R3= 2.8890.

In the wide-angle imaging lens group of the first embodiment, the first lens 110 has a dispersion coefficient of V1, the second lens 120 has a dispersion coefficient of V2, and satisfies the following condition: V1 - V2 = 32.1.

Refer to Table 1 and Table 2 below for reference.

Table 1 is the detailed structural data of the first embodiment of Fig. 1A, in which the unit of curvature radius, thickness and focal length is mm, and the surface 0-13 sequentially indicates the surface from the object side to the image side. Table 2 is the aspherical data in the first embodiment, wherein the cone coefficients in the a-spherical curve equation of k, A, B, C, D, E, F, G, ... are high-order non- Spherical coefficient. In addition, the table of the following embodiments corresponds to the schematic diagram and the aberration diagram of each embodiment, and the definition of the data in the table is the same as the definitions of Table 1 and Table 2 of the first embodiment, and details are not described herein.

<Second embodiment>

2A and FIG. 2B, FIG. 2A is a schematic diagram of a wide-angle imaging lens group according to a second embodiment of the present invention, and FIG. 2B is a left-to-right spherical aberration of the wide-angle imaging lens group of the second embodiment. Astigmatic and distorted graphs. As can be seen from FIG. 2A, the wide-angle imaging lens assembly includes an aperture 200 and an optical group. The optical group sequentially includes a first lens 210, a second lens 220, a third lens 230, and a fourth lens 240 from the object side to the image side. , an infrared filter filter element 270, and an imaging surface 280, wherein the wide angle is There are four lenses with refractive power in the lens group. The aperture 200 is disposed between the image side surface 212 of the first lens 210 and the object.

The first lens 210 has a positive refractive power and is made of a plastic material. The object side surface 211 is convex at the near optical axis 290, and the image side surface 212 is convex at the near optical axis 290, and the object side surface 211 and the image side are Surface 212 is aspherical.

The second lens 220 has a negative refractive power and is made of a plastic material. The object side surface 221 is concave at the near optical axis 290, and the image side surface 222 is convex at the near optical axis 290, and the object side surface 221 and the image side are Surfaces 222 are all aspherical.

The third lens 230 has a positive refractive power and is made of a plastic material. The object side surface 231 is concave at the near optical axis 290, and the image side surface 232 is convex at the near optical axis 290, and the object side surface 231 and the image side are Surfaces 232 are all aspherical.

The fourth lens 240 has a negative refractive power and is made of a plastic material. The object side surface 241 is convex at the near optical axis 290, and the image side surface 242 is concave at the near optical axis 290, and the object side surface 241 and the image side are The surface 242 is aspherical, and at least one surface of the object side surface 241 and the image side surface 242 has at least one inflection point.

The infrared filter element 270 is made of glass and disposed between the fourth lens 240 and the imaging surface 280 without affecting the focal length of the wide-angle imaging lens group.

Refer to Table 3 and Table 4 below.

In the second embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

With Table 3 and Table 4, the following data can be derived:

<Third embodiment>

3A and FIG. 3B, FIG. 3A is a schematic diagram of a wide-angle imaging lens group according to a third embodiment of the present invention, and FIG. 3B is a left-to-right spherical aberration of the wide-angle imaging lens group of the third embodiment. Astigmatic and distorted graphs. As can be seen from FIG. 3A, the wide-angle imaging lens assembly includes an aperture 300 and an optical group. The optical group includes a first lens 310, a second lens 320, a third lens 330, and a fourth lens 340 from the object side to the image side. The infrared filter element 370 and the imaging surface 380, wherein the lens of the wide-angle imaging lens group has four refractive powers. The aperture 300 is disposed between the image side surface 312 of the first lens 310 and the subject.

The first lens 310 has a positive refractive power and is made of a plastic material. The object side surface 311 is convex at the near optical axis 390, and the image side surface 312 is convex at the near optical axis 390, and the object side surface 311 and the image side are Surfaces 312 are all aspherical.

The second lens 320 has a negative refractive power and is made of a plastic material. The object side surface 321 is concave at the near optical axis 390, and the image side surface 322 is convex at the near optical axis 390, and the object side surface 321 and the image side are Surfaces 322 are all aspherical.

The third lens 330 has a positive refractive power and is made of a plastic material. The object side surface 331 has a concave surface at the near optical axis 390, and the image side surface 332 has a convex surface at the near optical axis 390, and the object side surface 331 and the image side. Surface 332 is aspherical.

The fourth lens 340 has a negative refractive power and is made of a plastic material. The object side surface 341 is convex at the near optical axis 390, and the image side surface 342 is concave at the near optical axis 390, and the object side surface 341 and the image side are The surface 342 is aspherical, and at least one surface of the object side surface 341 and the image side surface 342 has at least one inflection point.

The infrared filter element 370 is made of glass and disposed between the fourth lens 340 and the imaging surface 380 without affecting the focal length of the wide-angle imaging lens group.

Refer to Table 5 and Table 6 below for reference.

In the third embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

With Table 5 and Table 6, the following data can be derived:

<Fourth embodiment>

4A and 4B, wherein FIG. 4A is a schematic diagram of a wide-angle imaging lens group according to a fourth embodiment of the present invention, and FIG. 4B is a left-to-right spherical aberration of the wide-angle imaging lens group of the fourth embodiment. Astigmatic and distorted graphs. As can be seen from FIG. 4A, the wide-angle imaging lens assembly includes an aperture 400 and an optical group. The optical group includes a first lens 410, a second lens 420, a third lens 430, and a fourth lens 440 from the object side to the image side. The infrared filter element 470 and the imaging surface 480, wherein the lens of the wide-angle imaging lens group has four refractive powers. The aperture 400 is disposed between the image side surface 412 of the first lens 410 and the object.

The first lens 410 has a positive refractive power and is made of a plastic material. The object side surface 411 is convex at the near optical axis 490, and the image side surface 412 is convex at the near optical axis 490, and the object side surface 411 and the image side are Surface 412 is aspherical.

The second lens 420 has a negative refractive power and is made of a plastic material. The object side surface 421 is concave at the near optical axis 490, and the image side surface 422 is convex at the near optical axis 490, and the object side surface 421 and the image side are Surface 422 is aspherical.

The third lens 430 has a positive refractive power and is made of a plastic material. The object side surface 431 is concave at the near optical axis 490, and the image side surface 432 is convex at the near optical axis 490, and the object side surface 431 and the image side are Surface 432 is aspherical.

The fourth lens 440 has a negative refractive power and is made of a plastic material. The object side surface 441 is convex at the near optical axis 490, and the image side surface 442 is concave at the near optical axis 490, and the object side surface 441 and the image side are The surface 442 is aspherical, and at least one surface of the object side surface 441 and the image side surface 442 has at least one inflection point.

The infrared filter element 470 is made of glass and disposed between the fourth lens 440 and the imaging surface 480 without affecting the focal length of the wide-angle imaging lens group.

Refer to Table 7 and Table 8 below for reference.

In the fourth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Table 7 and Table 8:

<Fifth Embodiment>

5A and 5B, wherein FIG. 5A is a schematic diagram of a wide-angle imaging lens group according to a fifth embodiment of the present invention, and FIG. 5B is a left-to-right spherical aberration of the wide-angle imaging lens group of the fifth embodiment. Astigmatic and distorted graphs. As can be seen from FIG. 5A, the wide-angle imaging lens assembly includes an aperture 500 and an optical group. The optical group sequentially includes a first lens 510, a second lens 520, a third lens 530, and a fourth lens 540 from the object side to the image side. The infrared filtering filter element 570 and the imaging surface 580, wherein the lens having the refractive power in the wide-angle imaging lens group is four. The aperture 500 is disposed between the image side surface 512 of the first lens 510 and the subject.

The first lens 510 has a positive refractive power and is made of a plastic material. The object side surface 511 is convex at the near optical axis 590, and the image side surface 512 is convex at the near optical axis 590, and the object side surface 511 and the image side are Surface 512 is aspherical.

The second lens 520 has a negative refractive power and is made of a plastic material. The object side surface 521 is concave at the near optical axis 590, and the image side surface 522 is concave at the near optical axis 590, and the object side surface 521 and the image side are Surface 522 is aspherical.

The third lens 530 has a positive refractive power and is made of a plastic material. The object side surface 531 is concave at the near optical axis 590, and the image side surface 532 is convex at the near optical axis 590, and the object side surface 531 and the image side are Surface 532 is aspherical.

The fourth lens 540 has a negative refractive power and is made of a plastic material. The object side surface 541 is convex at the near optical axis 590, and the image side surface 542 is concave at the near optical axis 590, and the object side surface 541 and the image side are The surface 542 is aspherical, and the object side surface 541 and the image side surface 542 have at least one surface having at least one inflection point.

The infrared filter element 570 is made of glass and disposed between the fourth lens 540 and the imaging surface 580 without affecting the focal length of the wide-angle imaging lens group.

Refer to Table 9 and Table 10 below.

In the fifth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Table 9 and Table 10:

<Sixth embodiment>

6A and FIG. 6B, FIG. 6A is a schematic diagram of a wide-angle imaging lens group according to a sixth embodiment of the present invention, and FIG. 6B is a left-to-right spherical aberration of the wide-angle imaging lens group of the sixth embodiment. Astigmatic and distorted graphs. As can be seen from FIG. 6A, the wide-angle imaging lens assembly includes an aperture 600 and an optical group. The optical group includes a first lens 610, a second lens 620, a third lens 630, and a fourth lens 640 from the object side to the image side. The infrared filter element 670 and the imaging surface 680, wherein the lens of the wide-angle imaging lens group has four refractive powers. The aperture 600 is disposed between the image side surface 612 of the first lens 610 and the object.

The first lens 610 has a positive refractive power and is made of a plastic material. The object side surface 611 is convex at the near optical axis 690, and the image side surface 612 is convex at the near optical axis 690, and the object side surface 611 and the image side are Surface 612 is aspherical.

The second lens 620 has a negative refractive power and is made of a plastic material. The object side surface 621 is concave at the near optical axis 690, and the image side surface 622 is concave at the near optical axis 690, and the object side surface 621 and the image side are Surface 622 is aspherical.

The third lens 630 has a positive refractive power and is made of a plastic material. The object side surface 631 is concave at the near optical axis 690, and the image side surface 632 is convex at the near optical axis 690, and the object side surface 631 and the image side are Surface 632 is aspherical.

The fourth lens 640 has a negative refractive power and is made of a plastic material. The object side surface 641 is convex at the near optical axis 690, and the image side surface 642 is concave at the near optical axis 690, and the object side surface 641 and the image side are The surface 642 is aspherical, and the object side surface 641 and the image side surface 642 have at least one surface having at least one inflection point.

The infrared filter element 670 is made of glass and disposed between the fourth lens 640 and the imaging surface 680 without affecting the focal length of the wide-angle imaging lens group.

Referring again to Table 11 and Table 12 below.

In the sixth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Table 11 and Table 12:

<Seventh embodiment>

7A and FIG. 7B, FIG. 7A is a schematic diagram of a wide-angle imaging lens group according to a seventh embodiment of the present invention, and FIG. 7B is a left-to-right spherical aberration of the wide-angle imaging lens group of the seventh embodiment. Astigmatic and distorted graphs. As can be seen from FIG. 7A, the wide-angle imaging lens set includes an aperture 700 and An optical group comprising, in order from the object side to the image side, a first lens 710, a second lens 720, a third lens 730, a fourth lens 740, an infrared filter element 770, and an imaging surface 780, wherein The lens with refractive power in the wide-angle imaging lens group is four. The aperture 700 is disposed between the image side surface 712 of the first lens 710 and the subject.

The first lens 710 has a positive refractive power and is made of a plastic material. The object side surface 711 is convex at the near optical axis 790, and the image side surface 712 is convex at the near optical axis 790, and the object side surface 711 and the image side are Surface 712 is aspherical.

The second lens 720 has a negative refractive power and is made of a plastic material. The object side surface 721 is concave at the near optical axis 790, and the image side surface 722 is concave at the near optical axis 790, and the object side surface 721 and the image side are Surface 722 is aspherical.

The third lens 730 has a positive refractive power and is made of a plastic material. The object side surface 731 is concave at the near optical axis 790, and the image side surface 732 is convex at the near optical axis 790, and the object side surface 731 and the image side are Surface 732 is aspherical.

The fourth lens 740 has a negative refractive power and is made of a plastic material. The object side surface 741 is convex at the near optical axis 790, and the image side surface 742 is concave at the near optical axis 790, and the object side surface 741 and the image side are The surface 742 is aspherical, and the object side surface 741 and the image side surface 742 have at least one surface having at least one inflection point.

The infrared filter element 770 is made of glass and disposed between the fourth lens 740 and the imaging surface 780 without affecting the focal length of the wide-angle imaging lens group.

Refer to Table 13 and Table 14 below.

In the seventh embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Table 13 and Table 14:

<Eighth Embodiment>

8A and 8B, wherein FIG. 8A is a schematic diagram of a wide-angle imaging lens group according to an eighth embodiment of the present invention, and FIG. 8B is a left-to-right spherical aberration of the wide-angle imaging lens group of the eighth embodiment. Astigmatic and distorted graphs. As can be seen from FIG. 8A, the wide-angle imaging lens assembly includes an aperture 800 and an optical group. The optical group includes a first lens 810, a second lens 820, a third lens 830, and a fourth lens 840 from the object side to the image side. The infrared filter element 870 and the imaging surface 880, wherein the lens having a refractive power in the wide-angle imaging lens group is four. The aperture 800 is disposed between the image side surface 812 of the first lens 810 and the subject.

The first lens 810 has a positive refractive power and is made of a plastic material. The object side surface 811 is convex at the near optical axis 890, and the image side surface 812 is convex at the near optical axis 890, and the object side surface 811 and the image side are Surface 812 is aspherical.

The second lens 820 has a negative refractive power and is made of a plastic material. The object side surface 821 is concave at the near optical axis 890, and the image side surface 822 is concave at the near optical axis 890, and the object side surface 821 and the image side are Surface 822 is aspherical.

The third lens 830 has a positive refractive power and is made of a plastic material. The object side surface 831 is concave at the near optical axis 890, and the image side surface 832 is convex at the near optical axis 890, and the object side surface 831 and the image side are Surface 832 is aspherical.

The fourth lens 840 has a negative refractive power and is made of a plastic material. The object side surface 841 is convex at the near optical axis 890, and the image side surface 842 is concave at the near optical axis 890, and the object side surface 841 and the image are The side surfaces 842 are all aspherical, and the object side surface 841 and the image side surface 842 have at least one surface having at least one inflection point.

The infrared filter element 870 is made of glass and disposed between the fourth lens 840 and the imaging surface 880 without affecting the focal length of the wide-angle imaging lens group.

Refer to Table 15 and Table 16 below for reference.

In the eighth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Table 15 and Table 16:

The wide-angle imaging lens set provided by the invention can be made of plastic or glass. When the lens material is plastic, the production cost can be effectively reduced. When the lens is made of glass, the refractive power of the wide-angle imaging lens set can be increased. degree. In addition, the object side surface and the image side surface of the lens in the wide-angle imaging lens group may be aspherical, and the aspheric surface can be easily formed into a shape other than the spherical surface, and more control variables are obtained to reduce the aberration and thereby reduce the use of the lens. The number can therefore effectively reduce the overall length of the wide-angle imaging lens set of the present invention.

In the wide-angle imaging lens set provided by the present invention, in the case of a lens having a refractive power, if the surface of the lens is convex and the position of the convex surface is not defined, it means that the surface of the lens is convex at the near-optical axis; When the concave surface is not defined and the concave position is not defined, it indicates that the lens surface is concave at the near optical axis.

The wide-angle imaging lens set provided by the invention is more suitable for the optical system of moving focus, and has the characteristics of excellent aberration correction and good imaging quality, and can be applied to 3D (three-dimensional) image capturing, digital camera, and the like in various aspects. In electronic imaging systems such as mobile devices, digital tablets or car photography.

In the above, the above embodiments and drawings are only the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, that is, the equivalent changes and modifications made by the scope of the present invention are all It should be within the scope of the patent of the present invention.

100‧‧‧ aperture

110‧‧‧first lens

111‧‧‧Side side surface

112‧‧‧ image side surface

120‧‧‧second lens

121‧‧‧Side side surface

122‧‧‧ image side surface

130‧‧‧ third lens

131‧‧‧ object side surface

132‧‧‧Image side surface

140‧‧‧Fourth lens

141‧‧‧ object side surface

142‧‧‧ image side surface

170‧‧‧Infrared filter components

180‧‧‧ imaging surface

190‧‧‧ optical axis

Claims (14)

A wide-angle imaging lens group comprising: an aperture from the object side to the image side; a first lens having a positive refractive power, a convex surface of the object side surface near the optical axis, and a convex surface of the image side surface near the optical axis At least one surface of the object side surface and the image side surface is aspherical; a second lens has a negative refractive power, and the object side surface is concave at a near optical axis, and at least one surface of the object side surface and the image side surface is non- a third lens having a positive refractive power, the image side surface having a convex surface at a near optical axis, and at least one surface of the object side surface and the image side surface being aspherical; a fourth lens having a negative refractive power, The side surface near the optical axis is a convex surface, and at least one surface of the object side surface and the image side surface is aspherical, and at least one surface of the object side surface and the image side surface has at least one inflection point; wherein the focal length of the first lens is F1, the combined focal length of the second lens and the third lens is f23, and satisfies the following condition: 0.4<f1/f23<1.7; wherein the image side surface of the first lens has a radius of curvature R2, and the object side of the second lens The radius of curvature of the surface is R3 and the following conditions are met. 0.3595 ≦ R2 / R3 <4.3. The wide-angle imaging lens set according to claim 1, wherein the object side surface of the third lens has a concave surface at a near optical axis, and the image side surface has a convex surface at a near optical axis; the object side surface of the fourth lens has a near optical axis The convex surface and the image side surface are concave at the near optical axis. The wide-angle imaging lens set according to claim 1, wherein the focal length of the first lens is f1, the focal length of the second lens is f2, and the following condition is satisfied: -0.9 < f1/f2 < -0.3. The wide-angle imaging lens set according to claim 1, wherein the focal length of the second lens is f2, the focal length of the third lens is f3, and the following condition is satisfied: -4.2 < f2 / f3 < -1.3. The wide-angle imaging lens set according to claim 1, wherein the focal length of the third lens is f3, the focal length of the fourth lens is f4, and the following condition is satisfied: -1.1 < f3 / f4 < -0.4. The wide-angle imaging lens set according to claim 1, wherein the focal length of the first lens is f1, the focal length of the third lens is f3, and the following condition is satisfied: 0.7 < f1/f3 < 2.1. The wide-angle imaging lens set according to claim 1, wherein the focal length of the second lens is f2, the focal length of the fourth lens is f4, and the following condition is satisfied: 0.55 < f2 / f4 < 4.0. The wide-angle imaging lens set according to claim 1, wherein the second lens and the third lens have a combined focal length of f23, the fourth lens has a focal length of f4, and satisfies the following condition: -1.3<f23/f4<-0.6 . The wide-angle imaging lens set according to claim 1, wherein the combined focal length of the first lens and the second lens is f12, the combined focal length of the third lens and the fourth lens is f34, and the following condition is satisfied: 0.3<f12/ F34<2.2. The wide-angle imaging lens set according to claim 1, wherein the total focal length of the wide-angle imaging lens group is f, the distance from the object-side surface of the first lens to the imaging surface on the optical axis is TL, and the following condition is satisfied: 0.5 <f/TL<0.8. The wide-angle imaging lens set according to claim 1, wherein the wide-angle imaging lens group has a maximum angle of view of FOV and satisfies the following condition: 75 degrees < FOV < 95 degrees. The wide-angle imaging lens set according to claim 1, wherein the thickness of the second lens on the optical axis is CT2, the thickness of the first lens on the optical axis is CT1, and the following condition is satisfied: 0.2<CT2/CT1< 0.7. The wide-angle imaging lens set according to claim 1, wherein the distance between the first lens and the second lens on the optical axis is T12, the thickness of the second lens on the optical axis is CT2, and the following condition is satisfied: 0.05 <T12/CT2<1.25. The wide-angle imaging lens set according to claim 1, wherein the first lens has a dispersion coefficient of V1, the second lens has a dispersion coefficient of V2, and satisfies the following condition: 30 < V1 - V2 < 42.