CN106980172A - Wide-angle imaging lens group - Google Patents

Abstract

The present invention is a wide-angle imaging lens group, which comprises, from the object side to the image side, an aperture; a first lens having positive refractive power; a second lens having negative refractive power; a third lens having positive refractive power; and a fourth lens having negative refractive power. The invention is characterized in that the focal length of the first lens is f1, the composite focal length of the second lens and the third lens is f23, and the following condition is satisfied: 0.4<f1/f23<1.7. Thus, the wide-angle imaging lens group can obtain a wide picture angle (field of view) while significantly improving its resolution capability.

Description

Wide Angle Imaging Lens Group

technical field

The invention relates to a wide-angle imaging lens set, in particular to a miniaturized four-piece wide-angle imaging lens set applied to electronic products.

Background technique

With the rise of electronic products with photographic functions, the demand for optical systems is increasing day by day. In shooting, in order to obtain a wider shooting range, the viewing angle of the lens needs to meet certain requirements, so the requirements for the shooting angle and image quality of the lens are becoming more and more stringent. Usually the picture angle (field of view FOV) of the lens is designed to be 50 degrees to 60 degrees. If the angle exceeds the above design angle, not only the aberration will be large, but the design of the lens will also be more complicated. It is known that US 8335043 and US 8576497 use 2 lens groups and 5 to 6 lenses to achieve the purpose of large angles, but their distortion is too large, and such as US 8593737, US 8576497, and US 8395853, although they can achieve the purpose of large angles, But the total length (TL) of its lens group is too long.

Therefore, how to develop a miniaturized wide-angle imaging lens group, which can be configured in electronic products such as digital camera lenses, network camera lenses, or mobile phone lenses, and has a larger viewing angle and lower The efficacy of aberrations to reduce the complexity of lens design is the motivation behind the development of this invention.

Contents of the invention

The object of the present invention is to provide a wide-angle imaging lens set, especially a four-piece wide-angle imaging lens set with improved picture angle, high resolution capability, short lens length, and small distortion.

In order to achieve the aforementioned object, according to a kind of wide-angle imaging lens group provided by the present invention, it includes in order from the object side to the image side: an aperture; a first lens with positive refractive power, and the near optical axis on the object side surface is a convex surface, the near optical axis of the image side surface is convex, and at least one surface of the object side surface and the image side surface is an aspheric surface; a second lens has negative refractive power, and the near optical axis of the object side surface is concave, and its At least one of the object-side surface and the image-side surface is an aspherical surface; a third lens has positive refractive power, the image-side surface is convex near the optical axis, and at least one of the object-side surface and the image-side surface is aspherical; A fourth lens with negative refractive power, its object-side surface near the optical axis is convex, at least one of its object-side surface and image-side surface is aspheric, and at least one of its object-side surface and 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 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 obtain a wide range of picture angles (field of view), while its resolution ability is significantly improved.

Preferably, the near optical axis of the object side surface of the third lens is concave, and the near optical axis of the image side surface is convex; the object side surface of the fourth lens is convex near the optical axis, and the near optical axis of the image side surface is convex. is concave.

Preferably, the focal length of the first lens is f1, the focal length of the second lens is f2, and the following conditions are satisfied: -0.9<f1/f2<-0.3. In this way, the refractive power configuration of the first lens and the second lens is more appropriate, which is beneficial to obtain a wide range of picture angles (field of view) and reduce the excessive increase of system aberrations.

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. In this way, the configuration of the refractive power of the second lens and the third lens is relatively balanced, which helps to correct aberrations and reduce sensitivity.

Preferably, the focal length of the third lens is f3, the focal length of the fourth lens is f4, and the following conditions are satisfied: -1.1<f3/f4<-0.4. Thereby, it is beneficial 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 conditions are 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. Thereby, the distribution of the negative refractive force of the system is more appropriate, which is beneficial to correct the system aberration and 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. In this way, the wide-angle imaging lens group can obtain a wide range of picture angles (field of view), while its resolution ability is significantly improved.

Preferably, 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. Thereby, it is beneficial to obtain a wide picture angle (angle of view) and effectively correct curvature of field.

Preferably, the overall focal length of the wide-angle imaging lens group is f, the distance on the optical axis from the object-side surface of the first lens to the imaging surface is TL, and the following conditions are satisfied: 0.5<f/TL<0.8. Thereby, it is beneficial to obtain a wide angle of view (angle of view) and maintain the miniaturization of the wide-angle imaging lens group so that it can be mounted on thin and light electronic products.

Preferably, the maximum field of view angle of the wide-angle imaging lens group is FOV, and satisfies the following condition: 75<FOV<95. Thereby, the wide-angle imaging lens group can have a relatively large viewing angle.

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. In this way, the first lens and the second lens have appropriate thicknesses, making 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 conditions are satisfied: 0.05<T12/CT2<1.25. Thereby, the maximum viewing angle of the wide-angle imaging lens group can be further increased.

Preferably, the curvature radius of the image-side surface of the first lens is R2, the curvature radius of the object-side surface of the second lens is R3, and the following conditions are satisfied: 0.01<R2/R3<4.3. The spherical aberration and astigmatism of the wide-angle imaging lens group are effectively reduced.

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

Regarding the technology, means and other effects adopted in order to achieve the above-mentioned purpose in the present invention, eight preferred feasible embodiments are given and described in detail in conjunction with the drawings as follows.

Description of drawings

In order to illustrate the technical solution of the present invention more clearly, the accompanying drawings used in the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, In other words, other drawings can also be obtained from these drawings on the premise of not paying creative work.

FIG. 1A is a schematic diagram of a wide-angle imaging lens set according to a first embodiment of the present invention.

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

FIG. 2A is a schematic diagram of a wide-angle imaging lens set according to a second embodiment of the present invention.

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

FIG. 3A is a schematic diagram of a wide-angle imaging lens set according to a third embodiment of the present invention.

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

FIG. 4A is a schematic diagram of a wide-angle imaging lens set according to a fourth embodiment of the present invention.

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

FIG. 5A is a schematic diagram of a wide-angle imaging lens set according to a fifth embodiment of the present invention.

FIG. 5B is a graph of spherical aberration, astigmatism and distortion of the wide-angle imaging lens set of the fifth embodiment in order from left to right.

FIG. 6A is a schematic diagram of a wide-angle imaging lens set according to a sixth embodiment of the present invention.

6B is a graph of spherical aberration, astigmatism and distortion of the wide-angle imaging lens set of the sixth embodiment in order from left to right.

FIG. 7A is a schematic diagram of a wide-angle imaging lens set according to a seventh embodiment of the present invention.

FIG. 7B is a curve diagram of spherical aberration, astigmatism and distortion of the wide-angle imaging lens set of the seventh embodiment in order from left to right.

FIG. 8A is a schematic diagram of a wide-angle imaging lens set according to an eighth embodiment of the present invention.

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

Explanation of reference signs

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: object 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: object side surface

122, 222, 322, 422, 522, 622, 722, 822: image side surface

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

131, 231, 331, 431, 531, 631, 731, 831: object side surface

132, 232, 332, 432, 532, 632, 732, 832: image side surface

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

141, 241, 341, 441, 541, 641, 741, 841: object side surface

142, 242, 342, 442, 542, 642, 742, 842: image side surface

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

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

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

f: focal length of wide-angle imaging lens group Fno: aperture value of wide-angle imaging lens group

FOV: the largest field of view in the wide-angle imaging lens group f1: the focal length of the first lens

f2: focal length of the second lens f3: focal length of the third lens

f4: focal length of the fourth lens f12: composite focal length of the first lens and the second lens

f23: composite focal length of the second lens and the third lens f34: composite focal length of the third lens and the fourth lens

R2: Radius of curvature of the image-side surface 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 plane on the optical axis

detailed description

<First embodiment>

Please refer to FIG. 1A and FIG. 1B , wherein FIG. 1A shows a schematic diagram of the wide-angle imaging lens group according to the first embodiment of the present invention, and FIG. 1B shows the spherical aberration, Astigmatism and Distortion Curves. It can be seen from FIG. 1A that the wide-angle imaging lens group includes an aperture 100 and an optical group, and the optical group includes a first lens 110, a second lens 120, a third lens 130, and a fourth lens 140 in sequence from the object side to the image side. , the infrared filter assembly 170, and the imaging surface 180, which are characterized in that there are four lenses with refractive power in the wide-angle imaging 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 plastic material. Its object-side surface 111 is convex near the optical axis 190, and its image-side surface 112 is convex near the optical axis 190. The object-side surface 111 and the image-side Surfaces 112 are all aspherical.

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

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

The fourth lens 140 has negative refractive power and is made of plastic material. Its object-side surface 141 is convex near the optical axis 190, and its image-side surface 142 is concave near the optical axis 190. The object-side surface 141 and the image-side The surfaces 142 are both aspherical, and at least one 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, which is disposed between the fourth lens 140 and the imaging surface 180 and does not affect the focal length of the wide-angle imaging lens group.

The curve equations of the aspheric surfaces of the above-mentioned lenses are expressed as follows:

Wherein, z is the position value with the surface vertex as reference at the position of height h along the optical axis 190 direction; c is the curvature of the lens surface close to the optical axis 190, and is the reciprocal (c=1/R) of the radius of curvature (R) ), R is the radius of curvature of the lens surface close to the optical axis 190, h is the vertical distance from the lens surface to the optical axis 190, k is the conic constant, and A, B, C, D, E, G, ... is the 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 field of view (angle of view) in the wide-angle imaging lens group is FOV , and its values are as follows: f=1.978 (mm); Fno=2.0; and FOV=88 (degrees).

In the wide-angle imaging lens set 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 set 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 set 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 set 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 set 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 set 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 set of the first embodiment, the focal length of the first lens 110 is f1, the composite 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 combined focal length of the first lens 110 and the second lens 120 is f12, the combined focal length of the third lens 130 and the fourth lens 140 is f34, and the following conditions are 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 of the first lens 110 to the imaging surface 180 on the optical axis 190 is TL, and the following conditions are satisfied : f/TL=0.6571.

In the wide-angle imaging lens group 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 satisfied: CT2/CT1= 0.3537.

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

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

In the wide-angle imaging lens set of the first embodiment, the dispersion coefficient of the first lens 110 is V1, the dispersion coefficient of the second lens 120 is V2, and the following condition is satisfied: V1-V2=32.1.

Then refer to Table 1 and Table 2 below.

Table 1 is the detailed structural data of the first embodiment in FIG. 1A , where the units of the radius of curvature, thickness and focal length are mm, and surfaces 0-13 represent surfaces from the object side to the image side in sequence. Table 2 is the aspheric surface data in the first embodiment, wherein, k represents the cone coefficient in the aspheric surface curve equation, and A, B, C, D, E, F, G, ... are high-order aspheric surface coefficients. In addition, the tables of the following embodiments are schematic diagrams and aberration curves corresponding to the respective embodiments, and the definitions of the data in the tables are the same as those in Table 1 and Table 2 of the first embodiment, and will not be repeated here.

<Second Embodiment>

Please refer to FIG. 2A and FIG. 2B, wherein FIG. 2A shows a schematic diagram of the wide-angle imaging lens group according to the second embodiment of the present invention, and FIG. 2B shows the spherical aberration, Astigmatism and Distortion Curves. It can be seen from FIG. 2A that the wide-angle imaging lens system includes a diaphragm 200 and an optical group, and the optical group 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 in sequence. , an infrared filter assembly 270 , and an imaging surface 280 , wherein there are four lenses with refractive power in the wide-angle imaging lens group. The aperture 200 is disposed between the image-side surface 212 of the first lens 210 and the subject.

The first lens 210 has positive refractive power and is made of plastic material. Its object-side surface 211 is convex near the optical axis 290, and its image-side surface 212 is convex near the optical axis 290. The object-side surface 211 and the image-side Surfaces 212 are all aspherical.

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

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

The fourth lens 240 has a negative refractive power and is made of plastic material. Its object-side surface 241 near the optical axis 290 is convex, its image-side surface 242 near the optical axis 290 is concave, and the object-side surface 241 and the image-side The surfaces 242 are both aspherical, and at least one 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, which is disposed between the fourth lens 240 and the imaging surface 280 and does not affect the focal length of the wide-angle imaging lens group.

Then refer to Table 3 and Table 4 below.

In the second embodiment, the curve equation of the aspheric surface is expressed in the form of the first embodiment. In addition, the definitions of the parameters in the table below are the same as those in the first embodiment, and will not be repeated here.

Cooperating with Table 3 and Table 4, the following data can be deduced:

<Third embodiment>

Please refer to FIG. 3A and FIG. 3B , wherein FIG. 3A shows a schematic diagram of the wide-angle imaging lens group according to the third embodiment of the present invention, and FIG. 3B shows the spherical aberration, Astigmatism and Distortion Curves. It can be seen from FIG. 3A that the wide-angle imaging lens group includes a diaphragm 300 and an optical group, and 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 in sequence. , an infrared filtering filter assembly 370, and an imaging surface 380, wherein there are four lenses with refractive power in the wide-angle imaging lens group. 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 plastic material. Its object-side surface 311 is convex near the optical axis 390, and its image-side surface 312 is convex near the optical axis 390. The object-side surface 311 and the image-side Surfaces 312 are all aspherical.

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

The third lens 330 has positive refractive power and is made of plastic material. Its object-side surface 331 near the optical axis 390 is concave, its image-side surface 332 near the optical axis 390 is convex, and the object-side surface 331 and the image-side Surfaces 332 are all aspherical.

The fourth lens 340 has negative refractive power and is made of plastic material. Its object-side surface 341 is convex near the optical axis 390, and its image-side surface 342 is concave near the optical axis 390. The object-side surface 341 and the image-side The surfaces 342 are both aspherical, and at least one 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, which is disposed between the fourth lens 340 and the imaging surface 380 and does not affect the focal length of the wide-angle imaging lens group.

Then refer to Table 5 and Table 6 below.

In the third embodiment, the curve equation of the aspheric surface is expressed in the form of the first embodiment. In addition, the definitions of the parameters in the table below are the same as those in the first embodiment, and will not be repeated here.

Cooperating with Table 5 and Table 6, the following data can be deduced:

<Fourth Embodiment>

Please refer to FIG. 4A and FIG. 4B, wherein FIG. 4A shows a schematic diagram of a wide-angle imaging lens group according to a fourth embodiment of the present invention, and FIG. 4B shows the spherical aberration, Astigmatism and Distortion Curves. It can be seen from FIG. 4A that the wide-angle imaging lens group includes a diaphragm 400 and an optical group, and 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 in sequence. , an infrared filter assembly 470, and an imaging surface 480, wherein there are four lenses with refractive power in the wide-angle imaging lens group. The aperture 400 is disposed between the image-side surface 412 of the first lens 410 and the subject.

The first lens 410 has positive refractive power and is made of plastic material. Its object-side surface 411 is convex near the optical axis 490, and its image-side surface 412 is convex near the optical axis 490. The object-side surface 411 and the image-side Surfaces 412 are all aspherical.

The second lens 420 has negative refractive power and is made of plastic material. Its object-side surface 421 near the optical axis 490 is concave, and its image-side surface 422 near the optical axis 490 is convex. The object-side surface 421 and the image-side Surfaces 422 are all aspherical.

The third lens 430 has positive refractive power and is made of plastic material. Its object-side surface 431 near the optical axis 490 is concave, and its image-side surface 432 near the optical axis 490 is convex. The object-side surface 431 and the image-side Surfaces 432 are all aspherical.

The fourth lens 440 has a negative refractive power and is made of plastic material. Its object-side surface 441 is convex near the optical axis 490, and its image-side surface 442 is concave near the optical axis 490. The object-side surface 441 and the image-side The surfaces 442 are both aspherical, and at least one 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, which is disposed between the fourth lens 440 and the imaging surface 480 and does not affect the focal length of the wide-angle imaging lens group.

Then refer to Table 7 and Table 8 below.

In the fourth embodiment, the curve equation of the aspheric surface is expressed in the form of the first embodiment. In addition, the definitions of the parameters in the table below are the same as those in the first embodiment, and will not be repeated here.

Cooperating with Table 7 and Table 8, the following data can be deduced:

<Fifth Embodiment>

Please refer to FIG. 5A and FIG. 5B , wherein FIG. 5A shows a schematic diagram of a wide-angle imaging lens group according to a fifth embodiment of the present invention, and FIG. 5B shows the spherical aberration, Astigmatism and Distortion Curves. It can be seen from FIG. 5A that the wide-angle imaging lens group includes a diaphragm 500 and an optical group, and the optical group 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 in sequence. , an infrared filter assembly 570, and an imaging surface 580, wherein there are four lenses with refractive power in the wide-angle imaging lens group. 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 plastic material. Its object-side surface 511 is convex near the optical axis 590, and its image-side surface 512 is convex near the optical axis 590. The object-side surface 511 and the image-side Surfaces 512 are all aspherical.

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

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

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

The infrared filter element 570 is made of glass, which is disposed between the fourth lens 540 and the imaging surface 580 and does not affect the focal length of the wide-angle imaging lens group.

Then refer to Table 9 and Table 10 below.

In the fifth embodiment, the curve equation of the aspheric surface is expressed in the form of the first embodiment. In addition, the definitions of the parameters in the table below are the same as those in the first embodiment, and will not be repeated here.

Cooperating with Table 9 and Table 10, the following data can be deduced:

<Sixth Embodiment>

Please refer to FIG. 6A and FIG. 6B, wherein FIG. 6A shows a schematic diagram of the wide-angle imaging lens group according to the sixth embodiment of the present invention, and FIG. 6B shows the spherical aberration, Astigmatism and Distortion Curves. It can be seen from FIG. 6A that the wide-angle imaging lens group includes a diaphragm 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 in sequence. , an infrared filter assembly 670, and an imaging surface 680, wherein the wide-angle imaging lens group has four lenses with refractive power. The aperture 600 is disposed between the image-side surface 612 of the first lens 610 and the subject.

The first lens 610 has positive refractive power and is made of plastic material. Its object-side surface 611 is convex near the optical axis 690, and its image-side surface 612 is convex near the optical axis 690. The object-side surface 611 and the image-side Surfaces 612 are all aspherical.

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

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

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

The infrared filter element 670 is made of glass, which is disposed between the fourth lens 640 and the imaging surface 680 and does not affect the focal length of the wide-angle imaging lens group.

Then refer to Table 11 and Table 12 below.

In the sixth embodiment, the curve equation of the aspheric surface is expressed in the form of the first embodiment. In addition, the definitions of the parameters in the table below are the same as those in the first embodiment, and will not be repeated here.

Cooperating with Table 11 and Table 12, the following data can be deduced:

<Seventh Embodiment>

Please refer to FIG. 7A and FIG. 7B , wherein FIG. 7A shows a schematic diagram of the wide-angle imaging lens group according to the seventh embodiment of the present invention, and FIG. 7B shows the spherical aberration, Astigmatism and Distortion Curves. It can be seen from FIG. 7A that the wide-angle imaging lens group includes a diaphragm 700 and an optical group, and the optical group includes a first lens 710, a second lens 720, a third lens 730, and a fourth lens 740 from the object side to the image side in sequence. , an infrared filter assembly 770, and an imaging surface 780, wherein there are four lenses with refractive power in the wide-angle imaging lens group. 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 plastic material. Its object-side surface 711 is convex near the optical axis 790, and its image-side surface 712 is convex near the optical axis 790. The object-side surface 711 and the image-side Surfaces 712 are all aspherical.

The second lens 720 has negative refractive power and is made of plastic material. Its object-side surface 721 is concave near the optical axis 790, and its image-side surface 722 is concave near the optical axis 790. The object-side surface 721 and the image-side Surfaces 722 are both aspherical.

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

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

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

Then refer to the following Table 13 and Table 14.

In the seventh embodiment, the curve equation of the aspheric surface is expressed in the form of the first embodiment. In addition, the definitions of the parameters in the table below are the same as those in the first embodiment, and will not be repeated here.

Cooperating with Table 13 and Table 14, the following data can be deduced:

<Eighth embodiment>

Please refer to FIG. 8A and FIG. 8B, wherein FIG. 8A shows a schematic diagram of the wide-angle imaging lens group according to the eighth embodiment of the present invention, and FIG. 8B shows the spherical aberration, Astigmatism and Distortion Curves. It can be seen from FIG. 8A that the wide-angle imaging lens group includes a diaphragm 800 and an optical group, and 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 in sequence. , an infrared filtering filter assembly 870, and an imaging surface 880, wherein there are four lenses with refractive power in the wide-angle imaging lens group. 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 plastic material. Its object-side surface 811 is convex near the optical axis 890, and its image-side surface 812 is convex near the optical axis 890. The object-side surface 811 and the image-side Surfaces 812 are all aspherical.

The second lens 820 has negative refractive power and is made of plastic material. Its object-side surface 821 is concave near the optical axis 890, and its image-side surface 822 is concave near the optical axis 890. The object-side surface 821 and the image-side Surfaces 822 are all aspherical.

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

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

The infrared filter element 870 is made of glass, which is disposed between the fourth lens 840 and the imaging surface 880 and does not affect the focal length of the wide-angle imaging lens group.

Then refer to Table 15 and Table 16 below.

In the eighth embodiment, the curve equation of the aspheric surface is expressed in the form of the first embodiment. In addition, the definitions of the parameters in the table below are the same as those in the first embodiment, and will not be repeated here.

Cooperating with Table 15 and Table 16, the following data can be deduced:

In the wide-angle imaging lens group provided by the present invention, the material of the lens can be plastic or glass. When the lens material is plastic, the production cost can be effectively reduced, and when the lens is made of glass, the freedom of refractive power configuration of the wide-angle imaging lens group can be increased. Spend. In addition, the object-side surface and image-side surface of the lens in the wide-angle imaging lens group can be aspherical, and the aspheric surface can be easily made into a shape other than spherical, so that more control variables can be obtained to reduce aberrations, thereby reducing the cost of the lens. Therefore, the total length of the wide-angle imaging lens group of the present invention can be effectively reduced.

In the wide-angle imaging lens group provided by the present invention, as far as the lens with refractive power is concerned, if the lens surface is convex and the position of the convex surface is not defined, it means that the lens surface is convex at the near optical axis; if the lens surface If it is a concave surface and the position of the concave surface is not defined, it means that the surface of the lens is concave at the near optical axis.

The wide-angle imaging lens group provided by the present invention can be applied to the optical system of moving focus according to the requirements, and has the characteristics of excellent aberration correction and good imaging quality, and can be applied in 3D (three-dimensional) image capture and digital cameras in many aspects. , Mobile devices, digital drawing tablets or electronic imaging systems such as car photography.

In summary, the above-mentioned embodiments and drawings are only preferred embodiments of the present invention, and should not be used to limit the scope of the present invention, that is, all equivalent changes and modifications made according to the patent scope of the present invention are all It should belong to the scope covered by the patent of the present invention.

Claims (15)

1. A wide-angle imaging lens group, characterized in that it comprises sequentially from the object side to the image side: an aperture; A first lens with positive refractive power, its object-side surface near the optical axis is convex, its image-side surface near the optical axis is convex, and at least one of the object-side surface and the image-side surface is aspherical; A second lens with negative refractive power, its object-side surface near the optical axis is concave, and at least one of its object-side surface and image-side surface is aspheric; A third lens with positive refractive power, its image-side surface near the optical axis is convex, and at least one of its object-side surface and image-side surface is aspherical; A fourth lens with negative refractive power, its object-side surface near the optical axis is convex, at least one of its object-side surface and image-side surface is aspheric, and at least one of its object-side surface and image-side surface has at least one inflection point; The focal length of the first lens is f1, the composite focal length of the second lens and the third lens is f23, and the following conditions are satisfied: 0.4<f1/f23<1.7. 2. wide-angle imaging lens group as claimed in claim 1, is characterized in that, the near optical axis place of object side surface of this 3rd lens is concave surface, as side surface near optical axis place is convex surface; The object side of this 4th lens The near optical axis of the surface is convex, and the near optical axis of the image side surface is concave. 3. 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 conditions are satisfied: -0.9<f1/f2<-0.3 . 4. 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 conditions are satisfied: -4.2<f2/f3<-1.3. 5. The wide-angle imaging lens group 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 conditions are satisfied: -1.1<f3/f4<-0.4 . 6. 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 conditions are satisfied: 0.7<f1/f3<2.1. 7. 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 conditions are satisfied: 0.55<f2/f4<4.0. 8. The wide-angle imaging lens set according to claim 1, wherein 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 conditions are satisfied: -1.3<f23 /f4<-0.6. 9. 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 conditions are met : 0.3<f12/f34<2.2. 10. The wide-angle imaging lens group according to claim 1, wherein 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 Satisfy the following conditions: 0.5<f/TL<0.8. 11. The wide-angle imaging lens set according to claim 1, wherein the maximum field of view angle of the wide-angle imaging lens set is FOV, and satisfies the following condition: 75<FOV<95. 12. 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 conditions are satisfied: 0.2< CT2/CT1<0.7. 13. 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 Satisfy the following condition: 0.05<T12/CT2<1.25. 14. The wide-angle imaging lens group according to claim 1, wherein the radius of curvature of the image-side surface of the first lens is R2, and the radius of curvature of the object-side surface of the second lens is R3, and satisfy the following conditions: 0.01 <R2/R3<4.3. 15. The wide-angle imaging lens set according to claim 1, wherein the dispersion coefficient of the first lens is V1, the dispersion coefficient of the second lens is V2, and the following conditions are satisfied: 30<V1-V2<42 .