TW201544842A - Optical lens system with a wide field of view - Google Patents

Abstract

An optical lens system with a wide field of view comprises, in order from the object side to the image side: a stop, a first lens element with a positive refractive power having a convex image-side surface and at least one aspheric surface; a second lens element with a negative refractive power having a concave image-side surface and at least one aspheric surface; a third lens element with a positive refractive power having a concave object-side surface and at least one aspheric surface; a fourth lens element with a negative refractive power having a convex object-side surface and at least one aspheric surface, and at least one of the object-side and image-side surfaces of the fourth lens element has an inflection point. Such arrangements can improve the field of view and reduce the aberrations caused by the system.

Description

Wide-angle imaging lens set

The present invention relates to an imaging lens set, and more particularly to a miniaturized wide-angle imaging lens set.

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. Usually, the angle of the lens (the angle of view) 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.

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 that primarily enhances the angle of view while attenuating aberrations.

In order to achieve the foregoing objective, a wide-angle imaging lens set according to the present invention comprises, in order from the object side to the image side, an aperture; a first lens having a positive refractive power, the image side surface being convex, And at least one side of the object side surface and the image side surface of the first lens is aspherical; a second lens having a negative refractive power, the image side surface is concave, and the second lens object At least one side of the side surface and the image side surface is aspherical; a third lens having a positive refractive power, the object side surface is a concave surface, and at least one side of the object side surface and the image side surface of the third lens is aspherical; a fourth lens having a negative refractive power, wherein the object side surface is a convex surface, and at least one side of the object side surface and the image side surface of the fourth lens is aspherical, and the object side surface and the image side surface of the fourth lens At least one mask has an inflection point.

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: -0.8 <f1/f2 < -0.4. 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 second lens has a focal length of f2, and the third lens has a focal length of f3, and The following conditions are satisfied: -3.5 < f2 / f3 < - 1.2. Thereby, the refractive power arrangement of the second lens and the third lens is balanced, which contributes to the correction of the aberration and the decrease of the sensitivity.

Preferably, the third lens has a focal length of f3, and the fourth lens has a focal length of f4, and The following conditions are satisfied: -1.2 <f3/f4<-0.5. 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, and the focal length of the third lens is f3, and The following conditions are satisfied: 0.8 < f1/f3 < 2.0. 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, and the focal length of the fourth lens is f4, and The following conditions are satisfied: 1.0 < f2 / f4 < 3.5. 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 focal length of the first lens is f1, and the second lens and the third lens The combined focal length is f23 and the following conditions are satisfied: 0.5 < f1/f23 < 1.8. 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 second lens and the third lens is f23, the fourth The focal length of the lens is f4 and the following conditions are satisfied: -1.7 < f23 / f4 < -0.7. 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, the third The combined focal length of the lens and the fourth lens is f34, and the following conditions are satisfied: 0.1 < f12 / f34 < 1.0. 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 first lens The distance from the object side surface to the imaging plane on the optical axis is TL, and the following conditions are satisfied: 0.5 < f / TL < 0.85. 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.

The techniques, means, and other functions employed by the present invention to achieve the above objectives For the sake of efficiency, the following five preferred embodiments are described in detail with reference to the drawings.

100, 200, 300, 400, 500‧ ‧ aperture

110, 210, 310, 410, 510‧‧‧ first lens

111, 211, 311, 411, 511 ‧ ‧ ‧ side surface

112, 212, 312, 412, 512‧‧‧ image side surface

120, 220, 320, 420, 520‧‧‧ second lens

121, 221, 321, 421, 521‧‧‧ ‧ side surface

122, 222, 322, 422, 522‧‧‧ image side surface

130, 230, 330, 430, 530‧‧‧ third lens

131, 231, 331, 431, 531‧‧‧ ‧ side surface

132, 232, 332, 432, 532‧‧‧ image side surface

140, 240, 340, 440, 540‧‧‧ fourth lens

141, 241, 341, 441, 541 ‧ ‧ ‧ side surface

142, 242, 342, 442, 542‧‧‧ side surface

150, 250, 350, 450, 550 ‧ ‧ infrared filter components

160, 260, 360, 460, 560‧ ‧ imaging surface

170, 270, 370, 470, 570‧‧‧ optical axis

f‧‧‧The overall focal length of the wide-angle imaging lens set

Overall aperture value of the Fno‧‧‧ wide-angle imaging lens set

2ω‧‧‧ 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‧‧‧Focus of the fourth lens

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

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

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

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 the first embodiment of the present invention.

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

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.

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

Fig. 4A is a schematic view showing a wide-angle imaging lens group 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.

<First Embodiment>

Please refer to FIG. 1A and FIG. 1B , wherein FIG. 1A illustrates the first embodiment according to the present invention. A schematic view of a wide-angle imaging lens set of the embodiment, and FIG. 1B is a left-to-right sequence of spherical aberration, astigmatism, and distortion of the wide-angle imaging lens group of the first embodiment. As can be seen from FIG. 1A, the wide-angle imaging lens group sequentially includes an aperture 100, a first lens 110, a second lens 120, a third lens 130, and a fourth lens 140 from the object side to the image side.

The first lens 110 has a positive refractive power and is made of a plastic material, and the object side surface 111 thereof The near optical axis 170 is a convex surface, and the image side surface 112 is convex at the near optical axis 170, and the object side surface 111 and the image side surface 112 are all aspherical.

The second lens 120 has a negative refractive power and is made of a plastic material, and the object side surface 121 The near optical axis 170 is a convex surface, and the image side surface 122 is concave at the near optical axis 170, and the object side surface 121 and the image side surface 122 are all aspherical.

The third lens 130 has a positive refractive power and is made of a plastic material, and the object side surface 131 The near optical axis 170 is a concave surface, and the image side surface 132 is convex at the near optical axis 170, and the object side surface 131 and the image side surface 132 are all aspherical.

The fourth lens 140 has a negative refractive power and is made of a plastic material, and its object side surface 141 The near optical axis 170 is a convex surface, and the image side surface 142 is concave at the near optical axis 170, and the object side surface 141 and the image side surface 142 are all aspherical.

The infrared filter element 150 is made of glass and disposed between the fourth lens 140 and the imaging surface 160 without affecting the focal length of the wide-angle imaging lens group.

The equation for the above aspheric curve is 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 170; c is the curvature of the lens surface near the optical axis 170, 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 170, h is the vertical distance of the lens surface from the optical axis 170, k is a conic constant, and A, B, C, D, E, G, ... are high order Aspheric coefficient.

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 overall aperture value (f-number) of the wide-angle imaging lens group is Fno, and the angle of the wide-angle imaging lens group is 2ω, and the numerical value thereof is As follows: f = 1.944 mm (mm); Fno = 2.0; and 2ω = 89 degrees.

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=-0.5899.

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 = -1.9689.

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=-0.7772.

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=1.1615.

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 = 1.5303.

In the wide-angle imaging lens set 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=0.8434.

In the wide-angle imaging lens set of the first embodiment, the second lens 120 and the third mirror The combined focal length of the sheet 130 is f23, the focal length of the fourth lens 140 is f4, and the following condition is satisfied: f23/f4 = -1.0704.

In the wide-angle imaging lens set of the first embodiment, the first lens 110 and the second mirror The combined focal length of the sheet 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=0.8104.

In the wide-angle imaging lens set of the first embodiment, the overall focus of the wide-angle imaging lens group The distance f is f, the distance from the object side surface 111 to the imaging surface 160 of the first lens 110 on the optical axis 170 is TL, and the following condition is satisfied: f/TL = 0.6700.

Refer to Table 1 and Table 2 below for reference.

Table 1 is the detailed structural data of the first embodiment of Fig. 1, wherein the radius of curvature and thickness And the unit of the focal length is mm, and the surfaces 3-10 sequentially represent 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, G, ... are high-order aspheric coefficients. 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>

Please refer to FIG. 2A and FIG. 2B , wherein FIG. 2A illustrates the second embodiment according to the present invention. A schematic diagram of a wide-angle imaging lens set of the embodiment, and FIG. 2B is a left-to-right sequence of spherical aberration, astigmatism, and distortion of the wide-angle imaging lens group of the second embodiment. As can be seen from FIG. 2A, the wide-angle imaging lens group sequentially includes an aperture 200, 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.

The first lens 210 has a positive refractive power and is made of a plastic material, and the object side surface 211 thereof The near optical axis 270 is a convex surface, and the image side surface 212 is convex at the near optical axis 270, and the object side surface 211 and the image side surface 212 are all aspherical.

The second lens 220 has a negative refractive power and is made of a plastic material, and the object side surface 221 The near optical axis 270 is a convex surface, and the image side surface 222 is concave at the near optical axis 270, and the object side surface 221 and the image side surface 222 are all aspherical.

The third lens 230 has a positive refractive power and is made of a plastic material, and its object side surface 231 The near optical axis 270 is a concave surface, and the image side surface 232 is convex at the near optical axis 270, and the object side surface 231 The image side surface 232 is aspherical.

The fourth lens 240 has a negative refractive power and is made of a plastic material, and its object side surface 241 The near optical axis 270 is a convex surface, and the image side surface 242 is concave at the near optical axis 270, and the object side surface 241 and the image side surface 242 are all aspherical.

The infrared filter element 250 is made of glass and disposed on the fourth lens 240. And the imaging surface 260 does not affect the focal length of the wide-angle imaging lens group.

The above equation of the aspheric curve represents the form as in the first embodiment, This will not be repeated.

In the wide-angle imaging lens set of the second embodiment, the overall focus of the wide-angle imaging lens group The distance f is f, the overall aperture value (f-number) of the wide-angle imaging lens group is Fno, and the angle of the wide-angle imaging lens group is 2ω, and the values are as follows: f = 2.129 mm (mm); Fno = 2.0; and 2ω = 85 degrees.

In the wide-angle imaging lens set of the second embodiment, the focal length of the first lens 210 is f1, The second lens 220 has a focal length of f2 and satisfies the following condition: f1/f2 = -0.5530.

In the wide-angle imaging lens set of the second embodiment, the second lens 220 has a focal length of f2. The third lens 230 has a focal length of f3 and satisfies the following condition: f2/f3 = -2.1201.

In the wide-angle imaging lens set of the second embodiment, the focal length of the third lens 230 is f3. The fourth lens 240 has a focal length of f4 and satisfies the following condition: f3/f4 = -0.9122.

In the wide-angle imaging lens set of the second embodiment, the focal length of the first lens 210 is f1, The third lens 230 has a focal length of f3 and satisfies the following condition: f1/f3 = 1.1725.

In the wide-angle imaging lens set of the second embodiment, the second lens 220 has a focal length of f2. The fourth lens 240 has a focal length of f4 and satisfies the following condition: f2/f4 = 1.9340.

In the wide-angle imaging lens set of the second embodiment, the focal length of the first lens 210 is f1, The combined focal length of the second lens 220 and the third lens 230 is f23, and the following condition is satisfied: f1/f23=0.8544.

In the wide-angle imaging lens set of the second embodiment, the second lens 220 and the third mirror The combined focal length of the sheet 230 is f23, and the focal length of the fourth lens 240 is f4, and the following condition is satisfied: f23/f4 = -1.2518.

In the wide-angle imaging lens set of the second embodiment, the first lens 210 and the second mirror The combined focal length of the sheet 220 is f12, and the combined focal length of the third lens 230 and the fourth lens 240 is f34, and the following condition is satisfied: f12/f34=0.4998.

In the wide-angle imaging lens set of the second embodiment, the overall focus of the wide-angle imaging lens group The distance f is f, the distance from the object side surface 211 to the imaging surface 260 of the first lens 210 on the optical axis 270 is TL, and the following condition is satisfied: f/TL = 0.7256.

Refer to Table 3 and Table 4 below. Table 3 is a detailed description of the second embodiment of Figure 2A Structural data. Table 4 shows the aspherical data in the second embodiment.

<Third embodiment>

Please refer to FIG. 3A and FIG. 3B , wherein FIG. 3A illustrates the third embodiment according to the present invention. A schematic view of a wide-angle imaging lens set of the embodiment, and FIG. 3B is a left-to-right sequence of spherical aberration, astigmatism, and distortion of the wide-angle imaging lens group of the third embodiment. As can be seen from FIG. 3A, the wide-angle imaging lens group sequentially includes an aperture 300, 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 first lens 310 has a positive refractive power and is made of a plastic material, and its object side surface 311 The near optical axis 370 is a convex surface, and the image side surface 312 is convex at the near optical axis 370, and the object side surface 311 and the image side surface 312 are all aspherical.

The second lens 320 has a negative refractive power and is made of a plastic material, and the object side surface 321 The near optical axis 370 is a convex surface, and the image side surface 322 is concave at the near optical axis 370, and the object side surface 321 and the image side surface 322 are all aspherical.

The third lens 330 has a positive refractive power and is made of a plastic material, and the object side surface 331 The near optical axis 370 is a concave surface, and the image side surface 332 is convex at the near optical axis 370, and the object side surface 331 and the image side surface 332 are all aspherical.

The fourth lens 340 has a negative refractive power and is made of a plastic material, and the object side surface 341 The near optical axis 370 is a convex surface, and the image side surface 342 is concave at the near optical axis 370, and the object side surface 341 and the image side surface 342 are all aspherical.

The infrared filter element 350 is made of glass and is disposed on the fourth lens 340. And the imaging surface 360 does not affect the focal length of the wide-angle imaging lens group.

The above equation of the aspheric curve represents the form as in the first embodiment, This will not be repeated.

In the wide-angle imaging lens set of the third embodiment, the overall focus of the wide-angle imaging lens group The distance f is f, the overall aperture value (f-number) of the wide-angle imaging lens group is Fno, and the angle of the wide-angle imaging lens group is 2ω, and the values are as follows: f=2.607 mm (mm); Fno=2.0; and 2ω= 85 degrees.

In the wide-angle imaging lens set of the third embodiment, the focal length of the first lens 310 is f1, the focal length of the second lens 320 is f2, and the following condition is satisfied: f1/f2=-0.5847.

In the wide-angle imaging lens group of the third embodiment, the focal length of the second lens 320 is f2, the focal length of the third lens 330 is f3, and the following condition is satisfied: f2/f3 = -2.0616.

In the wide-angle imaging lens group of the third embodiment, the focal length of the third lens 330 is f3, the focal length of the fourth lens 340 is f4, and the following condition is satisfied: f3/f4=-1.0438.

In the wide-angle imaging lens group of the third embodiment, the focal length of the first lens 310 is f1, the focal length of the third lens 330 is f3, and the following condition is satisfied: f1/f3=1.2054.

In the wide-angle imaging lens group of the third embodiment, the focal length of the second lens 320 is f2, the focal length of the fourth lens 340 is f4, and the following condition is satisfied: f2/f4 = 2.1519.

In the wide-angle imaging lens set of the third embodiment, the focal length of the first lens 310 is f1, the combined focal length of the second lens 320 and the third lens 330 is f23, and the following condition is satisfied: f1/f23=0.9019.

In the wide-angle imaging lens set of the third embodiment, the combined focal length of the second lens 320 and the third lens 330 is f23, the focal length of the fourth lens 340 is f4, and the following condition is satisfied: f23/f4=-1.3950.

In the wide-angle imaging lens set of the third embodiment, the combined focal length of the first lens 310 and the second lens 320 is f12, and the combined focal length of the third lens 330 and the fourth lens 340 is f34, and the following conditions are met: F12/f34=0.3571.

In the wide-angle imaging lens group of the third embodiment, the overall focal length of the wide-angle imaging lens group is f, the distance from the object-side surface 311 of the first lens 310 to the imaging surface 360 on the optical axis 370 is TL, and the following conditions are satisfied. :f/TL=0.7559.

Refer to Table 5 and Table 6 below for reference. Table 5 is the detailed structural data of the third embodiment of Fig. 3A. Table 6 shows the aspherical data in the third embodiment.

<Fourth embodiment>

Please refer to FIG. 4A and FIG. 4B , wherein FIG. 4A illustrates the fourth embodiment according to the present invention. A schematic diagram of a wide-angle imaging lens set of the embodiment, and FIG. 4B is a left-to-right sequence of spherical aberration, astigmatism, and distortion of the wide-angle imaging lens group of the fourth embodiment. As can be seen from FIG. 4A, the wide-angle imaging lens group includes an aperture 400, 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 first lens 410 has a positive refractive power and is made of a plastic material, and its object side surface 411 The near optical axis 470 is a convex surface, and the image side surface 412 is convex at the near optical axis 470, and the object side surface 411 The image side 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 470, and the image side surface 422 is concave at the near optical axis 470, 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 470, and the image side surface 432 is convex at the near optical axis 470, 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 470, and the image side surface 442 is concave at the near optical axis 470, and the object side surface 441 and the image side are Surface 442 is aspherical.

The infrared filter element 450 is made of glass and disposed between the fourth lens 440 and the imaging surface 460 without affecting the focal length of the wide-angle imaging lens group.

The equation of the aspheric curve described above is expressed in the form of the first embodiment, and will not be described herein.

In the wide-angle imaging lens group of the fourth embodiment, the overall focal length of the wide-angle imaging lens group is f, the overall aperture value (f-number) of the wide-angle imaging lens group is Fno, and the angle of the wide-angle imaging lens group is 2ω, and the numerical value thereof is As follows: f = 3.903 mm (mm); Fno = 2.4; and 2ω = 79 degrees.

In the wide-angle imaging lens group of the fourth embodiment, the focal length of the first lens 410 is f1, the focal length of the second lens 420 is f2, and the following condition is satisfied: f1/f2=-0.6878.

In the wide-angle imaging lens group of the fourth embodiment, the focal length of the second lens 420 is f2, the focal length of the third lens 430 is f3, and the following condition is satisfied: f2/f3 = -2.2403.

In the wide-angle imaging lens group of the fourth embodiment, the focal length of the third lens 430 is f3, the focal length of the fourth lens 440 is f4, and the following condition is satisfied: f3/f4=-0.9863.

In the wide-angle imaging lens set of the fourth embodiment, the focal length of the first lens 410 is f1, The third lens 430 has a focal length of f3 and satisfies the following condition: f1/f3 = 1.5410.

In the wide-angle imaging lens set of the fourth embodiment, the focal length of the second lens 420 is f2. The fourth lens 440 has a focal length of f4 and satisfies the following condition: f2/f4 = 2.2096.

In the wide-angle imaging lens set of the fourth embodiment, the focal length of the first lens 410 is f1, The combined focal length of the second lens 420 and the third lens 430 is f23, and the following condition is satisfied: f1/f23=1.4183.

In the wide-angle imaging lens set of the fourth embodiment, the second lens 420 and the third mirror The combined focal length of the sheet 430 is f23, and the focal length of the fourth lens 440 is f4, and the following condition is satisfied: f23/f4 = -1.0716.

In the wide-angle imaging lens set of the fourth embodiment, the first lens 410 and the second mirror The combined focal length of the sheet 420 is f12, and the combined focal length of the third lens 430 and the fourth lens 440 is f34, and the following condition is satisfied: f12/f34=0.5146.

In the wide-angle imaging lens group of the fourth embodiment, the overall focus of the wide-angle imaging lens group The distance f is f, the distance from the object side surface 411 to the imaging surface 460 of the first lens 410 on the optical axis 470 is TL, and the following condition is satisfied: f/TL = 0.7965.

Refer to Table 7 and Table 8 below for reference. Table 7 is a detailed description of the fourth embodiment of Figure 4A. Structural data. Table 8 shows the aspherical data in the fourth embodiment.

<Fifth Embodiment>

Please refer to FIG. 5A and FIG. 5B , wherein FIG. 5A illustrates the fifth embodiment according to the present invention. A schematic diagram of a wide-angle imaging lens set of the embodiment, and FIG. 5B is a left-to-right sequence of spherical aberration, astigmatism, and distortion of the wide-angle imaging lens group of the fifth embodiment. As can be seen from FIG. 5A, the wide-angle imaging lens group sequentially includes an aperture 500, 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 first lens 510 has a positive refractive power and is made of a plastic material, and its object side surface 511 The near optical axis 570 is a convex surface, and the image side surface 512 is convex at the near optical axis 570, and the object side surface 511 and the image side surface 512 are all aspherical.

The second lens 520 has a negative refractive power and is made of a plastic material, and the object side surface 521 The near optical axis 570 is a convex surface, and the image side surface 522 is concave at the near optical axis 570, and the object side surface 521 and the image side surface 522 are all aspherical.

The third lens 530 has a positive refractive power and is made of a plastic material, and its object side surface 531 The near optical axis 570 is a concave surface, and the image side surface 532 is convex at the near optical axis 570, and the object side surface 531 and the image side surface 532 are all aspherical.

The fourth lens 540 has a negative refractive power and is made of a plastic material, and its object side surface 541 The near optical axis 570 is a convex surface, and the image side surface 542 is concave at the near optical axis 570, and the object side surface 541 and the image side surface 542 are all aspherical.

The infrared filter element 550 is made of glass and disposed on the fourth lens 540. And the imaging surface 560 does not affect the focal length of the wide-angle imaging lens group.

The above equation of the aspheric curve represents the form as in the first embodiment, This will not be repeated.

In the wide-angle imaging lens group of the fifth embodiment, the overall focus of the wide-angle imaging lens group The distance f is f, the overall aperture value (f-number) of the wide-angle imaging lens group is Fno, and the angle of the wide-angle imaging lens group is 2ω, and the values are as follows: f=3.684 mm (mm); Fno=2.4; and 2ω= 79 degrees.

In the wide-angle imaging lens set of the fifth embodiment, the focal length of the first lens 510 is f1, The second lens 520 has a focal length of f2 and satisfies the following condition: f1/f2 = -0.5737.

In the wide-angle imaging lens set of the fifth embodiment, the focal length of the second lens 520 is f2. The third lens 530 has a focal length of f3 and satisfies the following condition: f2/f3 = -2.8478.

In the wide-angle imaging lens set of the fifth embodiment, the focal length of the third lens 530 is f3. The fourth lens 540 has a focal length of f4 and satisfies the following condition: f3/f4 = -0.9878.

In the wide-angle imaging lens set of the fifth embodiment, the focal length of the first lens 510 is f1, The third lens 530 has a focal length of f3 and satisfies the following condition: f1/f3 = 1.6339.

In the wide-angle imaging lens set of the fifth embodiment, the focal length of the second lens 520 is f2. The fourth lens 540 has a focal length of f4 and satisfies the following condition: f2/f4 = 2.8130.

In the wide-angle imaging lens set of the fifth embodiment, the focal length of the first lens 510 is f1, The combined focal length of the second lens 520 and the third lens 530 is f23, and the following condition is satisfied: f1/f23=1.4778.

In the wide-angle imaging lens set of the fifth embodiment, the second lens 520 and the third mirror The combined focal length of the sheet 530 is f23, and the focal length of the fourth lens 540 is f4, and the following condition is satisfied: f23/f4 = -1.0921.

In the wide-angle imaging lens set of the fifth embodiment, the first lens 510 and the second mirror The combined focal length of the sheet 520 is f12, and the combined focal length of the third lens 530 and the fourth lens 540 is f34, and the following condition is satisfied: f12/f34=0.4245.

In the wide-angle imaging lens group of the fifth embodiment, the overall focus of the wide-angle imaging lens group The distance f is f, the distance from the object side surface 511 of the first lens 510 to the imaging surface 560 on the optical axis 570 is TL, and the following condition is satisfied: f/TL = 0.7142.

Refer to Table 9 and Table 10 below. Table 9 is a fifth embodiment of Figure 5A. Fine structural data. Table 10 shows the aspherical data in the fifth embodiment.

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 material is glass, the degree of freedom of the refractive power configuration of the wide-angle imaging lens group can be increased. In addition, in the wide-angle imaging lens group The object side surface and the image side surface of the lens may be aspherical surfaces, and the aspherical 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 number of lenses used, thereby effectively reducing the number of the lenses. The total length of the wide-angle imaging lens set was invented.

In the wide-angle imaging lens set provided by the present invention, the lens has a refractive power. In other words, if the surface of the lens is convex and the position of the convex surface is not defined, it indicates that the surface of the lens is convex at the near optical axis; if the surface of the lens is concave and the position of the concave surface is not defined, it indicates that the surface of the lens is near The optical axis is concave. In addition, Table 11 is a correspondence table of each relational expression in each Example.

In the above, the above embodiments and the illustrations are only the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, that is, the equal variations and modifications made by the scope of the patent application of the present invention are 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

150‧‧‧Infrared filter element filter element

160‧‧‧ imaging surface

170‧‧‧ optical axis

Claims (10)

A wide-angle imaging lens set comprising: an aperture from the object side to the image side; a first lens having a positive refractive power, the image side surface is a convex surface, and the object side surface and the image side surface of the first lens are at least One side having an aspherical surface; a second lens having a negative refractive power, the image side surface being concave, and the object side surface and the image side surface of the second lens having at least one side being aspherical; a positive refractive power a three-lens having a concave side on the object side surface, and at least one side of the object side surface and the image side surface of the third lens is aspherical; a fourth lens having a negative refractive power, the object side surface is a convex surface, and the first surface At least one side of the object side surface and the image side surface of the four lenses is aspherical, and at least one of the object side surface and the image side surface of the fourth lens has an inflection point. The wide-angle imaging lens set according to claim 1, wherein the first lens has a focal length of f1, the second lens has a focal length of f2, and satisfies the following condition: -0.8 < f1/f2 < -0.4. The wide-angle imaging lens set according to claim 1, wherein the second lens has a focal length of f2, the third lens has a focal length of f3, and satisfies the following condition: -3.5 < f2 / f3 < -1.2. The wide-angle imaging lens set according to claim 1, wherein the third lens has a focal length of f3, the fourth lens has a focal length of f4, and satisfies the following condition: -1.2 < f3 / f4 < -0.5. The wide-angle imaging lens set according to claim 1, wherein the first lens has a focal length of f1, the third lens has a focal length of f3, and satisfies the following condition: 0.8 < f1/f3 < 2.0. The wide-angle imaging lens set according to claim 1, wherein the second lens has a focal length of f2, the fourth lens has a focal length of f4, and satisfies the following condition: 1.0 < f2 / f4 < 3.5. The wide-angle imaging lens set according to claim 1, wherein a focal length of the first lens is f1, a combined focal length of the second lens and the third lens is f23, and the following condition is satisfied: 0.5< F1/f23<1.8. 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, and the focal length of the fourth lens is f4, and the following condition is satisfied: -1.7<f23/ F4<-0.7. 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, and the combined focal length of the third lens and the fourth lens is f34, and the following conditions are met. :0.1<f12/f34<1.0. The wide-angle imaging lens set according to claim 1, wherein the wide-angle imaging lens group has an overall focal length f, and the distance from the object-side surface of the first lens to the imaging surface on the optical axis is TL, and satisfies the following Conditions: 0.5 < f / TL < 0.85.