TWI716220B - Three-piece compact optical lens system - Google Patents

Abstract

A three-piece compact optical lens system includes, in order from the object side to the image side: a flat panel assembly made of glass, a first lens element with a negative refractive power; a stop; a second lens element with a positive refractive power, and a third lens element with a refractive power. Wherein the system has a total of three lens elements with refractive power, a distance from an object in the image plane of the flat panel to an image plane along an optical axis is OTL, a distance from an image-side surface of the flat panel assembly to the image plane along the optical axis is PTL, an image height of the image plane is Y, a height of a main light of the image height corresponding to the image-side surface of the flat panel assembly is P, satisfying the relations: 2.5 mm < PTL < 4.5 mm; 2.2 < P/Y < 7.0; 4 < OTL/Y < 12.

Description

Three-piece thin imaging lens group

The present invention relates to a lens group, in particular to a three-piece thin imaging lens group applied to electronic products.

The biometric system based on the unique biological characteristics of each creature is often used because of its uniqueness, universality, permanence, measurability, convenience, acceptance, and non-deception. It can be used on existing mobile devices currently on the market, and can even be used on future electronic devices. However, the current biometric identification systems equipped with mobile devices mostly use the capacitance principle, which can reduce the volume required by the biometric identification system, but the circuit structure is too complicated, which makes the manufacturing cost too high and the relative product unit price is also high.

Although there are traditional biometric systems that use optical imaging principles, such as fingerprint recognition and vein recognition, the traditional biometric system has the problem of being too large, which makes it difficult for electronic devices equipped with biometric systems to be miniaturized and even more difficult to carry.

In view of this, how to provide a thin imaging lens set that can be used as a biometric system and can be mounted on an electronic device so that the electronic device can be miniaturized for portability is a technical bottleneck that is urgently to be overcome.

The purpose of the present invention is to provide a three-element thin imaging lens group, especially a three-element thin imaging lens group that helps reduce the distance between the subject and the three-element thin imaging lens group, effectively reduces the volume, and maintains its miniaturization Imaging lens group.

Another object of the present invention is to provide a three-piece thin imaging lens set, especially an effective collection of large-angle light, so that the three-piece thin imaging lens set can receive a larger range of images and achieve recognition within a very short object distance Effective three-element thin imaging lens group.

In order to achieve the foregoing objective, a three-piece thin imaging lens set according to the present invention includes in order from the object side to the image side: a flat element made of glass; a first lens having a negative refractive power; At least one of the object side surface and the image side surface of a lens is aspherical; an aperture; a second lens with positive refractive power, the object side surface of the second lens is convex near the optical axis, and the second lens At least one of the object side surface and the image side surface is aspherical; and a third lens having refractive power, and at least one of the object side surface and the image side surface of the third lens is aspherical; Among them, the three-piece thin imaging lens group has three lenses with refractive power. The distance from an object on the object side surface of the flat element to an imaging surface on the optical axis is OTL, and the image of the flat element The distance from the side surface to the imaging surface on the optical axis is PTL, the image height of the imaging surface is Y, the chief ray of the image height of the imaging surface corresponds to the object height of the image side surface of the flat panel element, and the following conditions are met: 2.5 km Centimeter<PTL<4.5mm; 2.2<P/Y<7.0; 4<OTL/Y<12.

Preferably, the overall focal length of the three-piece thin imaging lens set is f, and the focal length of the first lens is f1, and the following conditions are satisfied: -0.86<f/f1<-0.22. In this way, the refractive power configuration of the three-piece thin imaging lens group can be balanced to effectively correct the aberration of the three-piece thin imaging lens group, while reducing the sensitivity of the three-piece thin imaging lens group.

Preferably, the overall focal length of the three-piece thin imaging lens group is f, and the focal length of the second lens is f2, and the following conditions are satisfied: 0.05<f/f2<1.27. In this way, the refractive power configuration of the three-piece thin imaging lens group can be balanced to effectively correct the aberration of the three-piece thin imaging lens group, while reducing the sensitivity of the three-piece thin imaging lens group.

Preferably, the overall focal length of the three-piece thin imaging lens set is f, and the focal length of the third lens is f3, and the following conditions are satisfied: -0.17<f/f3<0.82. In this way, the refractive power configuration of the three-piece thin imaging lens group can be balanced to effectively correct the aberration of the three-piece thin imaging lens group, while reducing the sensitivity of the three-piece thin imaging lens group.

Preferably, the overall focal length of the three-piece thin imaging lens group is f, and the combined focal length of the second lens and the third lens is f23, and the following conditions are satisfied: 0.45<f/f23<1.04. Thereby, the three-piece thin imaging lens group can strike a balance between shortening the total optical length and correcting aberrations.

Preferably, the focal length of the first lens is f1, and the combined focal length of the second lens and the third lens is f23, and the following conditions are met: -3.07<f1/f23<-0.63. As a result, the resolution capability of the three-piece thin imaging lens set is significantly improved.

Preferably, the focal length of the first lens is f1, and the radius of curvature of the object side surface of the first lens is R1, and the following conditions are satisfied: -0.13<f1/R1<4.95. This can help reduce distortion.

Preferably, the focal length of the first lens is f1, the radius of curvature of the image side surface of the first lens is R2, and the following conditions are satisfied: -2.41<f1/R2<1.93. Thereby, the curvature of the image side surface of the first lens is more suitable, which helps to shorten the total length of the three-piece thin imaging lens group.

Preferably, the focal length of the second lens is f2, the radius of curvature of the object side surface of the second lens is R3, and the following conditions are satisfied: 0.25<f2/R3<5.64. This will help reduce the sensitivity of the system and effectively increase the production yield.

Preferably, the focal length of the second lens is f2, the radius of curvature of the image side surface of the second lens is R4, and the following conditions are satisfied: -2.04<f2/R4<3.87. Thereby, the peripheral curvature of the image side surface of the second lens can be further reduced, and the characteristic of reducing stray light can be more realized.

Preferably, the focal length of the third lens is f3, and the radius of curvature of the object side surface of the third lens is R5, and the following conditions are satisfied: -56.34<f3/R5<2.58. This corrects the magnification of imaging.

Preferably, the focal length of the third lens is f3, the radius of curvature of the image side surface of the third lens is R6, and the following conditions are satisfied: -40.72<f3/R6<0.49. This corrects the magnification of imaging.

Preferably, the radius of curvature of the object side surface of the first lens is R1, and the radius of curvature of the image side surface of the first lens is R2, and the following conditions are satisfied: -38.2<R1/R2<276.13. Thereby, the spherical aberration and astigmatism of the three-piece thin imaging lens group can be reduced.

Preferably, the radius of curvature of the object side surface of the second lens is R3, and the radius of curvature of the image side surface of the second lens is R4, and the following conditions are satisfied: -5.91<R3/R4<0.82. Thereby, the astigmatism of the three-piece thin imaging lens group can be reduced.

Preferably, the radius of curvature of the object side surface of the third lens is R5, and the radius of curvature of the image side surface of the third lens is R6, and the following conditions are satisfied: -2.86<R5/R6<22.19. Thereby, the curvature configuration of the third lens surface is effectively balanced to achieve a balance between the angle of view and the total length.

Preferably, the overall focal length of the three-piece thin imaging lens set is f, and the distance from the object on the object side surface of the flat panel element to the imaging surface on the optical axis is OTL, and the following conditions are met: 7.71< OTL/f<17.62. In this way, it is beneficial to maintain the miniaturization and long focus of the three-piece thin imaging lens set for mounting on thin and light electronic products.

Preferably, the focal length of the first lens is f1, the focal length of the second lens is f2, and the focal length of the third lens is f3, and the following conditions are met: -4.56 mm ^-2 <(f1+f2+f3 )/(f1*f2*f3)<-0.53mm ^-2 . In this way, the object can be well imaged on the imaging surface with small aberration and high contrast at a short object distance.

Preferably, the object side surface of the first lens is a concave surface near the optical axis. In this way, a large angle of light can be effectively collected within a very short object distance to receive a larger range of images.

Preferably, the image side surface of the second lens is a convex surface near the optical axis. In this way, the image resolution of the three-piece thin imaging lens group is improved.

Preferably, the image side surface of the third lens is a convex surface near the optical axis. In this way, the aberration under the large viewing angle is corrected and compensated.

Regarding the technologies, means and other effects used by the present invention to achieve the above-mentioned objects, fourteen preferred and feasible embodiments are described in detail below in conjunction with the drawings.

100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400: aperture

110, 210, 310, 410, 510, 610, 710, 810, 910, 1010, 1110, 1210, 1310, 1410: first lens

111, 211, 311, 411, 511, 611, 711, 811, 911, 1011, 1111, 1211, 1311, 1411: Object side surface

112, 212, 312, 412, 512, 612, 712, 812, 912, 1012, 1112, 1212, 1312, 1412: image side surface

120, 220, 320, 420, 520, 620, 720, 820, 920, 1020, 1120, 1220, 1320, 1420: second lens

121, 221, 321, 421, 521, 621, 721, 821, 921, 1021, 1121, 1221, 1321, 1421: Object side surface

122, 222, 322, 422, 522, 622, 722, 822, 922, 1022, 1122, 1222, 1322, 1422: Image side surface

130, 230, 330, 430, 530, 630, 730, 830, 930, 1030, 1130, 1230, 1330, 1430: third lens

131, 231, 331, 431, 531, 631, 731, 831, 931, 1031, 1131, 1231, 1331, 1431: Object side surface

132, 232, 332, 432, 532, 632, 732, 832, 932, 1032, 1132, 1232, 1332, 1432: Image side surface

160, 260, 360, 460, 560, 660, 760, 860, 960, 1060, 1160, 1260, 1360, 1460: flat element

170, 270, 370, 470, 570, 670, 770, 870, 970, 1070, 1170, 1270, 1370, 1470: infrared filter

180, 280, 380, 480, 580, 680, 780, 880, 980, 1080, 1180, 1280, 1380, 1480: imaging surface

190, 290, 390, 490, 590, 690, 790, 890, 990, 1090, 1190, 1290, 1390, 1490: optical axis

f: The focal length of the three-element thin imaging lens group

Fno: The aperture value of the three-element thin imaging lens group

FOV: The largest angle of view in the three-element thin imaging lens group

f1: focal length of the first lens

f2: the focal length of the second lens

f3: focal length of the third lens

R1: The radius of curvature of the object side surface of the first lens

R2: The radius of curvature of the image side surface of the first lens

R3: The radius of curvature of the object side surface of the second lens

R4: The radius of curvature of the image side surface of the second lens

R5: The radius of curvature of the object side surface of the third lens

R6: The radius of curvature of the image side surface of the third lens

OTL: The distance from the subject on the object side surface of the flat panel element to the imaging surface on the optical axis

PTL: The distance from the image side surface of the flat panel element to the imaging surface on the optical axis

Y: image height

P: The chief ray of the imaging surface image height corresponds to the object height on the image side surface of the flat panel element

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

Fig. 1B is a partial enlarged view of Fig. 1A.

FIG. 1C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the first embodiment from left to right.

2A is a schematic diagram of a three-piece thin imaging lens set according to the second embodiment of the present invention.

Fig. 2B is a partial enlarged view of Fig. 2A.

FIG. 2C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the second embodiment from left to right.

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

Fig. 3B is a partial enlarged view of Fig. 3A.

Fig. 3C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the third embodiment from left to right.

4A is a schematic diagram of a three-piece thin imaging lens group according to the fourth embodiment of the present invention.

Fig. 4B is a partial enlarged view of Fig. 4A.

FIG. 4C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the fourth embodiment from left to right.

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

Fig. 5B is a partial enlarged view of Fig. 5A.

FIG. 5C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the fifth embodiment from left to right.

Fig. 6A is a schematic diagram of a three-piece thin imaging lens set according to a sixth embodiment of the present invention.

Fig. 6B is a partial enlarged view of Fig. 6A.

Fig. 6C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the sixth embodiment from left to right.

FIG. 7A is a schematic diagram of a three-piece thin imaging lens group according to a seventh embodiment of the present invention.

Fig. 7B is a partial enlarged view of Fig. 7A.

Fig. 7C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the seventh embodiment from left to right.

FIG. 8A is a schematic diagram of a three-piece thin imaging lens set of the eighth embodiment of the present invention.

Fig. 8B is a partial enlarged view of Fig. 8A.

FIG. 8C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the eighth embodiment from left to right.

FIG. 9A is a schematic diagram of a three-piece thin imaging lens group in the ninth embodiment of the present invention.

Fig. 9B is a partial enlarged view of Fig. 9A.

FIG. 9C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the ninth embodiment from left to right.

FIG. 10A is a schematic diagram of a three-piece thin imaging lens set of the tenth embodiment of the present invention.

Fig. 10B is a partial enlarged view of Fig. 10A.

Fig. 10C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the tenth embodiment from left to right.

FIG. 11A is a schematic diagram of a three-piece thin imaging lens group in the eleventh embodiment of the present invention.

Fig. 11B is a partial enlarged view of Fig. 11A.

Fig. 11C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the eleventh embodiment from left to right.

Fig. 12A is a schematic diagram of a three-piece thin imaging lens group in the twelfth embodiment of the present invention.

Fig. 12B is a partial enlarged view of Fig. 12A.

Fig. 12C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the twelfth embodiment from left to right.

FIG. 13A is a schematic diagram of a three-piece thin imaging lens group in the thirteenth embodiment of the present invention.

Fig. 13B is a partial enlarged view of Fig. 13A.

FIG. 13C is a graph showing the curvature of field and distortion of the three-piece thin imaging lens set in the thirteenth embodiment from left to right.

Fig. 14A is a schematic diagram of a three-piece thin imaging lens set of the fourteenth embodiment of the present invention.

Fig. 14B is a partial enlarged view of Fig. 14A.

Fig. 14C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set of the fourteenth embodiment from left to right.

<First embodiment>

Please refer to FIG. 1A, FIG. 1B and FIG. 1C. FIG. 1A is a schematic diagram of a three-piece thin imaging lens set according to a first embodiment of the present invention. FIG. 1B is a partial enlarged view of FIG. 1A. FIG. 1C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the first embodiment from left to right. It can be seen from Figure 1A and Figure 1B that the three-piece thin imaging lens set includes flat elements in sequence from the object side to the image side. 160, a first lens 110, an aperture 100, a second lens 120, a third lens 130, an infrared filter 170, and an imaging surface 180, wherein the three lenses with refractive power in the three-piece thin imaging lens group are three Pieces (110, 120, 130). The aperture 100 is arranged between the first lens 110 and the second lens 120.

The plate element 160 is made of glass, which is arranged between an object O and the first lens 110, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 110 has a negative refractive power and is made of plastic. Its object side surface 111 is convex near the optical axis 190, and its image side surface 112 is concave near the optical axis 190, and the object side surface 111 and the image side The surfaces 112 are all aspherical.

The second lens 120 has positive refractive power and is made of plastic. Its object side surface 121 is convex near the optical axis 190, and its image side surface 122 is convex near the optical axis 190, and the object side surface 121 and the image side are convex. The surfaces 122 are all aspherical.

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

The infrared filter 170 is made of glass, which is arranged between the third lens 130 and the imaging surface 180 and does not affect the focal length of the three-piece thin imaging lens group.

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

Where z is the position value referenced by the apex of the surface at a height h along the optical axis 190; c is the curvature of the lens surface close to 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 close to the optical axis 190, h is the vertical distance between the lens surface and the optical axis 190, k is the conic constant, and A, B, C, D, E, F, G,... … Are high-order aspheric coefficients.

In the three-piece thin imaging lens group of the first embodiment, the focal length of the three-piece thin imaging lens group is f, the aperture value (f-number) of the three-piece thin imaging lens group is Fno, and the three-piece thin imaging lens The maximum field of view (angle of view) in the film set is FOV, and its values are as follows: f=0.47 (mm); Fno=1.34; and FOV=145.8 (degree).

In the three-piece thin imaging lens set of the first embodiment, the distance from an object O on the object side surface 161 of the flat panel element 160 to an imaging surface 180 on the optical axis 190 is OTL, and the flat panel element 160 The distance from the image side surface 162 to the imaging surface 180 on the optical axis 190 is PTL, the image height of the imaging surface 180 is Y, and the chief ray of the image height of the imaging surface 180 corresponds to the object height of the image side surface 162 of the flat element 160 as P , And meet the following conditions: PTL=3.71mm; P/Y=4.21; OTL/Y=5.29.

In the three-piece thin imaging lens group of the first embodiment, the focal length of the three-piece thin imaging lens group is f, and the focal length of the first lens 110 is f1, and the following condition is satisfied: f/f1=-0.55.

In the three-piece thin imaging lens group of the first embodiment, the focal length of the three-piece thin imaging lens group is f, and the focal length of the second lens 120 is f2, and the following condition is satisfied: f/f2=0.27.

In the three-piece thin imaging lens group of the first embodiment, the focal length of the three-piece thin imaging lens group is f, and the focal length of the third lens 130 is f3, and the following conditions are satisfied: f/f3=0.55.

In the three-piece thin imaging lens group of the first embodiment, the focal length of the three-piece thin imaging lens group is f, and the combined focal length of the second lens 120 and the third lens 130 is f23, and the following conditions are met: f/ f23=0.67.

In the three-piece thin 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 conditions are met: f1/f23=- 1.21.

In the three-piece thin imaging lens group of the first embodiment, the focal length of the first lens 110 is f1, the radius of curvature of the object side surface 111 of the first lens 110 is R1, and the following conditions are met: f1/R1=-0.11 .

In the three-piece thin imaging lens set of the first embodiment, the focal length of the first lens 110 is f1, the radius of curvature of the image side surface 112 of the first lens 110 is R2, and the following conditions are met: f1/R2=-2.01 .

In the three-piece thin imaging lens set of the first embodiment, the focal length of the second lens 120 is f2, the radius of curvature of the object side surface 121 of the second lens 120 is R3, and the following conditions are met: f2/R3=1.24.

In the three-piece thin imaging lens set of the first embodiment, the focal length of the second lens 120 is f2, the radius of curvature of the image side surface 122 of the second lens 120 is R4, and the following conditions are met: f2/R4=-0.73 .

In the three-piece thin imaging lens set of the first embodiment, the focal length of the third lens 130 is f3, the radius of curvature of the object side surface 131 of the third lens 130 is R5, and the following conditions are met: f3/R5=1.10.

In the three-piece thin imaging lens set of the first embodiment, the focal length of the third lens 130 is f3, the radius of curvature of the image side surface 132 of the third lens 130 is R6, and the following conditions are met: f3/R6=-0.93 .

In the three-piece thin imaging lens set of the first embodiment, the radius of curvature of the object side surface 111 of the first lens 110 is R1, and the radius of curvature of the image side surface 112 of the first lens 110 is R2, and the following conditions are met: R1 /R2=18.66.

In the three-piece thin imaging lens set of the first embodiment, the radius of curvature of the object side surface 121 of the second lens 120 is R3, and the radius of curvature of the image side surface 122 of the second lens 120 is R4, and the following conditions are met: R3 /R4=-0.59.

In the three-piece thin imaging lens group of the first embodiment, the radius of curvature of the object side surface 131 of the third lens 130 is R5, and the radius of curvature of the image side surface 132 of the third lens 130 is R6, and the following conditions are met: R5 /R6=-0.84.

Refer to Table 1 and Table 2 below for cooperation.

Table 1 shows the detailed structure data of the first embodiment in FIGS. 1A and 1B, in which the unit of the radius of curvature, the thickness and the focal length is mm, and the surface 0-12 indicates the surface from the object side to the image side in sequence. Table 2 is the aspheric surface data in the first embodiment, where k represents the conical surface coefficient in the aspheric curve equation, and A, B, C, D, E, F, G, ... are high-order aspheric surface coefficients. In addition, the following example tables correspond to each implementation The schematic diagram and the aberration curve diagram of the example, and the definitions of the data in the table 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, FIG. 2B and FIG. 2C, where FIG. 2A is a schematic diagram of a three-piece thin imaging lens set according to the second embodiment of the present invention, and FIG. 2B is a partial enlarged view of FIG. 2A. FIG. 2C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the second embodiment from left to right. It can be seen from FIGS. 2A and 2B that the three-piece thin imaging lens set includes a flat panel element 260, a first lens 210, an aperture 200, a second lens 220, a third lens 230, and an infrared filter in sequence from the object side to the image side. The light sheet 270 and the imaging surface 280, wherein the three-piece thin imaging lens group has three lenses (210, 220, 230) with refractive power. The aperture 200 is arranged between the first lens 210 and the second lens 220.

The plate element 260 is made of glass, which is arranged between a subject O and the first lens 210, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 210 has a negative refractive power and is made of plastic. Its object side surface 211 is concave near the optical axis 290, and its image side surface 212 is concave near the optical axis 290, and the object side surface 211 and the image side are concave. The surfaces 212 are all aspherical.

The second lens 220 has a positive refractive power and is made of plastic. Its object side surface 221 is convex near the optical axis 290, and its image side surface 222 is convex near the optical axis 290, and the object side surface 221 and the image side are convex. The surfaces 222 are all aspherical.

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

The infrared filter 270 is made of glass, which is arranged between the third lens 230 and the imaging surface 280 and does not affect the focal length of the three-piece thin imaging lens group.

Refer to Table 3 and Table 4 below for cooperation.

In the second embodiment, the curve equation of the aspheric surface is expressed 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 will not be repeated here.

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

<Third Embodiment>

Please refer to FIGS. 3A, 3B and 3C. FIG. 3A is a schematic diagram of a three-piece thin imaging lens set according to a third embodiment of the present invention, and FIG. 3B is a partial enlarged view of FIG. 3A. Fig. 3C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the third embodiment from left to right. It can be seen from FIGS. 3A and 3B that the three-piece thin imaging lens set includes a flat element 360, a first lens 310, an aperture 300, a second lens 320, a third lens 330, and an infrared filter in sequence from the object side to the image side. The light sheet 370 and the imaging surface 380, wherein the three-piece thin imaging lens group has three lenses (310, 320, 330) with refractive power. The aperture 300 is arranged between the first lens 310 and the second lens 320.

The flat element 360 is made of glass, which is arranged between an object O and the first lens 310, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 310 has a negative refractive power and is made of plastic. Its object-side surface 311 is concave near the optical axis 390, and its image-side surface 312 is concave near the optical axis 390. The object-side surface 311 and the image side are concave. The surfaces 312 are all aspherical.

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

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

The infrared filter 370 is made of glass material, which is arranged between the third lens 330 and the imaging surface 380 and does not affect the focal length of the three-piece thin imaging lens group.

Refer to Table 5 and Table 6 below for cooperation.

In the third embodiment, the curve equation of the aspheric surface is expressed 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 will not be repeated here.

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

<Fourth Embodiment>

Please refer to FIG. 4A, FIG. 4B and FIG. 4C. FIG. 4A is a schematic diagram of a three-piece thin imaging lens assembly according to a fourth embodiment of the present invention, and FIG. 4B is a partial enlarged view of FIG. 4A. FIG. 4C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the fourth embodiment from left to right. It can be seen from FIGS. 4A and 4B that the three-piece thin imaging lens set includes a flat element 460, a first lens 410, an aperture 400, a second lens 420, a third lens 430, and an infrared filter in sequence from the object side to the image side. The light sheet 470 and the imaging surface 480, wherein the three-piece thin imaging lens group has three refractive lenses (410, 420, 430). The aperture 400 is arranged between the first lens 410 and the second lens 420.

The plate element 460 is made of glass, which is arranged between an object O and the first lens 410, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 410 has negative refractive power and is made of plastic. Its object side surface 411 is concave near the optical axis 490, and its image side surface 412 is concave near the optical axis 490. The object side surface 411 and the image side are concave. The surfaces 412 are all aspherical.

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

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

The infrared filter 470 is made of glass, which is disposed between the third lens 430 and the imaging surface 480 and does not affect the focal length of the three-piece thin imaging lens group.

Refer to Table 7 and Table 8 below for cooperation.

In the fourth embodiment, the curve equation of the aspheric surface is expressed 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 will not be repeated here.

With Table 7 and Table 8, the following data can be calculated:

<Fifth Embodiment>

Please refer to FIG. 5A, FIG. 5B and FIG. 5C. FIG. 5A is a schematic diagram of a three-piece thin imaging lens set according to a fifth embodiment of the present invention, and FIG. 5B is a partial enlarged view of FIG. 5A. FIG. 5C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the fifth embodiment from left to right. It can be seen from Fig. 5A and Fig. 5B that the three-piece thin imaging lens group includes flat elements in sequence from the object side to the image side 560, a first lens 510, an aperture 500, a second lens 520, a third lens 530, an infrared filter 570, and an imaging surface 580, wherein the lenses with refractive power in the three-piece thin imaging lens group are three Pieces (510, 520, 530). The aperture 500 is arranged between the first lens 510 and the second lens 520.

The plate element 560 is made of glass, which is arranged between a subject O and the first lens 510, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 510 has negative refractive power and is made of plastic. Its object side surface 511 is concave near the optical axis 590, and its image side surface 512 is convex near the optical axis 590, and the object side surface 511 and the image side The surfaces 512 are all aspherical.

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

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

The infrared filter 570 is made of glass material, which is arranged between the third lens 530 and the imaging surface 580 and does not affect the focal length of the three-piece thin imaging lens group.

Refer to Table 9 and Table 10 below for cooperation.

In the fifth embodiment, the aspherical curve equation is expressed 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 will not be repeated here.

In conjunction with Table 9 and Table 10, the following data can be calculated:

<Sixth Embodiment>

Please refer to FIGS. 6A, 6B and 6C. FIG. 6A is a schematic diagram of a three-piece thin imaging lens set according to a sixth embodiment of the present invention, and FIG. 6B is a partial enlarged view of FIG. 6A. Fig. 6C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the sixth embodiment from left to right. It can be seen from FIGS. 6A and 6B that the three-piece thin imaging lens set includes a flat element 660, a first lens 610, an aperture 600, a second lens 620, a third lens 630, and an infrared filter in sequence from the object side to the image side. The light sheet 670 and the imaging surface 680, wherein the three-piece thin imaging lens group has three lenses (610, 620, 630) with refractive power. The aperture 600 is arranged between the first lens 610 and the second lens 620.

The plate element 660 is made of glass, which is arranged between a subject O and the first lens 610, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 610 has a negative refractive power and is made of plastic material. Its object side surface 611 is concave near the optical axis 690, and its image side surface 612 is concave near the optical axis 690. The object side surface 611 and the image side The surfaces 612 are all aspherical.

The second lens 620 has positive refractive power and is made of plastic. Its object-side surface 621 is convex near the optical axis 690, and its image-side surface 622 is convex near the optical axis 690, and the object-side surface 621 and the image side The surfaces 622 are all aspherical.

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

The infrared filter 670 is made of glass, which is arranged between the third lens 630 and the imaging surface 680 and does not affect the focal length of the three-piece thin imaging lens group.

Refer to Table 11 and Table 12 below for cooperation.

In the sixth embodiment, the curve equation of the aspheric surface is expressed 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 will not be repeated here.

With Table 11 and Table 12, the following data can be calculated:

<Seventh Embodiment>

Please refer to FIGS. 7A, 7B and 7C. FIG. 7A is a schematic diagram of a three-piece thin imaging lens set according to a seventh embodiment of the present invention, and FIG. 7B is a partial enlarged view of FIG. 7A. Fig. 7C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the seventh embodiment from left to right. It can be seen from FIGS. 7A and 7B that the three-piece thin imaging lens set includes a flat element 760, a first lens 710, an aperture 700, a second lens 720, a third lens 730, and an infrared filter in sequence from the object side to the image side. The light sheet 770, and the imaging surface 780, wherein the three-piece thin imaging lens group has three refractive lenses (710, 720, 730). The aperture 700 is arranged between the first lens 710 and the second lens 720.

The plate element 760 is made of glass, which is arranged between a subject O and the first lens 710, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 710 has a negative refractive power and is made of plastic. Its object side surface 711 is concave near the optical axis 790, and its image side surface 712 is concave near the optical axis 790, and the object side surface 711 and the image side are concave. The surfaces 712 are all aspherical.

The second lens 720 has positive refractive power and is made of plastic. Its object side surface 721 is convex near the optical axis 790, and its image side surface 722 is convex near the optical axis 790. The object side surface 721 and the image side The surfaces 722 are all aspherical.

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

The infrared filter 770 is made of glass material, which is disposed between the third lens 730 and the imaging surface 780 and does not affect the focal length of the three-piece thin imaging lens group.

Refer to Table 13 and Table 14 below for cooperation.

In the seventh embodiment, the aspherical curve equation is expressed 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 will not be repeated here.

With Table 13 and Table 14, the following data can be calculated:

<Eighth Embodiment>

Please refer to FIG. 8A, FIG. 8B and FIG. 8C. FIG. 8A is a schematic diagram of a three-piece thin imaging lens set according to an eighth embodiment of the present invention, and FIG. 8B is a partial enlarged view of FIG. 8A. FIG. 8C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the eighth embodiment from left to right. It can be seen from FIGS. 8A and 8B that the three-piece thin imaging lens group includes a flat element 860, a first lens 810, an aperture 800, a second lens 820, a third lens 830, and an infrared filter in sequence from the object side to the image side. The light sheet 870 and the imaging surface 880, wherein the three-piece thin imaging lens group has three refractive lenses (810, 820, 830). The aperture 800 is arranged between the first lens 810 and the second lens 820.

The flat element 860 is made of glass, which is arranged between a subject O and the first lens 810, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 810 has negative refractive power and is made of plastic. Its object-side surface 811 is concave near the optical axis 890, and its image-side surface 812 is concave near the optical axis 890, and the object-side surface 811 and the image side are concave. The surfaces 812 are all aspherical.

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

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

The infrared filter 870 is made of glass material, which is arranged between the third lens 830 and the imaging surface 880 and does not affect the focal length of the three-piece thin imaging lens group.

Refer to Table 15 and Table 16 below for cooperation.

In the eighth embodiment, the curve equation of the aspheric surface is expressed 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 will not be repeated here.

With Table 15 and Table 16, the following data can be calculated:

<Ninth Embodiment>

Please refer to FIGS. 9A, 9B and 9C. FIG. 9A is a schematic diagram of a three-piece thin imaging lens set according to a ninth embodiment of the present invention, and FIG. 9B is a partial enlarged view of FIG. 9A. FIG. 9C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the ninth embodiment from left to right. It can be seen from FIGS. 9A and 9B that the three-piece thin imaging lens group includes a flat element 960, a first lens 910, an aperture 900, a second lens 920, a third lens 930, and an infrared filter in order from the object side to the image side. The light sheet 970 and the imaging surface 980, wherein the three-piece thin imaging lens group has three refractive lenses (910, 920, and 930). The aperture 900 is disposed between the first lens 910 and the second lens 920.

The flat element 960 is made of glass, which is arranged between a subject O and the first lens 910, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 910 has a negative refractive power and is made of plastic. Its object-side surface 911 is concave near the optical axis 990, and its image-side surface 912 is concave near the optical axis 990, and the object-side surface 911 and the image side The surfaces 912 are all aspherical.

The second lens 920 has a positive refractive power and is made of plastic. Its object side surface 921 is convex near the optical axis 990, and its image side surface 922 is convex near the optical axis 990, and the object side surface 921 and the image side are convex. The surfaces 922 are all aspherical.

The third lens 930 has positive refractive power and is made of plastic. Its object-side surface 931 is concave near the optical axis 990, and its image-side surface 932 is convex near the optical axis 990, and the object-side surface 931 and the image side are convex. The surfaces 932 are all aspherical.

The infrared filter 970 is made of glass, and is disposed between the third lens 930 and the imaging surface 980 and does not affect the focal length of the three-piece thin imaging lens group.

Refer to Table 17 and Table 18 below for cooperation.

In the ninth embodiment, the aspherical curve equation is expressed 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 will not be repeated here.

In conjunction with Table 17 and Table 18, the following data can be calculated:

<Tenth Embodiment>

Please refer to FIGS. 10A, 10B and 10C. FIG. 10A is a schematic diagram of a three-piece thin imaging lens set according to a tenth embodiment of the present invention, and FIG. 10B is a partial enlarged view of FIG. 10A. Figure 10C From left to right are the graphs of field curvature and distortion tolerance of the three-piece thin imaging lens set of the tenth embodiment. It can be seen from FIGS. 10A and 10B that the three-piece thin imaging lens set includes a flat element 1060, a first lens 1010, an aperture 1000, a second lens 1020, a third lens 1030, and an infrared filter in sequence from the object side to the image side. The light sheet 1070 and the imaging surface 1080, wherein the three-piece thin imaging lens group has three refractive lenses (1010, 1020, 1030). The aperture 1000 is arranged between the first lens 1010 and the second lens 1020.

The flat element 1060 is made of glass, which is arranged between an object O and the first lens 1010, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 1010 has negative refractive power and is made of plastic. Its object side surface 1011 is concave near the optical axis 1090, and its image side surface 1012 is concave near the optical axis 1090. The object side surface 1011 and the image side The surfaces 1012 are all aspherical.

The second lens 1020 has a positive refractive power and is made of plastic. Its object side surface 1021 is convex near the optical axis 1090, and its image side surface 1022 is convex near the optical axis 1090, and the object side surface 1021 and the image side The surfaces 1022 are all aspherical.

The third lens 1030 has positive refractive power and is made of plastic. Its object side surface 1031 is convex near the optical axis 1090, and its image side surface 1032 is convex near the optical axis 1090, and the object side surface 1031 and the image side The surfaces 1032 are all aspherical.

The infrared filtering filter 1070 is made of glass, which is arranged between the third lens 1030 and the imaging surface 1080 and does not affect the focal length of the three-piece thin imaging lens group.

Refer to Table 19 and Table 20 below for cooperation.

In the tenth embodiment, the curve equation of the aspheric surface is expressed 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 will not be repeated here.

With Table 19 and Table 20, the following data can be calculated:

<Eleventh Embodiment>

Please refer to FIGS. 11A, 11B, and 11C. FIG. 11A is a schematic diagram of a three-piece thin imaging lens set according to an eleventh embodiment of the present invention, and FIG. 11B is a partial enlarged view of FIG. 11A. Fig. 11C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the eleventh embodiment from left to right. It can be seen from FIGS. 11A and 11B that the three-piece thin imaging lens set includes a flat element 1160, a first lens 1110, an aperture 1100, a second lens 1120, a third lens 1130, and an infrared filter in order from the object side to the image side. The light sheet 1170 and the imaging surface 1180, wherein the three-piece thin imaging lens group has three refractive lenses (1110, 1120, 1130). The aperture 1100 is arranged between the first lens 1110 and the second lens 1120.

The flat element 1160 is made of glass, which is arranged between a subject O and the first lens 1110, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 1110 has negative refractive power and is made of plastic. Its object side surface 1111 is concave near the optical axis 1190, and its image side surface 1112 is convex near the optical axis 1190. The object side surface 1111 and the image side The surfaces 1112 are all aspherical.

The second lens 1120 has a positive refractive power and is made of plastic. Its object side surface 1121 is convex near the optical axis 1190, and its image side surface 1122 is concave near the optical axis 1190. The object side surface 1121 and the image side The surfaces 1122 are all aspherical.

The third lens 1130 has positive refractive power and is made of plastic. Its object side surface 1131 is convex near the optical axis 1190, and its image side surface 1132 is convex near the optical axis 1190. The object side surface 1131 and the image side The surfaces 1132 are all aspherical.

The infrared filter 1170 is made of glass, which is arranged between the third lens 1130 and the imaging surface 1180 and does not affect the focal length of the three-piece thin imaging lens group.

Refer to Table 21 and Table 22 below for cooperation.

In the eleventh embodiment, the aspherical curve equation is expressed 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 will not be repeated here.

With Table 21 and Table 22, the following data can be calculated:

<Twelfth Embodiment>

Please refer to FIGS. 12A, 12B, and 12C. FIG. 12A is a schematic diagram of a three-piece thin imaging lens set according to a twelfth embodiment of the present invention, and FIG. 12B is a partial enlarged view of FIG. 12A. Fig. 12C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set in the twelfth embodiment from left to right. It can be seen from FIGS. 12A and 12B that the three-piece thin imaging lens group includes a flat element 1260, a first lens 1210, an aperture 1200, a second lens 1220, a third lens 1230, and an infrared filter in order from the object side to the image side. The light sheet 1270 and the imaging surface 1280, wherein the three-piece thin imaging lens group has three refractive lenses (1210, 1220, 1230). The aperture 1200 is arranged between the first lens 1210 and the second lens 1220.

The plate element 1260 is made of glass, which is arranged between a subject O and the first lens 1210, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 1210 has negative refractive power and is made of plastic. Its object side surface 1211 is concave near the optical axis 1290, and its image side surface 1212 is convex near the optical axis 1290. The object side surface 1211 and the image side The surfaces 1212 are all aspherical.

The second lens 1220 has positive refractive power and is made of plastic. Its object side surface 1221 is convex near the optical axis 1290, and its image side surface 1222 is convex near the optical axis 1290. The object side surface 1221 and the image side The surfaces 1222 are all aspherical.

The third lens 1230 has positive refractive power and is made of plastic. Its object side surface 1231 is convex near the optical axis 1290, and its image side surface 1232 is convex near the optical axis 1290. The object side surface 1231 and the image side The surfaces 1232 are all aspherical.

The infrared filtering filter 1270 is made of glass, which is arranged between the third lens 1230 and the imaging surface 1280 and does not affect the focal length of the three-piece thin imaging lens group.

Refer to Table 23 and Table 24 below for cooperation.

In the twelfth embodiment, the aspherical curve equation is expressed 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 will not be repeated here.

With Table 23 and Table 24, the following data can be calculated:

<Thirteenth Embodiment>

Please refer to FIGS. 13A, 13B and 13C. FIG. 13A is a schematic diagram of a three-piece thin imaging lens set according to a thirteenth embodiment of the present invention, and FIG. 13B is a partial enlarged view of FIG. 13A. FIG. 13C is a graph showing the curvature of field and distortion of the three-piece thin imaging lens set in the thirteenth embodiment from left to right. It can be seen from FIGS. 13A and 13B that the three-piece thin imaging lens group includes a flat element 1360, a first lens 1310, an aperture 1300, a second lens 1320, a third lens 1330, and an infrared filter in sequence from the object side to the image side. The light sheet 1370 and the imaging surface 1380, wherein the three-piece thin imaging lens group has a The refractive lens is three pieces (1310, 1320, 1330). The aperture 1300 is arranged between the first lens 1310 and the second lens 1320.

The plate element 1360 is made of glass, which is arranged between a subject O and the first lens 1310, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 1310 has a negative refractive power and is made of plastic. Its object side surface 1311 is concave near the optical axis 1390, and its image side surface 1312 is concave near the optical axis 1390. The object side surface 1311 and the image side The surfaces 1312 are all aspherical.

The second lens 1320 has positive refractive power and is made of plastic material. Its object side surface 1321 is convex near the optical axis 1390, and its image side surface 1322 is convex near the optical axis 1390. The object side surface 1321 and the image side The surfaces 1322 are all aspherical.

The third lens 1330 has positive refractive power and is made of plastic material. Its object side surface 1331 is concave near the optical axis 1390, and its image side surface 1332 is convex near the optical axis 1390. The object side surface 1331 and the image side The surfaces 1332 are all aspherical.

The infrared filtering filter 1370 is made of glass, which is arranged between the third lens 1330 and the imaging surface 1380 and does not affect the focal length of the three-piece thin imaging lens group.

Refer to Table 25 and Table 26 below for cooperation.

In the thirteenth embodiment, the aspherical curve equation is expressed 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 will not be repeated here.

With Table 25 and Table 26, the following data can be calculated:

<Fourteenth Embodiment>

Please refer to FIGS. 14A, 14B and 14C. FIG. 14A is a schematic diagram of a three-piece thin imaging lens set according to a fourteenth embodiment of the present invention, and FIG. 14B is a partial enlarged view of FIG. 14A. Fig. 14C is a graph showing the curvature of field and the distortion of the three-piece thin imaging lens set of the fourteenth embodiment from left to right. It can be seen from FIGS. 14A and 14B that the three-piece thin imaging lens group includes a flat panel element 1460, a first lens 1410, an aperture 1400, a second lens 1420, a third lens 1430, and an infrared filter in order from the object side to the image side. The light sheet 1470 and the imaging surface 1480, wherein the three-piece thin imaging lens group has three refractive lenses (1410, 1420, 1430). The aperture 1400 is arranged between the first lens 1410 and the second lens 1420.

The flat element 1460 is made of glass, which is arranged between an object O and the first lens 1410, and does not affect the focal length of the three-piece thin imaging lens group.

The first lens 1410 has a negative refractive power and is made of plastic. Its object side surface 1411 is convex near the optical axis 1490, and its image side surface 1412 is concave near the optical axis 1490. The object side surface 1411 and the image side The surfaces 1412 are all aspherical.

The second lens 1420 has positive refractive power and is made of plastic material. Its object side surface 1421 is convex near the optical axis 1490, and its image side surface 1422 is convex near the optical axis 1490. The object side surface 1421 and the image side The surfaces 1422 are all aspherical.

The third lens 1430 has positive refractive power and is made of plastic material. Its object side surface 1431 is convex near the optical axis 1490, and its image side surface 1432 is convex near the optical axis 1490. The object side surface 1431 and the image side The surfaces 1432 are all aspherical.

The infrared filter 1470 is made of glass, which is arranged between the third lens 1430 and the imaging surface 1480 and does not affect the focal length of the three-piece thin imaging lens group.

Refer to Table 27 and Table 28 below for cooperation.

In the fourteenth embodiment, the aspherical curve equation is expressed 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 will not be repeated here.

With Table 27 and Table 28, the following data can be calculated:

In the three-piece thin imaging lens set provided by the present invention, the lens material can be plastic or glass. When the lens material is plastic, the production cost can be effectively reduced. When the lens material is glass, three thin imaging lenses can be added The degrees of freedom for the configuration of the group bending force. In addition, the object-side surface and image-side surface of the lens in the three-element thin imaging lens group can be aspherical, and the aspherical surface can be easily made into a shape other than a spherical surface to obtain more control variables to reduce aberrations and thereby reduce The number of lenses used can effectively reduce the total length of the three-piece thin imaging lens set of the present invention.

In the three-piece thin imaging lens set provided by the present invention, for a lens with refractive power, 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 is concave and the position of the concave surface is not defined, it means that the lens surface is concave at the near optical axis.

To sum up, the above-mentioned embodiments and drawings are only preferred embodiments of the present invention, and should not be used to limit the scope of implementation of the present invention, that is, all equal changes and modifications made in accordance with the scope of the patent application of the present invention are all It should fall within the scope of the invention patent.

100: aperture

110: first lens

111: Object side surface

112: Image side surface

120: second lens

121: Object side surface

122: image side surface

130: third lens

131: Object side surface

132: Image side surface

160: flat element

162: Image side surface

170: Infrared filter filter

180: imaging surface

190: optical axis

O: Subject

OTL: The distance from the subject on the object side surface of the flat panel element to the imaging surface on the optical axis

PTL: The distance from the image side surface of the flat panel element to the imaging surface on the optical axis

Y: image height

P: The chief ray of the imaging surface image height corresponds to the object height on the image side surface of the flat panel element

Claims (19)

A three-piece thin imaging lens group, from the object side to the image side, sequentially includes: a flat element made of glass; a first lens having a negative refractive power, and the object side surface and the image side surface of the first lens are at least An aspheric surface; an aperture; a second lens with positive refractive power, the object side surface of the second lens is convex near the optical axis, and at least one of the object side surface and the image side surface of the second lens is Aspherical surface; and a third lens having refractive power, at least one of the object side surface and the image side surface of the third lens is aspherical; wherein the three-piece thin imaging lens group has three refractive power lenses , The distance from an object on the object side surface of the plate element to an imaging surface on the optical axis is OTL, and the distance from the image side surface of the plate element to the imaging surface on the optical axis is PTL, and the imaging surface image The height is Y, the principal ray of the imaging surface image height corresponds to the object height on the image side surface of the flat element P, the overall focal length of the three-piece thin imaging lens group is f, and the focal length of the second lens is f2, and satisfies The following conditions: 0.17≦f/f2<1.27; 2.5mm<PTL<4.5mm; 2.85≦P/Y<7.0; 4<OTL/Y<12. The three-piece thin imaging lens group according to claim 1, wherein the overall focal length of the three-piece thin imaging lens group is f, the focal length of the first lens is f1, and the following conditions are met: -0.86<f/f1 <-0.22. The three-piece thin imaging lens group according to claim 1, wherein the overall focal length of the three-piece thin imaging lens group is f, and the focal length of the third lens is f3, and the following conditions are met: -0.17<f/f3 <0.82. The three-piece thin imaging lens group according to claim 1, wherein the overall focal length of the three-piece thin imaging lens group is f, the combined focal length of the second lens and the third lens is f23, and the following conditions are met: 0.45 <f/f23<1.04. The three-piece thin imaging lens set according to claim 1, 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 conditions are met: -3.07<f1/f23 <-0.63. The three-piece thin imaging lens set according to claim 1, wherein the focal length of the first lens is f1, the radius of curvature of the object side surface of the first lens is R1, and the following conditions are met: -0.13<f1/R1< 4.95. The three-piece thin imaging lens set according to claim 1, wherein the focal length of the first lens is f1, the radius of curvature of the image side surface of the first lens is R2, and the following conditions are met: -2.41<f1/R2< 1.93. The three-piece thin imaging lens group according to claim 1, wherein the focal length of the second lens is f2, the radius of curvature of the object side surface of the second lens is R3, and the following conditions are met: 0.25<f2/R3<5.64 . The three-piece thin imaging lens set according to claim 1, wherein the focal length of the second lens is f2, the radius of curvature of the image side surface of the second lens is R4, and the following conditions are met: -2.04<f2/R4< 3.87. The three-piece thin imaging lens set according to claim 1, wherein the focal length of the third lens is f3, the radius of curvature of the object side surface of the third lens is R5, and the following conditions are met: -56.34<f3/R5< 2.58. The three-piece thin imaging lens set according to claim 1, wherein the focal length of the third lens is f3, the radius of curvature of the image side surface of the third lens is R6, and the following conditions are met: -40.72<f3/R6< 0.49. The three-piece thin imaging lens group according to claim 1, wherein the radius of curvature of the object side surface of the first lens is R1, and the radius of curvature of the image side surface of the first lens is R2, and the following conditions are met: -38.2< R1/R2<276.13. The three-piece thin imaging lens set according to claim 1, wherein the radius of curvature of the object side surface of the second lens is R3, and the radius of curvature of the image side surface of the second lens is R4, and the following conditions are met: -5.91< R3/R4<0.82. The three-piece thin imaging lens set according to claim 1, wherein the radius of curvature of the object side surface of the third lens is R5, and the radius of curvature of the image side surface of the third lens is R6, and the following conditions are met: -2.86< R5/R6<22.19. The three-piece thin imaging lens group according to claim 1, wherein the overall focal length of the three-piece thin imaging lens group is f, and the object on the object side surface of the plate element reaches the distance between the imaging surface and the optical axis The distance is OTL and meets the following conditions: 7.71<OTL/f<17.62. The three-piece thin 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, the focal length of the third lens is f3, and the following conditions are met: -4.56 Mm ^-2 <(f1+f2+f3)/(f1*f2*f3)<-0.53 mm ^-2 . The three-piece thin imaging lens set according to claim 1, wherein the object side surface of the first lens is a concave surface near the optical axis. The three-piece thin imaging lens set according to claim 1, wherein the image side surface of the second lens is convex near the optical axis. The three-piece thin imaging lens set according to claim 1, wherein the image side surface of the third lens is convex near the optical axis.

Images