Imaging lens group

Abstract

The present invention discloses an imaging lens assembly comprising, from the object side to the image side, a first lens; an aperture; a second lens; a third lens; and an infrared bandpass filter. The imaging lens assembly has a maximum viewing angle of FOV, an aperture value of Fno, an object-side surface curvature radius of R5, a distance from the object-side surface of the first lens to the imaging plane on the optical axis of TL, an entrance pupil diameter of EPD, and a distance between the first and second lenses on the optical axis of T12. The lens assembly satisfies the following conditions: 19.82° / mm. 2 <FOV*Fno / (R5*TL)<50.37° / mm 2 , and 6.58mm

Description

Technical Field

[0001] The present invention relates to an imaging lens assembly, and more particularly to an imaging lens assembly used in electronic devices. Background Art

[0002] With the rapid development of 3D sensing technology in various fields, such as mobile phones, drones, and robot vacuums, miniaturized optical lenses have become indispensable for portability. Furthermore, advances in semiconductor manufacturing have led to the development of smaller, higher-pixel image sensors, making large aperture, wide-angle, and miniaturized optical lenses important research directions.

[0003] Known TOF (Time of Flight) optical lenses with ultra-large aperture characteristics generally consist of an infrared sensing optical lens assembly with more than four lenses. Their large size makes them difficult to install in portable electronic devices such as mobile phones and tablet computers. In addition, their high production cost is also an issue that needs to be improved. Summary of the Invention

[0004] The present invention aims to solve the problems of large size and high cost associated with the aforementioned prior art ultra-large aperture infrared sensing optical lens assembly. To achieve this, the present invention provides an imaging lens assembly comprising, from the object side to the image side, the following: a first lens having refractive power; an aperture stop; a second lens having positive refractive power, the object-side surface of the second lens being convex near the optical axis, and the image-side surface of the second lens being convex near the optical axis; a third lens having positive refractive power, the object-side surface of the third lens being convex near the optical axis; and an infrared bandpass filter.

[0005] The maximum viewing angle of the imaging lens group is FOV, the aperture value of the imaging lens group is Fno, the radius of curvature of the object side surface of the third lens is R5, the distance from the object side surface of the first lens to the imaging plane on the optical axis is TL, the entrance pupil diameter of the imaging lens group is EPD, and the distance between the first lens and the second lens on the optical axis is T12, and the following conditions are met: 19.82° / mm 2 <FOV*Fno / (R5*TL)<50.37° / mm 2 , and 6.58mm <EPD*TL / T12<24.94mm。

[0006] When the above imaging lens group satisfies 19.82° / mm 2 <FOV*Fno / (R5*TL)<50.37° / mm 2 , and 6.58mm

[0007] When <EPD*TL / T12 < 24.94 mm, through this appropriate configuration, the effects of achieving a super large aperture that takes into account wide-angle characteristics and miniaturization can be achieved.

[0008] The total number of lenses with refractive power in this imaging lens group is three.

[0009] The overall focal length of this imaging lens group is f, and the focal length of the second lens is f2, and the following conditions are satisfied: 0.33 < f / f2 < 0.86. Through the appropriate configuration of the focal length of the second lens and the overall focal length, the aberration generated by the large aperture can be corrected, and the optical distortion can be reduced to improve the imaging quality.

[0010] 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: -3.93 < f1 / f3 < 1.44. Thereby, the proportional distribution of the focal length of the second lens and the focal length of the third lens is relatively appropriate, which is conducive to providing a larger illuminance of this imaging lens group.

[0011] The focal length of the second lens is f2, and the thickness of the second lens on the optical axis is CT2, and the following conditions are satisfied: 0.87 < f2 / CT2 < 3.66. Thereby, the refractive power of the second lens and the formability of the lens thickness reach the best balance for manufacturing.

[0012] The focal length of the third lens is f3, and the thickness of the third lens on the optical axis is CT3, and the following conditions are satisfied: 1.86 < f3 / CT3 < 68.30. Thereby, the ratio of the refractive power of the third lens to the thickness reaches the best, meeting the required refractive power and maintaining good manufacturability.

[0013] 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: 0.72 < R1 / R2 < 3.39. Through the better lens curvature configuration, the characteristics of the large aperture are satisfied.

[0014] 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: -0.08 < R5 / R6 < 1.25. Through the appropriate configuration of the lens curvature, the aberration can be corrected and the imaging quality can be improved. <00憨00037>[[ID=憨24]]The thickness of the third lens on the optical axis is CT3, and the radius of curvature of the object side surface of the third lens is R5, and the following conditions are satisfied: 0.24 < CT3 / R5 < 0.89. Thereby, the ratio of the refractive power of the third lens to the thickness reaches the best to reduce the aberration.

[0016] The radius of curvature of the object-side surface of the second lens is R3, the radius of curvature of the image-side surface of the second lens is R4, and the focal length of the second lens is f2, and the following conditions are satisfied: -69.59 1 / mm < R3 / (R4*f2) < -0.01 1 / mm. Thus, the refractive power and curvature of the second lens reach the optimal ratio to improve the imaging quality of the imaging lens group.

[0017] The thickness of the first lens on the optical axis is CT1, the thickness of the second lens on the optical axis is CT2, and the thickness of the third lens on the optical axis is CT3, and the following conditions are satisfied: 2.37 < (CT1 + CT2) / CT3 < 7.61. By appropriately adjusting the thickness distribution of the lenses, miniaturization and the performance of the imaging lens group can be taken into account.

[0018] The distance between the first lens and the second lens on the optical axis is T12, and the distance between the second lens and the third lens on the optical axis is T23, and the following conditions are satisfied: 0.92 < T12 / T23 < 7.52. Thus, the assembly tolerance of the imaging lens group can be optimized.

[0019] The thickness of the second lens on the optical axis is CT2, the entrance pupil diameter of the imaging lens group is EPD, and the distance from the image-side surface of the third lens to the imaging surface on the optical axis is BFL, and the following conditions are satisfied: 0.85mm < CT2*EPD / BFL < 2.93mm. It can provide an appropriate configuration of a large-aperture lens and an optical back focal length to meet the miniaturization effect.

[0020] The distance from the image-side surface of the third lens to the imaging surface on the optical axis is BFL, and the distance from the object-side surface of the first lens to the imaging surface on the optical axis is TL, and the following conditions are satisfied: 0.19 < BFL / TL < 0.34. Thus, the back focus and the height of the lens group reach the optimal state to meet the miniaturization and the requirements of the module back focal space.

[0021] The distance from the object-side surface of the first lens to the imaging surface on the optical axis is TL, and the maximum imaging height of the imaging lens group is IMH, and the following conditions are satisfied: 2.36 < TL / IMH < 3.76. Thus, it helps to achieve an appropriate balance between miniaturization and the imaging area.

[0022] Half of the maximum viewing angle of the imaging lens group is HFOV, the F-number of the imaging lens group is Fno, the refractive index of the first lens is nd1, the refractive index of the second lens is nd2, and the refractive index of the third lens is nd3, and the following conditions are satisfied: 7.40° < HFOV*Fno / (nd1 + nd2 + nd3) < 13.05°. By appropriately adjusting the refractive indices of these lenses, a large aperture and a suitable viewing angle range can be taken into account.

[0023] The imaging lens assembly of the present invention can provide a three-piece infrared sensing lens with an ultra-large aperture and a wide angle for use in 3D sensing technology. In addition, the imaging lens assembly of the present invention has a low manufacturing cost and a small module, and can provide sufficient relative illumination under ultra-large aperture and wide angle conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1A FIG. 4 is a schematic diagram of an imaging lens assembly according to a first embodiment of the present invention.

[0025] Figure 1B From left to right are the field curvature and distortion curves of the imaging lens assembly of the first embodiment.

[0026] Figure 2A FIG. 4 is a schematic diagram of an imaging lens assembly according to a second embodiment of the present invention.

[0027] Figure 2B From left to right are the field curvature and distortion curves of the imaging lens assembly of the second embodiment.

[0028] Figure 3A FIG. 4 is a schematic diagram of an imaging lens assembly according to a third embodiment of the present invention.

[0029] Figure 3B From left to right are the field curvature and distortion curves of the imaging lens assembly of the third embodiment.

[0030] Figure 4A FIG. 4 is a schematic diagram of an imaging lens assembly according to a fourth embodiment of the present invention.

[0031] Figure 4B From left to right are the field curvature and distortion curves of the imaging lens assembly of the fourth embodiment.

[0032] Figure 5A FIG. 4 is a schematic diagram of an imaging lens assembly according to a fifth embodiment of the present invention.

[0033] Figure 5B From left to right are the field curvature and distortion curves of the imaging lens assembly of the fifth embodiment.

[0034] Figure 6A FIG. 4 is a schematic diagram of an imaging lens assembly according to a sixth embodiment of the present invention.

[0035] Figure 6B From left to right are the field curvature and distortion curves of the imaging lens assembly of the sixth embodiment.

[0036] Description of symbols in the accompanying drawings:

[0037] 100, 200, 300, 400, 500, 600: aperture;

[0038] 110, 210, 310, 410, 510, 610: first lens;

[0039] 111, 211, 311, 411, 511, 611: object side surface;

[0040] 112, 212, 312, 412, 512, 612: image side surface;

[0041] 120, 220, 320, 420, 520, 620: second lens;

[0042] 121, 221, 321, 421, 521, 621: object side surface;

[0043] 122, 222, 322, 422, 522, 622: image side surface;

[0044] 130, 230, 330, 430, 530, 630: third lens;

[0045] 131, 231, 331, 431, 531, 631: object side surface;

[0046] 132, 232, 332, 432, 532, 632: image side surface;

[0047] 140, 240, 340, 440, 540, 640: infrared bandpass filters;

[0048] 180, 280, 380, 480, 580, 680: imaging plane;

[0049] 190, 290, 390, 490, 590, 690: optical axis; DETAILED DESCRIPTION

[0050] In order to enable those with ordinary knowledge in the relevant technical field to understand the content of the present invention and to implement the content of the present invention accordingly, the following is an illustration with appropriate embodiments. Equivalent replacements and modifications made based on the content of the present invention are all included in the scope of the rights of the present invention. In addition, it is stated that the illustrations attached to the present invention are not depicted according to actual dimensions. Although the present invention provides embodiments of specific parameters, it should be understood that the parameters do not need to be exactly equal to the corresponding values. Within an acceptable error range, they are approximate to their corresponding parameters. The following embodiments will further explain the technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of the rights of the present invention.

[0051] <First embodiment>

[0052] Please refer to Figure 1A and Figure 1B ,in, Figure 1Ais a schematic diagram of an imaging lens assembly according to a first embodiment of the present invention, Figure 1B From left to right are the field curvature and distortion curves of the imaging lens assembly of the first embodiment. Figure 1A As can be seen, the imaging lens assembly includes, from the object side to the image side, a first lens 110, an aperture 100, a second lens 120, a third lens 130, an infrared bandpass filter 140, and an imaging surface 180. The imaging lens assembly includes three lenses with refractive power, but the present invention is not limited to this.

[0053] The first lens 110 has positive refractive power. Its object-side surface 111 is concave near the optical axis 190 , and its image-side surface 112 is convex near the optical axis 190 . Both the object-side surface 111 and the image-side surface 112 are aspherical.

[0054] The second lens 120 has positive refractive power. 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 . Both the object-side surface 121 and the image-side surface 122 are aspherical.

[0055] The third lens 130 has positive refractive power. Its object-side surface 131 is convex near the optical axis 190 , and its image-side surface 132 is concave near the optical axis 190 . Both the object-side surface 131 and the image-side surface 132 are aspherical.

[0056] The infrared bandpass filter 140 is made of glass and is disposed between the third lens 130 and the imaging surface 180 without affecting the focal length of the imaging lens group. In this embodiment, a filter that can pass light in the wavelength band of 940nm±30nm is selected. It is understood that the infrared bandpass filter 140 component can also be formed on the lens surface, and the infrared bandpass filter 140 can also be made of other materials.

[0057] The curve equations of the aspheric surfaces of the above lenses are expressed as follows:

[0058]

[0059] Wherein, z is the position value at a height h along the optical axis 190 with reference to the surface vertex; c is the curvature of the lens surface near the optical axis 190 and is the inverse of the radius of curvature (R) (c = 1 / R), R is the radius of curvature of the lens surface near the optical axis 190, h is the vertical distance of the lens surface from the optical axis 190, k is the conic constant, and Ai is the i-th order aspheric coefficient.

[0060] In the first embodiment, the overall focal length of the imaging lens group is f, the aperture value (f-number) of the imaging lens group is Fno, and the maximum viewing angle (viewing angle 2ω) of the imaging lens group is FOV, whose values ​​are as follows: f = 1.18 (mm); Fno = 0.98; and FOV = 88.6 (degrees).

[0061] In the imaging lens assembly 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 focal length of the third lens 130 is f3, and their values ​​are as follows: f1 = 17.32 (mm); f2 = 1.68 (mm); and f3 = 13.85 (mm).

[0062] In the imaging lens assembly of the first embodiment, the maximum viewing angle of the imaging lens assembly is FOV, the aperture value of the imaging lens assembly is Fno, the radius of curvature of the object-side surface 131 of the third lens 130 is R5, the distance between the object-side surface 111 of the first lens 110 and the imaging plane 180 on the optical axis 190 is TL, the entrance pupil diameter of the imaging lens assembly is EPD, and the distance between the first lens 110 and the second lens 120 on the optical axis 190 is T12, and the following conditions are satisfied: FOV*Fno / (R5*TL)=

[0063] 32.38° / mm 2 , and EPD*TL / T12=19.52mm.

[0064] In the imaging lens assembly of the first embodiment, the overall focal length of the imaging lens assembly is f, the focal length of the second lens 120 is f2, and the following condition is satisfied: f / f2=0.70.

[0065] In the imaging lens assembly of the first embodiment, the focal length of the first lens is f1, the focal length of the third lens 130 is f3, and the following condition is satisfied: f1 / f3=1.25.

[0066] In the imaging lens assembly of the first embodiment, the focal length of the second lens 120 is f2, the thickness of the second lens 120 on the optical axis 190 is CT2, and the following condition is satisfied: f2 / CT2=1.06.

[0067] In the imaging lens assembly of the first embodiment, the focal length of the third lens 130 is f3, the thickness of the third lens 130 on the optical axis 190 is CT3, and the following condition is satisfied: f3 / CT3=49.30.

[0068] In the imaging lens assembly of the first embodiment, the object-side surface 111 of the first lens 110 has a curvature radius of R1, the image-side surface 112 of the first lens 110 has a curvature radius of R2, and the following condition is satisfied: R1 / R2=0.98.

[0069] In the imaging lens assembly of the first embodiment, the object-side surface 131 of the third lens 130 has a curvature radius of R5, and the image-side surface 132 of the third lens 130 has a curvature radius of R6, and the following condition is satisfied: R5 / R6=1.05.

[0070] In the imaging lens assembly of the first embodiment, the thickness of the third lens 130 on the optical axis 190 is CT3, the curvature radius of the object-side surface 131 of the third lens 130 is R5, and the following condition is satisfied: CT3 / R5=0.35.

[0071] In the imaging lens assembly of the first embodiment, the object-side surface 121 of the second lens 120 has a curvature radius of R3, the image-side surface 122 of the second lens 120 has a curvature radius of R4, and the focal length of the second lens 120 is f2, and the following conditions are satisfied:

[0072] R3 / (R4*f2)=-60.51 1 / mm.

[0073] In the imaging lens assembly of the first embodiment, the thickness of the first lens 110 on the optical axis 190 is CT1, the thickness of the second lens 120 on the optical axis 190 is CT2, and the thickness of the third lens 130 on the optical axis 190 is CT3, and the following condition is satisfied: (CT1+CT2) / CT3=6.61.

[0074] In the imaging lens assembly of the first embodiment, the distance between the first lens 110 and the second lens 120 on the optical axis 190 is T12, and the distance between the second lens 120 and the third lens 130 on the optical axis 190 is T23, and the following condition is satisfied: T12 / T23=5.74.

[0075] In the imaging lens assembly of the first embodiment, the thickness of the second lens 120 on the optical axis 190 is CT2, the entrance pupil diameter of the imaging lens assembly is EPD, and the distance from the image-side surface 132 of the third lens 130 to the imaging plane 180 on the optical axis 190 is BFL, and the following condition is satisfied: CT2*EPD / BFL=1.94 mm.

[0076] In the imaging lens assembly of the first embodiment, the distance between the image-side surface 132 of the third lens element 130 and the imaging plane 180 on the optical axis 190 is BFL, and the distance between the object-side surface 111 of the first lens element 110 and the imaging plane 180 on the optical axis 190 is TL, and the following condition is satisfied: BFL / TL=0.29.

[0077] In the imaging lens assembly of the first embodiment, the distance between the object-side surface 111 of the first lens 110 and the imaging plane 180 on the optical axis 190 is TL, the maximum imaging height of the imaging lens assembly is IMH, and the following condition is satisfied: TL / IMH=3.18.

[0078] In the imaging lens group of the first embodiment, half of the maximum viewing angle of the imaging lens group is HFOV, the aperture value of the imaging lens group is Fno, the refractive index of the first lens 110 is nd1, the refractive index of the second lens 120 is nd2, and the refractive index of the third lens 130 is nd3, and the following condition is satisfied: HFOV*Fno / (nd1+nd2+nd3)=8.77°.

[0079] Please refer to Table 1 and Table 2 below.

[0080]

[0081]

[0082]

[0083] Table 1 is Figure 1A Detailed structural data of the first embodiment, where the unit of curvature radius, thickness, gap, and focal length is mm, and surfaces 0-10 represent the surfaces from the object side to the image side in sequence, where surface 0 is the gap between the object and the aperture 100 on the optical axis 190; surface 3 is the gap between the aperture 100 and the object-side surface 121 of the second lens 120 on the optical axis 190. Since the object-side surface 121 of the second lens 120 is closer to the object side than the aperture 100, it is represented by a negative value. Conversely, if the aperture 100 is closer to the object side than the object-side surface 121 of the second lens 120, it is represented by a positive value. Indicates; surfaces 1, 4, 6, and 8 are respectively the thicknesses of the first lens 110, the second lens 120, the third lens 130, and the infrared band-pass filter 140 on the optical axis 190; surfaces 2, 5, 7, and 9 are respectively the gap on the optical axis 190 between the first lens 110 and the second lens 120, the gap on the optical axis 190 between the second lens 120 and the third lens 130, the gap on the optical axis 190 between the third lens 130 and the infrared band-pass filter 140, and the gap on the optical axis 190 between the infrared band-pass filter 140 and the imaging surface 180.

[0084] Table 2 shows the aspheric surface data for the first embodiment, where k represents the conic coefficient in the aspheric curve equation, and A2, A4, A6, A8, A10, A12, A14, A16, A18, and A20 represent higher-order aspheric coefficients. Furthermore, the following tables of the embodiments correspond to the schematic diagrams and aberration curves of each embodiment. The definitions of the data in the tables are the same as those in Tables 1 and 2 of the first embodiment and are not further detailed.

[0085] <Second embodiment>

[0086] Please refer to Figure 2A and Figure 2B ,in, Figure 2A is a schematic diagram of an imaging lens assembly according to a second embodiment of the present invention, Figure 2B From left to right are the field curvature and distortion curves of the imaging lens assembly of the second embodiment. Figure 2A As can be seen, the imaging lens assembly includes, from the object side to the image side, a first lens 210, an aperture 200, a second lens 220, a third lens 230, an infrared bandpass filter 240, and an imaging surface 280. The imaging lens assembly includes three lenses with refractive power, but the present invention is not limited to this.

[0087] The first lens 210 has positive refractive power. Its object-side surface 211 is concave near the optical axis 290 , and its image-side surface 212 is convex near the optical axis 290 . Both the object-side surface 211 and the image-side surface 212 are aspherical.

[0088] The second lens 220 has positive refractive power. 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 . Both the object-side surface 221 and the image-side surface 222 are aspherical.

[0089] The third lens 230 has positive refractive power. Its object-side surface 231 is convex near the optical axis 290 , and its image-side surface 232 is concave near the optical axis 290 . Both the object-side surface 231 and the image-side surface 232 are aspherical.

[0090] The infrared bandpass filter 240 is made of glass and is disposed between the third lens 230 and the imaging surface 280 without affecting the focal length of the imaging lens group. In this embodiment, a filter that can pass light in the wavelength band of 940nm±30nm is selected. It is understood that the infrared bandpass filter 240 component can also be formed on the lens surface, and the infrared bandpass filter 240 can also be made of other materials.

[0091] Please refer to Table 3 and Table 4 below.

[0092]

[0093]

[0094]

[0095] In the second embodiment, the curve equation of the aspheric surface is expressed in the same form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment and are not repeated here.

[0096] The following data can be calculated by combining Table 3 and Table 4:

[0097]

[0098] <Third embodiment>

[0099] Please refer to Figure 3A and Figure 3B ,in, Figure 3A is a schematic diagram of an imaging lens assembly according to a third embodiment of the present invention, Figure 3B From left to right are the field curvature and distortion curves of the imaging lens assembly of the third embodiment. Figure 3A As can be seen, the imaging lens assembly includes, from the object side to the image side, a first lens 310, an aperture 300, a second lens 320, a third lens 330, an infrared bandpass filter 340, and an imaging surface 380; wherein the imaging lens assembly has three lenses with refractive power, but is not limited to this.

[0100] The first lens 310 has negative refractive power. Its object-side surface 311 is concave near the optical axis 390 , and its image-side surface 312 is convex near the optical axis 390 . Both the object-side surface 311 and the image-side surface 312 are aspherical.

[0101] The second lens 320 has positive refractive power. Its object-side surface 321 is convex near the optical axis 390 , and its image-side surface 322 is convex near the optical axis 390 . Both the object-side surface 321 and the image-side surface 322 are aspherical.

[0102] The third lens 330 has positive refractive power. Its object-side surface 331 is convex near the optical axis 390 , and its image-side surface 332 is concave near the optical axis 390 . Both the object-side surface 331 and the image-side surface 332 are aspherical.

[0103] The IR bandpass filter 340 is made of glass and is disposed between the third lens 330 and the imaging surface 380 without affecting the focal length of the imaging lens group. In this embodiment, a filter that can pass light in the wavelength band of 940nm±30nm is selected. It is understood that the IR bandpass filter component can also be formed on the lens surface, and the IR bandpass filter 340 can also be made of other materials.

[0104] Please refer to Table 5 and Table 6 below.

[0105]

[0106]

[0107]

[0108] In the third embodiment, the curve equation of the aspheric surface is expressed in the same form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment and are not repeated here.

[0109] The following data can be calculated by combining Table 5 and Table 6:

[0110]

[0111] <Fourth embodiment>

[0112] Please refer to Figure 4A and Figure 4B ,in, Figure 4A is a schematic diagram of an imaging lens assembly according to a fourth embodiment of the present invention, Figure 4B From left to right are the field curvature and distortion curves of the imaging lens assembly of the fourth embodiment. Figure 4A As can be seen, the imaging lens assembly includes, from the object side to the image side, a first lens 410, an aperture 400, a second lens 420, a third lens 430, an infrared bandpass filter 440, and an imaging surface 480; wherein the imaging lens assembly has three lenses with refractive power, but is not limited to this.

[0113] The first lens 410 has negative refractive power. Its object-side surface 411 is concave near the optical axis 490 , and its image-side surface 412 is convex near the optical axis 490 . Both the object-side surface 411 and the image-side surface 412 are aspherical.

[0114] The second lens 420 has positive refractive power. Its object-side surface 421 is convex near the optical axis 490 , and its image-side surface 422 is convex near the optical axis 490 . Both the object-side surface 421 and the image-side surface 422 are aspherical.

[0115] The third lens 430 has positive refractive power. Its object-side surface 431 is convex near the optical axis 490 , and its image-side surface 432 is concave near the optical axis 490 . Both the object-side surface 431 and the image-side surface 432 are aspherical.

[0116] The infrared bandpass filter 440 is made of glass and is disposed between the third lens 430 and the imaging surface 480 without affecting the focal length of the imaging lens group. In this embodiment, a filter that can pass light in the wavelength band of 940nm±30nm is selected. It can be understood that the infrared bandpass filter 440 component can also be formed on the lens surface, and the infrared bandpass filter 440 can also be made of other materials.

[0117] Please refer to Table 7 and Table 8 below.

[0118]

[0119]

[0120] In the fourth embodiment, the curve equation of the aspheric surface is expressed in the same form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment and are not repeated here.

[0121] The following data can be calculated by combining Table 7 and Table 8:

[0122]

[0123] <Fifth embodiment>

[0124] Please refer to Figure 5A and Figure 5B ,in, Figure 5A is a schematic diagram of an imaging lens assembly according to a fifth embodiment of the present invention, Figure 5B From left to right are the field curvature and distortion curves of the imaging lens assembly of the fifth embodiment. Figure 5A As can be seen, the imaging lens assembly includes, from the object side to the image side, a first lens 510, an aperture 500, a second lens 520, a third lens 530, an infrared bandpass filter 540, and an imaging surface 580; wherein the imaging lens assembly has three lenses with refractive power, but is not limited to this.

[0125] The first lens 510 has negative refractive power. Its object-side surface 511 is convex near the optical axis 590 , and its image-side surface 512 is concave near the optical axis 590 . Both the object-side surface 511 and the image-side surface 512 are aspherical.

[0126] The second lens 520 has positive refractive power. 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 . Both the object-side surface 521 and the image-side surface 522 are aspherical.

[0127] The third lens 530 has positive refractive power, an object-side surface 531 thereof is convex near the optical axis 590 , and an image-side surface 532 thereof is concave near the optical axis 590 . Both the object-side surface 531 and the image-side surface 532 are aspherical.

[0128] The infrared bandpass filter 540 is made of glass and is disposed between the third lens 530 and the imaging surface 580 without affecting the focal length of the imaging lens group. In this embodiment, a filter that can pass light in the wavelength band of 940nm±30nm is selected. It can be understood that the infrared bandpass filter component can also be formed on the lens surface, and the infrared bandpass filter 540 can also be made of other materials.

[0129] Please refer to Table 9 and Table 10 below.

[0130]

[0131]

[0132]

[0133] In the fifth embodiment, the curve equation of the aspheric surface is expressed in the same form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment and are not repeated here.

[0134] The following data can be calculated by combining Table 9 and Table 10:

[0135]

[0136]

[0137] <Sixth embodiment>

[0138] Please refer to Figure 6A and Figure 6B ,in, Figure 6A is a schematic diagram of an imaging lens assembly according to a fifth embodiment of the present invention, Figure 6B From left to right are the field curvature and distortion curves of the imaging lens assembly of the sixth embodiment. Figure 6A As can be seen, the imaging lens group includes, from the object side to the image side, a first lens 610, an aperture 600, a second lens 620, a third lens 630, an infrared bandpass filter 640, and an imaging surface 680; wherein the imaging lens group has three lenses with refractive power, but is not limited to this.

[0139] The first lens 610 has negative refractive power. Its object-side surface 611 is convex near the optical axis 690 , and its image-side surface 612 is concave near the optical axis 690 . Both the object-side surface 611 and the image-side surface 612 are aspherical.

[0140] The second lens 620 has positive refractive power. 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 . Both the object-side surface 621 and the image-side surface 622 are aspherical.

[0141] The third lens 630 has positive refractive power. 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 . Both the object-side surface 631 and the image-side surface 632 are aspherical.

[0142] The infrared bandpass filter 640 is made of glass and is disposed between the third lens 630 and the imaging surface 680 without affecting the focal length of the imaging lens group. In this embodiment, a filter that can pass light in the wavelength band of 940nm±30nm is selected. It is understood that the infrared bandpass filter component can also be formed on the lens surface, and the infrared bandpass filter 640 can also be made of other materials.

[0143] Please refer to Table 11 and Table 12 below.

[0144]

[0145]

[0146]

[0147] In the sixth embodiment, the curve equation of the aspheric surface is expressed in the same form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as in the first embodiment and are not repeated here.

[0148] The following data can be calculated by combining Table 11 and Table 12:

[0149]

[0150] In the aforementioned embodiments, persons having ordinary knowledge in the relevant field should understand that in the imaging lens group provided by the present invention, the lens can be made of glass or plastic. The glass lens can increase the freedom of configuration of the refractive power of the imaging lens group, and the glass lens can be made by related technologies such as grinding or molding. The plastic lens can reduce production costs.

[0151] In the imaging lens assembly provided by the present invention, with respect to a lens having 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.

[0152] The imaging lens assembly provided by the present invention can be used in optical systems that require ultra-large aperture, wide angle, and miniaturization, and can be widely used in electronic imaging systems such as mobile phones, laptops, digital drawing tablets, mobile devices, digital cameras, car photography, or drones.

Claims

1. An imaging lens assembly, characterized in that: From object side to image side, it includes: a first lens having refractive power; One aperture; a second lens having positive refractive power, wherein the object-side surface of the second lens is convex near the optical axis, and the image-side surface of the second lens is convex near the optical axis; a third lens element having positive refractive power, wherein the object-side surface of the third lens element is convex near the optical axis; and an infrared bandpass filter; The total number of lenses with refractive power in the imaging lens group is three, the maximum viewing angle of the imaging lens group is FOV, the aperture value of the imaging lens group is Fno, the object-side surface curvature radius of the third lens is R5, the distance from the object-side surface of the first lens to the imaging plane on the optical axis is TL, the entrance pupil diameter of the imaging lens group is EPD, and the distance between the first lens and the second lens on the optical axis is T12, and the following conditions are met: 19.82° / mm 2 <FOV*Fno / (R5*TL)<50.37° / mm 2 , and 6.58mm <EPD*TL / T12<24.94mm。 2. The imaging lens assembly according to claim 1, wherein: The overall focal length of the imaging lens group is f, the focal length of the second lens is f2, and the following conditions are met: 0.33 <f / f2<0.86。 3. The imaging lens assembly according to claim 1, wherein: The focal length of the first lens is f1, the focal length of the third lens is f3, and the following conditions are met: -3.93 <f1 / f3<1.44。 4. The imaging lens assembly according to claim 1, wherein: The focal length of the second lens is f2, the thickness of the second lens on the optical axis is CT2, and the following conditions are met: 0.87 <f2 / CT2<3.66。 5. The imaging lens assembly according to claim 1, wherein: The focal length of the third lens is f3, the thickness of the third lens on the optical axis is CT3, and the following conditions are met: 1.86 <f3 / CT3<68.30。 6. The imaging lens assembly according to claim 1, wherein: The object side surface curvature radius of the first lens is R1, the image side surface curvature radius of the first lens is R2, and the following conditions are met: 0.72 <R1 / R2<3.39。 7. The imaging lens assembly according to claim 1, wherein: The object side surface curvature radius of the third lens is R5, the image side surface curvature radius of the third lens is R6, and the following conditions are met: -0.08 <R5 / R6<1.25。 8. The imaging lens assembly according to claim 1, wherein: The thickness of the third lens on the optical axis is CT3, the radius of curvature of the object side surface of the third lens is R5, and the following conditions are met: 0.24 <CT3 / R5<0.89。 9. The imaging lens assembly according to claim 1, wherein: The object side surface curvature radius of the second lens is R3, the image side surface curvature radius of the second lens is R4, the focal length of the second lens is f2, and the following conditions are met: -69.59 1 / mm <R3 / (R4*f2)<-0.01 1 / mm。 10. The imaging lens assembly according to claim 1, wherein: The thickness of the first lens on the optical axis is CT1. The thickness of the second lens on the optical axis is CT2, the thickness of the third lens on the optical axis is CT3, and the following condition is satisfied: 2.37<(CT1+CT2) / CT3<7.

61.

11. The imaging lens assembly according to claim 1, wherein: The distance between the first lens and the second lens on the optical axis is T12, the distance between the second lens and the third lens on the optical axis is T23, and the following conditions are met: 0.92 <T12 / T23<7.52。 12. The imaging lens assembly according to claim 1, wherein: The thickness of the second lens on the optical axis is CT2. The entrance pupil diameter of the imaging lens group is EPD, the distance from the image side surface of the third lens to the imaging plane on the optical axis is BFL, and the following conditions are met: 0.85mm <CT2*EPD / BFL<2.93mm。 13. The imaging lens assembly according to claim 1, wherein: The distance between the image side surface of the third lens and the imaging plane on the optical axis is BFL, the distance between the object side surface of the first lens and the imaging plane on the optical axis is TL, and the following conditions are met: 0.19 <BFL / TL<0.34。 14. The imaging lens assembly according to claim 1, wherein: The distance between the object side surface of the first lens and the imaging plane on the optical axis is TL, the maximum imaging height of the imaging lens group is IMH, and the following conditions are met: 2.36 <TL / IMH<3.76。 15. The imaging lens assembly according to claim 1, wherein: The half of the maximum viewing angle of the imaging lens group is HFOV, the aperture value of the imaging lens group is Fno, the refractive index of the first lens is nd1, the refractive index of the second lens is nd2, the refractive index of the third lens is nd3, and the following conditions are met: 7.40° <HFOV*Fno / (nd1+nd2+nd3)<13.05°。

Images