Disclosure of Invention
The present invention provides a three-piece thin imaging lens assembly, and more particularly, to a three-piece thin imaging lens assembly which is helpful to reduce the distance between a subject and the three-piece thin imaging lens assembly, effectively reduce the size, and maintain the miniaturization of the three-piece thin imaging lens assembly.
Another objective of the present invention is to provide a three-piece thin imaging lens assembly, and more particularly, to a three-piece thin imaging lens assembly capable of effectively collecting light with a large angle, so that the three-piece thin imaging lens assembly can receive an image with a wider range and achieve an identification effect within a very short object distance.
To achieve the above object, the present invention provides a three-piece thin imaging lens assembly, in order from an object side to an image side, comprising: a flat plate element made of glass; a first lens element with negative refractive power having an object-side surface being concave at a paraxial region thereof and at least one of an object-side surface and an image-side surface being aspheric; an aperture; a second lens element with positive refractive power having an object-side surface being convex at a paraxial region thereof and an image-side surface being convex at a paraxial region thereof, wherein at least one of the object-side surface and the image-side surface thereof is aspheric; and a third lens element with positive refractive power having an object-side surface and an image-side surface, at least one of which is aspheric.
The three lens elements with refractive power in the three-piece thin imaging lens assembly have a maximum field of view (FOV), an optical axis distance from a subject to an imaging plane is OTL, an overall focal length of the three-piece thin imaging lens assembly is f, a focal length of the first lens element is f1, a focal length of the second lens element is f2, and a focal length of the third lens element is f3, and the following conditions are satisfied: 90 degrees < FOV <140 degrees; 2 mm < OTL <6 mm; 0.2< | f/(f1 f2 f3) | < 0.7.
Preferably, the overall focal length of the three-piece thin imaging lens assembly is f, and the focal length of the first lens element is f1, and the following conditions are satisfied: -0.7< f/f1< -0.1. Therefore, the refractive power configuration of the three-piece thin imaging lens group can be balanced, so that the aberration of the three-piece thin imaging lens group can be effectively corrected, and meanwhile, the sensitivity of the three-piece thin imaging lens group is reduced.
Preferably, the overall focal length of the three-piece thin imaging lens assembly is f, and the focal length of the second lens element is f2, and the following conditions are satisfied: 0.1< f/f2< 0.75. Therefore, the refractive power configuration of the three-piece thin imaging lens group can be balanced, so that the aberration of the three-piece thin imaging lens group can be effectively corrected, and meanwhile, the sensitivity of the three-piece thin imaging lens group is reduced.
Preferably, the overall focal length of the three-piece thin imaging lens assembly is f, and the focal length of the third lens element is f3, and the following conditions are satisfied: 0.07< f/f3< 0.68. Therefore, the refractive power configuration of the three-piece thin imaging lens group can be balanced, so that the aberration of the three-piece thin imaging lens group can be effectively corrected, and meanwhile, the sensitivity of the three-piece thin imaging lens group is reduced.
Preferably, the overall focal length of the three-piece thin imaging lens assembly is f, and the combined focal length of the second lens element and the third lens element is f23, and the following conditions are satisfied: 0.4< f/f23< 1.0. Therefore, the three-piece thin imaging lens group can balance between shortening the total optical length and correcting aberration.
Preferably, 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 satisfied: -2.9< f1/f23< -1.0. Therefore, the resolution capability of the three-piece thin imaging lens group is obviously improved.
Preferably, wherein the focal length of the first lens element is f1, the radius of curvature of the object-side surface of the first lens element is R1, and the following conditions are satisfied: 0.6< f1/R1< 2.4. Thus, distortion can be advantageously reduced.
Preferably, wherein the focal length of the first lens element is f1, the radius of curvature of the image-side surface of the first lens element is R2, and the following condition is satisfied: -1.0< f1/R2< 0.6. Therefore, the curvature of the image side surface of the first lens element is suitable, which is beneficial to shortening the total length of the three-piece thin imaging lens assembly.
Preferably, wherein the focal length of the second lens element is f2, the radius of curvature of the object-side surface of the second lens element is R3, and the following conditions are satisfied: 0.2< f2/R3< 1.6. Therefore, the method is beneficial to reducing the system sensitivity and can effectively improve the production yield.
Preferably, wherein the focal length of the second lens element is f2, the radius of curvature of the image-side surface of the second lens element is R4, and the following condition is satisfied: -1.8< f2/R4< -0.4. Therefore, the peripheral curvature of the surface of the image side of the second lens can be further reduced, and the characteristic of reducing stray light can be further realized.
Preferably, wherein the focal length of the third lens element is f3, the radius of curvature of the object-side surface of the third lens element is R5, and the following conditions are satisfied: -0.7< f3/R5< 2.7. Thereby, the magnification of the imaging is corrected.
Preferably, wherein the focal length of the third lens element is f3, the radius of curvature of the image-side surface of the third lens element is R6, and the following condition is satisfied: -2.1< f3/R6< 1.0. Thereby, the magnification of the imaging is corrected.
Preferably, a radius of curvature of the object-side surface of the first lens element is R1, a radius of curvature of the image-side surface of the first lens element is R2, and the following conditions are satisfied: -0.9< R1/R2< 0.6. Therefore, the spherical aberration and astigmatism of the three-piece thin imaging lens group can be reduced.
Preferably, a radius of curvature of the object-side surface of the second lens element is R3, a radius of curvature of the image-side surface of the second lens element is R4, and the following condition is satisfied: -3.2< R3/R4< -0.1. Therefore, the astigmatism of the three-piece thin imaging lens group can be reduced.
Preferably, a radius of curvature of the object-side surface of the third lens element is R5, a radius of curvature of the image-side surface of the third lens element is R6, and the following condition is satisfied: -95< R5/R6< 10. Thereby, the curvature configuration of the third lens surface is effectively balanced to achieve a balance between the angle of the field of view and the overall length.
Preferably, the overall focal length of the three-piece thin imaging lens set is f, the distance from the object to the image plane on the optical axis is OTL, and the following conditions are satisfied: 8.0< OTL/f < 18.0. Therefore, the three-piece thin imaging lens group can be kept small and have a long focus, and can be carried on a light and thin electronic product.
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, wherein the following conditions are satisfied: -2.4< (f1+ f2+ f3)/(f1 f2 f3) < -0.1. Therefore, the shot object can be imaged on the imaging surface well with small aberration and high relative illumination on a short object distance.
Drawings
FIG. 1A is a schematic view of a three-piece thin imaging lens assembly according to a first embodiment of the present invention.
Fig. 1B is a partially enlarged view of fig. 1A.
Fig. 1C is a graph sequentially showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the first embodiment from left to right.
FIG. 2A is a schematic view of a three-piece thin imaging lens assembly according to a second embodiment of the present invention.
Fig. 2B is a partially enlarged view of fig. 2A.
Fig. 2C is a graph of the field curvature and distortion aberration of the three-piece thin imaging lens assembly of the second embodiment in order from left to right.
FIG. 3A is a schematic view of a three-piece thin imaging lens assembly according to a third embodiment of the present invention.
Fig. 3B is a partially enlarged view of fig. 3A.
Fig. 3C is a graph sequentially showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the third embodiment from left to right.
FIG. 4A is a schematic view of a three-piece thin imaging lens assembly according to a fourth embodiment of the invention.
Fig. 4B is a partially enlarged view of fig. 4A.
Fig. 4C is a graph sequentially showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the fourth embodiment from left to right.
FIG. 5A is a schematic view of a three-piece thin imaging lens assembly according to a fifth embodiment of the present invention.
Fig. 5B is a partially enlarged view of fig. 5A.
Fig. 5C is a graph showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the fifth embodiment in order from left to right.
FIG. 6A is a schematic view of a three-piece thin imaging lens assembly according to a sixth embodiment of the present invention.
Fig. 6B is a partially enlarged view of fig. 6A.
Fig. 6C is a graph sequentially showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the sixth embodiment from left to right.
FIG. 7A is a schematic view of a three-piece thin imaging lens assembly according to a seventh embodiment of the invention.
Fig. 7B is a partially enlarged view of fig. 7A.
Fig. 7C is a graph sequentially showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the seventh embodiment from left to right.
FIG. 8A is a schematic view of a three-piece thin imaging lens assembly according to an eighth embodiment of the invention.
Fig. 8B is a partially enlarged view of fig. 8A.
Fig. 8C is a graph sequentially showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the eighth embodiment from left to right.
Description of the reference numerals
100. 200, 300, 400, 500, 600, 700, 800: aperture
110. 210, 310, 410, 510, 610, 710, 810: first lens
111. 211, 311, 411, 511, 611, 711, 811: object side surface
112. 212, 312, 412, 512, 612, 712, 812: surface of image side
120. 220, 320, 420, 520, 620, 720, 820: second lens
121. 221, 321, 421, 521, 621, 721, 821: object side surface
122. 222, 322, 422, 522, 622, 722, 822: surface of image side
130. 230, 330, 430, 530, 630, 730, 830: third lens
131. 231, 331, 431, 531, 631, 731, 831: object side surface
132. 232, 332, 432, 532, 632, 732, 832: surface of image side
160. 260, 360, 460, 560, 660, 760, 860: flat element
170. 270, 370, 470, 570, 670, 770, 870: infrared filtering filter
180. 280, 380, 480, 580, 680, 780, 880: image plane
190. 290, 390, 490, 590, 690, 790, 890: optical axis
f: focal length of three-piece thin imaging lens group
Fno: aperture value of three-piece thin imaging lens group
FOV: maximum field angle in three-piece thin imaging lens group
f 1: focal length of the first lens
f 2: focal length of the second lens
f 3: focal length of the third lens
R1: radius of curvature of object-side surface of first lens
R2: radius of curvature of image-side surface of first lens
R3: radius of curvature of object-side surface of second lens
R4: radius of curvature of image-side surface of second lens
R5: radius of curvature of object-side surface of third lens
R6: radius of curvature of image-side surface of the third lens
OTL: the distance between the object and the imaging surface on the optical axis.
Detailed Description
< first embodiment >
Referring to fig. 1A, fig. 1B and fig. 1C, wherein fig. 1A is a schematic view of a three-piece thin imaging lens assembly according to a first embodiment of the invention, and fig. 1B is a partially enlarged view of fig. 1A. Fig. 1C is a graph sequentially showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the first embodiment from left to right. In fig. 1A and 1B, the three-piece thin imaging lens assembly includes, in order from an object side to an image side, a plate element 160, a first lens element 110, an aperture stop 100, a second lens element 120, a third lens element 130, an ir-cut filter 170, and an image plane 180, wherein the three-piece thin imaging lens assembly includes three lens elements (110, 120, and 130). The aperture stop 100 is disposed between the first lens 110 and the second lens 120.
The flat plate element 160 is made of glass material, and is disposed between a subject O and the first lens element 110, and does not affect the focal length of the three-piece thin imaging lens assembly.
The first lens element 110 with negative refractive power has an object-side surface 111 being concave at a paraxial region 190 and an image-side surface 112 being convex at a paraxial region 190, and the object-side surface 111 and the image-side surface 112 are aspheric.
The second lens element 120 with positive refractive power has an object-side surface 121 being convex in a paraxial region 190 and an image-side surface 122 being convex in a paraxial region 190, and both the object-side surface 121 and the image-side surface 122 are aspheric.
The third lens element 130 with positive refractive power has an object-side surface 131 being convex at a paraxial region 190 and an image-side surface 132 being convex at a paraxial region 190, wherein the object-side surface 131 and the image-side surface 132 are aspheric.
The ir-cut filter 170 is made of glass, and is disposed between the third lens element 130 and the image plane 180 without affecting the focal length of the three-piece thin imaging lens assembly.
The curve equation of the aspherical surface of each lens described above is as follows:
wherein z is a position value referenced to the surface vertex at a position of height h along the optical axis 190; c is a curvature of the lens surface near the optical axis 190 and is an inverse of a curvature radius (R) (c is 1/R), R is a curvature radius of the lens surface near the optical axis 190, h is a perpendicular distance of the lens surface from the optical axis 190, k is a conic coefficient (conic constant), and A, B, C, D, E, F, G, … … are high order aspheric coefficients.
In the first embodiment of the three-piece thin imaging lens assembly, the focal length of the three-piece thin imaging lens assembly is f, the aperture value (f-number) of the three-piece thin imaging lens assembly is Fno, and the maximum field angle (view angle) of the three-piece thin imaging lens assembly is FOV, which has the following values: f ═ 0.37 (millimeters); fno 1.35; and FOV 105.0 (degrees).
In the first embodiment of the three-piece thin imaging lens assembly, the focal length of the three-piece thin imaging lens assembly is f, the focal length of the first lens element 110 is f1, the focal length of the second lens element 120 is f2, and the focal length of the third lens element 130 is f3, and the following conditions are satisfied: i/(f 1 f2 f3) | 0.38.
In the first embodiment of the three-piece thin imaging lens assembly, the focal length of the three-piece thin imaging lens assembly is f, the focal length of the first lens element 110 is f1, and the following conditions are satisfied: f/f1 is-0.32.
In the first embodiment of the three-piece thin imaging lens assembly, the focal length of the three-piece thin imaging lens assembly is f, and the focal length of the second lens element 120 is f2, and the following conditions are satisfied: f/f2 is 0.53.
In the first embodiment of the three-piece thin imaging lens assembly, the focal length of the three-piece thin imaging lens assembly is f, the focal length of the third lens element 130 is f3, and the following conditions are satisfied: f/f3 is 0.32.
In the first embodiment of the present invention, the focal length of the three-piece thin imaging lens assembly is f, and the combined focal length of the second lens element 120 and the third lens element 130 is f23, and the following conditions are satisfied: f/f23 is 0.75.
In the first embodiment of the three-piece thin imaging lens assembly, the focal length of the first lens element 110 is f1, the combined focal length of the second lens element 120 and the third lens element 130 is f23, and the following conditions are satisfied: f1/f23 is-2.38.
In the first embodiment of the three-piece thin imaging lens assembly, the focal length of the first lens element 110 is f1, the radius of curvature of the object-side surface 111 of the first lens element 110 is R1, and the following conditions are satisfied: f1/R1 equals 1.86.
In the first embodiment of the present invention, the focal length of the first lens element 110 is f1, the radius of curvature of the image-side surface 112 of the first lens element 110 is R2, and the following conditions are satisfied: f1/R2 is 0.02.
In the first embodiment of the three-piece thin imaging lens assembly, the focal length of the second lens element 120 is f2, the radius of curvature of the object-side surface 121 of the second lens element 120 is R3, and the following conditions are satisfied: f2/R3 equals 0.83.
In the first embodiment of the present invention, the focal length of the second lens element 120 is f2, the radius of curvature of the image-side surface 122 of the second lens element 120 is R4, and the following conditions are satisfied: f2/R4 is-1.19.
In the first embodiment of the three-piece thin imaging lens assembly, the focal length of the third lens element 130 is f3, the radius of curvature of the object-side surface 131 of the third lens element 130 is R5, and the following conditions are satisfied: f3/R5 equals 0.86.
In the first embodiment of the present three-piece thin imaging lens assembly, the focal length of the third lens element 130 is f3, the radius of curvature of the image-side surface 132 of the third lens element 130 is R6, and the following conditions are satisfied: f3/R6 is-0.75.
In the first embodiment of the present invention, a radius of curvature of the object-side surface 111 of the first lens element 110 is R1, a radius of curvature of the image-side surface 112 of the first lens element 110 is R2, and the following conditions are satisfied: R1/R2 is 0.01.
In the first embodiment of the present invention, a radius of curvature of the object-side surface 121 of the second lens element 120 is R3, a radius of curvature of the image-side surface 122 of the second lens element 120 is R4, and the following conditions are satisfied: R3/R4 ═ 1.42.
In the first embodiment of the present invention, a radius of curvature of the object-side surface 131 of the third lens element 130 is R5, a radius of curvature of the image-side surface 132 of the third lens element 130 is R6, and the following conditions are satisfied: R5/R6 ═ 0.86.
In the first embodiment of the three-piece thin imaging lens assembly, the overall focal length of the three-piece thin imaging lens assembly is f, the distance from the object O to the imaging plane 180 on the optical axis 190 is OTL, and the following conditions are satisfied: OTL/f 13.30.
Further, refer to the following Table 1 and Table 2.
Table 1 shows the detailed structural data of the first embodiment in fig. 1A and 1B, wherein the units of the radius of curvature, the thickness and the focal length are mm, and surfaces 0-12 sequentially represent the surfaces from the object side to the image side. Table 2 shows aspheric data in the first embodiment, where k denotes a cone coefficient in the aspheric curve equation, and A, B, C, D, E, F, G and … … denote higher-order aspheric coefficients. In addition, the following tables of the embodiments correspond to the schematic diagrams and aberration graphs of the embodiments, and the definitions of the data in the tables are the same as those in tables 1 and 2 of the first embodiment, which is not repeated herein.
< second embodiment >
Referring to fig. 2A, fig. 2B and fig. 2C, fig. 2A is a schematic view of a three-piece thin imaging lens assembly according to a second embodiment of the invention, and fig. 2B is a partially enlarged view of fig. 2A. Fig. 2C is a graph of the field curvature and distortion aberration of the three-piece thin imaging lens assembly of the second embodiment in order from left to right. In fig. 2A and 2B, the three-piece thin imaging lens assembly includes, in order from an object side to an image side, a plate element 260, a first lens element 210, an aperture stop 200, a second lens element 220, a third lens element 230, an ir-cut filter 270, and an image plane 280, wherein the three-piece thin imaging lens assembly includes three lens elements (210, 220, 230). The aperture stop 200 is disposed between the first lens 210 and the second lens 220.
The flat plate element 260 is made of glass, is disposed between a subject O and the first lens element 210, and does not affect the focal length of the three-piece thin imaging lens assembly.
The first lens element 210 with negative refractive power has an object-side surface 211 being concave at a paraxial region 290 and an image-side surface 212 being convex at a paraxial region 290, and both the object-side surface 211 and the image-side surface 212 are aspheric.
The second lens element 220 with positive refractive power has an object-side surface 221 being convex at a paraxial region 290 thereof and an image-side surface 222 being convex at a paraxial region 290 thereof, wherein the object-side surface 221 and the image-side surface 222 are aspheric.
The third lens element 230 with positive refractive power has an object-side surface 231 being convex at a paraxial region 290 and an image-side surface 232 being convex at a paraxial region 290, and is made of plastic material, wherein the object-side surface 231 and the image-side surface 232 are aspheric.
The ir-cut filter 270 is made of glass, and is disposed between the third lens element 230 and the image plane 280 without affecting the focal length of the three-piece thin imaging lens assembly.
Further, the following Table 3 and Table 4 are referred to.
In the second embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment and will not be described herein.
The following data can be derived from tables 3 and 4:
< third embodiment >
Referring to fig. 3A, fig. 3B and fig. 3C, fig. 3A is a schematic diagram of a three-piece thin imaging lens assembly according to a third embodiment of the invention, and fig. 3B is a partially enlarged view of fig. 3A. Fig. 3C is a graph sequentially showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the third embodiment from left to right. In fig. 3A and 3B, the three-piece thin imaging lens assembly includes, in order from an object side to an image side, a plate element 360, a first lens element 310, an aperture stop 300, a second lens element 320, a third lens element 330, an ir-cut filter 370 and an image plane 380, wherein the three-piece thin imaging lens assembly includes three lens elements (310, 320, 330). The aperture stop 300 is disposed between the first lens 310 and the second lens 320.
The flat plate element 360 is made of glass, and is disposed between a subject O and the first lens element 310 without affecting the focal length of the three-piece thin imaging lens assembly.
The first lens element 310 with negative refractive power has an object-side surface 311 being concave in a paraxial region 390 thereof and an image-side surface 312 being concave in a paraxial region 390 thereof, and the object-side surface 311 and the image-side surface 312 are aspheric.
The second lens element 320 with positive refractive power has an object-side surface 321 being convex at a paraxial region 390, and an image-side surface 322 being convex at a paraxial region 390, wherein the object-side surface 321 and the image-side surface 322 are aspheric.
The third lens element 330 with positive refractive power has an object-side surface 331 being convex at a paraxial region 390 and an image-side surface 332 being convex at a paraxial region 390, and the object-side surface 331 and the image-side surface 332 are aspheric.
The ir-cut filter 370 is made of glass and disposed between the third lens element 330 and the image plane 380 without affecting the focal length of the three-piece thin imaging lens assembly.
Further, the following Table 5 and Table 6 were referred to.
In the third embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment and will not be described herein.
The following data can be derived from tables 5 and 6:
< fourth embodiment >
Referring to fig. 4A, fig. 4B and fig. 4C, fig. 4A is a schematic view of a three-piece thin imaging lens assembly according to a fourth embodiment of the present invention, and fig. 4B is a partially enlarged view of fig. 4A. Fig. 4C is a graph sequentially showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the fourth embodiment from left to right. In fig. 4A and 4B, the three-piece thin imaging lens assembly includes, in order from an object side to an image side, a plate element 460, a first lens element 410, an aperture stop 400, a second lens element 420, a third lens element 430, an ir-cut filter 470 and an image plane 480, wherein the three lens elements (410, 420 and 430) have refractive power. The aperture stop 400 is disposed between the first lens 410 and the second lens 420.
The flat plate element 460 is made of glass, and is disposed between a subject O and the first lens element 410 without affecting the focal length of the three-piece thin imaging lens assembly.
The first lens element 410 with negative refractive power has an object-side surface 411 being concave at a paraxial region 490 thereof and an image-side surface 412 being concave at a paraxial region 490 thereof, and the object-side surface 411 and the image-side surface 412 are aspheric.
The second lens element 420 with positive refractive power has an object-side surface 421 being convex at a paraxial region 490 thereof and an image-side surface 422 being convex at a paraxial region 490 thereof, wherein the object-side surface 421 and the image-side surface 422 are aspheric.
The third lens element 430 with positive refractive power has an object-side surface 431 being convex at a paraxial region 490 thereof and an image-side surface 432 being convex at a paraxial region 490 thereof, and the object-side surface 431 and the image-side surface 432 are aspheric.
The ir-cut filter 470 is made of glass, and is disposed between the third lens element 430 and the image plane 480 without affecting the focal length of the three-piece thin imaging lens assembly.
Further, the following Table 7 and Table 8 are referred to.
In the fourth embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment and will not be described herein.
The following data can be derived from tables 7 and 8:
< fifth embodiment >
Referring to fig. 5A, fig. 5B and fig. 5C, wherein fig. 5A is a schematic view of a three-piece thin imaging lens assembly according to a fifth embodiment of the present invention, and fig. 5B is a partially enlarged view of fig. 5A. Fig. 5C is a graph showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the fifth embodiment in order from left to right. In fig. 5A and 5B, the three-piece thin imaging lens assembly includes, in order from an object side to an image side, a plate element 560, a first lens element 510, an aperture stop 500, a second lens element 520, a third lens element 530, an ir-cut filter 570 and an image plane 580, wherein the three lens elements (510, 520, 530) have refractive power. The aperture stop 500 is disposed between the first lens 510 and the second lens 520.
The flat plate element 560 is made of glass material, and is disposed between a subject O and the first lens element 510, and does not affect the focal length of the three-piece thin imaging lens assembly.
The first lens element 510 with negative refractive power has an object-side surface 511 being concave in a paraxial region 590, and an image-side surface 512 being convex in a paraxial region 590, wherein the object-side surface 511 and the image-side surface 512 are aspheric.
The second lens element 520 with positive refractive power has an object-side surface 521 being convex in a paraxial region 590, and an image-side surface 522 being convex in a paraxial region 590, and the object-side surface 521 and the image-side surface 522 are aspheric.
The third lens element 530 with positive refractive power has an object-side surface 531 being convex at a paraxial region 590 and an image-side surface 532 being convex at a paraxial region 590, wherein the object-side surface 531 and the image-side surface 532 are aspheric.
The ir-cut filter 570 is made of glass, and is disposed between the third lens element 530 and the image plane 580 without affecting the focal length of the three-piece thin imaging lens assembly.
Further, the following table 9 and table 10 are referred to.
In the fifth embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment and will not be described herein.
The following data can be derived from tables 9 and 10:
< sixth embodiment >
Referring to fig. 6A, fig. 6B and fig. 6C, fig. 6A is a schematic diagram illustrating a three-piece thin imaging lens assembly according to a sixth embodiment of the present invention, and fig. 6B is a partially enlarged view of fig. 6A. Fig. 6C is a graph sequentially showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the sixth embodiment from left to right. In fig. 6A and 6B, the three-piece thin imaging lens assembly includes, in order from an object side to an image side, a plate element 660, a first lens element 610, an aperture stop 600, a second lens element 620, a third lens element 630, an ir-cut filter 670 and an image plane 680, wherein the three lens elements (610, 620, 630) have refractive power. The aperture 600 is disposed between the first lens 610 and the second lens 620.
The flat plate element 660 is made of glass, and is disposed between a subject O and the first lens element 610, and does not affect the focal length of the three-piece thin imaging lens assembly.
The first lens element 610 with negative refractive power has an object-side surface 611 being concave in a paraxial region 690 and an image-side surface 612 being concave in a paraxial region 690, and the object-side surface 611 and the image-side surface 612 are aspheric.
The second lens element 620 with positive refractive power has an object-side surface 621 being convex in a paraxial region 690 thereof and an image-side surface 622 being convex in a paraxial region 690 thereof, and the object-side surface 621 and the image-side surface 622 are aspheric.
The third lens element 630 with positive refractive power has an object-side surface 631 being concave at a paraxial region 690 and an image-side surface 632 being convex at a paraxial region 690, and the object-side surface 631 and the image-side surface 632 are aspheric.
The ir-cut filter 670 is made of glass, and is disposed between the third lens element 630 and the image plane 680 without affecting the focal length of the three-piece thin imaging lens assembly.
Further, the following table 11 and table 12 are referred to.
In the sixth embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment and will not be described herein.
The following data can be derived from tables 11 and 12:
< seventh embodiment >
Referring to fig. 7A, fig. 7B and fig. 7C, fig. 7A is a schematic view of a three-piece thin imaging lens assembly according to a seventh embodiment of the present invention, and fig. 7B is a partially enlarged view of fig. 7A. Fig. 7C is a graph sequentially showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the seventh embodiment from left to right. In fig. 7A and 7B, the three-piece thin imaging lens assembly includes, in order from an object side to an image side, a plate element 760, a first lens element 710, an aperture stop 700, a second lens element 720, a third lens element 730, an ir-cut filter 770 and an image plane 780, wherein the three-piece thin imaging lens assembly includes three lens elements (710, 720 and 730). The aperture stop 700 is disposed between the first lens 710 and the second lens 720.
The plate element 760 is made of glass, and is disposed between a subject O and the first lens element 710, and does not affect the focal length of the three-piece thin imaging lens assembly.
The first lens element 710 with negative refractive power has an object-side surface 711 being concave at a paraxial region 790, and an image-side surface 712 being concave at a paraxial region 790, wherein the object-side surface 711 and the image-side surface 712 are aspheric.
The second lens element 720 with positive refractive power has an object-side surface 721 being convex at a paraxial region 790 and an image-side surface 722 being convex at a paraxial region 790, and is made of plastic material, wherein the object-side surface 721 and the image-side surface 722 are aspheric.
The third lens element 730 with positive refractive power has an object-side surface 731 being convex in a paraxial region 790 thereof and an image-side surface 732 being convex in a paraxial region 790 thereof, wherein the object-side surface 731 and the image-side surface 732 are aspheric.
The ir-cut filter 770 is made of glass and disposed between the third lens element 730 and the image plane 780 without affecting the focal length of the three-piece thin imaging lens assembly.
Further, the following table 13 and table 14 are referred to.
In the seventh embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment and will not be described herein.
The following data can be derived from the coordination tables 13 and 14:
< eighth embodiment >
Referring to fig. 8A, 8B and 8C, fig. 8A is a schematic view of a three-piece thin imaging lens assembly according to an eighth embodiment of the present invention, and fig. 8B is a partially enlarged view of fig. 8A. Fig. 8C is a graph sequentially showing the curvature of field and distortion aberration of the three-piece thin imaging lens assembly of the eighth embodiment from left to right. In fig. 8A and 8B, the three-piece thin imaging lens assembly includes, in order from an object side to an image side, a plate element 860, a first lens element 810, an aperture stop 800, a second lens element 820, a third lens element 830, an ir-cut filter 870 and an image plane 880, wherein the three lens elements (810, 820 and 830) have refractive power. The aperture stop 800 is disposed between the first lens 810 and the second lens 820.
The flat plate element 860 is made of glass material, and is disposed between a subject O and the first lens element 810, and does not affect the focal length of the three-piece thin imaging lens assembly.
The first lens element 810 with negative refractive power has an object-side surface 811 being concave at a paraxial region 890 thereof and an image-side surface 812 being concave at a paraxial region 890 thereof, wherein the object-side surface 811 and the image-side surface 812 are aspheric.
The second lens element 820 with positive refractive power has an object-side surface 821 being convex in a paraxial region 890 thereof and an image-side surface 822 being convex in a paraxial region 890 thereof, wherein the object-side surface 821 and the image-side surface 822 are aspheric.
The third lens element 830 with positive refractive power has an object-side surface 831 being convex in a paraxial region 890 thereof and an image-side surface 832 being convex in a paraxial region 890 thereof, wherein the object-side surface 831 and the image-side surface 832 are aspheric.
The ir-cut filter 870 is made of glass, and is disposed between the third lens element 830 and the image plane 880 and does not affect the focal length of the three-piece thin imaging lens assembly.
Further, the following table 15 and table 16 are referred to.
In the eighth embodiment, the curve equation of the aspherical surface represents the form as in the first embodiment. In addition, the following parameters are defined in the same way as in the first embodiment and will not be described herein.
The following data can be derived from the coordination tables 15 and 16:
the three-piece thin imaging lens group provided by the invention has the advantages that the material of the lens can be plastic or glass, the production cost can be effectively reduced when the material of the lens is plastic, and in addition, the degree of freedom of the refractive power configuration of the three-piece thin imaging lens group can be increased when the material of the lens is glass. In addition, the object side surface and the image side surface of the lens in the three-piece thin imaging lens assembly can be aspheric, the aspheric surface can be easily made into shapes other than spherical surfaces, more control variables are obtained for reducing the aberration, and the number of the lens is further reduced, so that the total length of the three-piece thin imaging lens assembly can be effectively reduced.
In the three-piece thin imaging lens assembly provided by the invention, regarding the lens with refractive power, if the lens surface is convex and the position of the convex surface is not defined, the lens surface is convex at a position close to the optical axis; if the lens surface is concave and the concave position is not defined, it means that the lens surface is concave at the paraxial region.
In summary, the above embodiments and drawings are only preferred embodiments of the present invention, and the scope of the present invention should not be limited thereby, that is, all equivalent changes and modifications made according to the claims of the present invention should be covered by the scope of the present invention.