Imaging lens

Abstract

An imaging lens includes a first lens group, a second lens group, a third lens group, and a fourth lens group. The first lens group, the second lens group, the third lens group, and the fourth lens group are arranged in order from an object side to an image side along an optical axis. The first lens group has positive refractive power, and includes a 1-1 lens, a 1-2 lens, a 1-3 lens, and a 1-4 lens. The second lens group has negative refractive power, and includes a 2-2 lens having negative refractive power and including a concave surface facing the object side. The third lens group has positive refractive power, and includes a 3-3 lens having positive refractive power and a 3-4 lens being a double concave lens. The fourth lens group has positive refractive power, and includes a 4-1 lens.

Description

Technical Field

[0001] This invention relates to an imaging lens. Background Technology

[0002] Current iris recognition technology has a short recognition distance, requiring the human eye to be close to the imaging lens for successful recognition, which makes it difficult to popularize. Therefore, there is a need for a new imaging lens architecture to increase the recognition distance of iris recognition. Summary of the Invention

[0003] In view of this, the main objective of the present invention is to provide an imaging lens with a large aperture and zoom function, which can improve the recognition distance of iris recognition when applied to iris recognition.

[0004] This invention provides an imaging lens comprising a first lens group, a second lens group, a third lens group, and a fourth lens group. The first lens group, the second lens group, the third lens group, and the fourth lens group are arranged sequentially along the optical axis from the object side to the image side. The first lens group has positive refractive power and includes lens 1-1, lens 1-2, lens 1-3, and lens 1-4. Lens 1-1, being the lens closest to the object side, has positive refractive power and includes a concave surface facing the image side. Lens 1-2, adjacent to lens 1-1, also has positive refractive power. Lens 1-3 has refractive power and includes a convex surface facing the object side. Lens 1-4 has refractive power and includes a concave surface facing the image side. Lens 1-1, lens 1-2, lens 1-3, and lens 1-4 are arranged sequentially along the optical axis from the object side to the image side. The second lens group has negative refractive power and includes a 2-2 lens, which has negative refractive power and includes a concave surface facing the object side. The third lens group has positive refractive power and includes a 3-3 lens and a 3-4 lens. The 3-3 lens has positive refractive power, and the 3-4 lens is a biconcave lens with negative refractive power, including a concave surface facing the object side and another concave surface facing the image side. The 3-3 lens and the 3-4 lens are arranged sequentially along the optical axis from the object side to the image side. The fourth lens group has positive refractive power and includes a 4-1 lens, which is a biconvex lens with positive refractive power, including a convex surface facing the object side and another convex surface facing the image side.

[0005] The third lens group may further include lens 3-1 and lens 3-2. Lens 3-1 is the lens closest to the object side in the third lens group, and lens 3-4 is the lens closest to the image side in the third lens group. Lens 3-1 is a biconvex lens with positive refractive power and includes one convex surface facing the object side and another convex surface facing the image side. Lens 3-2 and lens 3-3 are meniscus lenses. Lens 3-2 is disposed between and adjacent to lens 3-1 and lens 3-3.

[0006] The second lens group may further include a 2-1 lens disposed between the 2-2 lens and the object side, the 2-1 lens having negative refractive power and including a convex surface facing the object side.

[0007] Lens 1-1 is a meniscus lens closest to the object side, and may further include a convex surface facing the object side. Lens 1-2 is a meniscus lens. There are air gaps between lenses 1-1, 1-2, and 1-3.

[0008] The third lens group may further include lens 3-1 and lens 3-2. Lens 3-1 is the lens closest to the object side in the third lens group, and lens 3-4 is the lens closest to the image side in the third lens group. Lens 3-1 is a biconvex lens with positive refractive power and includes one convex surface facing the object side and another convex surface facing the image side. Lens 3-2 and lens 3-3 are meniscus lenses. Lens 3-2 is disposed between and adjacent to lens 3-1 and lens 3-3. The second lens group may further include lens 2-1 disposed between lens 2-2 and the object side. Lens 2-1 has negative refractive power and includes a convex surface facing the object side.

[0009] Lens 1-2 includes a convex surface facing the object side and a concave surface facing the image side. There is no air gap between lens 1-3 and lens 1-4, or lens 1-3 and lens 1-4 are cemented together, and the combination of lens 1-3 and lens 1-4 has negative refractive power. Lens 2-1 is a meniscus lens and may further include a concave surface facing the image side. Lens 3-2 is a meniscus lens with positive refractive power and includes a convex surface facing the object side and a concave surface facing the image side. Lens 3-3 is a meniscus lens and includes a convex surface facing the object side and a concave surface facing the image side. The lens group includes at least seven meniscus lenses. When the imaging lens zooms, the second lens group moves along the optical axis toward the image side, and the fourth lens group moves along the optical axis toward the object side or the image side, and the fourth lens group is the lens group closest to the image side.

[0010] The 2-2 lens is either a meniscus lens or a biconcave lens. When the 2-2 lens is a meniscus lens, it may further include a convex surface facing the image side. When the 2-2 lens is a biconcave lens, it may further include another concave surface facing the image side.

[0011] It may further include a meniscus lens disposed between the 2-1 lens and the 2-2 lens or between the 3-3 lens and the 3-4 lens, the meniscus lens having positive refractive power and including a convex surface facing the object side and a concave surface facing the image side.

[0012] The second lens group may further include a 2-3 lens disposed between the 2-1 lens and the 2-2 lens. The 2-3 lens is a biconvex lens with positive refractive power and includes a convex surface facing the object side and another convex surface facing the image side.

[0013] The imaging lens satisfies at least one of the following conditions: -92 mm -1 ≤ (rb / dc) / fw ≤ 2 mm -1 ;-1.5 ≤ (db-fa) / rb ≤ 0.8; -7.4 ≤ (ra-rc) / ft ≤ 5.4; -9.76 ≤ rc / (f3g-fc) ≤-0.76; 10 ≤ (ft-fw) / dc ≤ 26; -7.5 mm ≤ ft / (f34 / dc) ≤ -2 mm; -15.7 ≤ (rc / fa)-fw ≤ -1.7; -104 mm ≤ (fc / Y)×f4g ≤ -60 mm; 3.8 ≤ ft / fw ≤ 4.9; -30 mm ≤ (ra / fb)×dc ≤ 1.5 mm; where rb is the radius of curvature of the image-side surface of the lens closest to the aperture between the object side and the aperture, dc is the distance along the optical axis from the image-side surface of the second lens closest to the image side in the third lens group to the object-side surface of the lens closest to the image side in the third lens group, db is the distance along the optical axis from the image-side surface of the 4-1 lens to the imaging plane at the telescope distance, fa is the effective focal length of the 2-1 lens, rc is the radius of curvature of the object-side surface of the lens closest to the image side in the third lens group, and ft is the distance from the telescope distance of the imaging lens. The effective focal lengths at the long end are: f3g is the effective focal length of the third lens group; fc is the effective focal length of the lens closest to the image side in the second lens group; fw is the effective focal length of the imaging lens at the wide-angle end; f34 is the combined effective focal length of the combination of lenses 1-3 and lenses 1-4; Y is the maximum image height of the imaging lens; f4g is the effective focal length of the fourth lens group; ra is the radius of curvature of the image side of the lens with positive refractive power in the second lens group; and fb is the effective focal length of the lens with positive refractive power in the second lens group.

[0014] The imaging lens of the present invention has a large aperture and zoom function, which can improve the recognition distance of iris recognition when applied to iris recognition. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the lens configuration and optical path according to the first embodiment of the imaging lens of the present invention.

[0016] Figure 2 This is a schematic diagram of the lens configuration and optical path according to a second embodiment of the imaging lens of the present invention.

[0017] Figure 3 This is a diagram of longitudinal aberration at the wide-angle end of the second embodiment of the imaging lens according to the present invention.

[0018] Figure 4 This is a field curvature diagram at the wide-angle end of the second embodiment of the imaging lens according to the present invention.

[0019] Figure 5 This is a distortion diagram at the wide-angle end of the second embodiment of the imaging lens according to the present invention.

[0020] Figure 6 This is a longitudinal aberration map at the telescope according to a second embodiment of the imaging lens of the present invention.

[0021] Figure 7 This is a field curve diagram at a telescope based on a second embodiment of the imaging lens of the present invention.

[0022] Figure 8 This is a distortion image of a telescope based on a second embodiment of the imaging lens of the present invention.

[0023] Figure 9 This is a schematic diagram of the lens configuration and optical path according to a third embodiment of the imaging lens of the present invention.

[0024] Figure 10 This is a longitudinal aberration diagram at the wide-angle end according to the third embodiment of the imaging lens of the present invention.

[0025] Figure 11 This is a field curvature diagram at the wide-angle end of the imaging lens according to the third embodiment of the present invention.

[0026] Figure 12 This is a distortion diagram at the wide-angle end of the imaging lens according to the third embodiment of the present invention.

[0027] Figure 13 This is a longitudinal aberration map at the telescope based on the third embodiment of the imaging lens of the present invention.

[0028] Figure 14 This is a field curve diagram at a telescope based on a third embodiment of the imaging lens of the present invention.

[0029] Figure 15 This is a distortion image of a telescope based on a third embodiment of the imaging lens of the present invention.

[0030] Figure 16 This is a schematic diagram of the lens configuration and optical path according to the fourth embodiment of the imaging lens of the present invention.

[0031] Figure 17 This is a longitudinal aberration diagram at the wide-angle end according to the fourth embodiment of the imaging lens of the present invention.

[0032] Figure 18 This is a field curvature diagram at the wide-angle end of the fourth embodiment of the imaging lens according to the present invention.

[0033] Figure 19 This is a distortion diagram at the wide-angle end of the fourth embodiment of the imaging lens according to the present invention.

[0034] Figure 20 This is a longitudinal aberration map of the telescope based on the fourth embodiment of the imaging lens of the present invention.

[0035] Figure 21 This is a field curve diagram at a telescope based on the fourth embodiment of the imaging lens of the present invention.

[0036] Figure 22 This is a distortion image of a telescope based on the fourth embodiment of the imaging lens of the present invention.

[0037] Figure 23 This is a schematic diagram of the lens configuration and optical path according to the fifth embodiment of the imaging lens of the present invention. Detailed Implementation

[0038] This invention provides an imaging lens, comprising a first lens group, a second lens group, a third lens group, and a fourth lens group, wherein: the first lens group, the second lens group, the third lens group, and the fourth lens group are arranged sequentially along the optical axis from the object side to the image side; the first lens group has positive refractive power, and includes a 1-1 lens, a 1-2 lens, a 1-3 lens, and a 1-4 lens, wherein the 1-1 lens, being the lens closest to the object side, has positive refractive power and includes a concave surface facing the image side and a convex surface facing the object side; the 1-2 lens... Lenses 1-2, which have positive refractive power, can be biconvex, meniscus (convex-concave or concave-convex), or plano-convex (plano-convex or convex-plano). Lens 1-2 is adjacent to lens 1-1. Lens 1-3 has positive or negative refractive power and includes a convex surface facing the object side and a concave, convex, or flat surface facing the image side. When it is positive refractive, it is not a biconcave lens; when it is negative refractive, it is not a biconvex or plano-convex lens. Lens 1-4 has positive or negative refractive power and includes a concave surface facing the image side and a concave, convex, or flat surface facing the object side. When it is positive refractive, it is not a biconvex or plano-convex lens. A biconcave lens or a plano-concave lens, which is not a biconvex lens when it is used for negative refraction; the 1-1 lens, the 1-2 lens, the 1-3 lens, and the 1-4 lens are arranged sequentially along the optical axis from the object side to the image side; the second lens group has negative refractive power, and the second lens group includes a 2-2 lens, which has negative refractive power and includes a concave surface facing the object side, and a concave surface, a convex surface, or a flat surface facing the image side; the third lens group has positive refractive power, and the third lens group includes a 3-3 lens and a 3-4 lens, which has positive refractive power. The lens has refractive power and can be a biconvex lens, a meniscus lens (convex-concave or concave-convex), or a plano-convex lens (plano-convex or convex-plano). The 3-4 lenses are biconcave lenses with negative refractive power and include one concave surface facing the object side and another concave surface facing the image side. The 3-3 and 3-4 lenses are arranged sequentially along the optical axis from the object side to the image side. The fourth lens group has positive refractive power and includes a 4-1 lens, which is a biconvex lens with positive refractive power and includes one convex surface facing the object side and another convex surface facing the image side. When the imaging lens of the present invention satisfies the above characteristics, the basic operation of the imaging lens of the present invention can be achieved without the need for other additional features and conditions.

[0039] Please refer to Tables 1, 2, 4, 5, 7, 8, 10, 11, 13, and 14 below. Tables 1, 4, 7, 10, and 13 are the relevant parameter tables for each lens in the first to fifth embodiments of the imaging lens according to the present invention, and Tables 2, 5, 8, 11, and 14 are the relevant parameter tables for the aspherical surface of the aspherical lens in Tables 1, 4, 7, 10, and 13.

[0040] Figure 1 , 2Figures 9, 16, and 23 are schematic diagrams of lens configuration and optical path according to the first, second, third, fourth, and fifth embodiments of the imaging lens of the present invention. From top to bottom, each figure represents the imaging lens at the wide-angle end, the first intermediate end, the second intermediate end, and the telephoto end, respectively.

[0041] Among them, lenses 1-1 (1L11, 2L11, 3L11, 4L11, 5L11) are meniscus lenses with positive refractive power, made of glass. Their object-side surfaces (S11, S21, S31, S41, S51) are convex, while their image-side surfaces (S12, S22, S32, S42, S52) are concave. All of them are spherical surfaces and are the lenses closest to the object side. Lenses 1-2 (1L12, 2L12, 3L12, 4L12, 5L12) are meniscus lenses with positive refractive power, made of plastic. Their object sides (S13, S23, S33, S43, S53) are convex, and their image sides (S14, S24, S34, S44, S54) are concave. All are aspherical surfaces and are adjacent to lenses 1-1 (1L11, 2L11, 3L11, 4L11, 5L11) with an air gap. Lenses 1-3 (1L13, 2L13, 3L13, 4L13, 5L13) are meniscus lenses with positive refractive power, made of glass. Their object sides (S15, S25, S35, S45, S55) are convex, and their image sides (S16, S26, S36, S46, S56) are concave, all being spherical surfaces. They are adjacent to lenses 1-2 (1L12, 2L12, 3L12, 4L12, 5L12) with an air gap, which helps to correct lateral chromatic aberration. Lenses 1-4 (1L14, 2L14, 3L14, 4L14, 5L14) are meniscus lenses with negative refractive power, made of glass. Their object sides (S16, S26, S36, S46, S56) are convex, while their image sides (S17, S27, S37, S47, S57) are concave, all spherical surfaces, which helps correct lateral chromatic aberration. Lenses 1-3 (1L13, 2L13, 3L13, 4L13, 5L13) are cemented to or have no air gaps with lenses 1-4 (1L14, 2L14, 3L14, 4L14, 5L14), which also helps correct lateral chromatic aberration.

[0042] 2-1 Lenses 1L21, 2L21, 3L21, 4L21, and 5L21 are meniscus lenses with negative refractive power, made of plastic. Their object-side surfaces S18, S28, S38, S48, and S58 are convex, while their image-side surfaces S19, S29, S39, S49, and S59 are concave, all being aspherical surfaces. 2-2 Lenses 1L22, 2L22, 3L22, 4L22, and 5L22 are meniscus or biconcave lenses with negative refractive power, made of glass. Their object-side surfaces S110, S212, S312, S412, and S510 are concave, forming spherical surfaces, while their image-side surfaces S111, S213, S313, S413, and S511 are also spherical surfaces, which helps to increase zoom magnification.

[0043] Lenses 1L31, 2L31, 3L31, 4L31, and 5L31 are biconvex lenses with positive refractive power, made of glass. Their object-side surfaces S113, S215, S315, S415, and S512, and image-side surfaces S114, S216, S316, S416, and S513 are convex, and all are spherical surfaces. Lenses 1L32, 2L32, 3L32, 4L32, and 5L32 are meniscus lenses with positive refractive power, made of glass. Their object-side surfaces S115, S217, S317, S417, and S515 are convex, and their image-side surfaces S116, S218, S318, S418, and S516 are concave, and all are spherical surfaces. Lenses 1L33, 2L33, 3L33, 4L33, and 5L33 are meniscus lenses with positive refractive power, made of glass. Their object-side surfaces S117, S219, S319, S419, and S517 are convex, while their image-side surfaces S118, S220, S320, S420, and S518 are concave, and all are spherical surfaces. Lenses 1L34, 2L34, 3L34, 4L34, and 5L34 are biconcave lenses with negative refractive power, made of glass. Their object-side surfaces S119, S221, S321, S421, and S521, while their image-side surfaces S120, S222, S322, S422, and S522 are concave, and all are spherical surfaces, which helps to shorten the overall length.

[0044] Lenses 1L41, 2L41, 3L41, 4L41, and 5L41 are biconvex lenses with positive refractive power. They are made of plastic and have convex surfaces on their object sides (S121, S223, S323, S423, S523) and image sides (S122, S224, S324, S424, S524). All of these are aspherical surfaces, which helps to improve the zoom ratio.

[0045] The imaging lens may further satisfy at least one of the following conditions (1) to (10):

[0046] -92 mm-1 ≤ (rb / dc) / fw ≤ 2 mm -1 ;(1)

[0047] -1.5 ≤ (db-fa) / rb ≤ 0.8;(2)

[0048] -7.4 ≤ (ra-rc) / ft ≤ 5.4;(3)

[0049] -9.76 ≤ rc / (f3g-fc) ≤ -0.76; (4)

[0050] 10 ≤ (ft-fw) / dc ≤ 26;(5)

[0051] -7.5 mm ≤ ft / (f34 / dc) ≤ -2 mm;(6)

[0052] -15.7 ≤ (rc / fa)-fw ≤ -1.7;(7)

[0053] -104 mm ≤ (fc / Y)×f4g ≤ -60 mm; (8)

[0054] 3.8 ≤ ft / fw ≤ 4.9;(9)

[0055] -30 mm ≤ (ra / fb)×dc ≤ 1.5 mm; (10)

[0056] Wherein, rb represents the radius of curvature of the image-side surfaces S111, S213, S313, S413, and S513 of lenses 1L22, 2L22, 3L22, 4L22, and 5L31 closest to apertures ST1, ST2, ST3, ST4, and ST5 between the object side and apertures ST1, ST2, ST3, ST4, and ST5 in the first to fifth embodiments; dc represents the radius of curvature of the image-side surfaces S118, S220, S320, S420, and S520 of the second image-side closest lenses 1L33, 2L33, 3L33, 4L33, and 5L35 in the third lens group LG13, LG23, LG33, LG43, and LG53 in the first to fifth embodiments. 3. The distances of the object-side surfaces S119, S221, S321, S421, and S521 of the lenses 1L34, 2L34, 3L34, 4L34, and 5L34 closest to the image side in LG23, LG33, LG43, and LG53 along the optical axes OA1, OA2, OA3, OA4, and OA5, where db is the distance from the image-side surfaces S122, S224, S324, S424, and S524 of lenses 1L41, 2L41, 3L41, 4L41, and 5L41 of 4-1 to the imaging surfaces IMA1, IMA2, IMA3, IMA4, and IMA5 along the optical axes OA1, OA2, OA3, OA4, and OA5 to the telescope distance in the first to fifth embodiments, where fa is the distance from the first... In embodiments one through five, the effective focal lengths of lenses 1L21, 2L21, 3L21, 4L21, and 5L21 in 2-1 are: ra is the radius of curvature of the image-side surfaces S211, S311, and S411 of lenses 2L23, 3L23, and 4L23 with positive refractive power in the second lens group LG22, LG32, and LG42 in embodiments two through four; rc is the radius of curvature of the object-side surfaces S119, S221, S321, S421, and S521 of lenses 1L34, 2L34, 3L34, 4L34, and 5L34 closest to the image side in the third lens group LG13, LG23, LG33, LG43, and LG53 in embodiments one through five; and ft is the radius of curvature of the first embodiment. For example, in the fifth embodiment, the effective focal lengths of imaging lenses 1, 2, 3, 4, and 5 at the telescope distance are: f3g is the effective focal length of the third lens group LG13, LG23, LG33, LG43, and LG53 in the first to fifth embodiments; fc is the effective focal length of the lens 1L22, 2L22, 3L22, 4L22, and 5L22 closest to the image side in the second lens group LG12, LG22, LG32, LG42, and LG52 in the first to fifth embodiments; fb is the effective focal length of the lens 2L23, 3L23, and 4L23 with positive refractive power in the second lens group LG22, LG32, and LG42 in the second to fourth embodiments; and fw is the effective focal length of the lens 2L23 in the first to fifth embodiments.The effective focal lengths of imaging lenses 1, 2, 3, 4, and 5 at the wide-angle end are defined as follows: f34 is the combined effective focal length of the combination of lenses 1L13, 2L13, 3L13, 4L13, and 5L13 (1-3) and lenses 1L14, 2L14, 3L14, 4L14, and 5L14 (1-4) in the first to fifth embodiments; Y is the maximum image height of imaging lenses 1, 2, 3, 4, and 5 in the first to fifth embodiments; and f4g is the effective focal length of the fourth lens group LG14, LG24, LG34, LG44, and LG54 in the first to fifth embodiments. This allows imaging lenses 1, 2, 3, 4, and 5 to effectively shorten the overall lens length, effectively correct lateral chromatic aberration, effectively increase the zoom ratio, and effectively correct aberrations.

[0057] When condition (1) is met: -92 mm -1 ≤ (rb / dc) / fw ≤ 2 mm -1 When condition (2) is met: -1.5 ≤ (db-fa) / rb ≤ 0.8, lateral chromatic aberration can be effectively reduced, and basic operation can be achieved. When condition (3) is met: -7.4 ≤ (ra-rc) / ft ≤ 5.4, aberrations and astigmatism in the off-axis field of view can be effectively reduced, and basic operation can be achieved. When condition (4) is met: -9.76 ≤ rc / (f3g-fc) ≤ -0.76, spherical aberration can be effectively reduced and the total length of the lens can be shortened, and basic operation can be achieved. When condition (5) is met: 10 ≤ (ft-fw) / dc ≤ 26, image quality can be effectively improved, and basic operation can be achieved. When condition (6) is met: -7.5 mm ≤ ft / (f34 / dc) ≤ -2 mm, image quality can be effectively improved, and basic operation can be achieved. When condition (7) is met: -15.7 ≤ (rc / fa)-fw ≤ -1.7, the image quality can be effectively improved, and basic operation can be achieved. When condition (8) is met: -104 mm ≤ (fc / Y)×f4g ≤ -60 mm, the image quality can be effectively improved, and basic operation can be achieved. When condition (9) is met: 3.8 ≤ ft / fw ≤ 4.9, the image quality can be effectively improved, and basic operation can be achieved. When condition (10) is met: -30 mm ≤ (ra / fb)×dc ≤ 1.5 mm, distortion and longitudinal chromatic aberration can be effectively reduced to improve image quality, and basic operation can be achieved.

[0058] The first embodiment of the imaging lens of the present invention will now be described in detail. Please refer to... Figure 1Imaging lens 1, along the optical axis OA1 from the object side to the image side, sequentially includes a first lens group LG11, a second lens group LG12, an aperture ST1, a third lens group LG13, and a fourth lens group LG14. The first lens group LG11 has positive refractive power, the second lens group LG12 has negative refractive power, the third lens group LG13 has positive refractive power, and the fourth lens group LG14 has positive refractive power. The first lens group LG11, along the optical axis OA1 from the object side to the image side, sequentially includes lens 1-1 1L11, lens 1-2 1L12, lens 1-3 1L13, and lens 1-4 1L14. The second lens group LG12, along the optical axis OA1 from the object side to the image side, sequentially includes lens 2-1 1L21 and lens 2-2 1L22. The third lens group LG13, along the optical axis OA1 from the object side to the image side, sequentially includes lens 1L31 (3-1), lens 1L32 (3-2), lens 1L33 (3-3), and lens 1L34 (3-4). The fourth lens group LG14 includes lens 1L41 (4-1). When zooming from the wide-angle end to the telephoto end, the first lens group LG11 remains stationary, the second lens group LG12 moves along the optical axis OA1 from the object side to the image side, the third lens group LG13 remains stationary, and the fourth lens group LG14 moves along the optical axis OA1 towards either the image side or the object side. During imaging, the light rays from the object side are finally imaged onto the imaging plane IMA1. According to paragraphs 1 to 7 of the [Implementation Method], wherein: 2-2 lens 1L22 is a meniscus lens and its image side surface S111 is a convex surface; by using the above lens and the design that satisfies at least one of conditions (1) to (10), the imaging lens 1 can effectively shorten the total length of the lens, effectively correct lateral chromatic aberration, effectively increase the zoom ratio, and effectively correct aberrations.

[0059] Table 1 is... Figure 1 Table of relevant parameters for each lens in imaging lens 1.

[0060]

[0061] The aspherical surface concavity z of the aspherical lens in Table 1 is obtained by the following formula: z = ch 2 / {1+[1-(k+1)c 2 h 2 ] 1 / 2}+Ah 4 +Bh 6 +Ch 8 Where: c: curvature; h: perpendicular distance from any point on the lens surface to the first axis; k: conic constant; A~C: aspherical coefficients. Table 2 is a table of relevant parameters for the aspherical surface of the aspherical lens in Table 1, where k is the conic constant and A~C are the aspherical coefficients.

[0062]

[0063] Table 3 shows the relevant parameter values ​​of the imaging lens 1 in the first embodiment and the calculated values ​​of the corresponding conditions. By satisfying the conditions and the refractive power and surface shape in Table 1, the first embodiment is a preferred embodiment of the present invention.

[0064]

[0065] The second embodiment of the imaging lens of the present invention will now be described in detail. Please refer to... Figure 2 Imaging lens 2, along the optical axis OA2 from the object side to the image side, sequentially includes a first lens group LG21, a second lens group LG22, an aperture ST2, a third lens group LG23, and a fourth lens group LG24. The first lens group LG21 has positive refractive power, the second lens group LG22 has negative refractive power, the third lens group LG23 has positive refractive power, and the fourth lens group LG24 has positive refractive power. The first lens group LG21, along the optical axis OA2 from the object side to the image side, sequentially includes lens 2L11 (1-1), lens 2L12 (1-2), lens 2L13 (1-3), and lens 2L14 (1-4). The second lens group LG22, along the optical axis OA2 from the object side to the image side, sequentially includes lens 2L21 (2-1), lens 2L23 (2-3), and lens 2L22 (2-2). The third lens group LG23, along the optical axis OA2 from the object side to the image side, sequentially includes lens 2L31 (3-1), lens 2L32 (3-2), lens 2L33 (3-3), and lens 2L34 (3-4). The fourth lens group LG24 includes lens 2L41 (4-1). When zooming from the wide-angle end to the telephoto end, the first lens group LG21 remains stationary, the second lens group LG22 moves along the optical axis OA2 from the object side to the image side, the third lens group LG23 remains stationary, and the fourth lens group LG24 moves along the optical axis OA2 towards either the image side or the object side. During imaging, the light rays from the object side are finally imaged onto the imaging plane IMA2. According to paragraphs 1 to 7 of the [Implementation Method], wherein: 2-3 lens 2L23 is a meniscus lens with positive refractive power, made of glass, with its object side S210 being convex and its image side S211 being concave, and both the object side S210 and the image side S211 being aspherical surfaces; 2-2 lens 2L22 is a meniscus lens, with its image side S213 being convex; by utilizing the above-mentioned lens, aperture ST2 and the design that satisfies at least one of conditions (1) to (10), the imaging lens 2 can effectively shorten the total length of the lens, effectively correct lateral chromatic aberration, effectively increase the zoom ratio, and effectively correct aberrations.

[0066] Table 4 is... Figure 2 Table of relevant parameters for each lens in the imaging lens 2.

[0067]

[0068] The definition of the aspherical surface concavity z of each lens in Table 4 is the same as the definition of the aspherical surface concavity z of each lens in Table 1 of the first embodiment, and will not be repeated here. Table 5 is a table of relevant parameters of the aspherical surface of the aspherical lens in Table 4, where k is the conic constant and A to C are the aspherical coefficients.

[0069]

[0070] Table 6 shows the relevant parameter values ​​of the imaging lens 2 in the second embodiment and the calculated values ​​of the corresponding conditions (1) to (10). As can be seen from Table 6, the imaging lens 2 in the second embodiment can meet the requirements of conditions (1) to (10). Meeting the conditions and the refractive power and surface shape in Table 4 constitutes a preferred embodiment of the present invention.

[0071]

[0072] Furthermore, the optical performance of the imaging lens 2 in the second embodiment also meets the requirements. Figure 3 It can be seen that, at the wide-angle end, the longitudinal aberration of the imaging lens 2 in the second embodiment is between -0.01 mm and 0.01 mm. Figure 4 It can be seen that, at the wide-angle end, the field curvature of the imaging lens 2 in the second embodiment is between -0.02 mm and 0.06 mm. Figure 5 It can be seen that, at the wide-angle end, the distortion of the imaging lens 2 in the second embodiment is between -1.2% and 0%. Figure 6 It can be seen that the imaging lens 2 of the second embodiment, at the telescopic distance, has a longitudinal aberration between -0.03 mm and 0.0 mm. Figure 7 It can be seen that the imaging lens 2 of the second embodiment is at a telescopic distance, and its field curvature is between 0.0 mm and 0.17 mm. Figure 8 It can be seen that the distortion of the imaging lens 2 in the second embodiment at the telephoto end is between 0.0% and 0.7%. Clearly, the longitudinal aberration, field curvature, and distortion of the imaging lens 2 in the second embodiment can be effectively corrected, thereby achieving better optical performance.

[0073] The third embodiment of the imaging lens of the present invention will now be described in detail. Please refer to [link / reference]. Figure 9The imaging lens 3, along the optical axis OA3 from the object side to the image side, sequentially includes a first lens group LG31, a second lens group LG32, an aperture ST3, a third lens group LG33, and a fourth lens group LG34. The first lens group LG31 has positive refractive power, the second lens group LG32 has negative refractive power, the third lens group LG33 has positive refractive power, and the fourth lens group LG34 has positive refractive power. The first lens group LG31, along the optical axis OA3 from the object side to the image side, sequentially includes lens 3L11 (1-1), lens 3L12 (1-2), lens 3L13 (1-3), and lens 3L14 (1-4). The second lens group LG32, along the optical axis OA3 from the object side to the image side, sequentially includes lens 3L21 (2-1), lens 3L23 (2-3), and lens 3L22 (2-2). The third lens group LG33, along the optical axis OA3 from the object side to the image side, sequentially includes lens 3L31 (3-1), lens 3L32 (3-2), lens 3L33 (3-3), and lens 3L34 (3-4). The fourth lens group LG34 includes lens 3L41 (4-1). When zooming from the wide-angle end to the telephoto end, the first lens group LG31 remains stationary, the second lens group LG32 moves along the optical axis OA3 from the object side to the image side, the third lens group LG33 remains stationary, and the fourth lens group LG34 moves along the optical axis OA3 towards either the image side or the object side. During imaging, the light rays from the object side are finally imaged onto the imaging plane IMA3. According to paragraphs 1 to 7 of the [Implementation Method], wherein: 2-3 lens 3L23 is a biconvex lens with positive refractive power, made of glass, with its object side S310 being convex and its image side S311 being convex, and both the object side S310 and the image side S311 being aspherical surfaces; 2-2 lens 3L22 is a biconcave lens, with its image side S313 being concave; by utilizing the above-mentioned lens, aperture ST3 and the design that satisfies at least one of conditions (1) to (10), the imaging lens 3 can effectively shorten the total length of the lens, effectively correct lateral chromatic aberration, effectively increase the zoom ratio, and effectively correct aberrations.

[0074] Table 7 is... Figure 9 Table of relevant parameters for each lens in the imaging lens 3.

[0075]

[0076] The definition of the aspherical surface concavity z of each lens in Table 7 is the same as the definition of the aspherical surface concavity z of each lens in Table 1 of the first embodiment, and will not be repeated here. Table 8 is a table of relevant parameters of the aspherical surface of the aspherical lens in Table 7, where k is the conic constant and A to C are the aspherical coefficients.

[0077]

[0078] Table 9 shows the relevant parameter values ​​of the imaging lens 3 in the third embodiment and the calculated values ​​of the corresponding conditions. As can be seen from Table 9, the imaging lens 3 in the third embodiment can meet the requirements of conditions (1) to (10). Meeting the conditions and the refractive power and surface shape in Table 7 constitutes a preferred embodiment of the present invention.

[0079]

[0080] Furthermore, the optical performance of the imaging lens 3 in the third embodiment also meets the requirements. Figure 10 It can be seen that, at the wide-angle end, the longitudinal aberration of the imaging lens 3 in the third embodiment is between -0.02 mm and 0.01 mm. Figure 11 It can be seen that, at the wide-angle end, the field curvature of the imaging lens 3 in the third embodiment is between -0.02 mm and 0.02 mm. Figure 12 It can be seen that, at the wide-angle end, the distortion of the imaging lens 3 in the third embodiment is between -2.7% and 0%. Figure 13 It can be seen that the imaging lens 3 in the third embodiment, at the telescope distance, has a longitudinal aberration between -0.02 mm and 0.03 mm. Figure 14 It can be seen that the imaging lens 3 of the third embodiment is at a telescopic distance, and its field curvature is between -0.04 mm and 0.0 mm. Figure 15 It can be seen that the distortion of the imaging lens 3 in the third embodiment at the telephoto end is between 0.0% and 0.9%. Clearly, the longitudinal aberration, field curvature, and distortion of the imaging lens 3 in the third embodiment can be effectively corrected, thereby achieving better optical performance.

[0081] The fourth embodiment of the imaging lens of the present invention will now be described in detail. Please refer to... Figure 16The imaging lens 4, along the optical axis OA4 from the object side to the image side, sequentially includes a first lens group LG41, a second lens group LG42, an aperture ST4, a third lens group LG43, and a fourth lens group LG44. The first lens group LG41 has positive refractive power, the second lens group LG42 has negative refractive power, the third lens group LG43 has positive refractive power, and the fourth lens group LG44 has positive refractive power. The first lens group LG41, along the optical axis OA4 from the object side to the image side, sequentially includes a 1-1 lens 4L11, a 1-2 lens 4L12, a 1-3 lens 4L13, and a 1-4 lens 4L14. The second lens group LG42, along the optical axis OA4 from the object side to the image side, sequentially includes a 2-1 lens 4L21, a 2-3 lens 4L23, and a 2-2 lens 4L22. The third lens group LG43, along the optical axis OA4 from the object side to the image side, sequentially includes lens 4L31 (3-1), lens 4L32 (3-2), lens 4L33 (3-3), and lens 4L34 (3-4). The fourth lens group LG44 includes lens 4L41 (4-1). When zooming from the wide-angle end to the telephoto end, the first lens group LG41 remains stationary, the second lens group LG42 moves along the optical axis OA4 from the object side to the image side, the third lens group LG43 remains stationary, and the fourth lens group LG44 moves along the optical axis OA4 towards either the image side or the object side. During imaging, the light rays from the object side are finally imaged onto the imaging plane IMA4. According to paragraphs 1 to 7 of the [Implementation Method], wherein: 2-3 lens 4L23 is a meniscus lens with positive refractive power, made of glass, its object side S410 is convex and its image side S411 is concave, and both the object side S410 and the image side S411 are aspherical surfaces; 2-2 lens 4L22 is a meniscus lens, its image side S413 is convex; by utilizing the above-mentioned lens, aperture ST4 and the design that satisfies at least one of conditions (1) to (10), the imaging lens 4 can effectively shorten the total length of the lens, effectively correct lateral chromatic aberration, effectively increase the zoom ratio, and effectively correct aberrations.

[0082] Table 10 is... Figure 16 Table of relevant parameters for each lens in the imaging lens 4.

[0083]

[0084] The definition of the aspherical surface concavity z of each lens in Table 10 is the same as the definition of the aspherical surface concavity z of each lens in Table 1 of the first embodiment, and will not be repeated here. Table 11 is a table of relevant parameters of the aspherical surface of the aspherical lens in Table 10, where k is the conic constant and A to C are the aspherical coefficients.

[0085]

[0086] Table 12 shows the relevant parameter values ​​of the imaging lens 4 in the fourth embodiment and the calculated values ​​of the corresponding conditions. As can be seen from Table 12, the imaging lens 4 in the fourth embodiment can meet the requirements of conditions (1) to (10). Meeting the conditions and the refractive power and surface shape in Table 10 constitutes a preferred embodiment of the present invention.

[0087]

[0088] Furthermore, the optical performance of the imaging lens 4 in the fourth embodiment also meets the requirements. Figure 17 It can be seen that, at the wide-angle end, the longitudinal aberration of the imaging lens 4 in the fourth embodiment is between -0.01 mm and 0.02 mm. Figure 18 It can be seen that, at the wide-angle end, the field curvature of the imaging lens 4 in the fourth embodiment is between -0.025 mm and 0.025 mm. Figure 19 It can be seen that, at the wide-angle end, the distortion of the imaging lens 4 in the fourth embodiment is between -1.2% and 0%. Figure 20 It can be seen that the imaging lens 4 in the fourth embodiment, at the telescope distance, has a longitudinal aberration between -0.015 mm and 0.025 mm. Figure 21 It can be seen that the imaging lens 4 of the fourth embodiment is at a telescopic distance, and its field curvature is between 0.02 mm and 0.09 mm. Figure 22 It can be seen that the distortion of the imaging lens 4 in the fourth embodiment at the telephoto end is between 0.0% and 1.5%. Clearly, the longitudinal aberration, field curvature, and distortion of the imaging lens 4 in the fourth embodiment can be effectively corrected, thereby achieving better optical performance.

[0089] The fifth embodiment of the imaging lens of the present invention will now be described in detail. Please refer to... Figure 23The imaging lens 5, along the optical axis OA5 from the object side to the image side, sequentially includes a first lens group LG51, a second lens group LG52, a third lens group LG53, and a fourth lens group LG54. The first lens group LG51 has positive refractive power, the second lens group LG52 has negative refractive power, the third lens group LG53 has positive refractive power, and the fourth lens group LG54 has positive refractive power. The first lens group LG51, along the optical axis OA5 from the object side to the image side, sequentially includes lens 1-1 5L11, lens 1-2 5L12, lens 1-3 5L13, and lens 1-4 5L14. The second lens group LG52, along the optical axis OA5 from the object side to the image side, sequentially includes lens 2-1 5L21 and lens 2-2 5L22. The third lens group LG53, along the optical axis OA5 from the object side to the image side, sequentially includes lens 5L31 (3-1), lens 5L32 (3-2), lens 5L33 (3-3), lens 5L35 (3-5), and lens 5L34 (3-4). The fourth lens group LG54 includes lens 5L41 (4-1). The imaging lens 5 further includes an aperture ST5 positioned between lens 5L31 (3-1) and lens 5L32 (3-2). When zooming from the wide-angle end to the telephoto end, the first lens group LG51 remains stationary, the second lens group LG52 moves along the optical axis OA5 from the object side to the image side, the third lens group LG53 remains stationary, and the fourth lens group LG54 moves along the optical axis OA5 towards either the image side or the object side. During imaging, the light rays from the object side are finally imaged onto the imaging plane IMA5. According to paragraphs 1 to 7 of the [Implementation Method], wherein: 2-2 lens 5L22 is a meniscus lens with its image-side surface S511 being convex; 3-5 lens 5L35 is a meniscus lens with positive refractive power, made of glass, with its object-side surface S519 being convex and its image-side surface S520 being concave, and both the object-side surface S519 and the image-side surface S520 being spherical surfaces; by utilizing the above-mentioned lens, aperture ST5 and the design that satisfies at least one of conditions (1) to (9), the imaging lens 5 can effectively shorten the total length of the lens, effectively correct lateral chromatic aberration, effectively increase the zoom ratio, and effectively correct aberrations.

[0090] Table 13 is... Figure 23 Table of relevant parameters for each lens in the imaging lens 5.

[0091]

[0092] The definition of the aspherical surface concavity z of each lens in Table 13 is the same as the definition of the aspherical surface concavity z of each lens in Table 1 of the first embodiment, and will not be repeated here. Table 14 is a table of relevant parameters of the aspherical surface of the aspherical lens in Table 13, where k is the conic constant and A to C are the aspherical coefficients.

[0093]

[0094] Table 15 shows the relevant parameter values ​​of the imaging lens 5 in the fifth embodiment and the calculated values ​​of the corresponding conditions. Meeting the conditions and the refractive power and surface shape specified in Table 13 constitutes a preferred embodiment of the present invention.

[0095]

[0096] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. An imaging lens, characterized in that, It includes a first lens group, a second lens group, a third lens group, and a fourth lens group, wherein: The first lens group, the second lens group, the third lens group, and the fourth lens group are arranged sequentially from the object side to the image side along the optical axis; The first lens group has positive refractive power and includes lens 1-1, lens 1-2, lens 1-3, and lens 1-4. Lens 1-1 is the lens closest to the object side, has positive refractive power, and includes a concave surface facing the image side. Lens 1-2 is adjacent to lens 1-1 and has positive refractive power. Lens 1-3 has refractive power and includes a convex surface facing the object side. Lens 1-4 has refractive power and includes a concave surface facing the image side. Lens 1-1, lens 1-2, lens 1-3, and lens 1-4 are arranged sequentially along the optical axis from the object side to the image side. The second lens group has negative refractive power, and the second lens group includes a 2-2 lens, which has negative refractive power and includes a concave surface facing the object side; The third lens group has positive refractive power and includes a 3-3 lens and a 3-4 lens. The 3-3 lens has positive refractive power, and the 3-4 lens is a biconcave lens with negative refractive power, comprising one concave surface facing the object side and another concave surface facing the image side. The 3-3 lens and the 3-4 lens are arranged sequentially along the optical axis from the object side to the image side. The fourth lens group has positive refractive power. The fourth lens group includes a 4-1 lens, which is a biconvex lens with positive refractive power and includes one convex surface facing the object side and another convex surface facing the image side.

2. The imaging lens as described in claim 1, characterized in that: This third lens group further includes lens 3-1 and lens 3-2; The 3-1 lens is the lens closest to the object side in the third lens group, and the 3-4 lens is the lens closest to the image side in the third lens group. The 3-2 lens is a meniscus lens; and The 3-2 lens is positioned between the 3-1 lens and the 3-3 lens, and is adjacent to the 3-3 lens.

3. An imaging lens, characterized in that, It includes a first lens group, a second lens group, a third lens group, and a fourth lens group, wherein: The first lens group, the second lens group, the third lens group, and the fourth lens group are arranged sequentially from the object side to the image side along the optical axis; The first lens group has positive refractive power and includes lens 1-1, lens 1-2, lens 1-3, and lens 1-4. Lens 1-1 is the lens closest to the object side, has positive refractive power, and includes a concave surface facing the image side. Lens 1-2 is adjacent to lens 1-1 and has positive refractive power. Lens 1-3 has refractive power and includes a convex surface facing the object side. Lens 1-4 has refractive power and includes a concave surface facing the image side. Lens 1-1, lens 1-2, lens 1-3, and lens 1-4 are arranged sequentially along the optical axis from the object side to the image side. The second lens group has negative refractive power, and the second lens group includes a 2-2 lens, which has negative refractive power and includes a concave surface facing the object side; The third lens group has positive refractive power and includes a 3-3 lens and a 3-4 lens. The 3-3 lens has refractive power, and the 3-4 lens is a biconcave lens with negative refractive power, comprising one concave surface facing the object side and another concave surface facing the image side. The 3-3 lens and the 3-4 lens are arranged sequentially along the optical axis from the object side to the image side. The fourth lens group has positive refractive power. The fourth lens group includes a 4-1 lens, which is a biconvex lens with positive refractive power and includes one convex surface facing the object side and another convex surface facing the image side. This third lens group further includes lens 3-1 and lens 3-2; The 3-1 lens is the lens closest to the object side in the third lens group, and the 3-4 lens is the lens closest to the image side in the third lens group. The 3-2 lens is a meniscus lens; and The 3-2 lens is positioned between the 3-1 lens and the 3-3 lens, and is adjacent to the 3-3 lens.

4. The imaging lens as described in claim 1, characterized in that: The second lens group further includes a 2-1 lens disposed between the 2-2 lens and the object side, the 2-1 lens having negative refractive power and including a convex surface facing the object side, the 3-1 lens being a biconvex lens having positive refractive power and including a convex surface facing the object side and another convex surface facing the image side, and the 3-3 lens being a meniscus lens.

5. The imaging lens as described in claim 1, characterized in that: The 1-1 lens is a meniscus lens closest to the object side, and the 1-1 lens further includes a convex surface facing the object side; Lenses 1-2 are meniscus lenses; and There is an air gap between lens 1-1, lens 1-2 and lens 1-3. This third lens group further includes lens 3-1 and lens 3-2; The 3-1 lens is the lens closest to the object side in the third lens group, and the 3-4 lens is the lens closest to the image side in the third lens group. The 3-1 lens is a biconvex lens with positive refractive power, and includes one convex surface facing the object side and another convex surface facing the image side. The 3-2 lens and the 3-3 lens are meniscus lenses. The 3-2 lens is disposed between the 3-1 lens and the 3-3 lens, and is adjacent to the 3-3 lens; and The second lens group further includes a 2-1 lens disposed between the 2-2 lens and the object side, the 2-1 lens having negative refractive power and including a convex surface facing the object side.

6. The imaging lens as described in claim 5, characterized in that: The 1-2 lens includes a convex surface facing the object side and a concave surface facing the image side; There is no air gap between lens 1-3 and lens 1-4, or lens 1-3 and lens 1-4 are cemented together, and the combination of lens 1-3 and lens 1-4 has negative refractive power; The 2-1 lens is a meniscus lens, and further includes a concave surface facing the image side; The 3-2 lens has positive refractive power and includes a convex surface facing the object side and a concave surface facing the image side; The 3-3 lens includes a convex surface facing the object side and a concave surface facing the image side; This group of lenses includes at least seven meniscus lenses; as well as When the imaging lens zooms, the second lens group moves along the optical axis toward the image side and the fourth lens group moves along the optical axis toward the object side or the image side, and the fourth lens group is the lens group closest to the image side.

7. The imaging lens as described in claim 6, characterized in that: The 2-2 lens is a meniscus lens or a biconcave lens; when the 2-2 lens is a meniscus lens, the 2-2 lens further includes a convex surface facing the image side; when the 2-2 lens is a biconcave lens, the 2-2 lens further includes another concave surface facing the image side.

8. The imaging lens as described in claim 7, characterized in that: It further includes a meniscus lens disposed between the 2-1 lens and the 2-2 lens or between the 3-3 lens and the 3-4 lens. The meniscus lens has positive refractive power and includes a convex surface facing the object side and a concave surface facing the image side.

9. The imaging lens as described in claim 7, characterized in that: The second lens group further includes a 2-3 lens disposed between the 2-1 lens and the 2-2 lens. The 2-3 lens is a biconvex lens with positive refractive power and includes one convex surface facing the object side and another convex surface facing the image side.

10. The imaging lens as described in any one of claims 1 to 9, characterized in that: The imaging lens satisfies at least one of the following conditions: -92 mm -1 ≤ (rb / dc) / fw ≤ 2 mm -1 ; -1.5 ≤ (db-fa) / rb ≤ 0.8; -7.4 ≤ (ra-rc) / ft ≤ 5.4; -9.76 ≤ rc / (f3g-fc) ≤ -0.76; 10 ≤ (ft-fw) / dc ≤ 26; -7.5 mm ≤ ft / (f34 / dc) ≤ -2 mm; -15.7 ≤ (rc / fa)-fw ≤ -1.7; -104 mm ≤ (fc / Y)×f4g ≤ -60 mm; 3.8 ≤ ft / fw ≤ 4.9; -30 mm ≤ (ra / fb)×dc ≤ 1.5 mm; Wherein, rb is the radius of curvature of the image-side surface of the lens closest to the aperture between the object side and the aperture; dc is the distance along the optical axis from the image-side surface of the second lens closest to the image side in the third lens group to the object-side surface of the lens closest to the image side in the third lens group; db is the distance along the optical axis from the image-side surface of the 4-1 lens to the imaging plane at the telescope; fa is the effective focal length of the 2-1 lens; rc is the radius of curvature of the object-side surface of the lens closest to the image side in the third lens group; and ft is the distance from the telescope to the imaging lens. The effective focal lengths of the imaging lens are: f3g, fc, fw, f34, Y, f4g, ra, and fb.

Images