CN121186966A

CN121186966A - Optical lenses, projection modules and terminal equipment

Info

Publication number: CN121186966A
Application number: CN202511473072.2A
Authority: CN
Inventors: 请求不公布姓名; 万仁亮; 曾晗; 岳国强
Original assignee: Jiangxi Oufei Optics Co ltd
Current assignee: Jiangxi Oufei Optics Co ltd
Priority date: 2025-10-15
Filing date: 2025-10-15
Publication date: 2025-12-23

Abstract

This application relates to the field of optical imaging technology, specifically disclosing an optical lens, a projection module, and a terminal device. The optical lens comprises six refractive lenses, arranged sequentially along the optical axis from the imaging side to the image source side: a first lens with a concave imaging surface near the optical axis; a second lens with negative refractive power; a third lens with positive refractive power and a convex image source surface near the optical axis; a fourth lens with positive refractive power, with both its imaging and image source surfaces convex near the optical axis; a fifth lens with negative refractive power, with its imaging surface concave near the optical axis; and a sixth lens with positive refractive power, with both its imaging and image source surfaces convex near the optical axis. The optical lens satisfies the following relationship: 30° ≤ FOV ≤ 42°, where FOV is the maximum field of view of the optical lens. The aforementioned optical lens can simultaneously meet the requirements of a large field of view, miniaturization, and high resolution.

Description

Optical lens, projection module and terminal equipment

Technical Field

The application relates to the technical field of optical imaging, in particular to an optical lens, a projection module and terminal equipment.

Background

With the rapid development of automobile driving assisting systems, the requirements on the performance of an HUD (Head-up display) system mounted on an automobile are higher and higher, so that the volume of the HUD is larger and larger, and a PGU (Picture Generation Unit, image generating unit) is used as a core device of the HUD, so that the requirements on a projection lens are also higher and higher, and how to simultaneously consider a large field angle, miniaturization and high resolution becomes an important development direction of the current projection lens.

Disclosure of Invention

In view of the foregoing, it is necessary to provide an optical lens, a projection module and a terminal device, which are capable of satisfying the requirements of large angle of view, miniaturization and high resolution.

The embodiment of the application provides an optical lens which comprises six lenses with refractive power, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and an imaging surface, wherein the first lens is concave at a paraxial region, the second lens is negative in refractive power, the third lens is positive in refractive power, the image surface of the third lens is convex at a paraxial region, the fourth lens is positive in refractive power, the imaging surface of the fourth lens and the image surface of the image source are both convex at the paraxial region, the fifth lens is negative in refractive power, the imaging surface of the sixth lens is concave at the paraxial region, the imaging surface of the sixth lens is convex at the paraxial region, the imaging surface of the sixth lens and the image source are both convex at the paraxial region, the optical lens meets the following relation that the FOV is not more than 30 degrees and not more than 42 degrees, and the FOV is the maximum viewing angle of the optical lens.

According to the optical lens, the first lens is arranged, and the imaging surface of the first lens is concave at the position of the paraxial region, so that the aperture of the optical lens is reduced as much as possible; the second lens has negative refractive power, can collect light rays emitted by the third lens, can enable the light rays to move towards an imaging surface of the optical lens, ensures that the light rays emitted by the third lens and the light rays incident on the second lens have a good transition, reduces the sensitivity of the optical lens, improves the assembly yield of the optical lens, the third lens has positive refractive power, the imaging surface of the third lens is convex at a paraxial region, the second lens with negative refractive power is matched with the imaging surface of the optical lens, the chromatic aberration of the optical lens is effectively controlled, the risk of chromatic aberration of the optical lens is reduced, the imaging quality of the optical lens is improved, the imaging surface of the fourth lens and the imaging source surface of the fourth lens are convex at the paraxial region, the fifth lens has negative refractive power, the imaging surface of the fourth lens is concave at the paraxial region, chromatic aberration of the optical lens is further controlled, the light rays from the sixth lens can be converged and transitionally, various aberrations brought by the front optical lens can be corrected, various optical aberrations can be reduced, various optical lens imaging fields can be more effectively reduced, the imaging quality of the optical lens can be improved, the imaging quality of the optical lens can be more balanced than the imaging surface of the sixth lens can be more effectively, and the imaging quality of the optical lens can be more equal than the imaging surface of the fourth lens, and the optical lens can be more equal to the imaging quality of the imaging surface of the optical lens can be more than the imaging surface of the optical lens can. The optical lens has compact structure and good imaging quality while meeting miniaturization by reasonably configuring the refractive power and the surface shape of each lens.

Further, by enabling the optical lens to meet the FOV of 30 degrees or more and 42 degrees or less, and by reasonably setting the maximum field angle of the optical lens, a sufficient field angle can be provided for the optical lens so as to meet the requirement of the optical lens on a large field angle.

The embodiment of the application also provides a projection module which comprises the optical lens and an image sensor, wherein the image sensor is arranged on the image source side of the optical lens.

The projection module comprises the optical lens, and can meet the requirements of small caliber, high light incoming quantity and miniaturization.

The embodiment of the application also provides the terminal equipment, which comprises the shell and the projection module, wherein the projection module is arranged on the shell.

The terminal equipment comprises the optical lens, and can meet the requirements of small caliber, high light incoming quantity and miniaturization.

Drawings

Fig. 1 is a schematic structural view of an optical lens disclosed in a first embodiment of the present application.

Fig. 2 is a longitudinal spherical aberration curve, an astigmatic curve, and a distortion curve of an optical lens according to a first embodiment of the present application.

Fig. 3 is a schematic structural diagram of an optical lens according to a second embodiment of the present application.

Fig. 4 is a longitudinal spherical aberration curve, an astigmatic curve, and a distortion curve of an optical lens according to a second embodiment of the present application.

Fig. 5 is a schematic structural view of an optical lens according to a third embodiment of the present application.

Fig. 6 is a longitudinal spherical aberration curve, an astigmatic curve, and a distortion curve of an optical lens according to a third embodiment of the present application.

Fig. 7 is a schematic structural view of an optical lens disclosed in a fourth embodiment of the present application.

Fig. 8 is a longitudinal spherical aberration curve, an astigmatic curve, and a distortion curve of an optical lens according to a fourth embodiment of the present application.

Fig. 9 is a schematic structural view of an optical lens disclosed in a fifth embodiment of the present application.

Fig. 10 is a longitudinal spherical aberration curve, an astigmatic curve, and a distortion curve of an optical lens according to a fifth embodiment of the present application.

Fig. 11 is a schematic structural view of an optical lens disclosed in a sixth embodiment of the present application.

Fig. 12 is a longitudinal spherical aberration curve, an astigmatic curve, and a distortion curve of an optical lens according to a sixth embodiment of the present application.

Fig. 13 is a schematic structural diagram of a projection module according to an embodiment of the application.

Fig. 14 is a schematic structural diagram of a terminal device according to an embodiment of the present application.

The main reference numerals illustrate an optical lens 100, an optical axis O, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, imaging surfaces S1, S3, S5, S7, S9, S11, image source surfaces S2, S4, S6, S8, S10, S12, a stop STO, a polarizing plate POL, a wave plate WP, a cover glass CG, a light source surface IMG, a projection module 200, an image sensor 201, a terminal device 300, and a housing 301.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present application and are not to be construed as limiting the present application.

Referring to fig. 1, an optical lens 100 with six lens elements with refractive power includes, in order from an image-forming side to an image-source side along an optical axis O, a first lens element L1, a second lens element L2, a third lens element L3, a fourth lens element L4, a fifth lens element L5 and a sixth lens element L6. During imaging, light rays start from the image source side and sequentially enter the sixth lens L6, the fifth lens L5, the fourth lens L4, the third lens L3, the second lens L2 and the first lens L1, and finally are imaged on the imaging side of the optical lens 100.

The first lens element L1 with negative refractive power, the second lens element L2 with positive refractive power, the third lens element L3 with positive refractive power, the fourth lens element L4 with positive refractive power, the fifth lens element L5 with negative refractive power, and the sixth lens element L6 with positive refractive power.

The imaging surface S1 of the first lens element L1 is concave at the paraxial region O, the image source surface S6 of the third lens element L3 is convex at the paraxial region O, the imaging surface S7 of the fourth lens element L4 is convex at the paraxial region O, the image source surface S8 of the fourth lens element L4 is convex at the paraxial region O, the imaging surface S9 of the fifth lens element L5 is concave at the paraxial region O, the imaging surface S11 of the sixth lens element L6 is convex at the paraxial region O, and the image source surface S12 of the sixth lens element L6 is convex at the paraxial region O.

In the optical lens 100, the first lens L1 is disposed, and the imaging surface S1 thereof is concave at the paraxial region O, so that the aperture of the optical lens 100 is reduced as much as possible; the second lens element L2 with negative refractive power is capable of collecting light rays emitted from the third lens element L3 and moving the light rays toward the imaging surface of the optical lens assembly 100, so as to ensure a good transition between the light rays emitted from the third lens element L3 and the light rays incident into the second lens element L2, reduce the sensitivity of the optical lens assembly 100, and improve the assembly yield of the optical lens assembly 100; the third lens element L3 with positive refractive power has a convex imaging surface S5 at a paraxial region O, and is matched with a second lens element L2 with negative refractive power to enable light rays to move towards an imaging surface of the optical lens element 100, and meanwhile, chromatic aberration of the optical lens element 100 is effectively controlled, so that risks of chromatic aberration of the optical lens element 100 are reduced, and imaging quality of the optical lens element 100 is facilitated to be improved, the fourth lens element L4 with positive refractive power has a convex imaging surface S7 and an image source surface S8 at the paraxial region O, the fifth lens element L5 with negative refractive power has a concave imaging surface S9 at the paraxial region O, the fourth lens element L4 is matched with the fifth lens element L5 to further control chromatic aberration of the optical lens element 100, light rays emitted from the sixth lens element L6 can be converged and smoothly transited, various aberrations brought by the optical lens element 100 in front can be corrected, losses of light rays of various fields can be reduced, relative illumination of various fields can be improved, and imaging quality of the optical lens element 100 can be improved, the sixth lens element L6 with positive refractive power has a concave imaging surface S7 and an image source surface S11 at the paraxial region O, and various angles of the optical lens element L6 can be balanced to various edges of the optical lens element 100, the imaging quality of the optical lens 100 is improved. The optical lens 100 has a compact structure by reasonably configuring the refractive power and the surface shape of each lens, and the optical lens 100 has good imaging quality while satisfying miniaturization.

Further, the optical lens 100 satisfies the relation 30 DEG≤FOV≤42 DEG, wherein FOV is the maximum field angle of the optical lens 100. Illustratively, the FOV may be 30 °, 31 °, 32 °, 33 °, 34 °, 35 °, 36 °, 37 °, 38 °, 39 °, 40 °, 41 °, 42 °, etc. By reasonably setting the maximum field angle of the optical lens 100, a sufficient field angle can be provided for the optical lens 100 to meet the large field angle requirement of the optical lens 100.

When the optical lens 100 is applied to a terminal device such as a vehicle device or a wearable device, the materials of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 can be glass, so that the optical lens 100 has good imaging quality and can reduce the influence of temperature on the lenses. Of course, among the plurality of lenses of the optical lens 100, a part of the lenses may be made of glass, and a part of the lenses may be made of plastic, so that the processing cost of the lenses and the weight of the lenses can be reduced while the influence of temperature on the lenses is reduced to achieve better imaging quality, thereby reducing the processing cost of the optical lens 100 and the overall weight of the optical lens 100.

In some embodiments, the spherical lens is considered to have the characteristics of simple manufacturing process and low production cost, and the surface shape of the lens can be flexibly designed so as to improve the imaging resolution capability of the optical lens 100. The aspheric lens can make the imaging surface or the image source surface of the lens have more flexible design, so that the lens can well solve the adverse phenomena of unclear imaging, distortion of vision, narrow visual field and the like under the condition of smaller size and thinner lens, and the optical lens 100 can have good imaging quality without arranging too many lenses, thereby being beneficial to shortening the length of the optical lens 100. Based on this, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 may be aspheric lenses, so that the workability of each lens can be improved by the aspheric design, which is beneficial to the planar design, and the imaging surface or the image source surface of the lens can have a more flexible design, so that the adverse phenomena such as poor imaging, distortion of vision or narrow field of view can be well solved under the condition of smaller size and thinner each lens, and the optical lens 100 can have good imaging quality and higher resolution without providing too many lenses, and is beneficial to shortening the length of the optical lens 100. It is understood that in other embodiments, the surfaces of the lenses in the optical lens 100 may be spherical, aspherical, or any combination of spherical and aspherical, and may be specifically selected according to practical needs, so the present embodiment is not limited thereto.

In some embodiments, the optical lens 100 further includes a stop STO, which may be an aperture stop and/or a field stop, for example, the stop STO may be an aperture stop, or the stop STO may be a field stop, or the stop STO may be an aperture stop and a field stop. In the present embodiment, the stop STO is provided on one side of the imaging surface S1 of the first lens L1. It will be appreciated that in other embodiments, the stop STO may be disposed between other lenses, and the arrangement is adjusted according to the actual situation, which is not particularly limited in this embodiment.

In some embodiments, the optical lens 100 further includes a polarizing plate POL disposed between the image source surface S12 of the sixth lens L6 and the light source surface IMG of the optical lens 100. By providing the polarizing plate POL, the vibration direction of the light can be controlled and screened so that the light in the specific vibration direction passes through and enters the sixth lens L6, it can be understood that the polarizing plate POL may be made of plastic or made of an optical glass coating film, and may be selected according to actual needs, and the embodiment is not particularly limited.

In some embodiments, the optical lens 100 further includes a wave plate WP disposed between the polarizer POL and the light source face IMG of the optical lens 100. The polarization state of light can be changed by the wave plate WP, for example, linearly polarized light is converted into circularly polarized light. It is understood that the wave plate WP may be made of plastic or optical glass plating, and may be selected according to practical needs, and is not particularly limited in this embodiment.

In some embodiments, optical lens 100 further includes a cover glass CG disposed between waveplate WP and light source face IMG of optical lens 100. The light source can be prevented from being damaged by the protective glass CG, and the impact resistance and scratch resistance of the optical lens 100 can be improved to function as protection for the optical lens 100.

Further, the optical lens 100 satisfies the relation of TTL/F being 2.2-3.1, wherein TTL is the distance from the imaging surface S1 of the first lens L1 to the light source surface IMG of the optical lens 100 on the optical axis O, and F is the effective focal length of the optical lens 100. Illustratively, TTL/F can be 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, and the like. By making the optical lens 100 satisfy the above-described relational expression, the optical lens 100 satisfies a miniaturized design while ensuring high-quality imaging.

In some embodiments, the optical lens 100 satisfies the relationship 10.5≤TTL/ImgH≤14.6, where ImgH is half of the image height corresponding to the maximum field angle of the optical lens 100. Illustratively, TTL/ImgH can be 10.5, 11.0, 11.5, 12.0, 12.5, 13.0, 13.5, 14.0, 14.5, 14.6, and the like. By making the optical lens 100 satisfy the above relation, the range of TTL/ImgH is reasonably configured, which is beneficial to limiting the total optical length of the optical lens 100, making the optical lens 100 realize a miniaturized design, and meeting the requirement of light weight of the optical lens 100.

In some embodiments, optical lens 100 satisfies the relationship 4≤F/ImgH≤5.5. Illustratively, F/ImgH can be 4, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.5, etc. By making the optical lens 100 satisfy the above-described relational expression, it is advantageous to make the optical lens 100 satisfy the imaging quality of high resolution, while it is advantageous to realize that the optical lens 100 photographs in a larger field of view.

In some embodiments, optical lens 100 satisfies the relationship 0.4+.F1/F1+.1, where F1 is the effective focal length of first lens L1. Illustratively, |F1/F| can be 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, etc. By making the optical lens 100 satisfy the above relation, the first lens element L1 can have a proper negative refractive power, which is beneficial to alleviating the refractive angle variation of the incident light, avoiding excessive aberration caused by too strong refractive variation, and simultaneously, being beneficial to making more light enter the rear optical lens 100, increasing the angle of view of the optical lens 100 and improving the relative illuminance of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the relationship F2/F. Gtoreq. -5.1, where F2 is the effective focal length of the second lens L2. By making the optical lens 100 satisfy the above-mentioned relation, the second lens L2 can have a proper negative refractive power, which is beneficial to slowing down the light entering the optical lens 100, and at the same time, making the light move to the imaging surface of the optical lens 100, ensuring a better transition between the light exiting from the second lens L2 and the light entering the first lens L1, and reducing the sensitivity of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the relationship 0.6≤BFL/F≤1.4, where BFL is the distance on the optical axis O from the image source surface S12 of the sixth lens L6 to the light source surface IMG of the optical lens 100. Illustratively, BFL/F may be 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, etc. By making the optical lens 100 satisfy the above relation, the back focal length of the optical lens 100 can be shortened, and the optical lens 100 is prevented from being excessively large in volume, which is advantageous for satisfying the light-weight requirement of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the relationship of 0.3+.CT2/CT1+.4, where CT1 is the thickness of the first lens L1 on the optical axis and CT2 is the thickness of the second lens L2 on the optical axis. Illustratively, CT2/CT1 may be 0.3, 0.8, 1.3, 1.8, 2.3, 2.8, 3.3, 3.8, 4, etc. By making the optical lens 100 satisfy the above relation, the position of the second lens L2 relative to the first lens L1 can be reasonably configured, so that the light emitted from the second lens L2 enters the first lens L1 as much as possible, which is beneficial to improving the imaging quality of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the relationship of 0.7≤CT 3/CT 2≤3.6, wherein CT3 is the thickness of the third lens L3 on the optical axis. Illustratively, CT3/CT2 may be 0.7, 1.2, 1.7, 2.2, 2.7, 3.2, 3.6, etc. The position of the third lens L3 relative to the second lens L2 can be reasonably configured, so that the light emitted from the third lens L3 enters the second lens L2 as much as possible, which is beneficial to improving the imaging quality of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the relationship of 1.9+.CT6/CT5+.4.7, where CT5 is the thickness of the fifth lens element L5 on the optical axis and CT6 is the thickness of the sixth lens element L6 on the optical axis. Illustratively, CT6/CT5 may be 1.9, 2.4, 2.9, 3.4, 3.9, 4.4, 4.7, etc. By making the optical lens 100 satisfy the above relation, the position of the sixth lens L6 relative to the fifth lens L5 can be reasonably configured, so that the light emitted from the sixth lens L6 enters the fifth lens L5 as much as possible, which is beneficial to improving the imaging quality of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the relationship of-2+.R6/F3+.0.7, where F3 is the effective focal length of the third lens L3 and R6 is the radius of curvature of the image source surface S6 of the third lens L3 at the optical axis. Illustratively, R6/F3 may be-2, -1.8, -1.6, -1.4, -1.2, -1.0, -0.8, -0.7, and the like. By making the optical lens 100 satisfy the above relation, the second lens L2 can balance the spherical aberration generated by the third lens L3, thereby achieving good imaging quality, facilitating the divergence of light rays, expanding the angle of view, and shortening the total optical length of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the relationship R12/F. Gtoreq. -10, wherein R12 is the radius of curvature of the image source surface S12 of the sixth lens L6 at the optical axis O. By making the optical lens 100 satisfy the above relation, the shape of the sixth lens L6 is reasonably controlled, the spherical aberration, chromatic aberration and curvature of field of the optical lens 100 are comprehensively balanced, the risk of generating ghosts is reduced, the resolution of the optical lens 100 is improved, and meanwhile, the processing difficulty of the sixth lens L6 is also reduced.

In some embodiments, the optical lens 100 satisfies the relationship R11/R12. Gtoreq. -2, wherein R11 is a radius of curvature of the imaging surface S11 of the sixth lens L6 at the optical axis O. By making the optical lens 100 satisfy the above relation, the shape of the sixth lens L6 is reasonably controlled, the spherical aberration, chromatic aberration and curvature of field of the optical lens 100 are comprehensively balanced, the risk of generating ghosts is reduced, the resolution of the optical lens 100 is improved, and meanwhile, the processing difficulty of the sixth lens L6 is also reduced.

In some embodiments, the optical lens 100 satisfies the relationship 1.4+.CT6/ET 6+.3.6, where ET6 is the distance between the maximum effective aperture of the imaging surface S11 of the sixth lens L6 and the maximum effective aperture of the image source surface S12 of the sixth lens L6 in the optical axis direction. Illustratively, CT6/ET6 may be 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, etc. By making the optical lens 100 satisfy the above relation, the sixth lens L6 satisfies that the edge thickness and the center thickness are within a reasonable range, the variation of the surface shape of the sixth lens L6 is small, which can effectively control the aberration existing in the optical lens 100, and at the same time, is also beneficial to reducing the processing difficulty of the sixth lens L6.

In some embodiments, the optical lens 100 satisfies the relationship 0.8+.CT5/SAGS 10+.2.8, where SAGS10 is the distance on the optical axis from the intersection of the image source surface S10 of the fifth lens L5 and the optical axis to the maximum effective aperture of the image source surface S10 of the fifth lens L5. Illustratively, |CT5/SAGS10| may be 0.8, 1.0, 1.2, 1.4, 1.6, 2.0, 2.2, 2.4, 2.6, 2.8, etc. By making the optical lens 100 satisfy the above relation, it is beneficial to reasonably control the refractive power and thickness of the fifth lens element L5 in the direction perpendicular to the optical axis O, avoid the fifth lens element L5 being too thick or too thin, reduce the incident angle of light on the image source surface S10 of the fifth lens element L5, and reduce the tolerance sensitivity of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the relationship of-40+.CT6/SAGS 12+.1.8, where SAGS12 is the distance between the intersection of the image source surface S12 of the sixth lens L6 and the optical axis and the maximum effective caliber of the image source surface S12 of the sixth lens L6 on the optical axis. Illustratively, CT6/SAGS12 can be-40, -35, -30, -25, -20, -15, -10, -5, -1.8, etc. By making the optical lens 100 satisfy the above relation, it is beneficial to reasonably control the refractive power and thickness of the sixth lens element L6 in the direction perpendicular to the optical axis O, avoid the sixth lens element L6 being too thick or too thin, reduce the incident angle of light on the image source surface S10 of the sixth lens element L6, and reduce the tolerance sensitivity of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the relationship 1≤ImgH/SD 1≤1.45, wherein SD1 is half of the S1 maximum effective aperture of the imaging surface of the first lens L1. Illustratively, imgH/SD1 can be 1, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, and the like. By satisfying the above-described relational expression with respect to the optical lens 100, both the small aperture and the high-pass light amount of the optical lens 100 can be achieved.

In some embodiments, the optical lens 100 satisfies the relationship 1. Ltoreq.SD 7/SD 6. Ltoreq.1.3, wherein SD6 is half of the maximum effective aperture of the image source surface S6 of the third lens L3, and SD7 is half of the maximum effective aperture of the image plane S7 of the fourth lens L4. Illustratively, SD7/SD6 may be 1, 1.05, 1.10, 1.15, 1.20, 1.25, 1.3, etc. By satisfying the above relation with the optical lens 100, the half difference between the maximum effective aperture therebetween can be kept small, and the aperture step difference between the two can be reduced, so that the guided light beam can be more smoothly transferred from the fourth lens L4 to the third lens L3.

In some embodiments, the optical lens 100 satisfies the relationship of-3.1+.R8/SD 8+.1.2, wherein SD8 is half of the maximum effective aperture of the image source surface S8 of the fourth lens L4, and R8 is the radius of curvature of the image source surface S8 of the fourth lens L4 at the optical axis. Illustratively, R8/SD8 can be-3.1, -2.9, -2.7, -2.5, -2.3, -2.1, -1.9, -1.7, -1.5, -1.3, -1.2, and the like. By making the optical lens 100 satisfy the above-described relational expression, since the first lens L1 is closest to imaging, the first lens L1 is made to be a lens having negative refractive power, the entire volume of the fourth lens L4 can be compressed to a greater extent, and the ghost risk can be reduced.

In some embodiments, optical lens 100 satisfies the relationship 16 FOV/FNO 20, where FNO is the f-number of optical lens 100. Illustratively, the FOV/FNO may be 16, 17, 18, 19, 20, etc. By satisfying the above relation for the optical lens 100, the optical lens 100 can achieve both the characteristics of small aperture and high light flux.

In some embodiments, optical lens 100 satisfies the relationship 2.1. Ltoreq.TTL/BFL. Ltoreq.3.6. Illustratively, the TTL/BFL can be 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, and the like. By making the optical lens 100 satisfy the above relation, the back focal length of the optical lens 100 can be shortened, and the optical lens 100 is prevented from being excessively large in size, which is advantageous for realizing the demand of miniaturization of the optical lens 100.

In some embodiments, optical lens 100 satisfies the relationship 1.9≤FNO≤2.1. Illustratively, FNO can be 1.9, 1.95, 2.0, 2.05, 2.1, etc. By making the optical lens 100 satisfy the above-described relation, it is possible to ensure that the optical lens 100 has a large aperture characteristic, make the optical lens 100 have a high light incoming amount, and make the photographed image clearer.

In some embodiments, the optical lens 100 satisfies the relationship 0.6≤F3/F≤1.3, where F3 is the effective focal length of the third lens L3. Illustratively, F3/F may be 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, etc. By making the optical lens 100 satisfy the above-described relation, it is possible to correct the fringe field aberration of the optical lens 100, improve the imaging resolution of the optical lens 100, and further improve the imaging quality of the optical lens 100. When the upper limit of the above relation is exceeded, the insufficient refractive power of the third lens element L3 affects the chromatic aberration and the correction capability of the aberration of the optical lens 100, and further affects the imaging quality of the optical lens 100, and when the lower limit of the condition is exceeded, the effective focal length of the optical lens 100 is too large, resulting in a smaller angle of view of the optical lens 100, and the characteristics of large aperture and wide angle cannot be realized.

In some embodiments, the optical lens 100 satisfies the relationship 0.5≤F4/F≤0.95, where F4 is the effective focal length of the fourth lens L4. Illustratively, F4/F may be 0.5, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, etc. By making the optical lens 100 satisfy the above relation, the fourth lens element L4 provides a part of positive refractive power for the optical lens 100, and can be used to adjust the overall refractive power of the optical lens 100, and the fourth lens element L4 can balance the distortion generated by the fifth lens element L5 and the sixth lens element L6, so as to avoid higher-order aberration caused by excessive refractive index, and improve the imaging quality of the optical lens 100.

In some embodiments, the optical lens 100 satisfies the relationship of-1.2+.F5/F+. 0.3, where F5 is the effective focal length of the fifth lens L5. Illustratively, F5/F can be-1.2, -1.1, -0.9, -0.8, -0.7, -0.6, -0.5, -0.4, -0.3, and the like. By making the optical lens 100 satisfy the above relation, the fifth lens element L5 provides a part of negative refractive power for the optical lens 100, and can be used to adjust the overall refractive power of the optical lens 100, and the fifth lens element L5 can balance the distortion generated by the sixth lens element L6 to avoid higher-order aberration caused by excessive refractive index, thereby improving the imaging quality of the optical lens 100.

In some embodiments, optical lens 100 satisfies the relationship 0.7≤F6/F≤1.1. Wherein F6 is the effective focal length of the sixth lens L6. Illustratively, F6/F may be 0.7, 0.8, 0.9, 1.0, 1.1, etc. By making the optical lens 100 satisfy the above relation, the sixth lens L6 can have appropriate refractive power, which is beneficial to suppressing the angle of incidence of the fringe field of view, and can balance various aberrations of the optical lens 100, thereby improving the imaging quality of the optical lens 100.

In some embodiments, optical lens 100 satisfies the relationship 4≤F1/CT 1≤13. Illustratively, |F1/CT1| can be 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, etc. By making the optical lens 100 satisfy the above relation, the incident light rays with a large angle of the optical lens 100 can be emitted smoothly, and the range of the angle of view of the optical lens 100 is further enlarged, so as to ensure the imaging quality of the optical lens 100.

In some embodiments, optical lens 100 satisfies the relationship of-50≤F2/CT 2≤3. Illustratively, F2/CT2 may be-50, -45, -40, -35, -30, -25, -20, -15, -10, -5, -3, etc. By making the optical lens 100 satisfy the above-described relational expression, by reasonably disposing the effective focal length of the second lens L2 and the thickness of the second lens L2 on the optical axis, the aberration of the optical lens 100 can be effectively corrected, and the imaging quality can be improved.

In some embodiments, optical lens 100 satisfies the relationship 2≤F3/CT 3≤6. Illustratively, F3/CT3 may be 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, etc. By making the optical lens 100 satisfy the above relation, the refractive power and thickness of the third lens L3 can be reasonably configured, so that the incident angle of light in the optical lens 100 can be effectively controlled, the sensitivity of the optical lens 100 can be reduced, the aberration generated by the optical lens 100 can be corrected, and the imaging quality of the optical lens 100 can be improved.

In some embodiments, the optical lens 100 satisfies the relationship 1≤F4/CT 4≤3, wherein CT4 is the thickness of the fourth lens L4 on the optical axis O. Illustratively, F4/CT4 may be 1, 1.5, 2, 2.5, 3, etc. By making the optical lens 100 satisfy the above relation, the refractive power and thickness of the fourth lens L4 are reasonably configured, so that the incident angle of light in the optical lens 100 can be effectively controlled, the sensitivity of the optical lens 100 is reduced, the aberration generated by the optical lens 100 is corrected, and the imaging quality of the optical lens 100 is improved.

In some embodiments, optical lens 100 satisfies the relationship-20≤F5/CT 5≤1. Illustratively, F5/CT5 may be-20, -18, -16, -14, -12, -10, -8, -6, -4, -3, -1, etc. By making the optical lens 100 satisfy the above relation, the refractive power and thickness of the fifth lens L5 can be reasonably configured, so that the loss of light rays in each field of view can be effectively reduced, the relative illuminance of each field of view can be improved, and the imaging quality of the optical lens 100 can be improved.

In some embodiments, optical lens 100 satisfies the relationship 1.5≤F6/CT 6≤4. Illustratively, F6/CT6 may be 1.5, 2, 2.5, 3, 3.5, 4, etc. By making the optical lens 100 satisfy the above relation, the refractive power and thickness of the sixth lens L6 are reasonably configured, so that the loss of light rays in each field of view can be effectively reduced, the relative illuminance of each field of view is improved, and further the imaging quality of the optical lens 100 is improved.

In some embodiments, the optical lens 100 satisfies the relationship of 0.5+.R2/R1+.5, where R1 is the radius of curvature of the imaging surface S1 of the first lens L1 at the optical axis and R2 is the radius of curvature of the image source surface S2 of the first lens L1 at the optical axis. Illustratively, |r2/r1| may be 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, etc. By making the optical lens 100 satisfy the above relation, the shape of the first lens L1 is reasonably controlled, the spherical aberration, chromatic aberration and curvature of field of the optical lens 100 are comprehensively balanced, the risk of generating ghosts is reduced, the resolution of the optical lens 100 is improved, and meanwhile, the processing difficulty of the first lens L1 is also reduced.

In some embodiments, the optical lens 100 satisfies the relationship of R4/R3. Ltoreq.22, wherein R3 is a radius of curvature of the imaging surface S3 of the second lens L2 at the optical axis, and R4 is a radius of curvature of the image source surface S4 of the second lens at the optical axis. By making the optical lens 100 satisfy the above relation, the shape of the second lens L2 is reasonably controlled, the spherical aberration, chromatic aberration and curvature of field of the optical lens 100 are comprehensively balanced, the risk of generating ghosts is reduced, the resolution of the optical lens 100 is improved, and meanwhile, the processing difficulty of the second lens L2 is also reduced.

In some embodiments, the optical lens 100 satisfies the relationship 1.5+.R5/R6+.7.5, where R5 is the radius of curvature of the imaging surface S5 of the third lens L3 at the optical axis. Illustratively, |r5/r6| can be 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, etc. By making the optical lens 100 satisfy the above relation, the shape of the third lens L3 is reasonably controlled, the spherical aberration, chromatic aberration and curvature of field of the optical lens 100 are comprehensively balanced, the risk of generating ghosts is reduced, the resolution of the optical lens 100 is improved, and meanwhile, the processing difficulty of the third lens L3 is also reduced.

In some embodiments, the optical lens 100 satisfies the relationship of-7+.R7/R8+.0.5, where R7 is the radius of curvature of the imaging surface S7 of the fourth lens L4 at the optical axis. Illustratively, R7/R8 can be-7, -6, -5, -4, -3, -2, -1, -0.5, and the like. By making the optical lens 100 satisfy the above relation, the shape of the fourth lens L4 is reasonably controlled, the spherical aberration, chromatic aberration and curvature of field of the optical lens 100 are comprehensively balanced, the risk of generating ghosts is reduced, the resolution of the optical lens 100 is improved, and meanwhile, the processing difficulty of the fourth lens L4 is also reduced.

In some embodiments, the optical lens 100 satisfies the relationship of 0.5+.R10/R9+.7, where R9 is the radius of curvature of the imaging surface S9 of the fifth lens L5 at the optical axis and R10 is the radius of curvature of the imaging surface S10 of the fifth lens L5 at the optical axis. Illustratively, R10/R9 can be 0.5, 1,2, 3, 4, 5, 6, 7, etc. By making the optical lens 100 satisfy the above relation, the shape of the fifth lens L5 is reasonably controlled, the spherical aberration, chromatic aberration and curvature of field of the optical lens 100 are comprehensively balanced, the risk of generating ghosting is reduced, the resolution of the optical lens 100 is improved, and meanwhile, the processing difficulty of the fifth lens L5 is also reduced.

The surface shape of each aspherical lens can be defined by, but not limited to, the following aspherical formula:

;

Wherein Z is the distance from the corresponding point on the aspheric surface to the plane tangential to the surface vertex, c is the curvature of the aspheric vertex, c=1/Y, Y is the radius of curvature (i.e., paraxial curvature c is the inverse of the radius Y in table 1 a), r is the distance from any point on the aspheric surface to the optical axis O, k is the conic constant, ai is the coefficient corresponding to the i-th higher term in the aspheric surface type formula.

The optical lens 100 of the present embodiment will be described in detail below with reference to specific parameters.

First embodiment

As shown in fig. 1, a schematic structural diagram of an optical lens 100 according to a first embodiment of the present application, the optical lens 100 includes a stop STO, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a polarizer POL, a wave plate WP, and a cover glass CG sequentially disposed from an imaging side to an image source side along an optical axis O.

The first lens element L1 with negative refractive power, the second lens element L2 with negative refractive power, the third lens element L3 with positive refractive power, the fourth lens element L4 with positive refractive power, the fifth lens element L5 with negative refractive power, and the sixth lens element L6 with positive refractive power.

The imaging surface S1 of the first lens element L1 is concave at the paraxial region O, the imaging surface S2 of the first lens element L1 is concave at the paraxial region O, the imaging surface S3 of the second lens element L2 is concave at the paraxial region O, the imaging surface S4 of the second lens element L2 is concave at the paraxial region O, the imaging surface S5 of the third lens element L3 is convex at the paraxial region O, the imaging surface S6 of the third lens element L3 is convex at the paraxial region O, the imaging surface S7 of the fourth lens element L4 is convex at the paraxial region O, the imaging surface S8 of the fourth lens element L4 is convex at the paraxial region O, the imaging surface S9 of the fifth lens element L5 is concave at the paraxial region O, the imaging surface S10 of the fifth lens element L5 is convex at the paraxial region O, the imaging surface S11 of the sixth lens element L6 is convex at the paraxial region O, and the imaging surface S12 of the sixth lens element L6 is convex at the paraxial region O.

Specifically, the radius Y in table 1a is the radius of curvature of the imaging surface or the image source surface of the corresponding surface number at the optical axis O, where the fourth lens L4 and the fifth lens L5 are combined into a cemented lens group, the surface types of the image source surface S8 of the fourth lens L4 and the imaging surface S9 of the fifth lens L5 are the same, and the radii Y are different. The first value in the "thickness" parameter array of the lens is the thickness of the lens on the optical axis O, and the second value is the distance from the image source surface of the lens to the latter surface on the optical axis O. The value of the stop STO in the "thickness" parameter row is the distance between the stop STO and the vertex of the subsequent surface (the vertex refers to the intersection point of the surface and the optical axis O) on the optical axis O, and the direction of the imaging surface S1 of the first lens L1 to the image source surface S12 of the sixth lens L6 is the positive direction of the optical axis O by default. It is understood that the units of Y radius, thickness and effective focal length in Table 1a are all mm. And the refractive index, abbe number and effective focal length of each lens L in table 1a were each 555.0000nm.

In the first embodiment, the imaging surface S11 and the image source surface S12 of the sixth lens L6 are aspheric, and the conical constants k, the higher order coefficients A4, A6, A8, a10, which can be used for the aspheric mirror in the first embodiment, are given in table 1 b.

TABLE 1a

TABLE 1b

Referring to fig. 2 (a), fig. 2 (a) shows a longitudinal spherical aberration diagram of the optical lens 100 in the first embodiment at wavelengths 625.0000nm, 550.0000nm, and 455.0000nm, respectively. Wherein the abscissa along the X-axis represents focus offset in mm and the ordinate along the Y-axis represents normalized field of view. As can be seen from fig. 2 (a), the optical lens 100 in the first embodiment has a better spherical aberration value, which indicates that the optical lens 100 in the present embodiment has a better imaging quality. Referring to fig. 2 (B), fig. 2 (B) shows an astigmatism diagram of the optical lens 100 at a wavelength of 550.0000nm in the first embodiment. The abscissa along the X-axis direction represents the focus shift in mm, and the ordinate along the Y-axis direction represents the image height in mm. T in the astigmatism diagram represents the curvature of the imaging plane IMG in the direction of the sub-arc, and S represents the curvature of the imaging plane IMG in the direction of the sagittal. As can be seen from fig. 2 (B), at this wavelength, the astigmatism of the optical lens 100 is well compensated. Referring to fig. 2 (C), fig. 2 (C) shows a distortion curve of the optical lens 100 in the first embodiment at a wavelength of 550.0000 nm. Wherein, the abscissa along the X-axis direction represents distortion, and the ordinate along the Y-axis direction represents image height in mm. As can be seen from fig. 2 (C), at this wavelength, the distortion of the optical lens 100 becomes well corrected.

Second embodiment

As shown in fig. 3, a schematic structural diagram of an optical lens 100 according to a second embodiment of the present application, the optical lens 100 includes a stop STO, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a polarizer POL, a wave plate WP, and a cover glass CG sequentially disposed from an imaging side to an image source side along an optical axis O.

The imaging surface S1 of the first lens L1 is concave at the paraxial region O, the imaging surface S2 of the first lens L1 is concave at the paraxial region O, the imaging surface S3 of the second lens L2 is concave at the paraxial region O, the imaging surface S4 of the second lens L2 is convex at the paraxial region O, the imaging surface S5 of the third lens L3 is convex at the paraxial region O, the imaging surface S6 of the third lens L3 is convex at the paraxial region O, the imaging surface S7 of the fourth lens L4 is convex at the paraxial region O, the imaging surface S8 of the fourth lens L4 is convex at the paraxial region O, the imaging surface S9 of the fifth lens L5 is concave at the paraxial region O, the imaging surface S11 of the sixth lens L6 is convex at the paraxial region O, and the imaging surface S12 of the sixth lens L6 is convex at the paraxial region O.

Other parameters in the second embodiment are given in the following table 2a, and the definition of each parameter can be derived from the description of the foregoing embodiment, which is not repeated herein. It is understood that the units of Y radius, thickness and effective focal length in Table 2a are all mm. And the refractive index, abbe number and effective focal length of each lens L in table 2a are each 550.0000nm.

In the second embodiment, the imaging surface S11 and the image source surface S12 of the sixth lens L6 are aspheric, and the conic constant k, the higher order coefficients A4, A6, A8, a10, which can be used for the aspheric mirror in the second embodiment, are given in table 2b.

TABLE 2a

TABLE 2b

Referring to fig. 4, as can be seen from the (a) longitudinal spherical aberration diagram, (B) astigmatism diagram and (C) distortion diagram in fig. 4, the longitudinal spherical aberration, astigmatism and distortion of the optical lens 100 in the second embodiment are well controlled, so that the optical lens 100 of the embodiment has good imaging quality. In addition, regarding the wavelengths corresponding to the curves in fig. 4 (a), 4 (B) and 4 (C), reference may be made to the description in fig. 2 (a), 2 (B) and 2 (C) in the first embodiment, and the description is omitted here.

Third embodiment

As shown in fig. 5, a schematic structural diagram of an optical lens 100 according to a third embodiment of the present application, the optical lens 100 includes a stop STO, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a polarizer POL, a wave plate WP, and a cover glass CG, which are sequentially disposed from an imaging side to an image source side along an optical axis O.

Other parameters in the third embodiment are given in the following table 3a, and the definition of each parameter can be obtained from the description of the foregoing embodiment, which is not repeated here. It is understood that the units of Y radius, thickness and effective focal length in table 3a are all mm. And the refractive index, abbe number and effective focal length of each lens L in table 3a were each 550.0000nm.

In the third embodiment, the imaging surface S11 and the image source surface S12 of the sixth lens L6 are aspheric, and the conical constants k, the higher order coefficients A4, A6, A8, a10, which can be used for the aspheric mirror in the third embodiment, are given in table 3 b.

TABLE 3a

TABLE 3b

Referring to fig. 6, as can be seen from the (a) longitudinal spherical aberration diagram, (B) astigmatism diagram and (C) distortion diagram in fig. 6, the longitudinal spherical aberration, astigmatism and distortion of the optical lens 100 in the third embodiment are all well controlled, so that the optical lens 100 of this embodiment has good imaging quality. In addition, regarding the wavelengths corresponding to the curves in fig. 6 (a), 6 (B) and 6 (C), reference may be made to the description in fig. 2 (a), 2 (B) and 2 (C) in the first embodiment, and the description is omitted here.

Fourth embodiment

As shown in fig. 7, a schematic structural diagram of an optical lens 100 according to a fourth embodiment of the present application, the optical lens 100 includes a stop STO, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a polarizer POL, a wave plate WP, and a cover glass CG, which are sequentially disposed from an imaging side to an image source side along an optical axis O.

The imaging surface S1 of the first lens L1 is concave at the paraxial region O, the imaging surface S2 of the first lens L1 is concave at the paraxial region O, the imaging surface S3 of the second lens L2 is concave at the paraxial region O, the imaging surface S4 of the second lens L2 is convex at the paraxial region O, the imaging surface S5 of the third lens L3 is concave at the paraxial region O, the imaging surface S6 of the third lens L3 is convex at the paraxial region O, the imaging surface S7 of the fourth lens L4 is convex at the paraxial region O, the imaging surface S8 of the fourth lens L4 is convex at the paraxial region O, the imaging surface S9 of the fifth lens L5 is concave at the paraxial region O, the imaging surface S11 of the sixth lens L6 is convex at the paraxial region O, and the imaging surface S12 of the sixth lens L6 is convex at the paraxial region O.

Other parameters in the fourth embodiment are given in the following table 4a, and the definition of each parameter can be derived from the description of the foregoing embodiment, which is not repeated here. It is understood that the units of Y radius, thickness and effective focal length in Table 4a are all mm. And the refractive index, abbe number and effective focal length of each lens L in table 4a were each 550.0000nm.

In the fourth embodiment, the imaging surface S11 and the image source surface S12 of the sixth lens L6 are aspherical, and the conic constant k, the higher order coefficients A4, A6, A8, a10, which can be used for the aspherical mirror in the first embodiment, are given in table 4 b.

TABLE 4a

TABLE 4b

Referring to fig. 8, as can be seen from the (a) longitudinal spherical aberration diagram, (B) astigmatism diagram and (C) distortion diagram in fig. 8, the longitudinal spherical aberration, astigmatism and distortion of the optical lens 100 in the fourth embodiment are all well controlled, so that the optical lens 100 of this embodiment has good imaging quality. In addition, regarding the wavelengths corresponding to the curves in fig. 8 (a), 8 (B) and 8 (C), reference may be made to the description in fig. 2 (a), 2 (B) and 2 (C) in the first embodiment, and the description is omitted here.

Fifth embodiment

As shown in fig. 9, a schematic structural diagram of an optical lens 100 according to a fifth embodiment of the present application, the optical lens 100 includes a stop STO, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a polarizer POL, a wave plate WP, and a cover glass CG, which are sequentially disposed from an imaging side to an image source side along an optical axis O.

The imaging surface S1 of the first lens L1 is concave at the paraxial region O, the imaging surface S2 of the first lens L1 is concave at the paraxial region O, the imaging surface S3 of the second lens L2 is convex at the paraxial region O, the imaging surface S4 of the second lens L2 is concave at the paraxial region O, the imaging surface S5 of the third lens L3 is convex at the paraxial region O, the imaging surface S6 of the third lens L3 is convex at the paraxial region O, the imaging surface S7 of the fourth lens L4 is convex at the paraxial region O, the imaging surface S8 of the fourth lens L4 is convex at the paraxial region O, the imaging surface S9 of the fifth lens L5 is concave at the paraxial region O, the imaging surface S11 of the sixth lens L6 is convex at the paraxial region O, and the imaging surface S12 of the sixth lens L6 is convex at the paraxial region O.

Other parameters in the fifth embodiment are given in the following table 5a, and the definition of each parameter can be derived from the description of the foregoing embodiment, which is not repeated here. It is understood that the units of Y radius, thickness and effective focal length in Table 5a are all mm. And the refractive index, abbe number and effective focal length of each lens L in table 5a were each 550.0000nm.

In the fifth embodiment, the imaging surface S11 and the image source surface S12 of the sixth lens L6 are aspherical, and the conic constant k, the higher order coefficients A4, A6, A8, a10, which can be used for the aspherical mirror in the fifth embodiment, are given in table 5 b.

TABLE 5a

TABLE 5b

Referring to fig. 10, as can be seen from the (a) longitudinal spherical aberration diagram, (B) astigmatism diagram and (C) distortion diagram in fig. 10, the longitudinal spherical aberration, astigmatism and distortion of the optical lens 100 in the fifth embodiment are all well controlled, so that the optical lens 100 of this embodiment has good imaging quality. In addition, regarding the wavelengths corresponding to the curves in fig. 10 (a), 10 (B) and 10 (C), reference may be made to the description in fig. 2 (a), 2 (B) and 2 (C) in the first embodiment, and the description is omitted here.

Sixth embodiment

As shown in fig. 11, a schematic structural diagram of an optical lens 100 according to a sixth embodiment of the present application, the optical lens 100 includes a stop STO, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, a sixth lens L6, a polarizing plate POL, a wave plate WP, and a cover glass CG, which are sequentially disposed from an imaging side to an image source side along an optical axis O.

The first lens element L1 with positive refractive power, the second lens element L2 with negative refractive power, the third lens element L3 with positive refractive power, the fourth lens element L4 with positive refractive power, the fifth lens element L5 with negative refractive power, and the sixth lens element L6 with positive refractive power.

The imaging surface S1 of the first lens L1 is concave at the paraxial region O, the imaging surface S2 of the first lens L1 is convex at the paraxial region O, the imaging surface S3 of the second lens L2 is concave at the paraxial region O, the imaging surface S4 of the second lens L2 is concave at the paraxial region O, the imaging surface S5 of the third lens L3 is convex at the paraxial region O, the imaging surface S6 of the third lens L3 is convex at the paraxial region O, the imaging surface S7 of the fourth lens L4 is convex at the paraxial region O, the imaging surface S8 of the fourth lens L4 is convex at the paraxial region O, the imaging surface S9 of the fifth lens L5 is concave at the paraxial region O, the imaging surface S11 of the sixth lens L6 is convex at the paraxial region O, and the imaging surface S12 of the sixth lens L6 is convex at the paraxial region O.

Other parameters in the sixth embodiment are given in the following table 6a, and the definition of each parameter can be derived from the description of the foregoing embodiment, which is not repeated here. It is understood that the units of Y radius, thickness and effective focal length in Table 6a are all mm. And the refractive index, abbe number and effective focal length of each lens L in table 6a were each 550.0000nm.

In the sixth embodiment, both the imaging surface and the image source surface of the sixth lens L6 are aspherical, and the conic constant k, the higher order coefficients A4, A6, A8, a10 usable for the aspherical mirror in the sixth embodiment are given in table 6 b.

TABLE 6a

TABLE 6b

Referring to fig. 12, as can be seen from the (a) longitudinal spherical aberration diagram, (B) astigmatism diagram and (C) distortion diagram in fig. 12, the longitudinal spherical aberration, astigmatism and distortion of the optical lens 100 in the sixth embodiment are all well controlled, so that the optical lens 100 of this embodiment has good imaging quality. In addition, regarding the wavelengths corresponding to the curves in fig. 12 (a), 12 (B) and 12 (C), reference may be made to the description in the first embodiment regarding fig. 2 (a), 2 (B) and 2 (C), and the description is omitted here.

Table 7 shows values of a plurality of relational expressions in the optical lens 100 of the first embodiment to the sixth embodiment.

TABLE 7

Referring to fig. 13, an embodiment of the application further provides a projection module 200. The projection module 100 includes the optical lens 100 and the image sensor 201 of any of the above embodiments. The image sensor 201 is provided on the image source side of the optical lens 100. The image sensor 201 may be a complementary metal oxide semiconductor (CMOS, complementary Metal Oxide Semiconductor) image sensor or a Charge-coupled Device (CCD).

Referring to fig. 14, the embodiment of the present application further provides a terminal device 300. The terminal device 300 includes a housing 301 and a projection module 200, the projection module 200 being mounted on the housing 301. The terminal device 300 of the embodiment of the present application includes, but is not limited to, a terminal device supporting projection imaging, such as an unmanned aerial vehicle, a mobile phone, a tablet computer, a smart watch, a thumb camera, a vehicle-mounted device, an ambulatory medical device, a wearable device, and the like.

Finally, it should be noted that the above-mentioned embodiments are merely for illustrating the technical solution of the present application and not for limiting the same, and although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made to the technical solution of the present application without departing from the spirit and scope of the technical solution of the present application.

Claims

1. An optical lens, characterized in that it comprises six lenses with refractive power, arranged sequentially along the optical axis from the imaging side to the image source side:

The first lens has an image plane that is concave near the optical axis;

The second lens has negative refractive power;

The third lens has positive refractive power, and its image source surface is convex near the optical axis.

The fourth lens has positive refractive power, and both its imaging surface and image source surface are convex near the optical axis;

The fifth lens has negative refractive power, and its imaging surface is concave near the optical axis;

The sixth lens has positive refractive power, and both its imaging surface and image source surface are convex near the optical axis;

The optical lens satisfies the following relationship:

30°≤FOV≤42°;

Wherein, FOV is the maximum field of view of the optical lens.

2. The optical lens as described in claim 1, wherein the optical lens satisfies the following relationship:

2.2≤TTL/F≤3.1, and/or,

10.5 ≤ TTL/ImgH ≤ 14.6, and/or,

4 ≤ F/ImgH ≤ 5.5;

Wherein, TTL is the distance on the optical axis from the imaging surface of the first lens to the light source surface of the optical lens, F is the effective focal length of the optical lens, and ImgH is half of the image height corresponding to the maximum field of view of the optical lens.

3. The optical lens as described in claim 1, characterized in that the optical lens satisfies the following relationship:

0.4 ≤ |F1/F| ≤ 1.1, and/or,

F2/F ≥ -5.1, and/or,

0.6 ≤ BFL/F ≤ 1.4;

Wherein, F is the effective focal length of the optical lens, F1 is the effective focal length of the first lens, F2 is the effective focal length of the second lens, and BFL is the distance on the optical axis from the image source surface of the sixth lens to the light source surface of the optical lens.

4. The optical lens as described in claim 1, wherein the optical lens satisfies the following relationship:

0.3≤CT2/CT1≤4, and/or,

0.7 ≤ CT3/CT2 ≤ 3.6, and/or,

1.9≤CT6/CT5≤4.7;

Wherein, CT1 is the thickness of the first lens on the optical axis, CT2 is the thickness of the second lens on the optical axis, CT3 is the thickness of the third lens on the optical axis, CT5 is the thickness of the fifth lens on the optical axis, and CT6 is the thickness of the sixth lens on the optical axis.

5. The optical lens as claimed in claim 1, wherein the optical lens satisfies the following relationship:

-2≤R6/F3≤-0.7, and/or,

R12/F ≥ -10, and/or,

R11/R12≥-2;

Wherein, F is the effective focal length of the optical lens, F3 is the effective focal length of the third lens, R6 is the radius of curvature of the image source surface of the third lens at the optical axis, R11 is the radius of curvature of the imaging surface of the sixth lens at the optical axis, and R12 is the radius of curvature of the image source surface of the sixth lens at the optical axis.

6. The optical lens as claimed in claim 1, wherein the optical lens satisfies the following relationship:

1.4≤CT6/ET6≤3.6, and/or,

0.8 ≤ |CT5/SAGS10| ≤ 2.8, and/or,

-40≤CT6/SAGS12≤-1.8;

Wherein, CT5 is the thickness of the fifth lens on the optical axis, CT6 is the thickness of the sixth lens on the optical axis, ET6 is the distance from the maximum effective aperture of the imaging surface of the sixth lens to the maximum effective aperture of the image source surface of the sixth lens on the optical axis, SAGS10 is the distance from the intersection of the image source surface of the fifth lens and the optical axis to the maximum effective aperture of the image source surface of the fifth lens on the optical axis, and SAGS12 is the distance from the intersection of the image source surface of the sixth lens and the optical axis to the maximum effective aperture of the image source surface of the sixth lens on the optical axis.

7. The optical lens as claimed in claim 1, wherein the optical lens satisfies the following relationship:

1 ≤ ImgH/SD1 ≤ 1.45, and/or,

1 ≤ SD7 / SD6 ≤ 1.3, and/or,

-3.1≤R8/SD8≤-1.2;

Wherein, ImgH is half the image height corresponding to the maximum field of view of the optical lens, SD1 is half the maximum effective aperture of the imaging surface of the first lens, SD6 is half the maximum effective aperture of the image source surface of the third lens, SD7 is half the maximum effective aperture of the imaging surface of the fourth lens, SD8 is half the maximum effective aperture of the image source surface of the fourth lens, and R8 is the radius of curvature of the image source surface of the fourth lens at the optical axis.

8. The optical lens as claimed in claim 1, wherein the optical lens satisfies the following relationship:

16°≤FOV/FNO≤20°, and/or,

2.1≤TTL/BFL≤3.6, and/or,

1.9 ≤ FNO ≤ 2.1;

Wherein, FNO is the aperture number of the optical lens, TTL is the distance on the optical axis from the imaging surface of the first lens to the light source surface of the optical lens, and BFL is the distance on the optical axis from the image source surface of the sixth lens to the light source surface of the optical lens.

9. A projection module, characterized in that it comprises:

The optical lens as described in any one of claims 1 to 8; and

An image sensor is located on the image source side of the optical lens.

10. A terminal device, characterized in that it comprises:

Casing; and

The projection module as described in claim 9 is mounted on the housing.