Optical system, camera module and terminal device

Abstract

The application discloses an optical system, a camera module and a terminal device. The optical system has nine pieces of lenses with refractive power, and sequentially comprises, from an object side to an image side along an optical axis, a first lens with negative refractive power, a second lens with negative refractive power, a third lens with negative refractive power, a fourth lens with positive refractive power, a fifth lens with positive refractive power, a sixth lens with positive refractive power, a seventh lens with positive refractive power, an eighth lens with negative refractive power and a ninth lens with positive refractive power. The optical system satisfies the relationship: 39 (deg / mm) < FOV / f < 54 (deg / mm). The optical system has a large field of view and good imaging quality, and can obtain more scene content, thereby enriching the imaging information of the optical system.

Description

Technical Field

[0001] This invention relates to the field of photographic imaging technology, and in particular to an optical system, camera module and terminal device. Background Technology

[0002] Currently, with the advancement of sensing technology, the pixel pitch is becoming increasingly fine, requiring lenses to support sensors with higher pixel counts. Wide-angle lenses generally have a wide shooting range, but due to factors such as distortion and aberration, the peripheral area is easily compressed, ultimately reducing the amount of information that can be captured. Therefore, how to achieve a large field of view in an optical system while maintaining good image quality has become one of the urgent technical problems that the industry wants to solve. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the first aspect of the present invention proposes an optical system that has a large field of view while maintaining good imaging quality, which is beneficial for the optical system to acquire more scene content and thus enrich the imaging information of the optical system.

[0004] A second aspect of the present invention also proposes a camera module.

[0005] A third aspect of the present invention also proposes a terminal device.

[0006] According to the optical system of the first aspect of the present invention, the number of refractive lenses is nine, which are sequentially included along the optical axis from the object side to the image side: a first lens having negative refractive power, wherein the object side of the first lens is convex near the optical axis and the image side is concave near the optical axis; a second lens having negative refractive power, wherein the object side of the second lens is convex near the optical axis and the image side is concave near the optical axis; a third lens having negative refractive power, wherein the object side of the third lens is concave near the optical axis and the image side is concave near the optical axis; and a fourth lens having positive refractive power, wherein the object side of the fourth lens is convex near the optical axis. The image-side surface of the lens is convex near the optical axis; the fifth lens has positive refractive power, wherein the object-side surface of the fifth lens is convex near the optical axis and the image-side surface is concave near the optical axis; the sixth lens has positive refractive power, wherein both the object-side surface and the image-side surface are convex near the optical axis; the seventh lens has positive refractive power, wherein both the image-side surface and the image-side surface are convex near the optical axis; the eighth lens has negative refractive power, wherein both the object-side surface and the image-side surface are concave near the optical axis; and the ninth lens has positive refractive power, wherein both the object-side surface and the image-side surface are convex near the optical axis.

[0007] In the optical system, by making the first lens have negative refractive power, and its object-side surface is convex near the optical axis while its image-side surface is concave near the optical axis, it is beneficial to capture large-angle light rays entering the first lens, thereby achieving a wide-angle imaging effect and enabling the optical system to cover a wide field of view. The second lens is designed with a convex-concave shape near the optical axis, i.e., the object-side surface is convex and the image-side surface is concave, and it has negative refractive power, which helps to share the negative refractive power pressure of the first lens, making it easier to further converge the incident light rays. This allows the large-angle light rays from the first lens to enter the second lens smoothly at a reasonable angle, while also correcting the aberrations caused by the large field of view of the first lens. A third lens with negative refractive power has a concave object-side and a concave image-side, which helps to broaden the light beam and smoothly transition large-angle light rays. When paired with a fourth lens with positive refractive power, which has a convex object-side and a convex image-side, it facilitates the convergence of large-angle incident light rays, thus shortening the overall length of the optical system. Furthermore, the third lens with negative refractive power can cancel out the aberrations produced by the fourth lens with positive refractive power; that is, the fourth lens with positive refractive power helps correct the aberrations produced by the third lens with negative refractive power, thereby reducing the field curvature of the optical system. A fifth lens with positive refractive power, when paired with a fifth… The object-side surface of the lens is convex, and the image-side surface is concave. This balances the uncorrectable aberrations caused by the fourth lens when converging incident light. The sixth lens, with positive refractive power and a convex object-side and image-side surface design, further converges the light rays from the center and edge fields of view, thus helping to compress the overall length of the optical system. The seventh lens, with positive refractive power and a convex image-side surface design, enhances the optical power of the seventh lens, further shortening the overall length of the optical system. Combined with the eighth lens, which has negative refractive power and a concave object-side surface design, it facilitates smoother light transmission. The seventh lens, with its positive refractive power, can effectively correct image plane curvature and distortion at the periphery of the image. Furthermore, the eighth lens, with its negative refractive power, can counteract each other's aberrations when paired with the seventh lens, which has positive refractive power. In other words, the eighth lens with negative refractive power helps correct the aberrations produced by the seventh lens with positive refractive power, thereby reducing field curvature in the optical system. The ninth lens, with its positive refractive power and convex object and image sides, can effectively control the amount of light entering the image, increasing relative illumination and improving the brightness of the imaging surface. It can also reduce the incident angle of the incident light on the imaging surface, reducing chromatic aberration and thus improving the imaging quality of the optical system.

[0008] In one embodiment, the optical system satisfies the following relationship:

[0009] 39 (deg / mm) < FOV / f < 54 (deg / mm); FOV is the maximum field of view angle of the optical system, and f is the effective focal length of the optical system. By satisfying the above relationship, the ratio of the maximum field of view angle to the effective focal length of the optical system can be reasonably configured, thereby effectively increasing the view area of the picture and enabling the optical system to have wide-angle characteristics; at the same time, it is also beneficial to reduce the sensitivity of the optical system, which is conducive to the production and assembly of the optical system.

[0010] In one embodiment, the optical system satisfies the relationship:

[0011] 0.25 < f / f6 < 0.70; f is the effective focal length of the optical system, and f6 is the effective focal length of the sixth lens. By satisfying the above relationship, the sixth lens provides positive refractive power for the optical system. By controlling the ratio relationship between the effective focal length of the sixth lens and the effective focal length of the optical system, it is beneficial for the optical system to achieve wide-angle and high image quality imaging. Exceeding the upper limit of the relationship, the refractive power of the sixth lens is too strong, resulting in an overly curved lens surface, which is likely to generate strong astigmatism and chromatic aberration, thus being unfavorable for achieving the high-resolution imaging characteristics of the optical system; below the lower limit of the relationship, the effective focal length of the sixth lens is too large, and the refractive power in the middle of the optical system is insufficient, then the large-angle light captured is difficult to smoothly enter the rear lens group (i.e., the seventh, eighth, and ninth lenses) of the optical system, which is thus unfavorable for expanding the field of view angle range of the optical system.

[0012] In one embodiment, the optical system satisfies the relationship:

[0013] 0.20 < f / f9 < 0.60; f is the effective focal length of the optical system, and f9 is the effective focal length of the ninth lens. By satisfying the above relationship, the ninth lens can provide appropriate positive refractive power, which can effectively correct the spherical aberration generated by the front lens group (i.e., the first lens to the eighth lens), and improve the imaging resolution of the optical system; in addition, the positive refractive power can also reasonably deflect the large-angle incident light, which is beneficial for the ninth lens to compress the size of the entire optical system, and further promotes the formation of the miniaturization characteristics of the optical system.

[0014] In one embodiment, the optical system satisfies the relationship:

[0015] 0.7 < |f3 / f4| < 0.9; f3 is the effective focal length of the third lens; f4 is the effective focal length of the fourth lens. By satisfying the above relationship, through reasonable control of the ratio of the effective focal lengths between the third lens and the fourth lens, the refractive power near the object side is reasonably distributed, enabling the optical system to photograph objects at a relatively long distance, and the sufficient refractive power intensity can effectively converge light, which is beneficial for improving the imaging quality of the optical system.

[0016] In one embodiment, the optical system satisfies the relationship:

[0017] 1.50 < |f7 / f8| < 3.00; f7 is the effective focal length of the seventh lens; f8 is the effective focal length of the eighth lens. By satisfying the above relationship formula and reasonably controlling the ratio of the effective focal lengths between the seventh lens and the eighth lens, it is beneficial to make the optical system have a reasonable back focal length, and is beneficial to correcting aberrations such as chromatic aberration and astigmatism of the optical system, and improving the imaging quality of the optical system.

[0018] In one embodiment, the optical system satisfies the relationship:

[0019] 6 < |r82 / r81| < 11; r81 is the curvature radius of the object side surface of the eighth lens on the optical axis; r82 is the curvature radius of the image side surface of the eighth lens on the optical axis. By satisfying the above relationship formula, the changing trend of the curvature of the object side surface and the image side surface of the eighth lens can be well controlled, thereby restricting the shape of the eighth lens, which is beneficial to controlling the spherical aberration of the eighth lens, and making the imaging quality of the field of view on the optical axis and the field of view outside the optical axis not significantly degenerate due to the change in the contribution amount of spherical aberration, and is also beneficial to improving the optical performance of the optical system.

[0020] In one embodiment, the optical system satisfies the relationship: <00,00047>

[0021] -3.2 < r91 / r92 < -0.3; r91 is the curvature radius of the object side surface of the ninth lens on the optical axis; r92 is the curvature radius of the image side surface of the ninth lens on the optical axis. By satisfying the above relationship formula, the changing trend of the curvature of the object side surface and the image side surface of the ninth lens can be well controlled, so that the trend of the thickness-to-thickness ratio of the ninth lens is gentle, thereby restricting the shape of the ninth lens, which is beneficial to controlling the spherical aberration of the ninth lens, and making the imaging quality of the field of view on the optical axis and the field of view outside the optical axis not significantly degenerate due to the change in the contribution amount of spherical aberration, and is also beneficial to improving the optical performance of the optical system. At the same time, the surface shape of the ninth lens changes gently, which can reduce the processing and manufacturing difficulty of the ninth lens, thereby improving the processing yield.

[0022] In one embodiment, the optical system satisfies the relationship:

[0023] 0.8 < (CT1 / ET1) / (CT2 / ET2) < 1.85; CT1 is the thickness of the first lens on the optical axis; CT2 is the thickness of the second lens on the optical axis; ET1 is the distance in the optical axis direction from the maximum effective clear aperture of the object side of the first lens to the maximum effective clear aperture of the image side, and ET2 is the distance in the optical axis direction from the maximum effective clear aperture of the object side of the second lens to the maximum effective clear aperture of the image side. By satisfying the above relationship, by controlling the center thickness and edge thickness of the first lens, and the center thickness and edge thickness of the second lens, the thickness ratio of the first lens and the second lens can be reasonably controlled, so as to optimize the surface curvature freedom of the first lens and the second lens, which is beneficial to the effective convergence of large-angle incident light, and the light passing through the first lens and the second lens has a small deflection angle, thereby reducing the generation of stray light in the optical system, and then ensuring excellent imaging performance. At the same time, the reasonable surface change can optimize the lens processing technology, and reduce the design and assembly sensitivity of the first lens and the second lens.

[0024] In one embodiment, the optical system satisfies the relationship:

[0025] -0.2 < (NL8 - NL7) / r72 < -0.075; NL7 is the refractive index of the seventh lens, NL8 is the refractive index of the eighth lens, and r72 is the curvature radius of the image side of the seventh lens on the optical axis. By satisfying the above relationship, by reasonably configuring the refractive indices of the seventh lens and the eighth lens and the curvature radius of the object side of the seventh lens, it is beneficial to the smooth transition of light and is beneficial to improving the optical performance of the optical system.

[0026] In one embodiment, the optical system satisfies the relationship:

[0027] 9mm < TTL / FNO < 15mm; TTL is the distance on the optical axis from the object side of the first lens to the imaging surface of the optical system, and FNO is the f-number of the optical system. By satisfying the above relationship, on the premise of meeting the miniaturization of the optical system, the light passing amount can be reasonably configured, neither too large to cause overexposure nor too small to cause the brightness of the edge field of view of the optical system to be too low, increasing the risk of vignetting, which is beneficial to reducing the influence of off-axis aberration on the system and improving the imaging quality.

[0028] In one embodiment, the optical system satisfies the relationship:

[0029] 3.3 < SD11 / SD61 < 2.5; SD11 is the maximum effective aperture of the object side of the first lens, and SD61 is the maximum effective aperture of the object side of the sixth lens. By satisfying the above relational expression, by limiting the ratio of the maximum effective aperture of the object side of the first lens to the maximum effective aperture of the object side of the sixth lens, the overall size of the optical system is balanced, which is beneficial to accommodating the optical system in a lens barrel with a relatively simple structure and improving the assembly yield of the optical system.

[0030] In one embodiment, the optical system satisfies the relationship:

[0031] -8.50 < v3 - v4 < -2.50; v3 is the Abbe number of the third lens, and v4 is the Abbe number of the fourth lens. By satisfying the above relational expression, it is beneficial to reduce the chromatic aberration generated by the third lens and the fourth lens, reduce the tolerance sensitivity, and balance the overall chromatic aberration of the optical system by controlling part of the chromatic aberration; at the same time, it is convenient for the third lens and the fourth lens to be cemented together, which is beneficial to reducing the distance between the two lenses, thereby reducing the overall length of the system; reducing the assembly components between the lenses, thereby reducing the process and cost; reducing the tolerance sensitivity problems such as tilt / eccentricity generated during the assembly process of the lens unit and improving the production yield.

[0032] In one embodiment, the optical system satisfies the relationship:

[0033] 40.0 < v7 - v8 < 70.0, v7 is the Abbe number of the seventh lens, and v8 is the Abbe number of the eighth lens. By satisfying the above relational expression, it is beneficial to reduce the chromatic aberration generated by the seventh lens and the eighth lens, reduce the tolerance sensitivity, and balance the overall chromatic aberration of the optical system by controlling part of the chromatic aberration;

[0034] In one embodiment, the seventh lens and the eighth lens are cemented together, which is beneficial to reducing the distance between the two lenses, thereby reducing the overall length of the system; reducing the assembly components between the lenses, thereby reducing the process and cost; reducing the tolerance sensitivity problems such as tilt / eccentricity generated during the assembly process of the lens unit and improving the production yield.

[0035] In one embodiment, the optical system satisfies the relationship:

[0036] 0.15mm -1 <1 / (f12 * DST) < 0.65mm -1f12 is the combined effective focal length of the first lens and the second lens; DST is the distortion at the maximum field of view of the optical system. By satisfying the above relationship, the combined effective focal length of the first lens and the second lens can be rationally configured within a predetermined distortion range, ensuring a reasonable distribution of the refractive power of both lenses, which is beneficial for the effective convergence of large-angle incident light.

[0037] According to a second aspect of the present invention, a camera module includes a photosensitive chip and the optical system described in any one of the above embodiments, wherein the photosensitive chip is disposed on the image side of the optical system. By employing the above-described optical system, the camera module can achieve a large field of view while meeting the requirements for high image quality.

[0038] According to a third aspect of the present invention, a terminal device includes a fixing member and the aforementioned camera module, wherein the camera module is disposed on the fixing member. The aforementioned camera module can have a large field of view while meeting the requirement of high imaging quality.

[0039] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the optical system provided in the first embodiment of the present invention;

[0041] Figure 2 This includes the longitudinal spherical aberration map, astigmatism map, and distortion map of the optical system in the first embodiment;

[0042] Figure 3 This is a schematic diagram of the optical system provided in the second embodiment of the present invention;

[0043] Figure 4 This includes the longitudinal spherical aberration map, astigmatism map, and distortion map of the optical system in the second embodiment;

[0044] Figure 5 This is a schematic diagram of the optical system provided in the third embodiment of the present invention;

[0045] Figure 6 This includes the longitudinal spherical aberration map, astigmatism map, and distortion map of the optical system in the third embodiment;

[0046] Figure 7 This is a schematic diagram of the optical system provided in the fourth embodiment of the present invention;

[0047] Figure 8 This includes the longitudinal spherical aberration map, astigmatism map, and distortion map of the optical system in the fourth embodiment;

[0048] Figure 9This is a schematic diagram of the optical system provided in the fifth embodiment of the present invention;

[0049] Figure 10 This includes the longitudinal spherical aberration map, astigmatism map, and distortion map of the optical system in the fifth embodiment;

[0050] Figure 11 This is a schematic diagram of the optical system provided in the sixth embodiment of the present invention;

[0051] Figure 12 This includes the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system in the sixth embodiment;

[0052] Figure 13 This is a schematic diagram of a camera module provided in an embodiment of the present invention;

[0053] Figure 14 This is a schematic diagram of the structure of a terminal device provided in an embodiment of the present invention.

[0054] Figure label:

[0055] Optical system 10, camera module 20,

[0056] Optical axis 101, image sensor 210, aperture STO.

[0057] First lens L1: object-side surface S1, image-side surface S2

[0058] Second lens L2: object-side surface S3, image-side surface S4

[0059] Third lens L3: object-side surface S5, image-side surface S6.

[0060] Fourth lens L4: object-side surface S7, image-side surface S8.

[0061] Fifth lens L5: object-side surface S9, image-side surface S10.

[0062] Sixth lens L6: object-side surface S11, image-side surface S12.

[0063] Seventh lens L7: Object-side surface S13, Image-side surface S14.

[0064] Eighth lens L8: object-side surface S15, image-side surface S16.

[0065] Ninth lens L9: Object-side surface S17, Image-side surface S18.

[0066] The object-side surface of the filter is S19, and the image-side surface of the filter is S20.

[0067] Filter 110, imaging plane S21, terminal device 30,

[0068] Fastener 310. Detailed Implementation

[0069] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0070] An optical system 10 according to a specific embodiment of the present invention will now be described with reference to the accompanying drawings.

[0071] refer to Figure 1 An embodiment of the present invention provides an optical system 10 with a nine-lens design. The optical system 10, along its optical axis 101, comprises, in sequence, a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, a sixth lens L6 with positive refractive power, a seventh lens L7 with positive refractive power, an eighth lens L8 with negative refractive power, and a ninth lens L9 with positive refractive power. All lenses in the optical system 10 should be coaxially arranged, and the common axis of all lenses is the optical axis 101 of the optical system 10. Each lens can be mounted inside a lens barrel to form a camera lens.

[0072] The first lens L1 has an object-side surface S1 and an image-side surface S2; the second lens L2 has an object-side surface S3 and an image-side surface S4; the third lens L3 has an object-side surface S5 and an image-side surface S6; the fourth lens L4 has an object-side surface S7 and an image-side surface S8; the fifth lens L5 has an object-side surface S9 and an image-side surface S10; the sixth lens L6 has an object-side surface S11 and an image-side surface S12; the seventh lens L7 has an object-side surface S13 and an image-side surface S14; the eighth lens L8 has an object-side surface S15 and an image-side surface S16; and the ninth lens L9 has an object-side surface S17 and an image-side surface S18. Simultaneously, the optical system 10 also has an imaging surface S21, located on the image side of the ninth lens L9. Light rays emitted from an on-axis object point at a corresponding object distance can converge onto the imaging surface S21 after being adjusted by the lenses of the optical system 10.

[0073] Continue to refer to the appendix Figure 13Generally, the imaging surface S21 of the optical system 10 coincides with the photosensitive surface of the photosensitive chip 210. It should be noted that in some embodiments, the optical system 10 can be matched with a photosensitive chip 210 having a rectangular photosensitive surface, and the imaging surface S21 of the optical system 10 coincides with the rectangular photosensitive surface of the photosensitive chip 210. In this case, the effective pixel area on the imaging surface S21 of the optical system 10 has horizontal, vertical, and diagonal directions. In this invention, the maximum field of view of the optical system 10 can be understood as the field of view along the diagonal direction of the optical system 10, and the image height corresponding to the maximum field of view can be understood as half the length of the effective pixel area along the diagonal direction on the imaging surface S21 of the optical system 10.

[0074] In an embodiment of the present invention, the object-side surface S1 of the first lens L1 is convex near the optical axis 101, and the image-side surface S2 is concave near the optical axis 101; the object-side surface S3 of the second lens L2 is convex near the optical axis 101, and the image-side surface S4 is concave near the optical axis 101; the object-side surface S5 of the third lens L3 is concave near the optical axis 101, and the image-side surface S6 is concave near the optical axis 101; the object-side surface S7 of the fourth lens L4 is convex near the optical axis 101, and the image-side surface S8 is convex near the optical axis 101; the object-side surface S9 of the fifth lens L5 is convex near the optical axis 101. The image-side surface S10 is concave near the optical axis 101; the object-side surface S11 of the sixth lens L6 is convex near the optical axis 101, and the image-side surface S12 is convex near the optical axis 101; the image-side surface S14 of the seventh lens L7 is convex near the optical axis 101; the object-side surface S15 of the eighth lens L8 is concave near the optical axis 101; the object-side surface S17 of the ninth lens L9 is convex near the optical axis 101, and the image-side surface S18 is convex near the optical axis 101; when describing a lens surface having a certain surface shape near the optical axis 101, it means that the lens surface has that surface shape near the optical axis 101.

[0075] In the optical system 10, by making the first lens L1 have negative refractive power, and the object-side surface S1 is convex near the optical axis, and the image-side surface S2 is concave near the optical axis, it is beneficial to capture large-angle light rays entering the first lens L1, thereby achieving a wide-angle imaging effect and enabling the optical system 10 to cover a wide field of view. The second lens L2 is designed with a convex-concave surface near the optical axis, that is, the object-side surface S3 is convex and the image-side surface S4 is concave, and it has negative refractive power, which helps to share the negative refractive power pressure of the first lens L1, making it easier to further converge the incident light rays, so that the large-angle light rays from the first lens L1 enter the second lens L2 smoothly at a reasonable angle, and at the same time, it can correct the aberrations caused by the large field of view of the first lens L1. The third lens L3, with negative refractive power, has a concave object-side surface S5 and a concave image-side surface S6, which helps to broaden the light beam and smoothly transition light rays at larger angles. Combined with the fourth lens L4, with positive refractive power, having a convex object-side surface S7 and a convex image-side surface S8, it facilitates the convergence of incident light rays at large angles, thus shortening the overall length of the optical system 10. Furthermore, the third lens L3 with negative refractive power can cancel out the aberrations produced by the fourth lens L4 with positive refractive power; that is, the fourth lens L4 with positive refractive power helps to correct the aberrations produced by the third lens L3 with negative refractive power, thereby reducing the field curvature of the optical system 10. The fifth lens L5, with positive refractive power, is combined with the fifth lens L5... The object-side surface S9 of the fourth lens L4 is convex, and the image-side surface S10 is concave, which can balance the uncorrectable aberrations caused by the fourth lens L4 when converging incident light. The sixth lens L6, which has positive refractive power, with a surface design where the object-side surface S11 is convex and the image-side surface S12 is convex, can further converge the light rays in the central and peripheral fields of view, thereby helping to compress the overall length of the optical system 10. The seventh lens L7, which has positive refractive power, with a surface design where the image-side surface S13 is convex, can enhance the optical power of the seventh lens L7, which can help to further shorten the overall length of the optical system 10. Combined with the eighth lens L8, which has negative refractive power and a surface design where the object-side surface S15 of the eighth lens L8 is concave, it can help to flatten the light rays. The gradual transition effectively corrects image plane curvature and distortion at the periphery of the image. Simultaneously, the seventh lens L7, with positive refractive power, can be paired with the eighth lens L8, with negative refractive power, to cancel each other out aberrations. In other words, the eighth lens L8, with its negative refractive power, helps correct the aberrations generated by the seventh lens L7, thus reducing field curvature in the optical system 10. The ninth lens L9, with its positive refractive power, has convex object-side surface S17 and image-side surface S18, which effectively controls the amount of light entering the image, thereby increasing relative illumination, enhancing the brightness of the imaging surface S21, and reducing the incident angle of incident light on the imaging surface S21, thus reducing chromatic aberration and improving the imaging quality of the optical system 10.

[0076] In one embodiment, the optical system 10 satisfies the relationship:

[0077] 39 (deg / mm) < FOV / f < 54 (deg / mm); FOV is the maximum field angle of the optical system 10, and f is the effective focal length of the optical system 10. Satisfying the above relationship can reasonably configure the ratio of the maximum field angle to the effective focal length of the optical system 10, thereby effectively increasing the view-finding area of the picture, making the optical system 10 have wide-angle characteristics; at the same time, it is also beneficial to reduce the sensitivity of the optical system 10, which is conducive to the production and assembly of the optical system 10.

[0078] In one embodiment, the optical system 10 satisfies the relationship:

[0079] 0.25 < f / f6 < 0.70; f is the effective focal length of the optical system, and f6 is the effective focal length of the sixth lens L6. Satisfying the above relationship, the sixth lens L6 provides a positive refractive power for the optical system 10. By controlling the ratio relationship between the effective focal length of the sixth lens L6 and the effective focal length of the optical system 10, it is beneficial for the optical system 10 to achieve wide-angle and high-image-quality imaging. Exceeding the upper limit of the relationship, the refractive power of the sixth lens L6 is too strong, resulting in an overly curved lens surface, which is likely to generate strong astigmatism and chromatic aberration, thus being unfavorable for achieving the high-resolution imaging characteristics of the optical system 10; below the lower limit of the relationship, the effective focal length of the sixth lens L6 is too large, and the refractive power in the middle of the optical system is insufficient, then the large-angle light captured is difficult to smoothly enter the rear lens group of the optical system 10 (i.e., the seventh lens L7, the eighth lens L8, and the ninth lens L9), which is unfavorable for expanding the field angle range of the optical system 10.

[0080] In one embodiment, the optical system 10 satisfies the relationship:

[0081] 0.20 < f / f9 < 0.60; f is the effective focal length of the optical system 10, and f9 is the effective focal length of the ninth lens L9. Satisfying the above relationship, the ninth lens L9 can provide an appropriate positive refractive power, which can effectively correct the spherical aberration generated by the front lens group (i.e., the first lens L1 to the eighth lens L8), and improve the imaging resolution of the optical system 10; in addition, the positive refractive power can also reasonably deflect the large-angle incident light, which is beneficial for the ninth lens L9 to compress the size of the entire optical system 10, and further promotes the formation of the miniaturization characteristics of the optical system 10.

[0082] In one embodiment, the optical system 10 satisfies the relationship:

[0083] 0.7 < |f3 / f4| < 0.9; f3 is the effective focal length of the third lens L3; f4 is the effective focal length of the fourth lens L4. By satisfying the above relationship and reasonably controlling the ratio of the effective focal lengths between the third lens L3 and the fourth lens L4, the refractive power near the object side is reasonably distributed, enabling the optical system 10 to photograph objects at a relatively long distance, and the sufficient refractive power intensity can effectively converge light, which is beneficial to improving the imaging quality of the optical system 10.

[0084] In one embodiment, the optical system 10 satisfies the relationship:

[0085] 1.50 < |f7 / f8| < 3.00; f7 is the effective focal length of the seventh lens L7; f8 is the effective focal length of the eighth lens L8. By satisfying the above relationship, the ratio of the effective focal lengths between the seventh lens L7 and the eighth lens L8 can be reasonably controlled, which is beneficial to enabling the optical system 10 to have a reasonable back focal length, beneficial to correcting aberrations such as chromatic aberration and astigmatism of the optical system 10, and improving the imaging quality of the optical system 10.

[0086] In one embodiment, the optical system 10 satisfies the relationship:

[0087] 6 < |r82 / r81| < 11; r81 is the radius of curvature of the object side S15 of the eighth lens L8 on the optical axis; r82 is the radius of curvature of the image side S16 of the eighth lens L8 on the optical axis. By satisfying the above relationship, the changing trend of the curvatures of the object side S15 and the image side S16 of the eighth lens L8 can be well controlled, thereby restricting the shape of the eighth lens L8, which is beneficial to controlling the spherical aberration of the eighth lens L8, so that the imaging quality of the field of view on the optical axis and the field of view off the optical axis will not significantly degrade due to the change in the contribution amount of spherical aberration, and is also beneficial to improving the optical performance of the optical system 10.

[0088] In one embodiment, the optical system 10 satisfies the relationship:

[0089] -3.2 < r91 / r92 < -0.3; r91 is the radius of curvature of the object side S17 of the ninth lens L9 on the optical axis; r92 is the radius of curvature of the image side S18 of the ninth lens L9 on the optical axis. By satisfying the above relationship, the changing trend of the curvatures of the object side S17 and the image side S18 of the ninth lens L9 can be well controlled, so that the thickness-to-thickness ratio trend of the ninth lens L9 is gentle, thereby restricting the shape of the ninth lens L9, which is beneficial to controlling the spherical aberration of the ninth lens L9, so that the imaging quality of the field of view on the optical axis and the field of view off the optical axis will not significantly degrade due to the change in the contribution amount of spherical aberration, and is also beneficial to improving the optical performance of the optical system 10. At the same time, the surface shape of the ninth lens L9 changes gently, which can reduce the processing and manufacturing difficulty of the ninth lens L9, thereby improving the processing yield.

[0090] In one embodiment, the optical system 10 satisfies the relationship:

[0091] 0.8 < (CT1 / ET1) / (CT2 / ET2) < 1.85; CT1 is the thickness of the first lens L1 on the optical axis; CT2 is the thickness of the second lens L2 on the optical axis; ET1 is the distance in the optical axis direction from the maximum effective clear aperture of the object side S1 of the first lens L1 to the maximum effective clear aperture of the image side, and ET2 is the distance in the optical axis direction from the maximum effective clear aperture of the object side S3 of the second lens L2 to the maximum effective clear aperture of the image side. By satisfying the above relationship formula, by controlling the center thickness and edge thickness of the first lens L1, and the center thickness and edge thickness of the second lens L2, the thickness ratio of the first lens L1 and the second lens L2 can be reasonably controlled, so as to optimize the surface shape bending freedom of the first lens L1 and the second lens L2, which is conducive to the effective convergence of large-angle incident light, and the light passing through the first lens L1 and the second lens L2 has a small deflection angle, thereby reducing the generation of stray light in the optical system 10, and further ensuring excellent imaging performance. At the same time, reasonable surface shape changes can optimize the lens processing technology and reduce the design and assembly sensitivity of the first lens L1 and the second lens L2.

[0092] In one embodiment, the optical system 10 satisfies the relationship:

[0093] -0.2 < (NL8 - NL7) / r72 < -0.075; NL7 is the refractive index of the seventh lens L7, NL8 is the refractive index of the eighth lens L8, and r72 is the curvature radius of the image side S13 of the seventh lens L7 on the optical axis. By satisfying the above relationship formula, by reasonably configuring the refractive indices of the seventh lens L7 and the eighth lens L8 and the curvature radius of the object side S13 of the seventh lens L7, it is beneficial to the smooth transition of light and is beneficial to improving the optical performance of the optical system 10.

[0094] In one embodiment, the optical system 10 satisfies the relationship:

[0095] 9mm < TTL / FNO < 15mm; TTL is the distance on the optical axis from the object side S1 of the first lens L1 to the imaging surface S21 of the optical system 10, and FNO is the f-number of the optical system 10. By satisfying the above relationship formula, on the premise of meeting the miniaturization of the optical system 10, the light transmission amount can be reasonably configured, neither too large to cause overexposure nor too small to cause the brightness of the edge field of view of the optical system to be too low, increasing the risk of vignetting, which is beneficial to reducing the influence of off-axis aberration on the system and improving the imaging quality.

[0096] In one embodiment, the optical system 10 satisfies the relationship:

[0097] 3.3 < SD11 / SD61 < 2.5; SD11 is the maximum effective aperture of the object side S1 of the first lens L1, and SD61 is the maximum effective aperture of the object side S11 of the sixth lens L6. By satisfying the above relational expression, by limiting the ratio of the maximum effective aperture of the object side S1 of the first lens L1 to the maximum effective aperture of the object side S11 of the sixth lens L6, the overall size of the optical system 10 is balanced, which is conducive to accommodating the optical system 10 in a lens barrel with a relatively simple structure and improving the assembly yield of the optical system 10.

[0098] In one embodiment, the optical system 10 satisfies the relation:

[0099] -8.50 < v3 - v4 < -2.50; v3 is the Abbe number of the third lens L3, and v4 is the Abbe number of the fourth lens L4. By satisfying the above relational expression, it is conducive to reducing the chromatic aberration generated by the third lens L3 and the fourth lens L4, reducing the tolerance sensitivity, and balancing the overall chromatic aberration of the optical system 10 by controlling part of the chromatic aberration; at the same time, it is convenient for the third lens L3 and the fourth lens L4 to be cemented together, which is conducive to reducing the spacing between the two lenses, thereby reducing the overall length of the system; reducing the assembly components between the lenses, thereby reducing the processes and costs; reducing the tolerance sensitivity problems such as tilt / eccentricity generated during the assembly process of the lens unit and improving the production yield.

[0100] In one embodiment, the optical system 10 satisfies the relation:

[0101] 40.0 < v7 - v8 < 70.0; v7 is the Abbe number of the seventh lens L7, and v8 is the Abbe number of the eighth lens L8. By satisfying the above relational expression, it is conducive to reducing the chromatic aberration generated by the seventh lens L7 and the eighth lens L8, reducing the tolerance sensitivity, and balancing the overall chromatic aberration of the optical system 10 by controlling part of the chromatic aberration;

[0102] In one embodiment, the seventh lens L7 and the eighth lens L8 are cemented together, which is conducive to reducing the spacing between the two lenses, thereby reducing the overall length of the system; reducing the assembly components between the lenses, thereby reducing the processes and costs; reducing the tolerance sensitivity problems such as tilt / eccentricity generated during the assembly process of the lens unit and improving the production yield.

[0103] In one embodiment, the optical system 10 satisfies the relation:

[0104] 0.15mm -1 <1 / (f12 * DST) < 0.65mm -1f12 is the combined effective focal length of the first lens L1 and the second lens L2; ​​DST is the distortion at the maximum field of view of the optical system 10. By satisfying the above relationship, the combined effective focal length of the first lens L1 and the second lens L2 can be rationally configured within a predetermined distortion range, ensuring a reasonable distribution of the refractive power of both lenses, which is beneficial for the effective convergence of large-angle incident light.

[0105] The effective focal length refers at least to the value of the corresponding lens at the perioptic axis 101, and the refractive power of the lens refers at least to the perioptic axis 101. Furthermore, the above relationships and their resulting technical effects apply to the optical system 10 with the aforementioned lens design. If the lens design (number of lenses, refractive power configuration, surface configuration, etc.) of the aforementioned optical system 10 cannot be guaranteed, it will be difficult to ensure that the optical system 10 still possesses the corresponding technical effects while satisfying these relationships, and it may even lead to a significant decrease in imaging performance.

[0106] In some embodiments, at least one lens in the optical system 10 may have a spherical surface, and the design of the spherical surface can reduce the difficulty of lens fabrication and reduce fabrication costs.

[0107] In some embodiments, at least one lens of the optical system 10 may also have an aspherical surface profile. A lens is said to have an aspherical surface profile when at least one surface (object-side or image-side) of the lens is aspherical. In one embodiment, both the object-side and image-side surfaces of each lens can be designed as aspherical. Aspherical design helps the optical system 10 more effectively eliminate aberrations and improve image quality. In some embodiments, to balance manufacturing cost, manufacturing difficulty, image quality, and assembly difficulty, the surface design of each lens in the optical system 10 can be a combination of spherical and aspherical surface profiles.

[0108] The surface shape of aspherical surfaces can be calculated using the aspherical formula:

[0109]

[0110] Where Z is the distance from the corresponding point on the aspherical surface to the tangent plane of the surface at the optical axis 101, r is the distance from the corresponding point on the aspherical surface to the optical axis 101, c is the curvature of the aspherical surface at the optical axis 101, k is the conic coefficient, and Ai is the coefficient of the higher-order term corresponding to the i-th higher-order term in the aspherical surface shape formula.

[0111] It should also be noted that when a lens surface is aspherical, it may have inflection points. In this case, the surface shape will change radially. For example, a lens surface may be convex near the optical axis 101 and concave near the maximum effective aperture. The surface shape design of the inflection points can effectively correct field curvature and distortion aberrations in the edge field of view of the optical system 10, thereby improving image quality.

[0112] In some embodiments, at least one lens in the optical system 10 is made of glass (GL). For example, the first lens L1 closest to the object side can be made of glass. Utilizing the temperature drift reduction effect of the glass material of the first lens L1, the influence of ambient temperature changes on the optical system 10 can be effectively reduced, thereby maintaining better and more stable imaging quality. In some embodiments, at least one lens in the optical system 10 can also be made of plastic (PC), such as polycarbonate or resin. Lenses made of plastic can reduce the production cost of the optical system 10, while lenses made of glass can withstand higher or lower temperatures and have excellent optical performance and better stability. In some embodiments, the optical system 10 can be equipped with lenses of different materials, such as a combination of glass lenses and plastic lenses. However, the specific configuration relationship can be determined according to actual needs and will not be exhaustively listed here.

[0113] It should be noted that the first lens L1 does not necessarily mean that there is only one lens. In some embodiments, the first lens L1 may contain two or more lenses, which can form a cemented lens. The surface of the cemented lens closest to the object side can be regarded as the object-side surface S1, and the surface closest to the image side can be regarded as the image-side surface S2. Alternatively, the lenses in the first lens L1 may not form a cemented lens, but the distance between the lenses is relatively fixed. In this case, the object-side surface of the lens closest to the object side is the object-side surface S1, and the image-side surface of the lens closest to the image side is the image-side surface S2. In addition, in some embodiments, the number of lenses in the second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, seventh lens L7, eighth lens L8, or ninth lens L9 may be greater than or equal to two, and any adjacent lenses may form a cemented lens or a non-cemented lens.

[0114] In some embodiments, the aperture stop ST0 of the present invention can be an aperture stop or a field stop. The aperture stop is used to control the amount of light entering the optical system 10 and the depth of field, and can also effectively intercept non-effective light rays to improve the imaging quality of the optical system 10. It can be disposed between the object side of the optical system 10 and the object side surface S1 of the first lens L1. It is understood that in other embodiments, the aperture stop ST0 can also be disposed between two adjacent lenses, for example, between the second lens L2 and the third lens L3, or between the third lens L3 and the fourth lens L4, or between the fourth lens L4 and the fifth lens L5, or between the fifth lens L5 and the sixth lens L6, or between the sixth lens L6 and the seventh lens L7, or between the seventh lens L7 and the eighth lens L8, or between the eighth lens L8 and the ninth lens L9. The setting can be adjusted according to the actual situation, and the embodiments of the present invention do not specifically limit it. The aperture stop ST0 can also be formed by a clamping member for fixing the lens.

[0115] The optical system 10 of the present invention will be described below through more specific embodiments:

[0116] First Embodiment

[0117] refer to Figure 1 In the first embodiment, the optical system 10, along the optical axis 101 from the object side to the image side, sequentially includes a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, an aperture stop STO, a sixth lens L6 with positive refractive power, a seventh lens L7 with positive refractive power, an eighth lens L8 with negative refractive power, and a ninth lens L9 with positive refractive power. The surface shapes of each lens in the optical system 10 are as follows:

[0118] The object side surface S1 of the first lens L1 is convex near the optical axis 101, and the image side surface S2 is concave near the optical axis 101.

[0119] The object-side surface S3 of the second lens L2 is convex near the optical axis 101, and the image-side surface S4 is concave near the optical axis 101.

[0120] The object-side surface S5 of the third lens L3 is concave near the optical axis 101, and the image-side surface S6 is concave near the optical axis 101.

[0121] The object-side surface S7 of the fourth lens L4 is convex near the optical axis 101, and the image-side surface S8 is convex near the optical axis 101.

[0122] The object-side surface S9 of the fifth lens L5 is convex near the optical axis 101, and the image-side surface S10 is concave near the optical axis 101.

[0123] The object-side surface S11 of the sixth lens L6 is convex near the optical axis 101, and the image-side surface S12 is convex near the optical axis 101.

[0124] The image-side surface S13 of the seventh lens L7 is convex near the optical axis 101; the image-side surface S14 is convex near the optical axis 101.

[0125] The object-side surface S15 of the eighth lens L8 is concave near the optical axis 101; the image-side surface S16 is concave near the optical axis 101.

[0126] The object-side surface S17 of the ninth lens L9 is convex near the optical axis 101, and the image-side surface S18 is convex near the optical axis 101.

[0127] Furthermore, in this embodiment, the aperture stop STO is an aperture stop located between the image-side surface S10 of the fifth lens L5 and the object-side surface S11 of the sixth lens L6. In the first embodiment, the surfaces of the first lens L1, second lens L2, third lens L3, fourth lens L4, seventh lens L7, and eighth lens L8 are spherical, while the surfaces of the fifth lens L5, sixth lens L6, and ninth lens L9 are aspherical. The lenses of the first lens L1, second lens L2, third lens L3, fourth lens L4, fifth lens L5, sixth lens L6, seventh lens L7, eighth lens L8, and ninth lens L9 are made of glass (GL).

[0128] The optical system 10 also includes a filter 110, which can be part of the optical system 10 or removed from it. However, when the filter 110 is removed, the total optical length (TTL) of the optical system 10 remains unchanged. The filter 110 can be an infrared cut-off filter, which is located between the image-side surface S8 of the fourth lens L4 and the imaging surface S21 of the optical system 10. This allows it to filter out invisible light, such as infrared light, while allowing only visible light to pass through, thus achieving better image quality. It is understood that the filter 110 can also filter out other light, such as visible light, while allowing only infrared light to pass through. The optical system 10 can then be used as an infrared optical lens, meaning that the optical system 10 can also image and achieve better image quality in dim environments and other special application scenarios.

[0129] In the first embodiment, the lens parameters of the optical system 10 are shown in Table 1 below. The elements of the optical system 10 from the object side to the image side are arranged sequentially from top to bottom according to Table 1, where the aperture stop STO represents the aperture stop. In Table 1, the Y-radius is the radius of curvature of the corresponding lens surface at the optical axis 101. In Table 1, the surface with surface number S1 represents the object side of the first lens L1, the surface with surface number S2 represents the image side of the first lens L1, and so on. The absolute value of the first value in the "thickness" parameter column is the thickness of the lens on the optical axis 101, and the absolute value of the second value is the distance from the image side of the lens to the next optical surface (the object side of the next lens or the aperture stop surface) on the optical axis 101, where the aperture stop thickness parameter represents the distance from the aperture stop surface to the object side of the adjacent lens on the image side on the optical axis 101. In the table, the reference wavelength for the refractive index and Abbe number of each lens is 587.56 nm, and the reference wavelength for the focal length is 546 nm. The units for the Y-radius, thickness, and focal length (effective focal length) are all millimeters (mm). Furthermore, the parameter data and lens surface structure used for relational calculations in the following embodiments are based on the data in the lens parameter tables of the corresponding embodiments.

[0130] Table 1

[0131]

[0132] As shown in Table 1, the effective focal length f of the optical system 10 in the first embodiment is 3.837 mm, the aperture number FNO is 2.0, the maximum field of view FOV of the optical system 10 is 151.7°, and the total optical length TTL is 29.493 mm. The total optical length TTL values ​​in the following embodiments are the sum of the thickness values ​​corresponding to the surface numbers S1 to S21.

[0133] Table 2 below shows the aspherical coefficients of the corresponding lens surfaces in Table 1, where k is the conic coefficient and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula.

[0134] Table 2

[0135]

[0136] Figure 2This includes the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram of the optical system 10 in the first embodiment. The reference wavelength for the astigmatism and distortion diagrams is 546 nm. The longitudinal spherical aberration diagram shows the deviation of the convergence focus of light rays of different wavelengths after passing through the lens. The vertical axis of the longitudinal spherical aberration diagram represents the normalized pupil coordinates from the pupil center to the pupil edge, and the horizontal axis represents the distance (in mm) from the imaging plane S21 to the intersection of the light ray and the optical axis 101. As can be seen from the longitudinal spherical aberration diagram, the degree of convergence focus deviation of light rays of different wavelengths in the first embodiment tends to be consistent, and the maximum focus deviation of each reference wavelength is controlled within ±0.025 mm. For the optical system 10, blur spots or halos in the image are effectively suppressed.

[0137] Figure 2 The diagram also includes astigmatic field curves of the optical system 10. The horizontal axis represents the distance (in mm) from the imaging plane S21 to the intersection of the ray and the optical axis 101, and the vertical axis represents the maximum field of view of the optical system 10 (in degrees). The S-curve represents the sagittal field curvature at 546 nm, and the T-curve represents the meridional field curvature at 546 nm. As shown in the figure, the field curvature of the optical system 10 is relatively small, and the maximum field curvature is controlled within ±0.025 mm. For the optical system 10, the curvature of the image plane is effectively suppressed, and the sagittal and meridional field curvatures at each field of view tend to be consistent. The astigmatism at each field of view is well controlled. Therefore, it can be seen that the optical system 10 has a clear image from the center to the edge of the field of view.

[0138] in addition Figure 2 It also includes a distortion diagram of the optical system 10, with the horizontal axis representing distortion (in %) and the vertical axis representing the maximum field of view of the optical system 10 (in deg). According to the distortion diagram, the distortion degree of the optical system 10, which has a large field of view, has also been well controlled.

[0139] Second Embodiment

[0140] refer to Figure 3 In the second embodiment, the optical system 10, along the optical axis 101 from the object side to the image side, sequentially includes a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, an aperture stop STO, a sixth lens L6 with positive refractive power, a seventh lens L7 with positive refractive power, an eighth lens L8 with negative refractive power, and a ninth lens L9 with positive refractive power. The surface shapes of each lens in the optical system 10 are as follows:

[0141] The object side surface S1 of the first lens L1 is convex near the optical axis 101, and the image side surface S2 is concave near the optical axis 101.

[0142] The object-side surface S3 of the second lens L2 is convex near the optical axis 101, and the image-side surface S4 is concave near the optical axis 101.

[0143] The object-side surface S5 of the third lens L3 is concave near the optical axis 101, and the image-side surface S6 is concave near the optical axis 101.

[0144] The object-side surface S7 of the fourth lens L4 is convex near the optical axis 101, and the image-side surface S8 is convex near the optical axis 101.

[0145] The object-side surface S9 of the fifth lens L5 is convex near the optical axis 101, and the image-side surface S10 is concave near the optical axis 101.

[0146] The object-side surface S11 of the sixth lens L6 is convex near the optical axis 101, and the image-side surface S12 is convex near the optical axis 101.

[0147] The image-side surface S13 of the seventh lens L7 is convex near the optical axis 101; the image-side surface S14 is convex near the optical axis 101.

[0148] The object-side surface S15 of the eighth lens L8 is concave near the optical axis 101; the image-side surface S16 is concave near the optical axis 101.

[0149] The object-side surface S17 of the ninth lens L9 is convex near the optical axis 101, and the image-side surface S18 is convex near the optical axis 101.

[0150] Furthermore, in this embodiment, the aperture stop STO is an aperture stop located between the image side S10 of the fifth lens L5 and the object side S11 of the sixth lens L6.

[0151] In the first embodiment, the surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the seventh lens L7, and the eighth lens L8 are spherical, while the surfaces of the fifth lens L5, the sixth lens L6, and the ninth lens L9 are aspherical. Furthermore, the lens material of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 is glass (GL).

[0152] The parameters of each lens in this optical system 10 are given in Table 3. The reference wavelength for the lens focal length is 546nm. The definitions of the names and parameters of other components can be derived from the first embodiment and will not be repeated here.

[0153] Table 3

[0154]

[0155] As shown in Table 3, the effective focal length f of the optical system 10 in the second embodiment is 3.739 mm, the aperture number FNO is 2.0, the maximum field of view FOV of the optical system 10 is 151.7°, and the total optical length TTL is 28.528 mm. The total optical length TTL values ​​in the following embodiments are the sum of the thickness values ​​corresponding to the surface numbers S1 to S21.

[0156] Table 4 below shows the aspherical coefficients of the corresponding lens surfaces in Table 3, where k is the conic coefficient and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula.

[0157] Table 4

[0158]

[0159] Depend on Figure 4 As can be seen from the longitudinal spherical aberration diagram, astigmatism diagram, and distortion diagram, the longitudinal spherical aberration, field curvature, astigmatism, and distortion of the optical system 10 with a large field of view are well controlled, and the optical system 10 of this embodiment can have good imaging quality.

[0160] Third Embodiment

[0161] refer to Figure 5 In the third embodiment, the optical system 10, along the optical axis 101 from the object side to the image side, sequentially includes a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, an aperture stop STO, a sixth lens L6 with positive refractive power, a seventh lens L7 with positive refractive power, an eighth lens L8 with negative refractive power, and a ninth lens L9 with positive refractive power. The surface shapes of each lens in the optical system 10 are as follows:

[0162] The object side surface S1 of the first lens L1 is convex near the optical axis 101, and the image side surface S2 is concave near the optical axis 101.

[0163] The object-side surface S3 of the second lens L2 is convex near the optical axis 101, and the image-side surface S4 is concave near the optical axis 101.

[0164] The object-side surface S5 of the third lens L3 is concave near the optical axis 101, and the image-side surface S6 is concave near the optical axis 101.

[0165] The object-side surface S7 of the fourth lens L4 is convex near the optical axis 101, and the image-side surface S8 is convex near the optical axis 101.

[0166] The object-side surface S9 of the fifth lens L5 is convex near the optical axis 101, and the image-side surface S10 is concave near the optical axis 101.

[0167] The object-side surface S11 of the sixth lens L6 is convex near the optical axis 101, and the image-side surface S12 is convex near the optical axis 101.

[0168] The image-side surface S13 of the seventh lens L7 is convex near the optical axis 101; the image-side surface S14 is convex near the optical axis 101.

[0169] The object-side surface S15 of the eighth lens L8 is concave near the optical axis 101; the image-side surface S16 is concave near the optical axis 101.

[0170] The object-side surface S17 of the ninth lens L9 is convex near the optical axis 101, and the image-side surface S18 is convex near the optical axis 101.

[0171] Furthermore, in this embodiment, the aperture stop STO is an aperture stop located between the image side S10 of the fifth lens L5 and the object side S11 of the sixth lens L6.

[0172] In the first embodiment, the surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the seventh lens L7, and the eighth lens L8 are spherical, while the surfaces of the fifth lens L5, the sixth lens L6, and the ninth lens L9 are aspherical. Furthermore, the lens material of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 is glass (GL).

[0173] In this embodiment, the lens parameters of the optical system 10 are given in Table 5. The reference wavelength for the lens focal length is 546nm. The definitions of the names and parameters of other components can be derived from the first embodiment and will not be repeated here.

[0174] Table 5

[0175]

[0176] As shown in Table 5, the effective focal length f of the optical system 10 in the third embodiment is 3.786 mm, the aperture number FNO is 2.0, the maximum field of view FOV of the optical system 10 is 150.9°, and the total optical length TTL is 29.953 mm. The total optical length TTL values ​​in the following embodiments are the sum of the thickness values ​​corresponding to the surface numbers S1 to S21.

[0177] Table 6 below shows the aspherical coefficients of the corresponding lens surfaces in Table 5, where k is the conic coefficient and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula.

[0178] Table 6

[0179]

[0180]

[0181] Depend on Figure 6 As can be seen from the various aberration diagrams, the longitudinal spherical aberration, field curvature, astigmatism, and distortion of the optical system 10 with its large field of view are well controlled, and the optical system 10 of this embodiment can have good imaging quality.

[0182] Fourth embodiment

[0183] refer to Figure 7 In the fourth embodiment, the optical system 10, along the optical axis 101 from the object side to the image side, sequentially includes a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, an aperture stop STO, a sixth lens L6 with positive refractive power, a seventh lens L7 with positive refractive power, an eighth lens L8 with negative refractive power, and a ninth lens L9 with positive refractive power. The surface shapes of each lens in the optical system 10 are as follows:

[0184] The object side surface S1 of the first lens L1 is convex near the optical axis 101, and the image side surface S2 is concave near the optical axis 101.

[0185] The object-side surface S3 of the second lens L2 is convex near the optical axis 101, and the image-side surface S4 is concave near the optical axis 101.

[0186] The object-side surface S5 of the third lens L3 is concave near the optical axis 101, and the image-side surface S6 is concave near the optical axis 101.

[0187] The object-side surface S7 of the fourth lens L4 is convex near the optical axis 101, and the image-side surface S8 is convex near the optical axis 101.

[0188] The object-side surface S9 of the fifth lens L5 is convex near the optical axis 101, and the image-side surface S10 is concave near the optical axis 101.

[0189] The object-side surface S11 of the sixth lens L6 is convex near the optical axis 101, and the image-side surface S12 is convex near the optical axis 101.

[0190] The image-side surface S13 of the seventh lens L7 is concave near the optical axis 101; the image-side surface S14 is convex near the optical axis 101.

[0191] The object-side surface S15 of the eighth lens L8 is concave near the optical axis 101; the image-side surface S16 is concave near the optical axis 101.

[0192] The object-side surface S17 of the ninth lens L9 is convex near the optical axis 101, and the image-side surface S18 is convex near the optical axis 101.

[0193] Furthermore, in this embodiment, the aperture stop STO is an aperture stop located between the image side S10 of the fifth lens L5 and the object side S11 of the sixth lens L6.

[0194] In the first embodiment, the surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the seventh lens L7, and the eighth lens L8 are spherical, while the surfaces of the fifth lens L5 and the sixth lens L6 are aspherical. Furthermore, the lens material of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 is glass (GL).

[0195] In this embodiment, the parameters of each lens in the optical system 10 are given in Table 7. The reference wavelength for the lens focal length is 546nm. The definitions of the names and parameters of other components can be derived from the first embodiment and will not be repeated here.

[0196] Table 7

[0197]

[0198]

[0199] As shown in Table 7, the effective focal length f of the optical system 10 in the fourth embodiment is 2.771 mm, the aperture number FNO is 2.4, the maximum field of view FOV of the optical system 10 is 142.3°, and the total optical length TTL is 24.999 mm. The total optical length TTL values ​​in the following embodiments are the sum of the thickness values ​​corresponding to the surface numbers S1 to S21.

[0200] Table 8 below shows the aspherical coefficients of the corresponding lens surfaces in Table 7, where k is the conic coefficient and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula.

[0201] Table 8

[0202] Face number S9 S10 S11 S12 S18 k 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 A4 6.6988E-04 1.8685E-03 1.4949E-03 1.7583E-03 2.8771E-03 A6 2.8911E-05 6.5666E-05 -2.8277E-04 -1.4669E-04 -1.0643E-04 A8 -1.0353E-06 -1.6026E-06 2.2047E-04 -5.8356E-05 4.5647E-05 A10 5.1087E-07 6.5836E-07 -1.5445E-04 1.6649E-05 -7.1357E-06 A12 -1.0312E-07 -7.6181E-08 5.3451E-05 -5.5359E-06 7.6370E-07 A14 9.8194E-09 9.0901E-09 -9.8270E-06 7.3136E-07 -4.3967E-08 A16 -3.6008E-10 -5.4814E-10 6.8774E-07 -6.3290E-08 1.0681E-09

[0203] Depend on Figure 8 As can be seen from the various aberration diagrams, the longitudinal spherical aberration, field curvature, astigmatism, and distortion of the optical system 10 with its large field of view are well controlled, and the optical system 10 of this embodiment can have good imaging quality.

[0204] Fifth embodiment

[0205] refer to Figure 9 In the fifth embodiment, the optical system 10, along the optical axis 101 from the object side to the image side, sequentially includes a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, an aperture stop STO, a sixth lens L6 with positive refractive power, a seventh lens L7 with positive refractive power, an eighth lens L8 with negative refractive power, and a ninth lens L9 with positive refractive power. The surface shapes of each lens in the optical system 10 are as follows:

[0206] The object side surface S1 of the first lens L1 is convex near the optical axis 101, and the image side surface S2 is concave near the optical axis 101.

[0207] The object-side surface S3 of the second lens L2 is convex near the optical axis 101, and the image-side surface S4 is concave near the optical axis 101.

[0208] The object-side surface S5 of the third lens L3 is concave near the optical axis 101, and the image-side surface S6 is concave near the optical axis 101.

[0209] The object-side surface S7 of the fourth lens L4 is convex near the optical axis 101, and the image-side surface S8 is convex near the optical axis 101.

[0210] The object-side surface S9 of the fifth lens L5 is convex near the optical axis 101, and the image-side surface S10 is concave near the optical axis 101.

[0211] The object-side surface S11 of the sixth lens L6 is convex near the optical axis 101, and the image-side surface S12 is convex near the optical axis 101.

[0212] The image-side surface S13 of the seventh lens L7 is concave near the optical axis 101; the image-side surface S14 is convex near the optical axis 101.

[0213] The object-side surface S15 of the eighth lens L8 is concave near the optical axis 101; the image-side surface S16 is concave near the optical axis 101.

[0214] The object-side surface S17 of the ninth lens L9 is convex near the optical axis 101, and the image-side surface S18 is convex near the optical axis 101.

[0215] Furthermore, in this embodiment, the aperture stop STO is an aperture stop located between the image side S10 of the fifth lens L5 and the object side S11 of the sixth lens L6.

[0216] In the first embodiment, the surfaces of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the seventh lens L7, and the eighth lens L8, as well as the object-side surface S17 of the ninth lens L9, are spherical, while the surfaces of the fifth lens L5, the sixth lens L6, and the image-side surface S18 of the ninth lens L9 are aspherical. Furthermore, the lens material of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 is glass (GL).

[0217] In this embodiment, the parameters of each lens in the optical system 10 are given in Table 9. The reference wavelength for the lens focal length is 546nm. The definitions of the names and parameters of other components can be derived from the first embodiment and will not be repeated here.

[0218] Table 9

[0219]

[0220]

[0221] As shown in Table 9, the effective focal length f of the optical system 10 in the fifth embodiment is 3.057 mm, the aperture number FNO is 2.4, the maximum field of view FOV of the optical system 10 is 150.8°, and the total optical length TTL is 24.001 mm. The total optical length TTL values ​​in the following embodiments are the sum of the thickness values ​​corresponding to the surface numbers S1 to S21.

[0222] Table 10 below shows the aspherical coefficients of the corresponding lens surfaces in Table 9, where k is the conic coefficient and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula.

[0223] Table 10

[0224] Face number S9 S10 S11 S12 S18 k 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 A4 6.5570E-04 2.6451E-03 9.2187E-04 1.3269E-03 1.0367E-03 A6 4.9979E-05 1.5716E-04 -4.2953E-04 -1.8818E-04 -8.1173E-06 A8 -3.5289E-06 1.8789E-05 4.8701E-04 1.8467E-04 5.8421E-06 A10 9.8304E-07 -4.3941E-06 -2.5900E-04 -9.0350E-05 -8.9037E-07 A12 -1.0517E-07 1.5683E-06 7.7442E-05 2.5082E-05 8.0601E-08 A14 6.6070E-09 -2.1147E-07 -1.2072E-05 -3.5840E-06 -3.9326E-09 A16 -1.8124E-10 1.2897E-08 7.6707E-07 2.0797E-07 7.9048E-11

[0225] Depend on Figure 10 As can be seen from the various aberration diagrams, the longitudinal spherical aberration, field curvature, astigmatism, and distortion of the optical system 10 with its large field of view are well controlled, and the optical system 10 of this embodiment can have good imaging quality.

[0226] Sixth Embodiment

[0227] refer to Figure 10In the fifth embodiment, the optical system 10, along the optical axis 101 from the object side to the image side, sequentially includes a first lens L1 with negative refractive power, a second lens L2 with negative refractive power, a third lens L3 with negative refractive power, a fourth lens L4 with positive refractive power, a fifth lens L5 with positive refractive power, an aperture stop STO, a sixth lens L6 with positive refractive power, a seventh lens L7 with positive refractive power, an eighth lens L8 with negative refractive power, and a ninth lens L9 with positive refractive power. The surface shapes of each lens in the optical system 10 are as follows:

[0228] The object side surface S1 of the first lens L1 is convex near the optical axis 101, and the image side surface S2 is concave near the optical axis 101.

[0229] The object-side surface S3 of the second lens L2 is convex near the optical axis 101, and the image-side surface S4 is concave near the optical axis 101.

[0230] The object-side surface S5 of the third lens L3 is concave near the optical axis 101, and the image-side surface S6 is concave near the optical axis 101.

[0231] The object-side surface S7 of the fourth lens L4 is convex near the optical axis 101, and the image-side surface S8 is convex near the optical axis 101.

[0232] The object-side surface S9 of the fifth lens L5 is convex near the optical axis 101, and the image-side surface S10 is concave near the optical axis 101.

[0233] The object-side surface S11 of the sixth lens L6 is convex near the optical axis 101, and the image-side surface S12 is convex near the optical axis 101.

[0234] The image-side surface S13 of the seventh lens L7 is concave near the optical axis 101; the image-side surface S14 is convex near the optical axis 101.

[0235] The object-side surface S15 of the eighth lens L8 is concave near the optical axis 101; the image-side surface S16 is convex near the optical axis 101.

[0236] The object-side surface S17 of the ninth lens L9 is convex near the optical axis 101, and the image-side surface S18 is convex near the optical axis 101.

[0237] Furthermore, in this embodiment, the aperture stop STO is an aperture stop located between the image side S10 of the fifth lens L5 and the object side S11 of the sixth lens L6.

[0238] In the first embodiment, the image-side surface S10 of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, and the fifth lens L5, the surface of the seventh lens L7 and the eighth lens L8, and the object-side surface S17 of the ninth lens L9 are spherical, while the object-side surface S9 of the fifth lens L5, the surface of the sixth lens L6, and the image-side surface S18 of the ninth lens L9 are aspherical. Furthermore, the lens material of the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8, and the ninth lens L9 is glass (GL).

[0239] In this embodiment, the parameters of each lens in the optical system 10 are given in Table 11. The reference wavelength for the lens focal length is 555nm. The definitions of the names and parameters of other components can be derived from the first embodiment and will not be repeated here.

[0240] Table 11

[0241]

[0242] As shown in Table 11, the effective focal length f of the optical system 10 in the sixth embodiment is 3.058 mm, the aperture number FNO is 2.4, the maximum field of view FOV of the optical system 10 is 150.0°, and the total optical length TTL is 23.5 mm. The total optical length TTL values ​​in the following embodiments are the sum of the thickness values ​​corresponding to the surface numbers S1 to S21.

[0243] Table 12 below shows the aspherical coefficients of the corresponding lens surfaces in Table 11, where k is the conic coefficient and Ai is the coefficient corresponding to the i-th higher-order term in the aspherical surface shape formula.

[0244] Table 12

[0245]

[0246]

[0247] Depend on Figure 10 As can be seen from the various aberration diagrams, the longitudinal spherical aberration, field curvature, astigmatism, and distortion of the optical system 10 with its large field of view are well controlled, and the optical system 10 of this embodiment can have good imaging quality.

[0248] Please refer to Table 13, which summarizes the ratios of the various relationships in the first to sixth embodiments of the present invention.

[0249] Table 13

[0250]

[0251] refer to Figure 13 Embodiments of the present invention also provide a camera module 20, which includes an optical system 10 and a photosensitive chip 210. The photosensitive chip 210 is disposed on the image side of the optical system 10, and the two can be fixed by a bracket. The photosensitive chip 210 can be a CCD sensor (Charge Coupled Device) or a CMOS sensor (Complementary Metal Oxide Semiconductor). Generally, during assembly, the imaging surface S21 of the optical system 10 overlaps with the photosensitive surface of the photosensitive chip 210. By employing the above-described optical system 10, the camera module 20 can meet the requirements of high imaging quality while having a large field of view.

[0252] refer to Figure 14 Some embodiments of the present invention also provide a terminal device 30. The terminal device 30 includes a fixing member 310, on which a camera module 20 is mounted. The fixing member 310 can be a display screen, circuit board, mid-frame, back cover, or other components. The terminal device 30 can be, but is not limited to, a vehicle, smartphone, smartwatch, smart glasses, e-book reader, tablet computer, PDA (Personal Digital Assistant), endoscope, etc. The aforementioned camera module 20 enables the terminal device 30 to meet the requirements of high imaging quality while having a large field of view.

[0253] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0254] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0255] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0256] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An optical system, characterized in that, The number of refractive lenses is nine, which are arranged along the optical axis from the object side to the image side as follows: A first lens with negative refractive power, wherein the object side of the first lens is convex near the optical axis and the image side is concave near the optical axis; A second lens with negative refractive power, wherein the object side of the second lens is convex near the optical axis and the image side is concave near the optical axis; A third lens with negative refractive power, wherein the object-side surface of the third lens is concave near the optical axis, and the image-side surface is concave near the optical axis; A fourth lens with positive refractive power, wherein the object-side surface of the fourth lens is convex near the optical axis, and the image-side surface is convex near the optical axis; A fifth lens with positive refractive power, wherein the object-side surface of the fifth lens is convex near the optical axis and the image-side surface is concave near the optical axis; A sixth lens with positive refractive power, wherein the object side of the sixth lens is convex near the optical axis, and the image side is convex near the optical axis; A seventh lens with positive refractive power, wherein the image-side surface of the seventh lens is convex near the optical axis; An eighth lens with negative refractive power, wherein the object-side surface of the eighth lens is concave near the optical axis; A ninth lens with positive refractive power, wherein the object-side surface of the ninth lens is convex near the optical axis, and the image-side surface is convex near the optical axis; The optical system satisfies the following relationship: 39 (deg / mm) <FOV / f<54(deg / mm);0.8<(CT1 / ET1) / (CT2 / ET2)<1.85; FOV is the maximum field of view of the optical system, f is the effective focal length of the optical system, CT1 is the thickness of the first lens on the optical axis, CT2 is the thickness of the second lens on the optical axis, ET1 is the distance from the maximum effective aperture on the object side of the first lens to the maximum effective aperture on the image side in the optical axis direction, and ET2 is the distance from the maximum effective aperture on the object side of the second lens to the maximum effective aperture on the image side in the optical axis direction.

2. The optical system according to claim 1, characterized in that, The optical system satisfies the following relationship: 0.25 <f / f6<0.70;0.20<f / f9<0.60; f6 is the effective focal length of the sixth lens; f9 is the effective focal length of the ninth lens.

3. The optical system according to claim 1, characterized in that, The optical system satisfies the following relationship: 0.7<|f3 / f4|<0.9; 1.50<|f7 / f8|<3.00; f3 is the effective focal length of the third lens; f4 is the effective focal length of the fourth lens; f7 is the effective focal length of the seventh lens; and f8 is the effective focal length of the eighth lens.

4. The optical system according to claim 1, characterized in that, The optical system satisfies the following relationship: 6<|r82 / r81|<11；-3.2<r91 / r92<-0.3； r81 is the radius of curvature of the object side of the eighth lens at the optical axis; r82 is the radius of curvature of the image side of the eighth lens at the optical axis; r91 is the radius of curvature of the object side of the ninth lens at the optical axis; r92 is the radius of curvature of the image side of the ninth lens at the optical axis.

5. The optical system according to claim 1, characterized in that, The optical system satisfies the following relationship: -0.2 < (NL8 - NL7) / r72 < -0.075; NL7 is the refractive index of the seventh lens, NL8 is the refractive index of the eighth lens, and r72 is the radius of curvature of the image side of the seventh lens at the optical axis.

6. The optical system according to claim 1, characterized in that, The optical system satisfies the following relationship: 9mm <TTL / FNO<15mm; TTL is the distance on the optical axis from the object side of the first lens to the imaging surface of the optical system, and FNO is the aperture number of the optical system.

7. The optical system according to claim 1, characterized in that, The optical system satisfies the following relationship: 2.5 <SD11 / SD61<3.3; SD11 is the maximum effective aperture of the object side of the first lens, and SD61 is the maximum effective aperture of the object side of the sixth lens.

8. A camera module, characterized in that, The system includes a photosensitive chip and an optical system as described in any one of claims 1 to 7, wherein the photosensitive chip is disposed on the image side of the optical system.

9. A terminal device, characterized in that, It includes a fixing member and the camera module as described in claim 8, wherein the camera module is disposed on the fixing member.

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