WO2022204923A1

WO2022204923A1 - Optical system, camera module, and electronic device

Info

Publication number: WO2022204923A1
Application number: PCT/CN2021/083858
Authority: WO
Inventors: 徐标; 李明; 宋琦
Original assignee: 欧菲光集团股份有限公司; 江西晶超光学有限公司
Priority date: 2021-03-30
Filing date: 2021-03-30
Publication date: 2022-10-06

Abstract

An optical system (100), a camera module (200), and an electronic device (300). The optical system (100) comprises: a first lens (L1) having positive refractive power, an object side surface (S1) being a convex surface and an image side surface (S2) being a concave surface; a second lens (L2) having refractive power, an object side surface (S3) being a convex surface and an image side surface (S4) being a concave surface; a third lens (L3) having refractive power; a fourth lens (L4) having refractive power, an image side surface (S8) being a concave surface; a fifth lens (L5) having refractive power, an object side surface (S9) being a concave surface; a sixth lens (L6) having refractive power, an image side surface (S12) being a concave surface; a seventh lens (L7) having positive refractive power; and an eighth lens (L8) having negative refractive power, an image side surface (S16) being a concave surface in a paraxial region. The optical system satisfies the following condition: 2.5 mm≤ImgH2/(TTL*FNO)≤2.53 mm.

Description

Optical system, imaging module and electronic equipment

technical field

The invention relates to the field of imaging, in particular to an optical system, an imaging module and an electronic device.

Background technique

With the rapid development of camera technology, users have higher and higher requirements for imaging quality of electronic devices such as smartphones and tablet computers. High-quality imaging can bring users a higher-quality shooting experience. The performance improvement of the system is one of the key factors to improve the imaging quality. However, the current optical system has poor shooting effect in low-light environments such as night scenes, rainy days, and starry sky, and it is difficult to meet the requirements of high imaging quality.

SUMMARY OF THE INVENTION

According to various embodiments of the present application, an optical imaging system, an imaging module, and an electronic device are provided.

An optical system, comprising in sequence from the object side to the image side along the optical axis:

The first lens with positive refractive power, the object side of the first lens is convex at the near optical axis, and the image side is concave at the near optical axis;

The second lens with refractive power, the object side of the second lens is convex at the near-optical axis, and the image side is concave at the near-optical axis;

a third lens having refractive power;

a fourth lens with refractive power, the image side of the fourth lens is concave at the near optical axis;

a fifth lens with refractive power, the object side of the fifth lens is concave at the near optical axis;

a sixth lens with refractive power, the image side of the sixth lens is concave at the near optical axis;

a seventh lens having a positive refractive power; and

an eighth lens with negative refractive power, wherein the image side of the eighth lens is concave at the near optical axis;

And the optical system satisfies the following conditional formula:

2.5mm≤ImgH ² /(TTL*FNO)≤2.53mm;

Wherein, ImgH is half of the image height corresponding to the maximum angle of view of the optical system, and TTL is the distance from the object side of the first lens to the imaging plane of the optical system on the optical axis, that is, the optical axis The total optical length of the system, FNO is the aperture number of the optical system.

An imaging module includes a photosensitive element and the optical system according to any one of the above embodiments, wherein the photosensitive element is arranged on the image side of the optical system.

An electronic device includes a casing and the above-mentioned imaging module, wherein the imaging module is arranged on the casing.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects and advantages of the present invention will become apparent from the description, drawings and claims.

Description of drawings

In order to better describe and illustrate embodiments and/or examples of those inventions disclosed herein, reference may be made to one or more of the accompanying drawings. The additional details or examples used to describe the drawings should not be construed as limiting the scope of any of the disclosed inventions, the presently described embodiments and/or examples, and the best mode presently understood of these inventions.

FIG. 1 is a schematic structural diagram of an optical system in a first embodiment of the present application;

2 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system in the first embodiment of the application;

3 is a schematic structural diagram of an optical system in a second embodiment of the present application;

4 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system in the second embodiment of the application;

5 is a schematic structural diagram of an optical system in a third embodiment of the present application;

6 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system in the third embodiment of the present application;

7 is a schematic structural diagram of an optical system in a fourth embodiment of the present application;

8 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system in the fourth embodiment of the present application;

9 is a schematic structural diagram of an optical system in a fifth embodiment of the present application;

10 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system in the fifth embodiment of the application;

11 is a schematic structural diagram of an optical system in a sixth embodiment of the present application;

12 is a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system in the sixth embodiment of the application;

13 is a schematic diagram of an imaging module in an embodiment of the application;

FIG. 14 is a schematic diagram of an electronic device in an embodiment of the present application.

Detailed ways

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the related drawings. The preferred embodiments of the invention are shown in the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that a thorough and complete understanding of the present disclosure is provided.

It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "inner", "outer", "left", "right" and similar expressions used herein are for the purpose of illustration only and do not represent the only embodiment.

Referring to FIG. 1 , in some embodiments of the present application, the optical system 100 includes a first lens L1 , a second lens L2 , a third lens L3 , a fourth lens L4 , a first lens L1 , a second lens L2 , a third lens L3 , a fourth lens L4 , and a second lens L1 , a second lens L2 , a third lens L3 A five lens L5, a sixth lens L6, a seventh lens L7, and an eighth lens L8. Specifically, the first lens L1 includes an object side S1 and an image side S2, the second lens L2 includes an object side S3 and an image side S4, the third lens L3 includes an object side S5 and an image side S6, and the fourth lens L4 includes an object side S7 and the image side S8, the fifth lens L5 includes the object side S9 and the image side S10, the sixth lens L6 includes the object side S11 and the image side S12, the seventh lens L7 includes the object side S13 and the image side S14, and the eighth lens L8 includes the object side S13 and the image side S14. Side S15 and like Side S16.

Wherein, the first lens L1 has a positive refractive power, which is helpful for shortening the total system length of the optical system 100 and satisfies the requirement of miniaturized design of the optical system 100 . The object side surface S2 of the first lens L1 is convex at the near optical axis 110, which is beneficial to enhance the positive refractive power of the first lens L1, further shortening the total system length of the optical system 100, and at the same time, it is also beneficial to make the light in each field of view uniform. into the optical system 100 . The image side surface S2 of the first lens L1 is concave at the near optical axis 110 . The second lens L2 has refractive power, the object side S3 of the second lens L2 is convex at the near optical axis 110 , and the image side S4 is concave at the near optical axis 110 . The third lens L3 has refractive power. The fourth lens L4 has refractive power, and the image side surface S8 of the fourth lens L4 is concave at the near optical axis 110 . The fifth lens L5 has refractive power, and the object side surface S9 of the fifth lens L5 is concave at the near optical axis 110 . The sixth lens L6 has refractive power. The image side surface S12 of the sixth lens L6 is concave at the paraxial position 110 , which is beneficial to shorten the overall system length of the optical system 100 . The seventh lens L7 has a positive refractive power, which is beneficial to improve the ability of the optical system 100 to focus light at the image side. The eighth lens L8 has a negative refractive power, which is beneficial to correct the aberration caused by the optical system 100 to shorten the total length of the system. The image side surface S16 of the eighth lens L8 is concave at the near optical axis 110 , which can keep the principal point away from the imaging surface of the optical system 100 , thereby further shortening the overall system length of the optical system 100 . The combination of different surface shapes of the lenses enables the light entering the optical system 100 to stably pass through the surfaces of the lenses and finally irradiate on the imaging surface of the optical system 100 for imaging. At the same time, a reasonable surface configuration helps to reduce the attenuation of the subject information by the optical system 100 and improve the resolution of the lens, so that the optical system 100 has good imaging quality.

In addition, in some embodiments, the optical system 100 is provided with a stop STO, and the stop STO can be arranged on the object side of the first lens L1 or on the object side S1 of the first lens L1. In some embodiments, the optical system 100 further includes an infrared cut filter L9 disposed on the image side of the eighth lens L8, and the infrared cut filter L9 includes an object side S17 and an image side S18. The infrared cut-off filter L9 is used to filter out interference light, so as to prevent the interference light from reaching the imaging surface of the optical system 100 and affecting normal imaging. Further, the optical system 100 further includes an image surface S19 located on the image side of the eighth lens L8, the image surface S19 is the imaging surface of the optical system 100, and the incident light passes through 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 and the eighth lens L8 can form an image on the image plane S19 after adjustment.

In some embodiments, the object side and the image side of each lens of the optical system 100 are aspherical. The adoption of the aspherical structure can improve the flexibility of lens design, effectively correct spherical aberration, and improve image quality. In other embodiments, the object side surface and the image side surface of each lens of the optical system 100 may also be spherical surfaces. It should be noted that the above embodiments are only examples of some embodiments of the present application. In some embodiments, the surfaces of the lenses in the optical system 100 may be aspherical or any combination of spherical surfaces.

In some embodiments, the material of each lens in the optical system 100 may be glass or plastic. The use of the plastic lens can reduce the weight of the optical system 100 and reduce the production cost, and realize the light and thin design of the optical system in conjunction with the miniaturization of the optical system. The lens made of glass enables the optical system 100 to have excellent optical performance and high temperature resistance. It should be noted that the material of each lens in the optical system 100 can also be any combination of glass and plastic, and not necessarily all of glass or all of plastic.

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

Further, in some embodiments, the optical system 100 satisfies the conditional formula: 2.5mm≤ImgH ² /(TTL*FNO)≤2.53mm; wherein, ImgH is half of the image height corresponding to the maximum angle of view of the optical system 100 , TTL is the distance from the object side S1 of the first lens L1 to the imaging surface of the optical system 100 on the optical axis 110 , that is, the total optical length of the optical system 100 , and FNO is the aperture number of the optical system 100 . Specifically, ImgH ² /(TTL*FNO) can be: 2.51, 2.52 or 2.53, and the numerical unit is mm. Satisfying the above conditional formula can reasonably configure the half image height, total optical length and aperture number of the optical system 100, which is beneficial to expand the maximum field of view of the optical system 100, so that the optical system 100 can obtain more scene contents, enriching the The imaging information of the optical system 100; in addition, it is also beneficial for the optical system 100 to realize the characteristics of a large aperture, which increases the amount of light entering the optical system 100, thereby improving the imaging quality of the optical system 100 in a low-light environment, and enables the optical system 100 to have A better blur effect can be achieved, thereby meeting the requirements of high imaging quality; in addition, it is also beneficial to shorten the total system length of the optical system 100 and realize a miniaturized design.

In some embodiments, the optical system 100 satisfies the conditional formula: 82.5°≦FOV≦84°; wherein, FOV is the maximum angle of view of the optical system 100 . Specifically, the FOV may be: 82.5, 82.6, 82.8, 82.9, 83, 83.1, 83.3, 83.6, 83.9 or 84, and the numerical unit is °. When the above conditional expressions are satisfied, the optical system 100 has a wide-angle characteristic, so that the optical system 100 can acquire more scene contents and enrich the imaging information of the optical system 100 .

It should be noted that, in some embodiments, the optical system 100 can be matched with a photosensitive element having a rectangular photosensitive surface, and the imaging surface of the optical system 100 is coincident with the photosensitive surface of the photosensitive element. At this time, the effective pixel area on the imaging surface of the optical system 100 has a horizontal direction and a diagonal direction, then ImgH can be understood as half of the diagonal length of the effective pixel area on the imaging surface of the optical system 100, and FOV can be understood as the optical system. 100 Maximum field of view in the diagonal direction.

In some embodiments, the optical system 100 satisfies the conditional formula: 5.4mm≦f*tan(HFOV)≦5.5mm; where f is the effective focal length of the optical system 100 , and HFOV is half of the maximum field angle of the optical system 100 . Specifically, f*tan(HFOV) can be: 5.41, 5.42, 5.43, 5.44, 5.45, 5.46, 5.47, 5.48 or 5.49, and the numerical unit is mm. Satisfying the above conditional formula, the effective focal length and the maximum half angle of view of the optical system 100 can be reasonably configured, which is beneficial to shorten the total system length of the optical system 100 and meet the requirements of miniaturized design; at the same time, it is also beneficial to reduce the amount of light in the optical system 100. Therefore, the surface shape of each lens in the optical system 100 will not be excessively bent or too flat, which is beneficial to improve the yield of injection molding of each lens; in addition, it is also beneficial to make the optical system 100 have a large image surface Therefore, the optical system 100 can be matched with a larger-sized photosensitive element, thereby helping to improve the imaging quality of the optical system 100 .

In some embodiments, the optical system 100 satisfies the conditional formula: 1.35≤TTL/ImgH≤1.4. Specifically, TTL/ImgH may be: 1.37 or 1.38. Satisfying the above conditional expression is beneficial to shorten the overall system length of the optical system 100 and meet the requirements of miniaturized design. Below the lower limit of the above conditional expression, the total system length of the optical system 100 is too short and/or the half image height is too large, resulting in poor edge imaging, which is not conducive to the improvement of the imaging quality of the optical system 100 while meeting the requirements of miniaturized design; The upper limit of the conditional expression is that the total system length of the optical system 100 is too long, which is not conducive to the miniaturization design of the optical system 100 .

In some embodiments, the optical system 100 satisfies the conditional formula: 1≤|R13+R14|/|R13-R14|≤1.2; wherein, R13 is the radius of curvature of the object side surface S13 of the seventh lens L7 at the optical axis 110, R14 is the radius of curvature of the image side surface S14 of the seventh lens L7 at the optical axis 110 . Specifically, |R13+R14|/|R13-R14| may be: 1.015, 1.033, 1.043, 1.067, 1.099, 1.122, 1.130, 1.139, 1.140 or 1.142. Satisfying the above conditional formula, the surface shape of the seventh lens L7 can be reasonably configured, so that the surface shape of the seventh lens L7 will not be excessively curved or too flat, thereby helping to reduce the tolerance sensitivity of the seventh lens L7 and improve the seventh lens L7 high injection molding yield; meanwhile, it is also beneficial to balance the advanced coma aberration of the optical system 100 and improve the imaging quality of the optical system 100 .

In some embodiments, the optical system 100 satisfies the conditional formula: 3≤|f1/(f7+f8)|≤25; wherein, f1 is the effective focal length of the first lens L1, f7 is the effective focal length of the seventh lens L7, and f8 is the effective focal length of the eighth lens L8. Specifically, |f1/(f7+f8)| may be: 3.43, 5.36, 7.31, 8.39, 11.25, 13.15, 16.58, 19.33, 20.02 or 24.44. Satisfying the above conditional formula, the ratio of the effective focal length of the first lens L1 to the sum of the effective focal lengths of the seventh lens L7 and the eighth lens L8 can be reasonably configured, so as to reasonably allocate the first lens L1, the seventh lens L7 and the eighth lens The spherical aberration of the lens L8 contributes, thereby enabling the on-axis region of the optical system 100 to have good imaging quality.

In some embodiments, the optical system 100 satisfies the conditional formula: 1≦f67/f≦1.5; where f67 is the combined focal length of the sixth lens L6 and the seventh lens L7 , and f is the effective focal length of the optical system 100 . Specifically, f67/f may be: 1.00, 1.05, 1.09, 1.11, 1.15, 1.18, 1.20, 1.25, 1.27 or 1.31. Satisfying the above conditional formula, the ratio of the combined focal length of the sixth lens L6 and the seventh lens L7 and the effective focal length of the optical system 100 can be reasonably configured, so that the combined focal length of the sixth lens L6 and the seventh lens L7 is in the optical system 100. It will not be too strong, which is beneficial to correct the high-order spherical aberration of the optical system 100 , thereby improving the imaging quality of the optical system 100 .

In some embodiments, the optical system 100 satisfies the conditional formula: 0.35mm≤ET2≤0.5mm; wherein, ET2 is the maximum effective aperture of the object side S3 of the second lens L2 to the maximum effective aperture of the image side S4 of the second lens L2 The distance of the aperture in the direction of the optical axis 110, that is, the edge thickness of the second lens L2. Specifically, ET2 may be: 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42 or 0.43, and the numerical unit is mm. Satisfying the above conditional formula can reasonably configure the edge thickness of the second lens L2, which is beneficial to suppress the distortion of the optical system 100, thereby improving the imaging quality of the optical system 100; Excessive curvature or too flatness is favorable for the processing and shaping of the second lens L2.

In some embodiments, the optical system 100 satisfies the conditional formula: 0.5≤|SAG61/CT6|≤1; wherein, SAG61 is the sagittal height at the maximum effective aperture of the object side surface S1 of the sixth lens L6, that is, the object of the sixth lens L6 The distance from the intersection of the side S1 and the optical axis 110 to the maximum effective aperture of the object side S11 of the sixth lens L6 in the direction of the optical axis 110, CT6 is the thickness of the sixth lens L6 on the optical axis 110, that is, the thickness of the sixth lens L6 Center thickness. Specifically, |SAG61/CT6| may be: 0.60, 0.62, 0.63, 0.65, 0.68, 0.70, 0.74, 0.75, 0.76 or 0.77. Satisfying the above conditional formula, the ratio of the sag height and the center thickness of the sixth lens L6 can be reasonably configured, which is beneficial to make the surface shape of the sixth lens L6 more reasonable, thereby reducing the tolerance sensitivity of the sixth lens L6, and improving the sixth lens L6. The processing and molding yield of lens L6.

In some embodiments, the optical system 100 satisfies the conditional formula: 5≤|V4-V5|≤10; wherein, V4 is the Abbe number of the fourth lens L4 under the d-line (587.56 nm wavelength), and V5 is the fifth lens Abbe number of L5 below the d-line. Specifically, |V4-V5| may be 7.95. Satisfying the above conditional formula, the difference between the Abbe numbers of the fourth lens L4 and the fifth lens L5 can be reasonably configured, which is beneficial to correct the chromatic aberration of the optical system 100, reduce the secondary spectrum of the optical system 100, and improve the optical system 100. image quality.

The reference wavelength of the above effective focal length is 555nm, and the reference wavelength of Abbe number is 587.56nm.

Based on the descriptions of the above embodiments, more specific embodiments and accompanying drawings are provided below for detailed description.

first embodiment

Please refer to FIG. 1 and FIG. 2. FIG. 1 is a schematic structural diagram of the optical system 100 in the first embodiment. The optical system 100 sequentially includes a diaphragm STO, a first lens L1 with positive refractive power, and a The second lens L2 with negative refractive power, the third lens L3 with positive refractive power, the fourth lens L4 with negative refractive power, the fifth lens L5 with negative refractive power, the sixth lens L6 with negative refractive power, the The seventh lens L7 with positive refractive power and the eighth lens L8 with negative refractive power. 2 is a graph of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the first embodiment from left to right, wherein the reference wavelength of the astigmatism graph and the distortion graph is 555 nm, and the other embodiments are the same.

The object side surface S1 of the first lens L1 is a convex surface at the near optical axis 110, and is a convex surface at the circumference;

The image side surface S2 of the first lens L1 is a concave surface at the near optical axis 110, and a convex surface at the circumference;

The object side surface S3 of the second lens L2 is a convex surface at the near optical axis 110, and is a convex surface at the circumference;

The image side surface S4 of the second lens L2 is concave at the near optical axis 110, and is concave at the circumference;

The object side surface S5 of the third lens L3 is concave at the near optical axis 110, and is concave at the circumference;

The image side surface S6 of the third lens L3 is a convex surface at the near optical axis 110, and is a convex surface at the circumference;

The object side surface S7 of the fourth lens L4 is a convex surface at the near optical axis 110, and is a concave surface at the circumference;

The image side surface S8 of the fourth lens L4 is a concave surface at the near optical axis 110 and a convex surface at the circumference;

The object side surface S9 of the fifth lens L5 is a concave surface at the near optical axis 110, and is a concave surface at the circumference;

The image side surface S10 of the fifth lens L5 is a convex surface at the near optical axis 110, and is a convex surface at the circumference;

The object side surface S11 of the sixth lens L6 is concave at the near optical axis 110, and is concave at the circumference;

The image side surface S12 of the sixth lens L6 is a concave surface at the near optical axis 110, and a convex surface at the circumference;

The object side surface S13 of the seventh lens L7 is a convex surface at the near optical axis 110 and a concave surface at the circumference;

The image side surface S14 of the seventh lens L7 is a concave surface at the near optical axis 110, and a convex surface at the circumference;

The object side surface S15 of the eighth lens L8 is a concave surface at the near optical axis 110, and a convex surface at the circumference;

The image side surface S16 of the eighth lens L8 is concave at the near optical axis 110 and convex at the circumference.

The object and image sides 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 and the eighth lens L8 are aspherical.

It should be noted that, in this application, when a surface of the lens is described as convex near the optical axis 110 (the central area of the surface), it can be understood that the area of the surface of the lens near the optical axis 110 is convex . When it is described that one surface of the lens is concave at the circumference, it can be understood that the area of the surface near the maximum effective radius is concave. For example, when the surface is convex at the near optical axis 110 and is also convex at the circumference, the shape of the surface from the center (the intersection of the surface and the optical axis 110) to the edge direction can be purely convex; Or transition from a convex shape at the center to a concave shape and then become convex near the maximum effective radius. This is only an example for illustrating the relationship between the optical axis 110 and the circumference. Various shapes and structures of the surface (concave-convex relationship) are not fully reflected, but other situations can be derived from the above examples.

The materials 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 and the eighth lens L8 are all plastics.

Further, the optical system 100 satisfies the conditional formula: ImgH ² /(TTL*FNO)=2.51mm; wherein, ImgH is half of the image height corresponding to the maximum angle of view of the optical system 100, and TTL is the object of the first lens L1 The distance from the side S1 to the imaging surface of the optical system 100 on the optical axis 110 is the total optical length of the optical system 100 , and FNO is the aperture number of the optical system 100 . Satisfying the above conditional formula can reasonably configure the half image height, total optical length and aperture number of the optical system 100, which is beneficial to expand the maximum field of view of the optical system 100, so that the optical system 100 can obtain more scene contents, enriching the The imaging information of the optical system 100; in addition, it is also beneficial for the optical system 100 to realize the characteristics of a large aperture, which increases the amount of light entering the optical system 100, thereby improving the imaging quality of the optical system 100 in a low-light environment, and enables the optical system 100 to have A better blur effect can be achieved, thereby meeting the requirements of high imaging quality; in addition, it is also beneficial to shorten the total system length of the optical system 100 and realize a miniaturized design.

The optical system 100 satisfies the conditional formula: f*tan(HFOV)=5.41mm; wherein, f is the effective focal length of the optical system 100 , and HFOV is half of the maximum angle of view of the optical system 100 . Satisfying the above conditional formula, the effective focal length and the maximum half angle of view of the optical system 100 can be reasonably configured, which is beneficial to shorten the total system length of the optical system 100 and meet the requirements of miniaturized design; at the same time, it is also beneficial to reduce the amount of light in the optical system 100. Therefore, the surface shape of each lens in the optical system 100 will not be excessively bent or too flat, which is beneficial to improve the yield of injection molding of each lens; in addition, it is also beneficial to make the optical system 100 have a large image surface Therefore, the optical system 100 can be matched with a larger-sized photosensitive element, thereby helping to improve the imaging quality of the optical system 100 .

The optical system 100 satisfies the conditional expression: TTL/ImgH=1.38. Satisfying the above conditional expression is beneficial to shorten the total system length of the optical system 100 and meet the requirements of miniaturized design;

The optical system 100 satisfies the conditional formula: |R13+R14|/|R13-R14|=1.121; wherein, R13 is the radius of curvature of the object side surface S13 of the seventh lens L7 at the optical axis 110, and R14 is the image of the seventh lens L7 The curvature radius of the side surface S14 at the optical axis 110 . Satisfying the above conditional formula, the surface shape of the seventh lens L7 can be reasonably configured, so that the surface shape of the seventh lens L7 will not be excessively curved or too flat, thereby helping to reduce the tolerance sensitivity of the seventh lens L7 and improve the seventh lens L7 high injection molding yield; meanwhile, it is also beneficial to balance the advanced coma aberration of the optical system 100 and improve the imaging quality of the optical system 100 .

The optical system 100 satisfies the conditional formula: |f1/(f7+f8)|=12.14; wherein, f1 is the effective focal length of the first lens L1, f7 is the effective focal length of the seventh lens L7, and f8 is the effective focal length of the eighth lens L8 . Satisfying the above conditional formula, the ratio of the effective focal length of the first lens L1 to the sum of the effective focal lengths of the seventh lens L7 and the eighth lens L8 can be reasonably configured, so as to reasonably allocate the first lens L1, the seventh lens L7 and the eighth lens The spherical aberration of the lens L8 contributes, thereby enabling the on-axis region of the optical system 100 to have good imaging quality.

The optical system 100 satisfies the conditional formula: f67/f=1.24; wherein, f67 is the combined focal length of the sixth lens L6 and the seventh lens L7 , and f is the effective focal length of the optical system 100 . Satisfying the above conditional formula, the ratio of the combined focal length of the sixth lens L6 and the seventh lens L7 and the effective focal length of the optical system 100 can be reasonably configured, so that the combined focal length of the sixth lens L6 and the seventh lens L7 is in the optical system 100. It will not be too strong, which is beneficial to correct the high-order spherical aberration of the optical system 100 , thereby improving the imaging quality of the optical system 100 .

The optical system 100 satisfies the conditional formula: ET2=0.40mm; wherein, ET2 is the distance from the maximum effective aperture of the object side S3 of the second lens L2 to the maximum effective aperture of the image side S4 of the second lens L2 in the direction of the optical axis 110 , that is, the edge thickness of the second lens L2. Satisfying the above conditional formula can reasonably configure the edge thickness of the second lens L2, which is beneficial to suppress the distortion of the optical system 100, thereby improving the imaging quality of the optical system 100; Excessive curvature or too flatness is favorable for the processing and shaping of the second lens L2.

The optical system 100 satisfies the conditional formula: |SAG61/CT6|=0.75; wherein, SAG61 is the sag at the maximum effective aperture of the object side S1 of the sixth lens L6, CT6 is the thickness of the sixth lens L6 on the optical axis 110, that is, The center thickness of the sixth lens L6. Satisfying the above conditional formula, the ratio of the sag height and the center thickness of the sixth lens L6 can be reasonably configured, which is beneficial to make the surface shape of the sixth lens L6 more reasonable, thereby reducing the tolerance sensitivity of the sixth lens L6, and improving the sixth lens L6. The processing and molding yield of lens L6.

The optical system 100 satisfies the conditional formula: |V4-V5|=7.95; wherein, V4 is the Abbe number of the fourth lens L4 under the d-line (587.56nm wavelength), and V5 is the Abbe of the fifth lens L5 under the d-line number. Satisfying the above conditional formula, the difference between the Abbe numbers of the fourth lens L4 and the fifth lens L5 can be reasonably configured, which is beneficial to correct the chromatic aberration of the optical system 100, reduce the secondary spectrum of the optical system 100, and improve the optical system 100. image quality.

In addition, various parameters of the optical system 100 are given in Table 1. The image plane S19 in Table 1 can be understood as the imaging plane of the optical system 100 . The elements from the object plane (not shown) to the image plane S19 are sequentially arranged in the order of the elements in Table 1 from top to bottom. The Y radius in Table 1 is the curvature radius of the object side surface or the image side surface of the corresponding surface number at the optical axis 110 . The surface number S1 and the surface number S2 are the object side S1 and the image side S2 of the first lens L1 respectively, that is, in the same lens, the surface with the smaller surface number is the object side, and the surface with the larger surface number is the image side. The first value in the "thickness" parameter column of the first lens L1 is the thickness of the lens on the optical axis 110, and the second value is the rear surface of the lens in the direction from the image side to the image side on the optical axis 110 the distance.

It should be noted that, in this embodiment and the following embodiments, the optical system 100 may not be provided with the infrared cut filter L9, but at this time, the distance from the image side S16 to the image plane S19 of the eighth lens L8 remains unchanged.

In the first embodiment, the effective focal length of the optical system 100 is f=6.14mm, the aperture number FNO=1.59, the maximum field angle FOV=82.8°, and the total optical length TTL=7.6mm. In the first embodiment and subsequent embodiments, the relational expressions are satisfied: 7.55mm≤TTL≤7.6mm; FNO=1.59; miniaturization design and large aperture design of the optical system can be realized.

In addition, the reference wavelength of the focal length of each lens is 555 nm, and the reference wavelengths of the refractive index and Abbe number are both 587.56 nm (d-line), and other embodiments are also the same.

Table 1

Further, the aspheric coefficients of the image side or object side of each lens of the optical system 100 are given in Table 2. Among them, the surface numbers from S1-S16 represent the image side or the object side S1-S16 respectively. From top to bottom, K-A20 represent the types of aspheric coefficients, where K represents the conic coefficient, A4 represents the fourth-order aspheric coefficient, A6 represents the sixth-order aspheric coefficient, and A8 represents the eight-order aspheric coefficient. analogy. In addition, the aspheric coefficient formula is as follows:

Among them, Z is the distance from the corresponding point on the aspherical surface to the plane tangent to the surface vertex, r is the distance from the corresponding point on the aspherical surface to the optical axis 110, c is the curvature of the aspherical vertex, k is the conic coefficient, and Ai is the aspherical surface. The coefficient corresponding to the higher-order term of the i-th term in the spherical surface formula.

Table 2

In addition, FIG. 2 includes a longitudinal spherical aberration diagram (Longitudinal Spherical Aberration) of the optical system 100 , which represents the deviation of the converging focus of light of different wavelengths after passing through the lens. The ordinate of the longitudinal spherical aberration map represents the normalized pupil coordinate (Normalized Pupil Coordinator) from the pupil center to the pupil edge, and the abscissa represents the distance from the imaging plane to the intersection of the light ray and the optical axis 110 (unit is mm) . It can be seen from the longitudinal spherical aberration diagram that in the first embodiment, the degree of deviation of the converging focus of each wavelength light tends to be the same, and the smear or color halo in the imaging picture is effectively suppressed. FIG. 2 also includes a field curvature diagram (ASTIGMATIC FIELD CURVES) of the optical system 100, wherein the S curve represents the sagittal field curvature at 555 nm, and the T curve represents the meridional field curvature at 555 nm. It can be seen from the figure that the field curvature of the optical system 100 is small, the field curvature and astigmatism of each field of view are well corrected, and the center and edge of the field of view have clear images. FIG. 2 also includes a distortion diagram (DISTORTION) of the optical system 100. It can be seen from the diagram that the image distortion caused by the main beam is small, and the imaging quality of the system is excellent.

Second Embodiment

Please refer to FIG. 3 and FIG. 4 . FIG. 3 is a schematic structural diagram of the optical system 100 in the second embodiment. The optical system 100 sequentially includes a diaphragm STO, a first lens L1 with positive refractive power, and a lens from the object side to the image side. The second lens L2 with negative refractive power, the third lens L3 with positive refractive power, the fourth lens L4 with positive refractive power, the fifth lens L5 with negative refractive power, the sixth lens L6 with negative refractive power, the The seventh lens L7 with positive refractive power and the eighth lens L8 with negative refractive power. FIG. 4 is a graph showing longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the second embodiment from left to right.

The object side surface S5 of the third lens L3 is a convex surface at the near optical axis 110 and a concave surface at the circumference;

The object side surface S15 of the eighth lens L8 is a convex surface at the near optical axis 110, and is a convex surface at the circumference;

In addition, the parameters of the optical system 100 are given in Table 3, and the definitions of the parameters can be obtained from the first embodiment, which will not be repeated here.

table 3

Further, the aspheric coefficients of the image side or object side of each lens of the optical system 100 are given in Table 4, and the definitions of the parameters can be obtained from the first embodiment, which will not be repeated here.

Table 4

And, according to the parameter information provided above, the following data can be inferred:

In addition, it can be seen from the aberration diagram in FIG. 4 that the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are well controlled, so that the optical system 100 of this embodiment has good imaging quality.

Third Embodiment

Please refer to FIG. 5 and FIG. 6 . FIG. 5 is a schematic structural diagram of the optical system 100 in the third embodiment. The optical system 100 sequentially includes a diaphragm STO, a first lens L1 with positive refractive power, and a The second lens L2 with negative refractive power, the third lens L3 with positive refractive power, the fourth lens L4 with negative refractive power, the fifth lens L5 with negative refractive power, the sixth lens L6 with positive refractive power, the The seventh lens L7 with positive refractive power and the eighth lens L8 with negative refractive power. FIG. 6 is a graph showing longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the third embodiment from left to right.

In addition, the parameters of the optical system 100 are given in Table 5, and the definitions of the parameters can be obtained from the first embodiment, which will not be repeated here.

table 5

Further, the aspheric coefficients of the image side or object side of each lens of the optical system 100 are given in Table 6, and the definitions of the parameters can be obtained from the first embodiment, which will not be repeated here.

Table 6

In addition, it can be seen from the aberration diagram in FIG. 6 that the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are well controlled, so that the optical system 100 of this embodiment has good imaging quality.

Fourth Embodiment

Please refer to FIG. 7 and FIG. 8 . FIG. 7 is a schematic structural diagram of the optical system 100 in the fourth embodiment. The optical system 100 sequentially includes a diaphragm STO, a first lens L1 with positive refractive power, and a lens from the object side to the image side. The second lens L2 with negative refractive power, the third lens L3 with negative refractive power, the fourth lens L4 with positive refractive power, the fifth lens L5 with negative refractive power, the sixth lens L6 with negative refractive power, the The seventh lens L7 with positive refractive power and the eighth lens L8 with negative refractive power. FIG. 8 is a graph showing longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the fourth embodiment from left to right.

The image side surface S6 of the third lens L3 is a concave surface at the near optical axis 110, and a convex surface at the circumference;

The image side surface S10 of the fifth lens L5 is a concave surface at the near optical axis 110, and a convex surface at the circumference;

In addition, the parameters of the optical system 100 are given in Table 7, and the definitions of the parameters can be obtained from the first embodiment, which will not be repeated here.

Table 7

Further, the aspheric coefficients of the image side or object side of each lens of the optical system 100 are given in Table 8, and the definitions of the parameters can be obtained from the first embodiment, which will not be repeated here.

Table 8

In addition, it can be seen from the aberration diagram in FIG. 8 that the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are well controlled, so that the optical system 100 of this embodiment has good imaging quality.

Fifth Embodiment

Please refer to FIGS. 9 and 10. FIG. 9 is a schematic structural diagram of the optical system 100 in the fifth embodiment. The optical system 100 sequentially includes a diaphragm STO, a first lens L1 with positive refractive power, and a The second lens L2 with positive refractive power, the third lens L3 with positive refractive power, the fourth lens L4 with negative refractive power, the fifth lens L5 with negative refractive power, the sixth lens L6 with negative refractive power, the The seventh lens L7 with positive refractive power and the eighth lens L8 with negative refractive power. FIG. 10 is a graph showing longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the fifth embodiment from left to right.

The image side surface S2 of the first lens L1 is concave at the near optical axis 110, and is concave at the circumference;

The object side surface S15 of the eighth lens L8 is a convex surface at the near optical axis 110 and a concave surface at the circumference;

In addition, the parameters of the optical system 100 are given in Table 9, and the definitions of the parameters can be obtained from the first embodiment, which will not be repeated here.

Table 9

Further, the aspheric coefficients of the image side or object side of each lens of the optical system 100 are given in Table 10, and the definitions of the parameters can be obtained from the first embodiment, which will not be repeated here.

Table 10

In addition, it can be seen from the aberration diagram in FIG. 10 that the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are well controlled, so that the optical system 100 of this embodiment has good imaging quality.

Sixth Embodiment

Please refer to FIGS. 11 and 12. FIG. 11 is a schematic structural diagram of the optical system 100 in the sixth embodiment. The optical system 100 sequentially includes a diaphragm STO, a first lens L1 with positive refractive power, and a The second lens L2 with negative refractive power, the third lens L3 with positive refractive power, the fourth lens L4 with negative refractive power, the fifth lens L5 with positive refractive power, the sixth lens L6 with negative refractive power, the The seventh lens L7 with positive refractive power and the eighth lens L8 with negative refractive power. FIG. 12 is a graph of longitudinal spherical aberration, astigmatism and distortion of the optical system 100 in the sixth embodiment from left to right.

The object side surface S7 of the fourth lens L4 is a concave surface at the near optical axis 110, and is a concave surface at the circumference;

The object side surface S11 of the sixth lens L6 is a convex surface at the near optical axis 110 and a concave surface at the circumference;

In addition, the parameters of the optical system 100 are given in Table 11, and the definitions of the parameters can be obtained from the first embodiment, which will not be repeated here.

Table 11

Further, the aspheric coefficients of the image side or object side of each lens of the optical system 100 are given in Table 12, and the definitions of the parameters can be obtained from the first embodiment, which will not be repeated here.

Table 12

In addition, it can be seen from the aberration diagram in FIG. 12 that the longitudinal spherical aberration, field curvature and distortion of the optical system 100 are well controlled, so that the optical system 100 of this embodiment has good imaging quality.

Referring to FIG. 13 , in some embodiments, the optical system 100 can be assembled with the photosensitive element 210 to form the imaging module 200 . At this time, the photosensitive surface of the photosensitive element 210 can be regarded as the image surface S19 of the optical system 100 . The imaging module 200 may also be provided with an infrared cut-off filter L9, and the infrared cut-off filter L9 is disposed between the image side S16 and the image surface S19 of the eighth lens L8. Specifically, the photosensitive element 210 may be a Charge Coupled Device (CCD) or a Complementary Metal-Oxide Semiconductor (Complementary Metal-Oxide Semiconductor Sensor, CMOS Sensor). The use of the above-mentioned optical system 100 in the image capturing module 200 is beneficial to achieve wide-angle characteristics and large aperture characteristics, and is also beneficial to the miniaturized design of the optical system 100 , thereby reducing the size of the image capturing module 200 .

Referring to FIG. 13 and FIG. 14 , in some embodiments, the imaging module 200 can be applied to an electronic device 300 , the electronic device includes a casing 310 , and the imaging module 200 is disposed in the casing 310 . Specifically, the electronic device 300 may be, but is not limited to, a mobile phone, a video phone, a smart phone, an electronic book reader, a vehicle-mounted camera device such as a driving recorder, or a wearable device such as a smart watch. When the electronic device 300 is a smart phone, the housing 310 may be a middle frame of the electronic device 300 . The use of the imaging module 200 in the electronic device 300 is conducive to achieving wide-angle characteristics and large aperture characteristics, and is also conducive to the miniaturized design of the optical system 100 , thereby reducing the size of the electronic device 300 .

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " Rear, Left, Right, Vertical, Horizontal, Top, Bottom, Inner, Outer, Clockwise, Counterclockwise, Axial, The orientations or positional relationships indicated by "radial direction", "circumferential direction", etc. are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated devices or elements. It must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between the two elements, unless otherwise specified limit. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may be in direct contact between the first and second features, or the first and second features indirectly through an intermediary touch. Also, the first feature being "above", "over" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine the different embodiments or examples described in this specification, as well as the features of the different embodiments or examples, without conflicting each other.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

An optical system, comprising in sequence from the object side to the image side along the optical axis:

The first lens with positive refractive power, the object side of the first lens is convex at the near optical axis, and the image side is concave at the near optical axis;

The second lens with refractive power, the object side of the second lens is convex at the near-optical axis, and the image side is concave at the near-optical axis;

a third lens having refractive power;

a fourth lens with refractive power, the image side of the fourth lens is concave at the near optical axis;

a fifth lens with refractive power, the object side of the fifth lens is concave at the near optical axis;

a sixth lens with refractive power, the image side of the sixth lens is concave at the near optical axis;

a seventh lens having a positive refractive power; and

an eighth lens with negative refractive power, wherein the image side of the eighth lens is concave at the near optical axis;

And the optical system satisfies the following conditional formula:

2.5mm≤ImgH 2 /(TTL*FNO)≤2.53mm;

Wherein, ImgH is half of the image height corresponding to the maximum field of view of the optical system, TTL is the distance from the object side of the first lens to the imaging surface of the optical system on the optical axis, and FNO is the The f-number of the optical system.
The optical system according to claim 1, wherein the following conditional formula is satisfied:

5.4mm≤f*tan(HFOV)≤5.5mm;

Wherein, f is the effective focal length of the optical system, and HFOV is half of the maximum angle of view of the optical system.
The optical system according to claim 1, wherein the following conditional formula is satisfied:

1.35≤TTL/ImgH≤1.4.
The optical system according to claim 1, wherein the following conditional formula is satisfied:

1≤|R13+R14|/|R13-R14|≤1.2;

Wherein, R13 is the radius of curvature of the object side of the seventh lens at the optical axis, and R14 is the radius of curvature of the image side of the seventh lens at the optical axis.
The optical system according to claim 1, wherein the following conditional formula is satisfied:

3≤|f1/(f7+f8)|≤25;

Wherein, f1 is the effective focal length of the first lens, f7 is the effective focal length of the seventh lens, and f8 is the effective focal length of the eighth lens.
The optical system according to claim 1, wherein the following conditional formula is satisfied:

1≤f67/f≤1.5;

Wherein, f67 is the combined focal length of the sixth lens and the seventh lens, and f is the effective focal length of the optical system.
The optical system according to claim 1, wherein the following conditional formula is satisfied:

0.35mm≤ET2≤0.5mm;

Wherein, ET2 is the distance from the maximum effective aperture of the object side of the second lens to the maximum effective aperture of the image side of the second lens in the direction of the optical axis.
The optical system according to claim 1, wherein the following conditional formula is satisfied:

0.5≤|SAG61/CT6|≤1;

Wherein, SAG61 is the sag at the maximum effective aperture on the object side of the sixth lens, and CT6 is the thickness of the sixth lens on the optical axis.
The optical system according to any one of claims 1-8, further comprising an infrared cut filter, wherein the infrared cut filter is arranged on the image side of the eighth lens.
The optical system according to any one of claims 1-8, wherein the object side surface and the image side surface of each lens of the optical system are aspherical surfaces.
The optical system according to any one of claims 1-8, wherein the material of each lens of the optical system is plastic.
The optical system according to any one of claims 1-8, wherein the following conditional formula is satisfied:

5≤|V4-V5|≤10;

Wherein, V4 is the Abbe number of the fourth lens under the d line, and V5 is the Abbe number of the fifth lens under the d line.
The optical system according to any one of claims 1-8, wherein the second lens has a negative refractive power, the third lens has a positive refractive power, the fourth lens has a negative refractive power, and the The fifth lens has negative refractive power, and the sixth lens has negative refractive power.
The optical system according to any one of claims 1-8, wherein the second lens has a negative refractive power, the third lens has a positive refractive power, the fourth lens has a positive refractive power, and the The fifth lens has negative refractive power, and the sixth lens has negative refractive power.
The optical system according to any one of claims 1-8, wherein the second lens has a negative refractive power, the third lens has a positive refractive power, the fourth lens has a negative refractive power, and the The fifth lens has a negative refractive power, and the sixth lens has a positive refractive power.
The optical system according to any one of claims 1-8, wherein the second lens has a negative refractive power, the third lens has a negative refractive power, the fourth lens has a positive refractive power, and the The fifth lens has negative refractive power, and the sixth lens has negative refractive power.
The optical system according to any one of claims 1-8, wherein the second lens has a positive refractive power, the third lens has a positive refractive power, the fourth lens has a negative refractive power, and the The fifth lens has negative refractive power, and the sixth lens has negative refractive power.
The optical system according to any one of claims 1-8, wherein the second lens has a negative refractive power, the third lens has a positive refractive power, the fourth lens has a negative refractive power, and the The fifth lens has a positive refractive power, and the sixth lens has a negative refractive power.
An imaging module, comprising a photosensitive element and the optical system according to any one of claims 1-18, wherein the photosensitive element is arranged on the image side of the optical system.
An electronic device, comprising a casing and the imaging module according to claim 19, wherein the imaging module is arranged on the casing.