WO2022120515A1 - Optical system, photographing module, and electronic device - Google Patents

Abstract

An optical system (10), comprising: a first lens (L1) having positive refractive power; a second lens (L2), an image side surface (S4) thereof being a convex surface at the circumference; a third lens (L3) having negative refractive power, an object side surface (S5) of the third lens being a convex surface at a paraxial area, and an image side surface (S6) being a concave surface at a paraxial area; a fourth lens (L4); a fifth lens (L5) having positive refractive power, an object side surface (S9) of the fifth lens being a concave surface, and an image side surface (S10) being a convex surface; a sixth lens (L6); and a seventh lens (L7) having negative refractive power, an object side surface (S13) of the seventh lens being a convex surface at a paraxial area, and an image side surface (S14) being a concave surface at a paraxial area. The optical system (10) satisfies: 1.8≤SD72/SD11≤2.5; SD11 is the maximum effective aperture of an object side surface (S1) of the first lens (L1), and SD72 is the maximum effective aperture of the image side surface (S14) of the seventh lens (L7).

Description

Optical systems, camera modules and electronic equipment technical field

The present invention relates to the technical field of electronic equipment, in particular to an optical system, a camera module and an electronic equipment.

Background technique

With the development of photography technology, common electronic devices generally use a hole-digging design on the side of the display screen to match the camera, and at the same time remove the bangs area to increase the screen ratio of the device. For devices with a screen-hole design, the structure of the camera lens largely determines the size of the screen's opening, which in turn affects the screen-to-body ratio of the device.

At present, the market has responded enthusiastically to devices with a high screen-to-body ratio. Therefore, how to design a camera lens that can match the display screen to increase the screen-to-body ratio of the device while maintaining good image quality has become the focus of the industry. one.

SUMMARY OF THE INVENTION

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

An optical system, comprising in order from the object side to the image side:

a first lens having a positive refractive power;

a second lens with refractive power, the image side of the second lens is convex at the circumference;

The third lens with negative refractive power, the object side of the third lens is convex at the paraxial position, and the image side is concave at the paraxial position;

a fourth lens with refractive power;

The fifth lens with positive refractive power, the object side of the fifth lens is concave, and the image side is convex;

The sixth lens with refractive power, the object side and the image side of the sixth lens are both aspherical, and at least one of the object side and the image side of the sixth lens is provided with an inflection point;

The seventh lens with negative refractive power, the object side of the seventh lens is convex at the paraxial position, and the image side is concave at the paraxial position;

And the optical system also satisfies the relation:

1.8≤SD72/SD11≤2.5;

SD11 is the maximum effective aperture of the object side of the first lens, and SD72 is the maximum effective aperture of the image side of the seventh lens.

A camera module includes an image sensor and the above-mentioned optical system, wherein the image sensor is arranged on the image side of the optical system.

An electronic device includes a fixing member and the above-mentioned camera module, wherein the camera module is arranged on the fixing member.

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.

1 is a schematic structural diagram of an optical system provided by a first embodiment of the present application;

FIG. 2 includes longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the first embodiment;

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

FIG. 4 includes longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the second embodiment;

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

6 includes longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the third embodiment;

FIG. 7 is a schematic structural diagram of an optical system provided by a fourth embodiment of the present application;

FIG. 8 includes longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the fourth embodiment;

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

FIG. 10 includes longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the fifth embodiment;

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

12 includes longitudinal spherical aberration diagram, astigmatism diagram and distortion diagram of the optical system in the sixth embodiment;

13 is a schematic diagram of a camera module provided by an embodiment of the application;

FIG. 14 is a schematic diagram of an electronic device according to 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.

1 , in the embodiment of the present application, the optical system 10 includes a first lens L1 , a second lens L2 , a third lens L3 , a fourth lens L4 , a fifth lens L5 , a sixth lens L1 , a second lens L2 , a third lens L3 , a fourth lens L4 , a fifth lens L5 , and a sixth lens from the object side to the image side Lens L6 and seventh lens L7. The first lens L1 has positive refractive power, the third lens L3 has negative refractive power, the fifth lens L5 has positive refractive power, and the seventh lens L7 has negative refractive power. The lenses in the optical system 10 are arranged coaxially, that is, the optical axes of the lenses are all located on the same straight line, and the straight line may be called the optical axis 101 of the optical system 10 . Each optical element in the optical system 10 can be assembled with the lens barrel to form an imaging lens.

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 an image side S8, the fifth lens L5 includes an object side S9 and an image side S10, the sixth lens L6 includes an object side S11 and an image side S12, and the seventh lens L7 includes an object side S13 and an image side S14. In addition, the optical system 10 has an imaging surface S15, and the imaging surface S15 is located on the image side of the seventh lens L7. Generally, the imaging surface S15 of the optical system 10 coincides with the photosensitive surface of the image sensor. For the convenience of understanding, the imaging surface S15 can be regarded as the photosensitive surface of the photosensitive element.

In some embodiments, the object side and/or the image side of at least one of the first lens L1 to the seventh lens L7 are aspherical. Specifically, in some embodiments, the object side surface and the image side surface of the first lens L1 to the seventh lens L7 can be designed as aspherical surfaces. The aspheric surface configuration can further help the optical system 10 to eliminate aberrations, solve the problem of distortion of the field of view, and at the same time, it is also conducive to the miniaturized design of the optical system 10, so that the optical system 10 can maintain the miniaturized design. optical effect. Of course, in other embodiments, the object side of any one of the first lens L1 to the seventh lens L7 may be spherical or aspheric; the image side of any one of the first lens L1 to the seventh lens L7 may be The spherical surface can also be an aspherical surface, and the aberration problem can also be effectively eliminated by the cooperation of the spherical surface and the aspherical surface, so that the optical system 10 has excellent imaging effect, and at the same time, the flexibility of lens design and assembly is improved. In particular, when the sixth lens L6 and the seventh lens L7 are aspherical lenses, it will facilitate the final correction of the aberrations generated by each lens on the object side, thereby helping to improve the imaging quality. In the embodiment of the present application, the object side surface S11 and the image side surface S12 of the sixth lens L6 are both aspherical surfaces. It should be noted that the actual surface shape of the lens is not limited to the spherical or aspherical shapes shown in the accompanying drawings, which are for example reference only and are not drawn strictly to scale.

For the calculation of the surface shape of the aspheric surface, please refer to the aspheric surface formula:

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

In some embodiments, when the object side or the image side of a lens is aspherical, the surface may be an overall convex surface or an overall concave structure. Alternatively, the surface can also be designed to have an inflection point, and the shape of the surface will change from the center to the edge, for example, the surface is convex at the center and concave at the edge. It should be noted that when the embodiments of the present application describe that one side surface of the lens is convex at the optical axis (the central area of the side surface), it can be understood that the area of the side surface of the lens near the optical axis is convex, so It can also be considered that the side surface is convex at the paraxial position; when one side surface of the lens is described as concave at the circumference, it can be understood that the area of the side surface near the maximum effective aperture is concave. For example, when the side surface is convex at the paraxial position and is also convex at the circumference, the shape of the side surface from the center (optical axis) to the edge direction can be purely convex; or a convex shape from the center first Transitions to a concave shape and then becomes convex near the maximum effective aperture. This is only an example to illustrate the relationship between the optical axis and the circumference. The various shapes and structures (concave-convex relationship) of the side surface are not fully reflected, but other situations can be deduced from the above examples and should also be regarded as content described in this application.

Further, in some embodiments, at least one of the sixth lens L6 and the seventh lens L7 is provided with an inflection point, and the setting of the inflection point can increase the flexibility of the lens to control the incident light. Especially for the sixth lens L6 and the seventh lens L7 located at the image end of the system, the light in the central field of view mainly passes through the area near the center of the two lenses, while the light in the edge field of view mainly passes through the two lenses close to the center Therefore, through the setting of the inflection point, the sixth lens L6 and the seventh lens L7 can control the light of the central field of view and the edge field of view in a targeted manner, which can effectively correct the on-axis and off-axis aberrations of the system . In the embodiment of the present application, at least one of the object side surface S11 and the image side surface S12 of the sixth lens L6 is provided with an inflection point.

Specifically, in the embodiments of the present application, the image side S4 of the second lens L2 is convex at the circumference; the object side S5 of the third lens L3 is convex at the paraxial position, and the image side S6 is concave at the paraxial position; The object side S9 of the fifth lens L5 is concave, and the image side S10 is convex; the object side S13 of the seventh lens L7 is convex at the paraxial position, and the image side S14 is concave at the paraxial position. In particular, the third lens L3 with the above-mentioned surface design is beneficial to correct the spherical aberration of the edge field of view of the optical system 10 and improve the relative brightness of the peripheral field of view; for the fifth lens L5 with the above-mentioned surface design, it can be compared The astigmatic aberration can be corrected well, so that the image surface of the system tends to be flat; and the seventh lens L7 with the above-mentioned surface design can effectively suppress the off-axis coma and astigmatism of the system.

In some embodiments, the optical system 10 includes a stop STO, the stop STO is an aperture stop, and the stop STO is disposed on the object side of the first lens L1. In particular, when the projection of the diaphragm STO on the optical axis 101 overlaps with the projection of the object side S1 of the first lens L1 on the optical axis 101, it can also be understood that the diaphragm STO is arranged on the object side of the first lens L1, At this time, at least a partial region of the object side surface S1 of the first lens L1 passes through the diaphragm STO toward the object side.

In addition, in the embodiment of the present application, the optical system 10 satisfies the relationship:

1.8≤SD72/SD11≤2.5;

SD11 is the maximum effective aperture of the object side surface S1 of the first lens L1, and SD72 is the maximum effective aperture of the image side surface S14 of the seventh lens L7. SD72/SD11 in some embodiments may be 2.05, 2.1, 2.15, 2.2, 2.3, 2.35, 2.4 or 2.45. In the embodiment of the present application, the optical system 10 having the above-mentioned seven-piece structure can reasonably configure the effective apertures of the object side S1 of the first lens L1 and the image side S14 of the seventh lens L7 by satisfying the relational expression, On the one hand, it is beneficial to reduce the size of the first lens L1 in the radial direction, so that the optical system 10 can realize a small head design, so that when the optical system 10 is applied to an electronic device, the aperture size of the screen can be reduced, thereby enabling The screen ratio of the device is increased; on the other hand, a larger entrance pupil can be provided for the system to expand the aperture, thereby enabling the optical system 10 to obtain higher image quality. In the optical system 10, when the above relationship is higher than the upper limit, it will be unfavorable to control the outer diameters of the object end and the image end of the system. If it is too small, it will be difficult for the optical system to expand the aperture and thus obtain good image quality. If the deflection degree in the system is too large, it is easy to increase the aberration of the system, resulting in poor imaging. When the above relationship is lower than the lower limit, the light exit aperture of the last lens of the system is too small to match a large-sized image sensor, which makes it difficult for the system to have the characteristics of large image area and high pixels; The angle of light incident on the imaging surface S15 is too large, which makes it difficult to fully exert the photosensitive performance of the image sensor, and easily increases the risk of vignetting. Further, in some embodiments, the optical system 10 satisfies 2.03≦SD72/SD11≦2.49, so that the above-mentioned effects of the optical system 10 can be more significant.

In addition, in some embodiments, the optical system 10 also satisfies at least one of the following relationships, and when any relationship is satisfied, it can bring corresponding effects:

1.0≦f123/f≦1.5; f123 is the combined focal length of the first lens L1 , the second lens L2 and the third lens L3 , and f is the effective focal length of the optical system 10 . The f123/f in some embodiments may be 1.05, 1.1, 1.15, 1.2, 1.3, 1.35, 1.4 or 1.45. When the above relationship is satisfied, the refractive power of the front lens group formed by the first lens L1 to the third lens L3 will be reasonably strengthened, so that the effective convergence of the incident light can be strengthened, and the overall length of the system can be shortened, and the system can obtain Larger field of view. At the same time, under the setting of this refractive power, the first lens L1 in the front lens group has a positive refractive power, and the third lens L3 has a negative refractive power. This refractive power distribution can also promote the spherical aberration of the system to reach a balance , so that the system has good imaging quality. When the relationship is lower than the lower limit, the equivalent positive refractive power of the front lens group is too strong, which easily leads to insufficient ability of the image-side lens to correct aberrations, thus causing the system to generate high-order aberrations and reducing imaging quality. When the relationship is higher than the upper limit, the equivalent positive refractive power of the front lens group is insufficient, and it is difficult to effectively converge the incident light, which makes it difficult to reduce the total length of the system, which is not conducive to the miniaturized design of the system.

1.50≤f/EPD≤1.65; f is the effective focal length of the optical system, and EPD is the entrance pupil diameter of the optical system 10 . The f/EPD in some embodiments may be 1.55, 1.57, 1.6, 1.62, 1.63 or 1.65. When the above relationship is satisfied, the optical system 10 will have the characteristics of a large aperture, so that the luminous flux per unit time of the system can be increased, and the imaging effect of the system in a dark environment can be enhanced.

-1.5≤f5/f7≤-0.2; f5 is the effective focal length of the fifth lens L5, and f7 is the effective focal length of the seventh lens L7. f5/f7 in some embodiments may be -1.25, -1.2, -1.15, -1, -0.9, -0.8, -0.7, -0.55, -0.5, or -0.47. When the above relationship is satisfied, the refractive power of the fifth lens L5 and the seventh lens L7 can be reasonably allocated, so as to effectively correct the astigmatism of the system, and at the same time, it is also beneficial to compress the axial size of the optical system 10 and achieve axial miniaturization The design of the device can also avoid excessive restrictions on the thickness reduction of the device.

1.5≤(f1+f5)/f≤5.0; f1 is the effective focal length of the first lens L1 , f5 is the effective focal length of the fifth lens L5 , and f is the effective focal length of the optical system 10 . (f1+f5)/f in some embodiments may be 2, 2.3, 2.5, 3, 3.5, 3.7, 4, 4.2, 4.4, 4.6, 4.7, or 4.8. Both the first lens L1 and the fifth lens L5 provide positive refractive power to the optical system 10, and when the above relationship is satisfied, the relationship between the first lens L1 and the fifth lens L5 can be reasonably configured so that the first lens L1 and the fifth lens The five-lens L5 can provide the system with sufficient light-converging ability, thereby effectively shortening the total optical length of the system, and can also balance the positive refractive power of the first lens L1 and the fifth lens L5, thereby improving the imaging quality.

1.5mm≤∑CT≤2.0mm; ∑CT is the sum of the thicknesses of the first lens L1, the second lens L2, the third lens L3 and the fourth lens L4 on the optical axis. It should be noted that when the lenses are arranged on the same optical axis, the thickness of the lens on the optical axis can also be understood as the central thickness of the lens. The ΣCT in some embodiments may be 1.58mm, 1.6mm, 1.65mm, 1.7mm, 1.75mm, 1.8mm, 1.85mm, 1.87mm, 1.89mm, 1.9mm or 1.92mm. When the above relationship is satisfied, the central thickness of the first four lenses of the system can be reasonably controlled, so that the structure between the lenses is compact, which is conducive to the design of the system to achieve axial miniaturization and thinning, and also enables the optical system 10 to have better performance. The ability to correct distortion, thereby improving image quality.

1.4≤TTL/ImgH≤1.6; TTL is the distance from the object side S1 of the first lens L1 to the imaging plane S15 of the optical system 10 on the optical axis, and ImgH is half of the image height corresponding to the maximum angle of view of the optical system 10 , or can also be referred to as half of the diagonal length of the rectangular effective imaging area on the imaging surface S15 . After the image sensor is assembled, ImgH can also be understood as the distance from the center of the rectangular effective pixel area to the diagonal edge of the image sensor, and the diagonal direction of the above-mentioned effective imaging area is the diagonal direction of the rectangular effective pixel area. . The TTL/ImgH in some embodiments may be 1.45, 1.47, 1.49, 1.5, 1.52, 1.54 or 1.56. When the above relationship is satisfied, the optical system 10 will have the characteristics of a large image plane, so that high-quality imaging effects can be achieved, and at the same time, the total length of the optical system 10 can be effectively reduced, thereby facilitating the realization of a miniaturized design in the axial direction.

0.9≤CT6/|SAG61|≤2.0; CT6 is the thickness of the sixth lens L6 on the optical axis, and SAG61 is the sagittal height of the object side surface S11 of the sixth lens L6 at the maximum effective aperture. CT6/|SAG61| in some embodiments may be 1, 1.05, 1.1, 1.2, 1.4, 1.5, 1.6, 1.7, 1.75, 1.8, or 1.85. When the above relationship is satisfied, the surface shape of the object side surface S11 of the sixth lens L6 will be reasonably controlled, thereby facilitating the manufacture and molding of the sixth lens L6 and reducing the defects of poor molding. In addition, by reasonably controlling the object side surface S11 of the sixth lens L6 as described above, the surface shape can be prevented from being overly curved and complicated, so it is also beneficial to trim the field curvature generated by the lens group on the object side, so that the system field curvature tends to be balanced. Further, the imaging quality of the optical system 10 is improved. It should be noted that the above-mentioned sag is the distance from the intersection of the object side surface S11 of the sixth lens L6 with the optical axis 101 to the maximum effective clear aperture of the surface in the direction parallel to the optical axis.

2.5≤(R6+R7)/(R6-R7)≤6.0; R6 is the curvature radius of the object side S5 of the third lens L3 at the optical axis, R7 is the curvature of the image side S6 of the third lens L3 at the optical axis radius. (R6+R7)/(R6-R7) in some embodiments can be 3.1, 3.2, 3.4, 3.8, 4, 4.2, 4.5, 4.7, 4.85, 4.9, or 4.95. When the above relationship is satisfied, the curvature radius of the object side surface S5 of the third lens L3 and the curvature radius of the image side surface S6 of the third lens L3 can be appropriately configured, which can prevent the refractive power of the third lens L3 from increasing excessively, so that the While correcting the astigmatic aberration of the system, it can also reduce the sensitivity of the system, which is beneficial to improve the product yield.

2.0≤R10/R11≤5.0; R10 is the radius of curvature of the object side S9 of the fifth lens L5 at the optical axis, and R11 is the radius of curvature of the image side S10 of the fifth lens L5 at the optical axis. R10/R11 in some embodiments may be 2.3, 2.4, 2.5, 2.7, 3, 3.5, 4, 4.3, 4.5, 4.6, or 4.7. When the above relationship is satisfied, the relationship between the object side S9 of the fifth lens L5 and the radius of curvature of the image side S10 can be reasonably restrained, so that the refractive power of the fifth lens L5 can be reasonably controlled, so that the fifth lens L5 can effectively bear the incident light The degree of deflection in the system can also improve the astigmatism problem in the off-axis field of view and improve the imaging quality of the optical system 10 . When it is lower than the lower limit of the relational expression, the surface shape of the object side surface S9 of the fifth lens L5 will be excessively curved, which will easily lead to poor molding and affect the manufacturing yield. When it is higher than the upper limit of the relational expression, the surface shape of the object side S9 of the fifth lens L5 is too smooth, which makes it difficult to correct the aberration, and it is difficult to suppress the astigmatism in the outer field of view, which affects the imaging quality.

4.0≤|f7|/R15≤10.0; f7 is the effective focal length of the seventh lens L7, and R15 is the radius of curvature of the image side S14 of the seventh lens L7 at the optical axis. |f7|/R15 in some embodiments may be 5, 5.2, 5.5, 6, 6.5, 7, 8, 8.5, 9, 9.4, 9.6, or 9.8. The seventh lens L7 is used as the last lens of the system. When the above relationship is satisfied, the relationship between the effective focal length of the seventh lens L7 and the radius of curvature of the image side surface S14 can be reasonably configured, thereby reducing the time when the light reaches the imaging surface S15. Therefore, the optical system 10 can be easily matched with the image sensor.

It should be noted that the ranges and corresponding effects of the relational expressions satisfied by the light system 10 above are for the aforementioned seven-piece lens structure.

On the other hand, in some embodiments, the material of each lens in the optical system 10 is plastic. Of course, the material of each lens in some embodiments may also be glass. The lens made of plastic can reduce the weight of the optical system 10 and the production cost, while the lens made of glass can withstand higher temperatures and have excellent optical effects. In other embodiments, the material of the first lens L1 is glass, and the material of the second lens L2 to the seventh lens L7 is all plastic. In this case, since the material of the lens on the object side in the optical system 10 is glass, Therefore, these glass lenses located on the object side have a good resistance to extreme environments, and are not easily affected by the object side environment and cause aging. Therefore, when the optical system 10 is in extreme environments such as exposure to high temperatures and other conditions, this structure can be more effective. A good balance between optical performance and cost of the system. Of course, the material configuration relationship of the lenses in the optical system 10 is not limited to the above-mentioned embodiment. The material of any lens can be plastic or glass, and the specific design can be determined according to actual needs. For example, in some embodiments, the material of at least one of the first lens L1 to the seventh lens L7 is plastic. In some embodiments, at least one of the first lens L1 to the seventh lens L7 is made of glass.

In some embodiments, the optical system 10 includes an infrared filter 110 , and the infrared filter 110 is disposed on the image side of the seventh lens L7 and is relatively fixed to each lens in the optical system 10 . The infrared filter 110 is used to filter out the infrared light to prevent the infrared light from reaching the imaging surface S15 of the system, thereby preventing the infrared light from interfering with normal imaging. Infrared filter 110 may be assembled with each lens as part of optical system 10 . In other embodiments, the infrared filter 110 does not belong to the component of the optical system 10. In this case, the infrared filter 110 can be installed in the optical system 10 when the optical system 10 and the photosensitive element are assembled into a camera module. between the sensor. In some embodiments, the infrared filter 110 may also be disposed on the object side of the first lens L1. In addition, in some embodiments, a filter coating layer can also be provided on at least one of the first lens L1 to the seventh lens L7 to achieve the effect of filtering out infrared light.

Next, the optical system 10 of the present application will be described with more specific and detailed embodiments:

first embodiment

1 and 2, in the first embodiment, the optical system 10 sequentially includes a diaphragm STO, a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, and a The third lens L3 with negative refractive power, the fourth lens L4 with positive refractive power, the fifth lens L5 with positive refractive power, the sixth lens L6 with negative refractive power, and the seventh lens L7 with negative refractive power. FIG. 2 includes a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system 10 in the first embodiment, wherein the reference wavelength of the astigmatism diagram and the distortion diagram is 587.56 nm.

The object side S1 of the first lens L1 is convex at the paraxial position, and the image side S2 is concave at the paraxial position; the object side S1 is convex at the circumference, and the image side S2 is concave at the circumference.

The object side S3 of the second lens L2 is convex at the paraxial position, and the image side S4 is concave at the paraxial position; the object side S3 is convex at the circumference, and the image side S4 is convex at the circumference.

The object side S5 of the third lens L3 is convex at the paraxial position, and the image side S6 is concave at the paraxial position; the object side S5 is convex at the circumference, and the image side S6 is concave at the circumference.

The object side S7 of the fourth lens L4 is convex at the paraxial position, and the image side S8 is concave at the paraxial position; the object side S7 is concave at the circumference, and the image side S8 is convex at the circumference.

The object side S9 of the fifth lens L5 is concave at the paraxial position, and the image side S10 is convex at the paraxial position; the object side S9 is concave at the circumference, and the image side S10 is convex at the circumference.

The object side S11 of the sixth lens L6 is convex at the paraxial position, and the image side S12 is concave at the paraxial position; the object side S11 is concave at the circumference, and the image side S12 is convex at the circumference.

The object side S13 of the seventh lens L7 is convex at the paraxial position, and the image side S14 is concave at the paraxial position; the object side S13 is convex at the circumference, and the image side S14 is convex at the circumference.

In particular, the third lens L3 with the above-mentioned surface design is beneficial to correct the spherical aberration of the edge field of the optical system 10 and improve the relative brightness of the peripheral field of view; the fifth lens L5 with the above-mentioned surface design can be better Astigmatic aberration can be corrected to make the image surface of the system flat; and the seventh lens L7 with the above-mentioned surface design can effectively suppress the off-axis coma and astigmatism of the system.

The object side surface and the image side surface of each of the first lens L1 to the seventh lens L7 are aspherical. By matching the aspherical surface type of each lens in the optical system 10, the problem of the distortion of the field of view of the optical system 10 can be effectively solved, and the lens can also achieve excellent optical effects in the case of a small and thin lens, thereby enabling the optical system 10 to achieve an excellent optical effect. Having a smaller volume is beneficial to realize the miniaturized design of the optical system 10 .

In addition, the material of each lens in the optical system 10 is plastic. The use of plastic lenses can reduce the manufacturing cost of the optical system 10 .

The respective lens parameters of the optical system 10 are given in Tables 1 and 2 below. Table 2 shows the aspheric coefficients of the corresponding surfaces of the lenses in Table 1, where k is the conic coefficient, and Ai is the coefficient corresponding to the i-th higher-order term in the aspheric surface formula. The elements from the object plane to the image plane (the imaging plane S15, which can also be understood as the photosensitive surface of the image sensor during later assembly) are arranged in order from top to bottom in Table 1. The surfaces corresponding to surface numbers 2 and 3 respectively represent the object side S1 and the image side S2 of the first lens L1, 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 Y radius in Table 1 is the curvature radius of the object side or image side of the corresponding surface number on the optical axis. The absolute value of the first value of the lens in the "Thickness" parameter column is the thickness of the lens on the optical axis, and the absolute value of the second value is the image side of the lens to the object side of the following optical element on the optical axis. on the distance.

In the first embodiment, the effective focal length of the optical system 10 is f=4.61mm, the aperture number FNO=1.57, the half of the maximum angle of view (that is, the half of the maximum angle of view in the diagonal direction) HFOV=38.7°, and the total optical length TTL= 5.7mm. In addition, in the parameter tables of the following embodiments (first embodiment to fifth embodiment), the reference wavelengths of the refractive index, Abbe number, and focal length of each lens are all 587.56 nm. In addition, the relational formula calculation and lens structure of each embodiment are based on lens parameters (such as Table 1, Table 2, Table 3, Table 4, etc.).

Table 1

Table 2

In the first embodiment, the optical system 10 satisfies the following relationships:

SD72/SD11=2.05; SD11 is the maximum effective aperture of the object side S1 of the first lens L1, and SD72 is the maximum effective aperture of the image side S14 of the seventh lens L7. In this embodiment, the optical system 10 having the above-mentioned seven-piece structure can reasonably configure the effective apertures of the object side S1 of the first lens L1 and the image side S14 of the seventh lens L7 by satisfying this relational expression. It is beneficial to reduce the size of the first lens L1 in the radial direction, so that the optical system 10 can realize a small head design, so that when the optical system 10 is applied to an electronic device, the aperture size of the screen can be reduced, and the device can be improved. On the other hand, it can also provide a larger entrance pupil for the system to expand the aperture, thereby enabling the optical system 10 to obtain higher image quality.

f123/f=1.19; f123 is the combined focal length of the first lens L1 , the second lens L2 and the third lens L3 , and f is the effective focal length of the optical system 10 . When the above relationship is satisfied, the refractive power of the front lens group formed by the first lens L1 to the third lens L3 will be reasonably strengthened, so that the effective convergence of the incident light can be strengthened, and the overall length of the system can be shortened, and the system can obtain Larger field of view. At the same time, under the setting of this refractive power, the first lens L1 in the front lens group has a positive refractive power, and the third lens L3 has a negative refractive power. This refractive power distribution can also promote the spherical aberration of the system to reach a balance , so that the system has good imaging quality.

f/EPD=1.57; f is the effective focal length of the optical system, and EPD is the entrance pupil diameter of the optical system 10 . When the above relationship is satisfied, the optical system 10 will have the characteristics of a large aperture, so that the luminous flux per unit time of the system can be increased, and the imaging effect of the system in a dark environment can be enhanced.

f5/f7=-0.959; f5 is the effective focal length of the fifth lens L5, and f7 is the effective focal length of the seventh lens L7. When the above relationship is satisfied, the refractive power of the fifth lens L5 and the seventh lens L7 can be reasonably allocated, so as to effectively correct the astigmatism of the system, and at the same time, it is also beneficial to compress the axial size of the optical system 10 and achieve axial miniaturization The design of the device can also avoid excessive restrictions on the thickness reduction of the device.

(f1+f5)/f=3.63; f1 is the effective focal length of the first lens L1 , f5 is the effective focal length of the fifth lens L5 , and f is the effective focal length of the optical system 10 . Both the first lens L1 and the fifth lens L5 provide positive refractive power to the optical system 10, and when the above relationship is satisfied, the relationship between the first lens L1 and the fifth lens L5 can be reasonably configured so that the first lens L1 and the fifth lens The five-lens L5 can provide the system with sufficient light-converging ability, thereby effectively shortening the total optical length of the system, and can also balance the positive refractive power of the first lens L1 and the fifth lens L5, thereby improving the imaging quality.

ΣCT=1.885mm; ΣCT is the sum of the thicknesses of the first lens L1, the second lens L2, the third lens L3 and the fourth lens L4 on the optical axis. When the above relationship is satisfied, the central thickness of the first four lenses of the system can be reasonably controlled, so that the structure between the lenses is compact, which is conducive to the design of the system to achieve axial miniaturization and thinning, and also enables the optical system 10 to have better performance. The ability to correct distortion, thereby improving image quality.

TTL/ImgH=1.52; TTL is the distance from the object side S1 of the first lens L1 to the imaging surface S15 of the optical system 10 on the optical axis, and ImgH is half of the image height corresponding to the maximum field angle of the optical system 10 . When the above relationship is satisfied, the optical system 10 will have the characteristics of a large image plane, so that high-quality imaging effects can be achieved, and at the same time, the total length of the optical system 10 can be effectively reduced, thereby facilitating the realization of a miniaturized design in the axial direction.

CT6/|SAG61|=1.05; CT6 is the thickness of the sixth lens L6 on the optical axis, and SAG61 is the sag of the object side surface S11 of the sixth lens L6 at the maximum effective aperture. When the above relationship is satisfied, the surface shape of the object side surface S11 of the sixth lens L6 will be reasonably controlled, thereby facilitating the manufacture and molding of the sixth lens L6 and reducing the defects of poor molding. In addition, by reasonably controlling the object side surface S11 of the sixth lens L6 as described above, the surface shape can be prevented from being overly curved and complicated, so it is also beneficial to trim the field curvature generated by the lens group on the object side, so that the system field curvature tends to be balanced. Further, the imaging quality of the optical system 10 is improved.

(R6+R7)/(R6-R7)=3.654; R6 is the curvature radius of the object side S5 of the third lens L3 at the optical axis, R7 is the curvature radius of the image side S6 of the third lens L3 at the optical axis. When the above relationship is satisfied, the curvature radius of the object side surface S5 of the third lens L3 and the curvature radius of the image side surface S6 of the third lens L3 can be appropriately configured, which can prevent the refractive power of the third lens L3 from increasing excessively, so that the While correcting the astigmatic aberration of the system, it can also reduce the sensitivity of the system, which is beneficial to improve the product yield.

R10/R11=2.87; R10 is the radius of curvature of the object side S9 of the fifth lens L5 at the optical axis, and R11 is the radius of curvature of the image side S10 of the fifth lens L5 at the optical axis. When the above relationship is satisfied, the relationship between the object side S9 of the fifth lens L5 and the radius of curvature of the image side S10 can be reasonably restrained, so that the refractive power of the fifth lens L5 can be reasonably controlled, so that the fifth lens L5 can effectively bear the incident light The degree of deflection in the system can also improve the astigmatism problem in the off-axis field of view and improve the imaging quality of the optical system 10 .

|f7|/R15=5.55; f7 is the effective focal length of the seventh lens L7, and R15 is the radius of curvature of the image side S14 of the seventh lens L7 at the optical axis. The seventh lens L7 is used as the last lens of the system. When the above relationship is satisfied, the relationship between the effective focal length of the seventh lens L7 and the radius of curvature of the image side surface S14 can be reasonably configured, thereby reducing the time when the light reaches the imaging surface S15. Therefore, the optical system 10 can be easily matched with the image sensor.

In addition, FIG. 2 includes a longitudinal spherical aberration diagram (Longitudinal Spherical Aberration) of the optical system 10, 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 and the optical axis (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 10, wherein the S curve represents the sagittal field curvature at 587.56 nm, and the T curve represents the meridional field curvature at 587.56 nm. It can be seen from the figure that the field curvature of the system 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 10. 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

3 and 4 , in the second embodiment, the optical system 10 sequentially includes a diaphragm STO, a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, and a The third lens L3 with negative 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, and the seventh lens L7 with negative refractive power. FIG. 4 includes a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system 10 in the second embodiment, wherein the reference wavelength of the astigmatism diagram and the distortion diagram is 587.56 nm.

The object side S1 of the first lens L1 is convex at the paraxial position, and the image side S2 is concave at the paraxial position; the object side S1 is convex at the circumference, and the image side S2 is concave at the circumference.

The object side S3 of the second lens L2 is convex at the paraxial position, and the image side S4 is concave at the paraxial position; the object side S3 is convex at the circumference, and the image side S4 is convex at the circumference.

The object side S5 of the third lens L3 is convex at the paraxial position, and the image side S6 is concave at the paraxial position; the object side S5 is convex at the circumference, and the image side S6 is concave at the circumference.

The object side S7 of the fourth lens L4 is convex at the paraxial position, and the image side S8 is concave at the paraxial position; the object side S7 is concave at the circumference, and the image side S8 is convex at the circumference.

The object side S9 of the fifth lens L5 is concave at the paraxial position, and the image side S10 is convex at the paraxial position; the object side S9 is concave at the circumference, and the image side S10 is convex at the circumference.

The object side S11 of the sixth lens L6 is convex at the paraxial position, and the image side S12 is concave at the paraxial position; the object side S11 is concave at the circumference, and the image side S12 is convex at the circumference.

The object side S13 of the seventh lens L7 is convex at the paraxial position, and the image side S14 is concave at the paraxial position; the object side S13 is convex at the circumference, and the image side S14 is convex at the circumference.

In addition, the lens parameters of the optical system 10 in the second embodiment are given in Table 3 and Table 4, wherein the definitions of the structures and parameters can be obtained from the first embodiment, and will not be repeated here.

table 3

Table 4

The camera module 10 in this embodiment satisfies the following relationship:

SD72/SD11	2.23	TTL/ImgH	1.53
f123/f	1.28	CT6/|SAG61|	1.494
f/EPD	1.65	(R6+R7)/(R6-R7)	3.055
f5/f7	-0.815	R10/R11	2.78
(f1+f5)/f	3.87	|f7|/R15	5.83
∑CT	1.789

It can be seen from the aberration diagram in FIG. 4 that the longitudinal spherical aberration, field curvature and distortion of the optical system 10 are well controlled, so that the optical system 10 of this embodiment has good imaging quality.

Third Embodiment

5 and 6 , in the third embodiment, the optical system 10 sequentially includes a diaphragm STO, a first lens L1 with positive refractive power, a second lens L2 with negative refractive power, and a The third lens L3 with negative 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, and the seventh lens L7 with negative refractive power. FIG. 6 includes a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system 10 in the third embodiment, wherein the reference wavelength of the astigmatism diagram and the distortion diagram is 587.56 nm.

The object side S1 of the first lens L1 is convex at the paraxial position, and the image side S2 is concave at the paraxial position; the object side S1 is convex at the circumference, and the image side S2 is convex at the circumference.

The object side S3 of the second lens L2 is concave at the paraxial position, and the image side S4 is convex at the paraxial position; the object side S3 is concave at the circumference, and the image side S4 is convex at the circumference.

The object side S5 of the third lens L3 is convex at the paraxial position, and the image side S6 is concave at the paraxial position; the object side S5 is convex at the circumference, and the image side S6 is concave at the circumference.

The object side S7 of the fourth lens L4 is concave at the paraxial position, and the image side S8 is concave at the paraxial position; the object side S7 is concave at the circumference, and the image side S8 is convex at the circumference.

The object side S9 of the fifth lens L5 is concave at the paraxial position, and the image side S10 is convex at the paraxial position; the object side S9 is concave at the circumference, and the image side S10 is convex at the circumference.

The object side S11 of the sixth lens L6 is concave at the paraxial position, and the image side S12 is concave at the paraxial position; the object side S11 is concave at the circumference, and the image side S12 is convex at the circumference.

The object side S13 of the seventh lens L7 is convex at the paraxial position, and the image side S14 is concave at the paraxial position; the object side S13 is convex at the circumference, and the image side S14 is convex at the circumference.

In addition, the lens parameters of the optical system 10 in the third embodiment are given in Table 5 and Table 6, wherein the definitions of the structures and parameters can be obtained from the first embodiment, which will not be repeated here.

table 5

Table 6

The camera module 10 in this embodiment satisfies the following relationship:

SD72/SD11	2.03	TTL/ImgH	1.55
f123/f	1.04	CT6/|SAG61|	0.998
f/EPD	1.6	(R6+R7)/(R6-R7)	4.959
f5/f7	-0.913	R10/R11	4.8
(f1+f5)/f	1.93	|f7|/R15	4.89
∑CT	1.927

It can be seen from the aberration diagram in FIG. 6 that the longitudinal spherical aberration, field curvature and distortion of the optical system 10 are well controlled, so that the optical system 10 of this embodiment has good imaging quality.

Fourth Embodiment

Referring to FIGS. 7 and 8 , in the fourth embodiment, the optical system 10 sequentially includes a diaphragm STO, a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, and a The third lens L3 with negative refractive power, the fourth lens L4 with negative refractive power, the fifth lens L5 with positive refractive power, the sixth lens L6 with positive refractive power, and the seventh lens L7 with negative refractive power. FIG. 8 includes a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system 10 in the fourth embodiment, wherein the reference wavelength of the astigmatism diagram and the distortion diagram is 587.56 nm.

The object side S1 of the first lens L1 is convex at the paraxial position, and the image side S2 is concave at the paraxial position; the object side S1 is convex at the circumference, and the image side S2 is concave at the circumference.

The object side S3 of the second lens L2 is convex at the paraxial position, and the image side S4 is concave at the paraxial position; the object side S3 is convex at the circumference, and the image side S4 is convex at the circumference.

The object side S5 of the third lens L3 is convex at the paraxial position, and the image side S6 is concave at the paraxial position; the object side S5 is convex at the circumference, and the image side S6 is concave at the circumference.

The object side S7 of the fourth lens L4 is convex at the paraxial position, and the image side S8 is concave at the paraxial position; the object side S7 is concave at the circumference, and the image side S8 is convex at the circumference.

The object side S9 of the fifth lens L5 is concave at the paraxial position, and the image side S10 is convex at the paraxial position; the object side S9 is concave at the circumference, and the image side S10 is convex at the circumference.

The object side S11 of the sixth lens L6 is convex at the paraxial position, and the image side S12 is concave at the paraxial position; the object side S11 is concave at the circumference, and the image side S12 is convex at the circumference.

The object side S13 of the seventh lens L7 is convex at the paraxial position, and the image side S14 is concave at the paraxial position; the object side S13 is convex at the circumference, and the image side S14 is convex at the circumference.

In addition, the lens parameters of the optical system 10 in the fourth embodiment are given in Table 7 and Table 8, wherein the definitions of the structures and parameters can be obtained from the first embodiment, which will not be repeated here.

Table 7

Table 8

The camera module 10 in this embodiment satisfies the following relationship:

SD72/SD11	2.07	TTL/ImgH	1.56
f123/f	1.29	CT6/|SAG61|	1.858
f/EPD	1.65	(R6+R7)/(R6-R7)	3.171
f5/f7	-1.25	R10/R11	2.24
(f1+f5)/f	4.58	|f7|/R15	5.64
∑CT	1.892

It can be seen from the aberration diagram in FIG. 8 that the longitudinal spherical aberration, field curvature and distortion of the optical system 10 are well controlled, so that the optical system 10 of this embodiment has good imaging quality.

Fifth Embodiment

Referring to FIGS. 9 and 10 , in the fifth embodiment, the optical system 10 sequentially includes a diaphragm STO, a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, and a The third lens L3 with negative 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, and the seventh lens L7 with negative refractive power. FIG. 10 includes a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system 10 in the fifth embodiment, wherein the reference wavelength of the astigmatism diagram and the distortion diagram is 587.56 nm.

The object side S1 of the first lens L1 is convex at the paraxial position, and the image side S2 is concave at the paraxial position; the object side S1 is convex at the circumference, and the image side S2 is concave at the circumference.

The object side S3 of the second lens L2 is convex at the paraxial position, and the image side S4 is concave at the paraxial position; the object side S3 is convex at the circumference, and the image side S4 is convex at the circumference.

The object side S5 of the third lens L3 is convex at the paraxial position, and the image side S6 is concave at the paraxial position; the object side S5 is convex at the circumference, and the image side S6 is concave at the circumference.

The object side S7 of the fourth lens L4 is convex at the paraxial position, and the image side S8 is concave at the paraxial position; the object side S7 is concave at the circumference, and the image side S8 is convex at the circumference.

The object side S9 of the fifth lens L5 is concave at the paraxial position, and the image side S10 is convex at the paraxial position; the object side S9 is concave at the circumference, and the image side S10 is convex at the circumference.

The object side S11 of the sixth lens L6 is convex at the paraxial position, and the image side S12 is concave at the paraxial position; the object side S11 is concave at the circumference, and the image side S12 is convex at the circumference.

The object side S13 of the seventh lens L7 is convex at the paraxial position, and the image side S14 is concave at the paraxial position; the object side S13 is convex at the circumference, and the image side S14 is convex at the circumference.

In addition, the lens parameters of the optical system 10 in the fifth embodiment are given in Table 9 and Table 10, wherein the definitions of the structures and parameters can be obtained from the first embodiment, which will not be repeated here.

Table 9

Table 10

The camera module 10 in this embodiment satisfies the following relationship:

SD72/SD11	2.49	TTL/ImgH	1.44
f123/f	1.47	CT6/|SAG61|	1.492
f/EPD	1.57	(R6+R7)/(R6-R7)	3.925
f5/f7	-0.46	R10/R11	2.65
(f1+f5)/f	4.86	|f7|/R15	9.83
∑CT	1.624

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

Sixth Embodiment

11 and 12 , in the sixth embodiment, the optical system 10 sequentially includes a diaphragm STO, a first lens L1 with positive refractive power, a second lens L2 with positive refractive power, and a The third lens L3 with negative refractive power, the fourth lens L4 with positive refractive power, the fifth lens L5 with positive refractive power, the sixth lens L6 with negative refractive power, and the seventh lens L7 with negative refractive power. FIG. 12 includes a longitudinal spherical aberration diagram, an astigmatism diagram and a distortion diagram of the optical system 10 in the sixth embodiment, wherein the reference wavelength of the astigmatism diagram and the distortion diagram is 587.56 nm.

The object side S1 of the first lens L1 is convex at the paraxial position, and the image side S2 is concave at the paraxial position; the object side S1 is convex at the circumference, and the image side S2 is concave at the circumference.

The object side S3 of the second lens L2 is convex at the paraxial position, and the image side S4 is concave at the paraxial position; the object side S3 is convex at the circumference, and the image side S4 is convex at the circumference.

The object side S5 of the third lens L3 is convex at the paraxial position, and the image side S6 is concave at the paraxial position; the object side S5 is convex at the circumference, and the image side S6 is concave at the circumference.

The object side S7 of the fourth lens L4 is convex at the paraxial position, and the image side S8 is concave at the paraxial position; the object side S7 is concave at the circumference, and the image side S8 is convex at the circumference.

The object side S9 of the fifth lens L5 is concave at the paraxial position, and the image side S10 is convex at the paraxial position; the object side S9 is concave at the circumference, and the image side S10 is convex at the circumference.

The object side S11 of the sixth lens L6 is convex at the paraxial position, and the image side S12 is concave at the paraxial position; the object side S11 is concave at the circumference, and the image side S12 is convex at the circumference.

The object side S13 of the seventh lens L7 is convex at the paraxial position, and the image side S14 is concave at the paraxial position; the object side S13 is convex at the circumference, and the image side S14 is convex at the circumference.

In addition, the lens parameters of the optical system 10 in the sixth embodiment are given in Table 11 and Table 12, wherein the definitions of the structures and parameters can be obtained from the first embodiment, which will not be repeated here.

Table 11

Table 12

The camera module 10 in this embodiment satisfies the following relationship:

SD72/SD11	2.14	TTL/ImgH	1.51
f123/f	1.25	CT6/|SAG61|	0.986
f/EPD	1.55	(R6+R7)/(R6-R7)	3.591
f5/f7	-0.833	R10/R11	2.72
(f1+f5)/f	3.92	|f7|/R15	6.68
∑CT	1.574

It can be seen from the aberration diagram in FIG. 12 that the longitudinal spherical aberration, field curvature and distortion of the optical system 10 are well controlled, so that the optical system 10 of this embodiment has good imaging quality.

Referring to FIG. 13 , some embodiments of the present application further provide a camera module 20 . The camera module 20 may include the optical system 10 and the image sensor 210 of any of the above-mentioned embodiments, and the image sensor 210 is disposed on the image of the optical system 10 . side. The image sensor 210 may be a CCD (Charge Coupled Device, charge coupled device) or a CMOS (Complementary Metal Oxide Semiconductor, complementary metal oxide semiconductor). Generally, when assembled, the imaging surface S15 of the optical system 10 overlaps the photosensitive surface of the image sensor 210 .

By using the above-mentioned optical system 10 , the camera module 20 can also have the characteristics of a small head, and since the aperture of the optical system 10 is well regulated, the camera module 20 can also obtain good image quality. In particular, when applied to an electronic device, the above-mentioned camera module 20 with a small head can reduce the size of the opening on the screen of the device, thereby increasing the screen ratio of the device.

In some embodiments, the camera module 20 includes an infrared filter 110 disposed between the optical system 10 and the image sensor 210 , and the infrared filter 110 is used to filter out infrared light. The infrared filter 110 can be installed together when the optical system 10 and the image sensor 210 are assembled, or the infrared filter 110 can be installed together with the image sensor 210 first, and then assembled together with the camera lens. In some embodiments, the infrared filter 110 may be mounted to the image end of the camera lens. In some embodiments, the camera module 20 further includes a protective glass, the protective glass is disposed between the infrared filter 110 and the image sensor 210 , and the protective glass is used to protect the image sensor 210 .

Referring to FIG. 14 , some embodiments of the present application further provide an electronic device 30 . The electronic device 30 includes a fixing member 310 , and the camera module 20 is mounted on the fixing member 310 , and the fixing member 310 may be a display screen, a circuit board, a middle frame, a back cover and other components. The electronic device 30 can be, but is not limited to, a smartphone, a smart watch, a smart glasses, an e-book reader, a vehicle camera device, a monitoring device, a drone, a medical device (such as an endoscope), a tablet computer, a biometric device (such as a Fingerprint recognition equipment or pupil recognition equipment, etc.), PDA (Personal Digital Assistant, personal digital assistant), drones, etc. By using the above-mentioned camera module 20 having the characteristics of a small head, the electronic device 30 can only provide a light-passing structure with a small aperture to match the camera module 20 . In addition, by using the above-mentioned camera module 20, the electronic device 30 can also obtain good image quality.

Particularly, in some embodiments, the electronic device 30 includes a display screen, the camera module 20 is disposed on the bottom side of the display screen, and the head of the camera module 20 faces the display screen to serve as a front camera module. The electronic device 30 is provided with the function of taking pictures under the screen. By using the above-mentioned camera module with a small head feature, the size of the opening on the screen can also be reduced, so that the screen ratio of the device can be increased, which is conducive to the realization of a full-screen design of the device.

The "electronic device" used in the embodiments of the present invention may include, but is not limited to, be configured to be connected via wired lines (eg, via a public switched telephone network (PSTN), digital subscriber line, DSL), digital cable, direct cable connection, and/or another data connection/network) and/or via (eg, for cellular networks, wireless local area networks (WLAN), such as digital video broadcast broadcasting handheld, DVB-H) network digital television network, satellite network, AM-FM (amplitude modulation-frequency modulation, AM-FM) broadcast transmitter, and/or another communication terminal) wireless interface to receive/transmit communication signals installation. Electronic devices arranged to communicate over a wireless interface may be referred to as "wireless communication terminals", "wireless terminals" and/or "mobile terminals". Examples of mobile terminals include, but are not limited to, satellite or cellular telephones; personal communication system (PCS) terminals that may combine cellular radio telephones with data processing, facsimile, and data communication capabilities; may include radio telephones, pagers, Internet/ Personal digital assistants (PDAs) with intranet access, web browsers, memo pads, calendars, and/or global positioning system (GPS) receivers; and conventional laptops and/or palmtops A receiver or other electronic device including a radiotelephone transceiver.

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 (20)

1. An optical system, comprising in order from the object side to the image side:

   a first lens having a positive refractive power;

   a second lens with refractive power, the image side of the second lens is convex at the circumference;

   The third lens with negative refractive power, the object side of the third lens is convex at the paraxial position, and the image side is concave at the paraxial position;

   a fourth lens with refractive power;

   The fifth lens with positive refractive power, the object side of the fifth lens is concave, and the image side is convex;

   The sixth lens with refractive power, the object side and the image side of the sixth lens are both aspherical, and at least one of the object side and the image side of the sixth lens is provided with an inflection point;

   The seventh lens with negative refractive power, the object side of the seventh lens is convex at the paraxial position, and the image side is concave at the paraxial position;

   And the optical system also satisfies the relation:

   1.8≤SD72/SD11≤2.5;

   SD11 is the maximum effective aperture of the object side of the first lens, and SD72 is the maximum effective aperture of the image side of the seventh lens.
2. The optical system according to claim 1, wherein the optical system satisfies the relationship:

   1.0≤f123/f≤1.5;

   f123 is the combined focal length of the first lens, the second lens and the third lens, and f is the effective focal length of the optical system.
3. The optical system according to claim 1, wherein the optical system satisfies the relationship:

   1.50≤f/EPD≤1.65;

   f is the effective focal length of the optical system, and EPD is the entrance pupil diameter of the optical system.
4. The optical system according to claim 1, wherein the optical system satisfies the relationship:

   -1.5≤f5/f7≤-0.2;

   f5 is the effective focal length of the fifth lens, and f7 is the effective focal length of the seventh lens.
5. The optical system according to claim 1, wherein the optical system satisfies the relationship:

   1.5≤(f1+f5)/f≤5.0;

   f1 is the effective focal length of the first lens, f5 is the effective focal length of the fifth lens, and f is the effective focal length of the optical system.
6. The optical system according to claim 1, wherein the optical system satisfies the relationship:

   1.5mm≤∑CT≤2.0mm;

   ΣCT is the sum of the thicknesses of the first lens, the second lens, the third lens and the fourth lens on the optical axis.
7. The optical system according to claim 1, wherein the optical system satisfies the relationship:

   1.4≤TTL/ImgH≤1.6;

   TTL is the distance from the object side of the first lens to the imaging plane of the optical system on the optical axis, and ImgH is half of the image height corresponding to the maximum angle of view of the optical system.
8. The optical system according to claim 1, wherein the optical system satisfies the relationship:

   0.9≤CT6/|SAG61|≤2.0;

   CT6 is the thickness of the sixth lens on the optical axis, and SAG61 is the sag of the object side of the sixth lens at the maximum effective aperture.
9. The optical system according to claim 1, wherein the optical system satisfies the relationship:

   2.5≤(R6+R7)/(R6-R7)≤6.0;

   R6 is the radius of curvature of the object side of the third lens at the optical axis, and R7 is the radius of curvature of the image side of the third lens at the optical axis.
10. The optical system according to claim 1, wherein the optical system satisfies the relationship:

    2.0≤R10/R11≤5.0;

    R10 is the radius of curvature of the object side of the fifth lens at the optical axis, and R11 is the radius of curvature of the image side of the fifth lens at the optical axis.
11. The optical system according to claim 1, wherein the optical system satisfies the relationship:

    4.0≤|f7|/R15≤10.0;

    f7 is the effective focal length of the seventh lens, and R15 is the radius of curvature of the image side of the seventh lens at the optical axis.
12. The optical system according to claim 1, wherein the optical system satisfies the relationship:

    2.03≤SD72/SD11≤2.49.
13. The optical system according to claim 1, wherein the object side of the first lens is convex at the paraxial position, the image side of the first lens is concave at the paraxial position, and the fourth lens has a The image side surface is concave at the paraxial position, and the image side surface of the sixth lens is concave at the paraxial position.
14. The optical system according to any one of claims 1 to 13, wherein the optical system comprises an aperture stop, and the aperture stop is provided on the object side of the first lens.
15. The optical system according to any one of claims 1 to 14, wherein at least one of the first lens to the seventh lens is made of plastic.
16. 16. The optical system according to claim 15, wherein, in the first lens to the seventh lens, the material of each lens is plastic.
17. The optical system according to any one of claims 1 to 14, wherein an object side surface and/or an image side surface of at least one of the first lens to the seventh lens is aspherical.
18. 18. The optical system according to claim 17, wherein in the first lens to the seventh lens, the object side surface and the image side surface of each lens are aspherical.
19. A camera module, comprising an image sensor and the optical system according to any one of claims 1 to 18, wherein the image sensor is arranged on the image side of the optical system.
20. An electronic device, comprising a fixing member and the camera module according to claim 19, wherein the camera module is arranged on the fixing member.

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