CN210129058U

CN210129058U - Lens, camera module and electronic equipment

Info

Publication number: CN210129058U
Application number: CN201920871278.4U
Authority: CN
Inventors: 杨鑫
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2019-06-11
Filing date: 2019-06-11
Publication date: 2020-03-06
Anticipated expiration: 2029-06-11

Abstract

The embodiment of the application discloses a lens, which comprises a reflecting component and a lens group which are arranged in sequence from an object side to an image side; the reflecting component has an aspheric reflecting surface which can deflect an optical path from an object side to the lens group; the lens group comprises at least two lenses, the optical axes of the lenses are overlapped, and the lens group is used for correcting the aberration of the optical path deflected by the reflecting surface. The embodiment of the application discloses a camera module and electronic equipment, wherein the camera module comprises an image sensor and a lens; the lens is used for forming an optical signal of a shot object and reflecting the optical signal to the image sensor; the image sensor converts an optical signal corresponding to an object into an image signal. The lens of the embodiment of the application increases design optimization variables, and reduces the number of lenses in the lens group or reduces the thickness and the distance between the lenses by optimizing the variables, the lenses and the parameters between the lenses, so that the overall length of the lens is shortened.

Description

Lens, camera module and electronic equipment

Technical Field

The application relates to the field of optical lenses, in particular to a lens, a camera module and electronic equipment.

Background

Along with the development of the improvement of science and technology and economy, people are higher and higher to the requirement of the function of making a video recording of portable electronic equipment, not only require that the module of making a video recording that this electronic equipment disposed can realize that the background is virtual, the night is shot clearly, more require the module of making a video recording that this electronic equipment disposed moreover can realize longer focus. Meanwhile, in order to comply with the trend of light and thin electronic devices, the height of the camera module disposed in the electronic device cannot be increased, so that the periscopic camera module has a long focal length and a short height, which is a popular direction for the development of camera modules in recent years.

In the periscopic lens in the related art, light entering the lens from an object space is refracted through the triangular prism, and the refracted light beam is projected on the image sensor through the lens group, so that the object is imaged. However, the three surfaces of the triangular prism of the periscopic lens are all flat, so that the number of lenses in the rear group lens group needs to be increased to improve the imaging quality, and the length of the whole lens is increased.

SUMMERY OF THE UTILITY MODEL

In view of the above, embodiments of the present disclosure are directed to a lens, a camera module and an electronic device, so as to solve the problem that the length of the entire lens needs to be increased to improve the imaging quality.

In order to achieve the above purpose, the technical solution of the embodiment of the present application is implemented as follows:

in one aspect, an embodiment of the present application provides a lens assembly including a reflective member and a lens group, which are disposed in order from an object side to an image side; the reflecting component has an aspheric reflecting surface which can deflect an optical path from an object side to the lens group; the lens group comprises at least two lenses, the optical axes of the lenses are overlapped, and the lens group is used for correcting the aberration of the optical path deflected by the reflecting surface.

Further, in the above aspect, the reflecting surface is a high-order aspherical surface.

Further, in the above solution, an object-side surface of each of the lenses and/or an image-side surface of the lens is aspheric.

Furthermore, in the above-mentioned optical lens system, the lens elements are sequentially arranged, from an object side to an image side, as a first lens element with positive refractive power, a second lens element with negative refractive power, a third lens element with positive refractive power and a fourth lens element with negative refractive power.

Further, in the foregoing solution, an object-side surface of the first lens element is a convex surface, and an image-side surface of the first lens element is a convex surface; and/or the presence of a gas in the gas,

the object side surface of the second lens is a concave surface, and the image side surface of the second lens is a concave surface; and/or the presence of a gas in the gas,

the object side surface of the third lens is a concave surface, and the image side surface of the third lens is a convex surface; and/or the presence of a gas in the gas,

the object side surface of the fourth lens comprises a convex surface positioned in the center of the object side and concave surfaces positioned at two ends of the object side, and the image side surface of the fourth lens comprises a concave surface positioned in the center of the image side and convex surfaces positioned at two ends of the image side.

Further, in the above aspect, the abbe number of at least one of the lenses in the lens group is different from the abbe numbers of the other lenses in the lens group, and the abbe numbers of the other lenses in the lens group are equal.

Further, in the above aspect, the reflecting member is a right-angle prism, and an inclined surface of the right-angle prism is the reflecting surface; or the like, or, alternatively,

the reflecting component comprises a triangular prism and a flat curved mirror, the plane of the flat curved mirror is connected with the inclined plane of the triangular prism, and the curved surface of the flat curved mirror is the reflecting surface; or the like, or, alternatively,

the reflecting component is an aspheric reflecting mirror, and the mirror surface of the aspheric reflecting mirror is the reflecting surface.

Further, in the above-described aspect, the lens includes an aperture stop located on an object side of the reflection member; and/or the presence of a gas in the gas,

the lens comprises a filter positioned on the image side of the lens group.

On the other hand, the embodiment of the application provides a camera module, which comprises an image sensor and the lens in any one of the schemes;

the lens is used for forming an optical signal of a shot object and reflecting the optical signal to the image sensor;

the image sensor converts an optical signal corresponding to an object into an image signal.

In another aspect, an embodiment of the present application provides an electronic device, the electronic device includes a housing, a display screen, and the aforementioned camera module, the display screen with the camera module is installed on the housing, the display screen is used for displaying an image shot by the camera module.

According to the lens, the reflecting surface of the reflecting component is designed to be the aspheric surface, so that design optimization variables are increased, the number of the lenses in the lens group can be reduced or the thickness and the distance between the lenses can be reduced under the condition of the same design index through optimizing the variables, the lenses and the parameters between the lenses, and the overall length of the lens is shortened.

The camera module and the electronic equipment in the embodiment of the application have the advantages that due to the adoption of the lens in the embodiment of the application, the overall length of the camera module is shortened, and the requirement of the market on further lightening and thinning of different electronic equipment is met.

Drawings

Fig. 1 is a schematic structural diagram of a lens barrel according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of a reflective member according to an embodiment of the present disclosure;

FIG. 3 is a schematic structural view of another reflective member according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of a camera module according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the present application;

FIG. 6 is a vertical axis chromatic aberration diagram of a lens imaging according to an embodiment of the present application;

FIG. 7 is a dot-sequence diagram of lens imaging according to an embodiment of the present application;

FIG. 8 is a graph of relative illumination of lens images according to an embodiment of the present application;

FIG. 9 is a field curvature graph of a lens imaging according to an embodiment of the present application;

FIG. 10 is a distortion graph of lens imaging according to an embodiment of the present application; and

fig. 11 is a polychromatic diffraction MTF graph of lens imaging according to an embodiment of the present application.

Description of reference numerals:

object side S1; an image side S2; optical axis S3;

a lens 100; an image sensor 200;

a reflective member 10; a lens group 20; an aperture stop 30; an optical filter 40;

a reflection surface 10 a; an incident surface 10 b; an exit surface 10 c; a right-angle prism 11; a triangular prism 12; a flat curved mirror 13;

a first lens 21; the object side 211 of the first lens; the image-side surface 212 of the first lens;

a second lens 22; the object-side surface 221 of the second lens; the image-side surface 222 of the second lens;

a third lens 23; the object side 231 of the third lens; the image-side surface 232 of the third lens;

a fourth lens 24; the object-side surface 241 of the fourth lens; the image-side surface 242 of the fourth lens element; an object-side center 241 a; an object side end 241 b; an image side center 242 a; image side ends 242 b;

a camera module 1; a housing 2; a display screen 3; a battery 4; a circuit board 5.

Detailed Description

It should be noted that, in the present application, technical features in examples and embodiments may be combined with each other without conflict, and the detailed description in the specific embodiment should be understood as an explanation of the gist of the present application and should not be construed as an improper limitation to the present application.

The present application will now be described in further detail with reference to the accompanying drawings and specific examples. The unit "mm" referred to in the examples of the present application is expressed in mm, and "μm" is expressed in μm.

In one aspect of the embodiments of the present application, a lens is provided. Referring to fig. 1, a lens 100 according to an embodiment of the present disclosure includes a reflective member 10 and a lens group 20 disposed in order from an object side S1 to an image side S2; the reflecting member 10 has an aspherical reflecting surface 10a, the reflecting surface 10a being capable of deflecting an optical path from the object side S1 to the lens group 20; the lens group 20 includes at least two lenses, optical axes S3 of the respective lenses coincide, and the lens group 20 is used to correct aberrations of an optical path deflected by the reflecting surface 10 a.

Since the reflecting surface 10a of the reflecting member 10 is designed to be an aspherical surface, design optimization variables are increased, and by optimizing these variables and parameters of each lens and between the lenses, the number of lenses in the lens group 20 or the thickness and the distance between the lenses can be reduced in the case of the same design index of the lens 100, so that the overall length of the lens 100 (see L1 in fig. 4) is shortened, and the weight of the lens 100 is reduced.

Compared with the case that the incident surface 10b or the emergent surface 10c of the reflecting component 10 is changed into an aspheric surface, the reflecting surface 10a is changed into the aspheric surface from a plane, the sensitivity of aberration correction of the reflecting component 10 is improved, new chromatic aberration cannot be generated, the design of the long-focus lens is easier to realize, and the imaging quality is improved. The lens 100 may be applied to a periscopic lens.

In the above embodiment, the angle between the reflecting surface 10a and the optical axis S3 may be 45 ° ± 15 °, for example, 30 °, 45 ° or 60 °.

Further, the aspheric surface of the reflecting surface 10a may be selected as a quadratic aspheric surface, such as a paraboloid, a hyperboloid, an ellipsoid, an aspheric surface, or the like.

In an embodiment of the present application, the aspheric surface of the reflecting surface 10a is a high-order aspheric surface, such as a convex even aspheric surface, a concave even aspheric surface, a convex odd aspheric surface, or a concave odd aspheric surface. The high-order aspheric surface has larger processing difficulty and high processing precision requirement, and is more suitable for the miniaturized periscopic lens.

Taking an even aspheric surface as an example, it satisfies the following equation:

z＝cy²/[1+{1－(1+k)c²y²}^1/2]+α₁y²+α₂y⁴+α₃y⁶+α₄y⁸+α₅y¹⁰+α₆y¹²+α₇y¹⁴+α₈y¹⁶

wherein z is aspheric sagittal height, c is aspheric paraxial curvature, y is lens caliber, k is cone coefficient, α₁Is a 2-degree aspheric coefficient, α₂Is 4-order aspheric coefficient, α₃Is a 6 th order aspheric coefficient, α₄Is 8-order aspheric coefficient, α₅Is a 10 th order aspherical coefficient, α₆Is a 12-degree aspheric coefficient, α₇Is a 14 th order aspherical coefficient, α₈Is a 16-degree aspheric coefficient.

This corresponds to an increase in curvature c, conic coefficient k and aspheric coefficient α₁～α₈The total of 10 design optimization variables, by optimizing these variables and parameters between each lens and each lens, and comprehensively considering factors such as processing and cost, the flexibility of the design of the lens assembly 20 can be improved, and the number of lenses can be reduced under the same design target requirement, thereby shortening the overall length of the lens 100.

It should be noted that the order of the aspheric surface coefficients in the even-order aspheric surface equation may be selected according to actual needs, i.e. the high-order aspheric surface coefficients may be increased or the unnecessary high-order aspheric surface coefficients may be set to 0. The odd aspheric equation can be processed in this way, and is not described in detail herein.

In an embodiment of the present application, an object-side surface of each lens of the lens group 20 and/or an image-side surface of the lens are aspheric.

In the scheme, at least one side surface of each lens is designed to be an aspheric surface, so that better aberration correction can be obtained, and the imaging sharpness and resolution are improved; further reducing the number of lenses, reducing the design cost, and reducing the overall length of the lens 100.

In the present embodiment, the lens elements are sequentially arranged from an object side S1 to an image side S2 as the first lens element 21 with positive refractive power, the second lens element 22 with negative refractive power, the third lens element 23 with positive refractive power and the fourth lens element 24 with negative refractive power.

It should be noted that the refractive power refers to the refractive power of the optical system for reflecting the incident parallel light beam. The optical system has positive refractive power, which indicates that the refraction of the light rays is convergent; the optical system has negative refractive power, indicating that the refraction of light is divergent.

In the above embodiment, the first lens element 21 with positive refractive power can provide the main converging capability of the lens assembly 20 for light. The second lens element 22 with negative refractive power is matched with the first lens element 21 with positive refractive power to form a positive-negative telescopic structure with refractive power, which can effectively shorten the length of the lens assembly 20. The third lens element 23 with positive refractive power can share the positive refractive power of the first lens element 21, and correct a portion of spherical aberration to improve the image quality. The fourth lens element 24 with negative refractive power can effectively control the direction of the light path, and is helpful for increasing the image height to achieve high pixel density.

Optionally, the first lens element 21 is biconvex, i.e. the object-side surface 211 of the first lens element is convex and the image-side surface 212 of the first lens element is convex; and/or the second lens 22 is biconcave, i.e. the object-side surface 221 of the second lens is concave and the image-side surface 222 of the second lens is concave; and/or the third lens element 23 is meniscus-shaped, i.e. the object-side surface 231 of the third lens element is concave and the image-side surface 232 of the third lens element is convex; and/or, the fourth lens element 24 is "W" shaped, i.e., the object side 241 of the fourth lens element includes a convex surface located at the object-side center 241a and concave surfaces located at the object-side ends 241b, and the image side 242 of the fourth lens element includes a concave surface located at the image-side center 242a and convex surfaces located at the image-side ends 242 b.

In the above embodiments, the object-side center 241a and the image-side center 242a refer to positions of the fourth lens 24 close to the optical axis S3, and the object-side ends 241b and the image-side ends 242b refer to positions of the fourth lens 24 far from the optical axis S3. By properly configuring the shapes and refractive powers of the lenses, the lens 100 can obtain a correspondingly better optical quality.

In an embodiment of the present application, the object-side surfaces and the image-side surfaces of the four lens elements are high-order aspheric surfaces, wherein the first lens element 21 has positive refractive power, and the object-side surface is convex; the second lens element 22 with negative refractive power has a concave image-side surface; the third lens element 23 with positive refractive power has a convex image-side surface; the fourth lens element 24 with negative refractive power has a convex object-side surface at a paraxial region and a concave image-side surface at a paraxial region.

In the above scheme, the lens 100 adopts a structure of four aspheric lenses, each lens selects a proper shape, various aberrations such as field curvature, astigmatism, vertical axis chromatic aberration and the like can be effectively corrected by using high-order aspheric coefficients, and meanwhile, the high-order aspheric coefficients have a good thickness ratio, the sensitivity of structural tolerance is reduced, so that the shape of the lens is uniform as a whole, the manufacturing yield is improved, and the production cost is reduced.

The configuration of the lens group 20 is described above by taking the arrangement order and the structural shape of the four lenses as examples, but the configuration of the lens group 20 is not limited thereto. The lens group 20 may be arranged by adding more lenses to the first lens 21, the second lens 22, the third lens 23, and the fourth lens 24. In other embodiments, the number of each lens is not limited to two, three, four or other multiple, and the number of the lenses may be selected according to the design target of the lens, the material selection of the lens, the processing conditions, the processing cost, the application scenario of the product, and other factors.

The material of each lens can be glass or plastic or other materials meeting the requirements, and can be selected by combining the comprehensive consideration of performance indexes, processing difficulty, processing cost and the like. For example, the lens may be made of glass or plastic, or may be made of glass and plastic.

In an embodiment of the present application, the material of the lens is preferably all plastic, and the plastic has the characteristic of precision mold pressing, so that batch production can be realized, the processing cost of the optical element can be greatly reduced, and further, the cost of the optical system is greatly reduced, and the wide-range popularization is facilitated.

In an embodiment of the present application, the refractive index of the first lens 21 is n1 and the abbe number is v1, the refractive index of the second lens 22 is n2 and the abbe number is v2, the refractive index of the third lens 23 is n3 and the abbe number is v3, and the refractive index of the fourth lens 24 is n4 and the abbe number is v 4;

wherein n3 is n1, v3 is v 1; n4 ═ n1, v4 ═ v 1; n2 > n1, v2< v 1.

In other embodiments, the abbe numbers of two lenses in the lens group 20 may be designed to be different from the abbe numbers of other lenses of the lens group 20.

By designing the abbe number of at least one lens in the lens group 20 to be different from the abbe numbers of the other lenses in the lens group 20, the abbe numbers of the other lenses in the lens group 20 are equal, which is more advantageous for eliminating chromatic aberration.

In an embodiment of the present application, referring to fig. 2, the reflection component 10 is a right-angle prism 11, an inclined surface of the right-angle prism 11 opposite to a right angle is a reflection surface 10a, the reflection surface 10a is an aspheric surface, a surface where a right-angle side of the object side is located is an incident surface 10b, and a surface where a right-angle side of the image side is located is an exit surface 10 c.

Specifically, the reflecting member 10 is integrally formed with the rectangular prism 11, and a reflecting film is coated on the inclined surface of the rectangular prism 11.

In an embodiment of the present application, referring to fig. 3, the reflective component 10 includes a triangular prism 12 and a flat curved mirror 13, a cross section of the triangular prism 12 may be a right triangle, a plane of the flat curved mirror 13 is connected to an inclined plane of the triangular prism 12, a plane of a side right angle of the triangular prism 12 is an incident plane 10b, a plane of a side right angle of the triangular prism 12 is an emergent plane 10c, a curved surface of the flat curved mirror 13 is a reflective plane 10a, and the reflective plane 10a is an aspheric surface.

Specifically, in the above-described reflecting member 10, the inclined surface of the triangular prism 12 is not coated with a reflecting film, and the curved surface of the flat-curved mirror 13 is coated with a reflecting film, and the same effect as that of the rectangular prism 11 coated with a reflecting film on the inclined surface can be obtained. The flat curved mirror 13 may be selected from a flat convex mirror or a flat concave mirror.

In an embodiment of the present application, the reflective element 10 is an aspheric mirror, and a mirror surface of the aspheric mirror is a reflective surface 10 a.

In the above solution, the reflecting component 10 has no incident surface and exit surface, and the light is deflected directly by the aspheric mirror and enters the lens group.

It should be noted that, according to the structural design of the lens or the requirements of different performance indexes, the reflecting member 10 may be designed into other structures, for example, the included angle between the incident surface 10b and the exit surface 10c of the triangular prism 12 is changed, the included angle between the incident surface 10b and the reflecting surface 10a is adjusted, and the like; the incident surface 10b and the exit surface 10c may not be flat.

In an embodiment of the present application, referring to fig. 1, a lens 100 includes an aperture stop 30 located on an object side of a reflective member 10. Disposing the aperture stop 30 on the object side of the reflective member 10, for example, on the incident surface 10b, is advantageous in reducing the thickness dimension of the lens 100 (see E1 in fig. 4), and when the lens is a rear lens in an electronic apparatus, it is advantageous in reducing the thickness of the electronic apparatus, making the electronic apparatus thinner.

In other embodiments, the aperture stop 20 may be provided at the exit surface 10c of the reflective member 10 or between some two lenses.

In an embodiment of the present application, the lens 100 includes a filter 40 located on an image side of the lens group 20. Specifically, the filter 40 is an infrared filter for filtering out infrared rays. The infrared filter may be reflective or absorptive, and the absorptive filter may be white glass filter or blue glass filter. The lens 100 adopts a blue glass optical filter, so that the problems of color cast, stray light and ghost image are obviously improved, and the color of the shot picture is softer and more natural.

On the other hand of the embodiment of the application, a camera module is provided. Referring to fig. 4, which is a schematic structural diagram of a camera module according to an embodiment of the present application, the camera module 1 includes an image sensor 200 and any one of the lenses 100 according to the above embodiments; a lens 100 for forming an optical signal of an object and reflecting the optical signal to an image sensor 200; the image sensor 200 converts an optical signal corresponding to an object into an image signal.

The image sensor 200 may be a Complementary Metal Oxide Semiconductor (CMOS) image sensor or a Charge-coupled Device (CCD) image sensor.

Since the camera module 1 adopts the lens 100 according to any of the above embodiments, the camera module 1 also has the technical effect corresponding to the lens 100, and details are not repeated herein.

In another aspect of the embodiments of the present application, an electronic device is provided. Referring to fig. 5, a schematic structural diagram of an electronic device according to an embodiment of the present application shows arrangement of components in a thickness direction of the electronic device, the electronic device includes a housing 2, a display screen 3, and any one of the camera modules 1 according to the above embodiments, the display screen 3 and the camera module 1 are mounted on the housing 2, and the display screen 3 is used for displaying an image captured by the camera module 1.

According to the embodiment of the application, the camera module 1 with the lens 100 of the embodiment can be completely packaged in the shell 2, so that the problem of thickening of the body of the electronic equipment caused by a telephoto lens is well solved; the sharpness difference between the center and the edge on the imaging is not large, so that the fineness of the picture is well balanced; the packaging design of the camera module 1 is favorable for dust and water prevention, thereby well protecting the lens 100.

Specifically, referring to fig. 5, the electronic device is exemplified by a smartphone, and the lens 100 of the camera module 1 may be placed in a rear position, that is, the incident surface 10b of the reflective member 10 faces the back surface of the housing 2, or light enters the reflective surface 10a of the reflective member 10 from the back surface of the housing 2, and the thickness direction of the lens 100 is set along the thickness direction of the smartphone.

Because the thickness E1 size of the camera lens 100 of this application embodiment is less, the display screen 2 can be made the full face screen, makes a video recording module 1 promptly and is located the back of display screen 2, when increasing the display screen display area for the whole thickness E2 of smart mobile phone is also thinner.

Meanwhile, as the length L1 of the lens 100 is smaller in size, other elements such as the battery 4 and the circuit board 5 can be reasonably arranged in the length direction of the smartphone, so that more elements can be reasonably arranged with fewer thickness levels on the premise that the overall length L2 of the smartphone meets the design requirements, and the overall lens of the smartphone can be thinner while achieving a long focal length.

It should be noted that, there are various arrangement modes of the camera module 1 in the electronic device housing 2, and when the internal structure of the electronic device is designed, the specific structure of the lens can be adjusted as required, for example, the included angle between the reflection surface 10a and the optical axis S3 is adjusted to adapt to different installation modes, so that the product structure is more compact while the lens of the electronic device realizes a long focal length.

The electronic device includes, but is not limited to, a smart phone, a Personal Digital Assistant (PDA), a tablet computer, an electronic reader, an electronic photo frame, a smart wearable device, a mobile medical device, a flight data recorder, a navigation device, an Automatic Teller Machine (ATM), a robot, a toy with a camera function, a home appliance, and the like.

Application examples

The application embodiment of the application is based on the innovative idea of the application, and aims to realize the design indexes of a long-focus periscopic lens with 13M (1300 ten thousand pixels) high image quality, a 35mm picture equivalent focal length of 80mm, a total lens length L1 of 11.6mm, a total thickness E1 of 4.4mm and an F/#2.0, and meet the design requirements of long focal length, light weight and thinness of the lens.

The design target is that the vertical chromatic aberration is controlled within +/-1.0 mu m, the RMS radius of a point diagram is controlled within 5 mu m, the GEO radius is controlled within 15 mu m, the relative illumination is not less than 0.5 at the maximum image height, the optical distortion is controlled within +/-1 percent, and the TV distortion is less than 1 percent.

It should be noted that, in other application embodiments, the design target may be adjusted according to different design criteria and design requirements.

To achieve the above design objectives, requirements and objectives, referring to fig. 1 and 4, the lens system 100 of the present application includes an aperture stop 30, a reflective member 10, a first lens element 21 with positive refractive power, a second lens element 22 with negative refractive power, a third lens element 23 with positive refractive power, a fourth lens element 24 with negative refractive power and a filter 40, which are sequentially disposed from an object side S1 to an image side S2.

In the above solution, the reflection member 10 has an incident surface 10b, a reflection surface 10a and an exit surface 10c, where the incident surface 10b and the exit surface 10c are both planar surfaces, an included angle between the incident surface 10b and the exit surface 10c is 90 °, the aperture stop 30 is located on the incident surface 10b, the reflection surface 10a is a convex even aspheric surface, an included angle between the reflection surface 10a and the optical axis S3 is 45 °, and the optical filter 40 is an infrared filter.

In the above-described embodiment, the optical axes S3 of the respective lenses overlap, the object-side surface and the image-side surface of the respective lenses are aspheric, and the respective lenses are made of optical plastic.

Specifically, the first lens element 21 with positive refractive power has a biconvex shape, i.e., the object-side surface 211 of the first lens element is convex, and the image-side surface 212 of the first lens element is convex; the second lens element 22 with negative refractive power has a biconcave shape, i.e., the object-side surface 221 of the second lens element is concave, and the image-side surface 222 of the second lens element is concave; the third lens element 23 with positive refractive power has a meniscus shape, i.e., the object-side surface 231 of the third lens element is concave, and the image-side surface 232 of the third lens element is convex; the fourth lens element 24 with negative refractive power has a "W" shape, i.e., the object-side surface 241 of the fourth lens element includes a convex surface at the object-side center 241a and concave surfaces at the object-side ends 241b, and the image-side surface 242 of the fourth lens element includes a concave surface at the image-side center 242a and convex surfaces at the image-side ends 242 b.

In the application embodiment of the present application, through the optimized design, the design parameter values of the lens 100 are determined as follows:

the field angle fov of the lens 100 is 31.6 degrees, and the half-image height is 2.04 mm;

the reflecting surface 10a of the reflecting member 10 has a radius of curvature of-6942.32 mm, a k value of 500,

the first lens 21 has an effective focal length f1 of 5.987mm, a refractive index n1 of 1.54, an abbe number v1 of 55.8,

the second lens 22 has an effective focal length f2 of-10.427 mm, a refractive index n2 of 1.64, an abbe number v2 of 23.5,

the third lens 23 has an effective focal length f3 of 9.345mm, a refractive index n3 of 1.54, an abbe number v3 of 55.8,

the effective focal length f4 of the fourth lens 24 is-10.423 mm, the refractive index n4 is 1.54, the abbe number v4 is 55.8,

the effective focal length efl of the lens 100 is 7.68mm,

the distance t1 from the exit face 10c of the reflective member 10 to the object side face 211 of the first lens is 0.1mm,

the thickness h1 of the first lens 21 is 0.838mm,

the distance t2 from the first lens 21 to the second lens 22 is 0.362mm,

the thickness h2 of the second lens 22 is 0.408mm,

the distance t3 from the second lens 22 to the third lens 23 is 2.346mm,

the thickness h3 of the third lens 23 is 0.553mm,

the distance t4 from the third lens 23 to the fourth lens 24 is 1.357mm,

the thickness h4 of the fourth lens 24 is 0.77mm,

the thickness h5 of the filter 40 is 0.21mm,

the distance t5 from the fourth lens 24 to the image sensor 200 is 2.371 mm.

Note that the total length L1 of the lens 100 is the length from the end of the reflection member 10 away from the image sensor 200 to the surface of the image sensor 200, and the size of the image sensor 200 is not calculated within L1.

The half height dimension takes into account a design margin, that is, the half height dimension calculated according to the following formula is larger than a set dimension. The formula is as follows:

half-image height efl tan (fov/2); wherein efl is the effective focal length of the lens; fov is the angle of view.

The lens 100 of the embodiment is applied to the application, because the reflecting surface 10a is designed into a high-order aspheric surface, the design optimization variable is increased, the imaging quality of the lens is improved, compared with the prior art, the number of the lenses in the lens group 20 can be reduced by one lens under the same design index, the total length of the lens 100 is reduced by more than 20%, and the beneficial effects of thinness and lightness are achieved.

Fig. 6 to 11 are diagrams showing the effect of analysis of the lens using optical design software, which may be selected as Zemax optical studio 17, according to the application example of the present application, and fig. 6 to 11 are described below.

Referring to fig. 6, which is a vertical axis chromatic aberration (lareal Color) diagram of lens imaging according to an embodiment of the present application, data is referenced to Real rays (Real rays used) with a wavelength of 0.5550 μm. Wherein the Maximum Field of view (Maximum Field) is 2.19mm, the ordinate represents the Real Image Height Field (Field: Real Image Height, unit mm), the abscissa represents the homeotropic chromatic aberration (lareal Color, unit μm), the number in the legend item represents the wavelength (unit μm) of each ray, and the curve represented by Airy is the Airy disk range.

The vertical axis chromatic aberration represents the difference between the focal positions of the light rays with different wavelengths (represented by different lines in fig. 6) and the reference wavelength light rays on the whole image surface of the system, and the smaller the vertical axis chromatic aberration is, the better the light rays with different wavelengths are converged. As can be seen from FIG. 6, the vertical axis chromatic aberration of the light with different wavelengths is between-0.8 μm and 0.9 μm, and is smaller than the range of Airy spots, the vertical axis chromatic aberration of the surface is well corrected, and the design requirements are met.

Referring to fig. 7, a Spot Diagram (Spot Diagram) for lens imaging according to an embodiment of the present application takes a principal Ray (Chief Ray) as a reference, and images of object points on an IMA plane (imaging plane) at different fields of view.

Fig. 7 shows a plot of 12 fields of view (0.000,0.000mm to 0.000,2.190mm) on the IMA plane on a Scale bar of 20.00, the numbers in the legend items representing the wavelength of each ray (in μm), and table 1 below is the root mean square radius (RMS radius) and the geometric radius (GEO radius) for the 12 fields of view from left to right, top to bottom, corresponding to fig. 7.

TABLE 1

The smaller the image point in fig. 7, the higher the resolution of the system, and as can be seen from table 1 above, the RMS root mean square radii of the image of the object point on the IMA plane are all smaller than 5 μm, and the GEO geometric radii are all smaller than 15 μm, which meet the design requirements.

Referring to fig. 8, a Relative illumination (Relative illumination) chart of a lens imaging according to an embodiment of the present application, a light ray with a wavelength of 0.555000 μm, a Relative illumination as a function of a radial field coordinate Y, a normalized Relative illumination value on the ordinate, and an image height on the abscissa.

As can be seen from fig. 8, the relative illumination of the lens is gradually decreased, and a higher relative illumination is still maintained at a maximum image height of 2.19mm, and the relative illumination is close to 0.6, which meets the design requirements.

Referring to fig. 9 to 10, fig. 9 is a Field Curvature (Field Curvature) graph of a lens image according to an embodiment of the present application, and fig. 10 is a Distortion (Distortion) graph of a lens image according to an embodiment of the present application, where the maximum Field angles of the two graphs of fig. 9 to 10 are 15.883 degrees, fig. 9 is a meridional (tagential) Field Curvature and a Sagittal (Sagittal) Field Curvature of a ray with a wavelength of 0.5550 μm, and the legend items are a meridional Field Curvature of a ray with a wavelength of 0.5550 μm and a Sagittal Field Curvature of a ray with a wavelength of 0.5550 μm; FIG. 10 shows F-Tan (theta) distortion of light of 0.5550 μm wavelength.

As can be seen from fig. 9, the meridional field curvature of the lens is within 6 μm, and the sagittal field curvature is within 15 μm; as can be seen from fig. 10, the optical distortion (also called geometric distortion) of the lens is less than 1%; after treatment, the TV distortion is less than 0.5%; meets the design requirements.

Referring to fig. 11, a diagram of a Polychromatic Diffraction Modulation Transfer Function (MTF) for imaging a lens according to an embodiment of the present application. The modulation transfer Function MTF is called "modulation transfer Function" in all english. The ordinate represents the MTF value (modules of the OTF) and the abscissa represents the evaluation Spatial Frequency (Spatial Frequency in cycles/mm).

Fig. 11 shows data of the field positions in 12 noon directions (tagential) and 12 Sagittal directions (Sagittal) for rays having wavelengths of 0.4700 μm to 0.6500 μm, where higher MTF values indicate better lens resolution. As can be seen from FIG. 11, the MTF values of all fields of the lens at 125cycles/mm are higher than 0.6, and at 250cycles/mm, the MTF values of the most marginal fields are also close to 0.4, and the overall MTF value is at a higher level.

The lens can be applied to a small-sized and long-focus periscopic lens, and the lens meets the design requirements of long focal length, light weight and thinness, and achieves good beneficial effects. The lens of the embodiment of the application is adopted on the portable electronic equipment, such as a smart phone, a Personal Digital Assistant (PDA), a tablet computer, an electronic reader or a camera, so that a camera module of the electronic equipment can realize long-focus camera shooting, and the whole electronic equipment can be lighter in weight and thinner in thickness.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A lens comprises a reflecting component and a lens group which are arranged from an object side to an image side in sequence; the reflecting component has an aspheric reflecting surface which can deflect an optical path from an object side to the lens group; the lens group comprises at least two lenses, the optical axes of the lenses are overlapped, and the lens group is used for correcting the aberration of the optical path deflected by the reflecting surface.

2. The lens barrel according to claim 1, wherein the reflection surface is a high-order aspherical surface.

3. The lens barrel according to claim 1, wherein an object side surface of each of the lenses and/or an image side surface of the lens is aspheric.

4. The lens element of claim 1, wherein the lens elements are sequentially arranged from an object side to an image side as a first lens element with positive refractive power, a second lens element with negative refractive power, a third lens element with positive refractive power and a fourth lens element with negative refractive power.

5. The lens barrel according to claim 4,

the object side surface of the first lens is a convex surface, and the image side surface of the first lens is a convex surface; and/or the presence of a gas in the gas,

6. The lens barrel according to claim 4,

the abbe number of at least one lens in the lens group is different from the abbe numbers of other lenses in the lens group, and the abbe numbers of other lenses in the lens group are equal.

7. The lens barrel according to claim 1, wherein the reflecting member is a right-angle prism, and an inclined surface of the right-angle prism is the reflecting surface; or the like, or, alternatively,

8. The lens barrel according to any one of claims 1 to 7, wherein the lens barrel includes an aperture stop on an object side of the reflection member; and/or the presence of a gas in the gas,

the lens comprises a filter positioned on the image side of the lens group.

9. A camera module, comprising an image sensor and the lens of any one of claims 1 to 8;

10. An electronic device, comprising a housing, a display screen, and the camera module of claim 9, wherein the display screen and the camera module are mounted on the housing, and the display screen is used for displaying an image captured by the camera module.