Visible light lens, camera module and terminal equipment

Abstract

The invention relates to a visible light lens, a camera module and terminal equipment, and belongs to the technical field of optical imaging, and the visible light lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens which are sequentially arranged from an object plane to an image plane along an optical axis; the first lens, the second lens and the fifth lens are lenses with negative focal power, the third lens, the fourth lens, the sixth lens and the seventh lens are lenses with positive focal power, and the fourth lens is a metasurface lens; the object side surfaces of the first lens, the third lens and the seventh lens are convex surfaces, the object side surfaces of the second lens and the sixth lens are concave surfaces, and the object side surfaces and the image side surfaces are spherical surfaces; the object side surface of the fourth lens has microstructure arrangement, and the image side surface is a plane; the object side surface of the fifth lens is a plane, and the object side surface and the image side surface are spherical surfaces. According to the invention, the technical scheme of folding and super mixing is adopted, and the large-aperture optical system is realized by six traditional glass material lenses and one super lens.

Description

Technical Field

[0001] The present invention belongs to the field of optical imaging, and in particular relates to a visible light lens, a camera module and a terminal device. Background Art

[0002] With the development of science and technology and the improvement of people's living standards, the demand for safer and smarter vehicle driving is getting higher and higher, so the demand for the resolution of vehicle lenses is also getting higher and higher. At present, vehicle lenses mainly use a combination of glass aspherical lenses + glass spherical lenses to achieve imaging functions. However, glass aspherical lenses are expensive and complex to process, and often cannot be made into more complex surface shapes. In addition, traditional vehicle lenses have a large number of lenses, large size and weight. Summary of the invention

[0003] The present application provides a visible light lens, a camera module and a terminal device to at least solve the above technical problems existing in the prior art.

[0004] In a first aspect, an embodiment of the present application provides a visible light lens, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged in sequence from an object plane to an image plane along an optical axis; the first lens is a lens with negative optical power, whose object side surface is a convex surface, and whose object side surface and image side surface are both spherical surfaces; the second lens is a lens with negative optical power, whose object side surface is a concave surface, and whose object side surface and image side surface are both spherical surfaces; the third lens is a lens with positive optical power, whose object side surface is a convex surface, and whose object side surface and image side surface are both spherical surfaces; the fourth lens is a metasurface lens with positive optical power, whose object side surface has a microstructure arrangement, and whose image side surface is a plane; the fifth lens is a lens with negative optical power, whose object side surface is a plane, and whose object side surface and image side surface are both spherical surfaces; the sixth lens is a lens with positive optical power, whose object side surface is a concave surface, and whose object side surface and image side surface are both spherical surfaces; the seventh lens is a lens with positive optical power, whose object side surface is a convex surface, and whose object side surface and image side surface are both spherical surfaces;

[0005] The visible light lens meets the following requirements:

[0006]

[0007] Wherein, Fno is the aperture number, FOV is the diagonal field of view, TTL is the total length of the optical system, which is defined as the distance from the center of the optical axis of the object side of the first lens to the image plane, and f is the focal length.

[0008] In one possible implementation manner, the focal length satisfies f≥4 mm.

[0009] In one possible implementation, the aperture number satisfies 1.2≤Fno≤2.4.

[0010] In one possible implementation, the field of view satisfies FOV ≥ 130°.

[0011] In one embodiment, a stop is also included.

[0012] In one possible implementation manner, the aperture stop is disposed between the third lens and the fourth lens.

[0013] In one embodiment, a filter is also included.

[0014] In one possible implementation manner, the filter is disposed on a side of the seventh lens close to the image plane.

[0015] In a second aspect, an embodiment of the present application provides a camera module, comprising an image sensor and any one of the visible light lenses described above, wherein the image sensor is arranged on the image side of the visible light lens.

[0016] In a third aspect, an embodiment of the present application provides a terminal device, comprising a shell and a camera module as described in the second aspect above, wherein the camera module is arranged in the shell.

[0017] Compared with the prior art, this application has the following advantages:

[0018] 1. This application adopts a hybrid technical solution of refractive and super lens, a seven-piece design, six traditional glass lenses plus a super lens to achieve a large aperture optical system;

[0019] 2. This application utilizes the light regulation characteristics of the metalens to reduce the total number of lenses and the number of aspherical lenses;

[0020] 3. This application utilizes the hybrid technology of refractive index and super refractive index to compress the total optical length and achieve miniaturization and lightweight design. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of the structure of the visible light lens in Example 1 of the present application;

[0022] Figure 2 is a schematic diagram of the MTF of the visible light lens in Example 1 of the present application;

[0023] Figure 3 is a schematic diagram of the diffuse spots of the visible light lens in Example 1 of the present application;

[0024] Figure 4 is a schematic diagram of relative illumination of the visible light lens in Example 1 of the present application;

[0025] Figure 5 is a schematic diagram of the structure of the visible light lens in Example 2 of the present application;

[0026] Figure 6is a schematic diagram of the MTF of the visible light lens in Example 2 of the present application;

[0027] Figure 7 is a schematic diagram of the diffuse spots of the visible light lens in Example 2 of the present application;

[0028] Figure 8 is a schematic diagram of relative illumination of the visible light lens in Example 2 of the present application;

[0029] Description of reference numerals:

[0030] 100, aperture; 110, first lens; 120, second lens; 130, third lens; 140, fourth lens; 150, fifth lens; 160, sixth lens; 170, seventh lens; 180, image plane; 190, filter. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0032] In the description of the present application, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0033] Figure 1 A schematic diagram of the structure of a visible light lens at room temperature provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, the refractive super hybrid visible light vehicle-mounted lens provided by the embodiment of the present invention comprises a first lens 110, a second lens 120, a third lens 130, a fourth lens 140, a fifth lens 150, a sixth lens 160, and a seventh lens 170 which are sequentially arranged along the optical axis from the object plane to the image plane 180. The refractive super hybrid visible light vehicle-mounted lens is arranged to meet Wherein, Fno is the aperture number, FOV is the diagonal field of view, and TTL is the total length of the optical system, which is defined as the distance from the center of the optical axis of the object side of the first lens to the image plane. The refractive super hybrid visible light vehicle-mounted lens provided in the embodiment of the present invention has a small aperture number, can have a large amount of light transmission, and has a large overall field of view (FOV ≥ 130°).

[0034] Among them, the metasurface lens can replace the aspherical lens. By setting at least one lens in the refractive-metahybrid visible light vehicle-mounted lens to be a metasurface lens, the image quality can be improved.

[0035] As a feasible implementation, at least one of the first lens 110, the second lens 120, the third lens 130, the fourth lens 140, the fifth lens 150, the sixth lens 160, and the seventh lens 170 is a metasurface lens. In this embodiment, the fourth lens 140 is set to be a metasurface lens.

[0036] As a feasible implementation manner, the first lens 110 is a lens with negative optical power, and both the object-side surface and the image-side surface thereof are spherical surfaces.

[0037] As a feasible implementation manner, the second lens 120 is a lens with negative optical power, and both the object-side surface and the image-side surface thereof are spherical surfaces.

[0038] As a feasible implementation manner, the third lens 130 is a lens with positive refractive power, and both the object-side surface and the image-side surface thereof are spherical surfaces.

[0039] As a feasible implementation, the fourth lens 140 is a metasurface lens with positive optical power, whose object side has a microstructure arrangement and whose image side is a plane.

[0040] As a feasible implementation manner, the fifth lens 150 is a lens with negative optical power, and both the object-side surface and the image-side surface thereof are spherical surfaces.

[0041] As a feasible implementation manner, the sixth lens 160 is a lens with positive refractive power, and both the object-side surface and the image-side surface thereof are spherical surfaces.

[0042] As a feasible implementation manner, the seventh lens 170 is a lens with positive refractive power, and both the object-side surface and the image-side surface thereof are spherical surfaces.

[0043] As a feasible implementation, the materials of the first lens 110 , the second lens 120 , the third lens 130 , the fifth lens 150 , the sixth lens 160 , and the seventh lens 170 are visible light glass materials, and the material of the fourth lens 140 is silicon dioxide.

[0044] Among them, the athermal design is achieved through the coordination of materials and the optical focal length of each lens, which not only reduces the material cost but also reduces the size of the system.

[0045] As a feasible implementation manner, the visible light lens system further includes an aperture 100 , and the aperture 100 is disposed between the third lens 130 and the fourth lens 140 .

[0046] like Figure 1 As shown, the incident light enters through the object side of the first lens 110 , and then passes through the second lens 120 , the third lens 130 , the aperture 140 , the fifth lens 150 , the sixth lens 160 , and the seventh lens 170 in sequence, and finally converges on the imaging surface 180 .

[0047] As a feasible implementation manner, the visible light lens system further includes a filter 190 , and the filter 190 is disposed on a side of the seventh lens 170 close to the image plane 180 .

[0048] Example 1

[0049] For example, Table 1 describes in detail the specific optical data parameters of each lens in the refractive super hybrid visible light vehicle-mounted lens provided by an embodiment of the present invention in a feasible implementation manner. The optical data parameters in Table 1 correspond to Figure 1 The refractive super hybrid visible light vehicle-mounted lens shown.

[0050] The first lens 110 is a spherical lens with negative power, whose object side surface is convex and whose image side surface is convex; the second lens 120 is a spherical lens with negative power, whose object side surface is concave and whose image side surface is concave; the third lens 130 is a spherical lens with positive power, whose object side surface is convex and whose image side surface is convex; the fourth lens 140 is a metasurface lens with positive power, whose object side surface has a microstructure arrangement and whose image side surface is a plane; the fifth lens 150 is a spherical lens with negative power, whose object side surface is a plane and whose image side surface is a concave; the sixth lens 160 is a spherical lens with positive power, whose object side surface is concave and whose image side surface is concave; the seventh lens 170 is a spherical lens with positive power, whose object side surface is convex and whose image side surface is a plane; and the aperture 100 is located between the third lens 130 and the fourth lens 140.

[0051] Table 1 Parameters of various surfaces in the visible light lens provided in Example 1

[0052]

[0053]

[0054] The surface numbers are numbered according to the order of the surfaces of each lens. For example, surface number 1 represents the object side surface of the first lens 110, surface number 2 represents the image side surface of the first lens 110, and so on. The radius of curvature represents the curvature of the lens surface. A positive value represents that the surface is curved toward the image side, and a negative value represents that the surface is curved toward the object side. "Infinity" represents that the surface is a plane. The spacing represents the central axial distance from the current surface to the next surface. The units of the radius of curvature and the spacing are both millimeters (mm).

[0055] The binary face BINARY2 increases the phase according to the following polynomial expansion:

[0056]

[0057] where N is the number of polynomial coefficients in the series, Ai is the squared coefficient of ρ, i.e. the normalized radial aperture coordinate, and M is the diffraction order.

[0058] Exemplarily, Table 2 details the phase added by the metasurface lens in this embodiment in a feasible implementation manner.

[0059] Table 2 Binary surface coefficients of the metasurface lens in the visible light lens provided in Example 1

[0060] Surface number R1 A1 A2 A3 A4 A5 A6 4 1 -7.56E+01 1.31E+01 -1.52E+01 7.87E+00 -2.48E+00 4.68E-01

[0061] Where R1 is the normalized radius of the binary surface.

[0062] In this embodiment, the aperture number, the field of view angle and the total length of the system meet The total length of the optical lens and the focal length meet the requirements.

[0063] The working band of the refractive super hybrid visible light vehicle-mounted lens provided in this embodiment is 436-656nm, the aperture number is 2.0, the focal length is 4.0mm, and the maximum full field of view angle is 155°, which meets the use requirements of vehicle-mounted lenses.

[0064] Figure 2 This is a schematic diagram of the modulation transfer function (MTF) of the folded super hybrid visible light vehicle-mounted lens provided in an embodiment of the present invention. The folded super hybrid visible light vehicle-mounted lens provided in an embodiment of the present invention has an MTF value ≥ 0.4 at 160lp / mm, which can match conventional vehicle-mounted chips and meet the needs of high-resolution imaging.

[0065] Figure 3 This is a schematic diagram of the diffuse spots of the refracted and super-hybrid visible light vehicle-mounted lens provided in an embodiment of the present invention. The refracted and super-hybrid visible light vehicle-mounted lens provided in an embodiment of the present invention has a relatively concentrated and evenly distributed diffuse pattern in the entire band, which can meet the needs of high-resolution imaging.

[0066] Figure 4 The relative illumination diagram of the refractive super hybrid visible light vehicle-mounted lens provided by the embodiment of the present invention represents the relative illumination values ​​corresponding to different fields of view, such as Figure 4 As shown, the refractive super hybrid visible light vehicle-mounted lens provided by the embodiment of the present invention has a relative illumination greater than 50% in the entire field of view in the working band and uniform brightness.

[0067] Example 2

[0068] For example, Table 3 describes in detail the specific optical data parameters of each lens in the refractive super hybrid visible light vehicle-mounted lens provided by the embodiment of the present invention in a feasible implementation manner. The optical data parameters in Table 3 correspond to Figure 5The refractive super hybrid visible light vehicle-mounted lens shown.

[0069] The first lens 110 is a spherical lens with negative power, whose object side surface is convex and whose image side surface is convex; the second lens 120 is a spherical lens with negative power, whose object side surface is concave and whose image side surface is concave; the third lens 130 is a spherical lens with positive power, whose object side surface is convex and whose image side surface is convex; the fourth lens 140 is a metasurface lens with positive power, whose object side surface has a microstructure arrangement and whose image side surface is a plane; the fifth lens 150 is a spherical lens with positive power, whose object side surface has a microstructure arrangement and whose image side surface is a plane; The spherical lens with negative optical power has a flat object side and a concave image side. The sixth lens 160 is a spherical lens with positive optical power, with a concave object side and a concave image side. The seventh lens 170 is a spherical lens with positive optical power, with a convex object side and a flat image side. The object side and image side of the filter 190 are both flat and are located between the seventh lens 170 and the image plane 180. The aperture 100 is located between the third lens 130 and the fourth lens 140.

[0070] Table 3 Parameters of various surfaces in the visible light lens provided in Example 2

[0071]

[0072] The surface numbers are numbered according to the order of the surfaces of each lens. For example, surface number 1 represents the object side surface of the first lens 110, surface number 2 represents the image side surface of the first lens 110, and so on. The radius of curvature represents the curvature of the lens surface. A positive value represents that the surface is curved toward the image side, and a negative value represents that the surface is curved toward the object side. "Infinity" represents that the surface is a plane. The spacing represents the central axial distance from the current surface to the next surface. The units of the radius of curvature and the spacing are both millimeters (mm).

[0073] The binary face BINARY2 increases the phase according to the following polynomial expansion:

[0074]

[0075] where N is the number of polynomial coefficients in the series, Ai is the squared coefficient of ρ, i.e. the normalized radial aperture coordinate, and M is the diffraction order.

[0076] Exemplarily, the phase added by the metasurface lens in this embodiment is described in detail in a feasible implementation manner.

[0077] Table 4 Binary surface coefficients of the metasurface lens in the visible light lens provided in Example 2

[0078] Surface number R1 A1 A2 A3 A4 4 1 -6E+01 1.52E+00 9.66E-02 -8.76E-03

[0079] Where R1 is the normalized radius of the binary surface.

[0080] In this embodiment, the aperture number, the field of view angle and the total length of the system meet The total length of the optical lens and the focal length meet the requirements.

[0081] The working band of the refracted and super-hybrid visible light vehicle-mounted lens provided in this embodiment is 436-656nm, the aperture number is 1.46, the focal length is 4.22mm, and the maximum full field of view angle is 140°, which meets the use requirements of vehicle-mounted lenses.

[0082] Figure 6 This is a schematic diagram of the MTF of the refracted super-hybrid visible light vehicle-mounted lens provided in an embodiment of the present invention. The refracted super-hybrid visible light vehicle-mounted lens provided in an embodiment of the present invention has an MTF value ≥ 0.4 at 160lp / mm, which can match conventional vehicle-mounted chips and meet the needs of high-resolution imaging.

[0083] Figure 7 This is a schematic diagram of the diffuse spots of the refracted and super-hybrid visible light vehicle-mounted lens provided in an embodiment of the present invention. The refracted and super-hybrid visible light vehicle-mounted lens provided in an embodiment of the present invention has a relatively concentrated and evenly distributed diffuse pattern in the entire band, which can meet the needs of high-resolution imaging.

[0084] Figure 8 The relative illumination diagram of the refractive super hybrid visible light vehicle-mounted lens provided by the embodiment of the present invention represents the relative illumination values ​​corresponding to different fields of view, such as Figure 8 As shown, the refractive super hybrid visible light vehicle-mounted lens provided by the embodiment of the present invention has a relative illumination greater than 50% in the entire field of view in the working band and uniform brightness.

[0085] In summary, the refractive-super hybrid visible light vehicle-mounted lens provided in the embodiment of the present invention has a large aperture, a small number of lenses, clear imaging, and a short total length, and can meet the needs of high-resolution imaging.

[0086] Embodiment 1 and Embodiment 2 respectively satisfy the relationship shown in Table 5 below:

[0087] Table 5 Optical system parameters provided by Example 1 and Example 2

[0088]

[0089] The present application also discloses a camera module, which includes an image sensor and any one of the visible light lenses described above, wherein the image sensor is arranged on the image side of the visible light lens.

[0090] The present application also discloses a terminal device, comprising a housing and the above-mentioned camera module, wherein the camera module is arranged in the housing.

[0091] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A visible light lens, characterized in that: It comprises a first lens (110), a second lens (120), a third lens (130), a fourth lens (140), a fifth lens (150), a sixth lens (160), and a seventh lens (170) which are sequentially arranged along the optical axis from the object plane to the image plane (180); The first lens (110) is a lens with negative optical power, the object side surface of which is a convex surface, and the object side surface and the image side surface of which are both spherical surfaces; The second lens (120) is a lens with negative optical power, the object side surface of which is a concave surface, and the object side surface and the image side surface of which are both spherical surfaces; The third lens (130) is a lens with positive refractive power, the object side surface of which is a convex surface, and the object side surface and the image side surface of which are both spherical surfaces; The fourth lens (140) is a metasurface lens with positive optical power, the object side of which has a microstructure arrangement and the image side is a plane; The fifth lens (150) is a lens with negative optical power, the object side surface of which is a plane, and the object side surface and the image side surface of which are both spherical surfaces; The sixth lens (160) is a lens with positive refractive power, the object side surface of which is a concave surface, and both the object side surface and the image side surface of which are spherical surfaces; The seventh lens (170) is a lens with positive refractive power, the object side surface of which is a convex surface, and the object side surface and the image side surface of which are both spherical surfaces; The visible light lens meets the following requirements: Wherein, Fno is the aperture number, FOV is the diagonal field of view, TTL is the total length of the optical system, which is defined as the distance from the center of the optical axis of the object side of the first lens (110) to the image plane, and f is the focal length.

2. The visible light lens according to claim 1, characterized in that: The focal length satisfies f≥4mm.

3. The visible light lens according to claim 1, characterized in that: The aperture number satisfies 1.2≤Fno≤2.

4.

4. The visible light lens according to claim 1, characterized in that: The field of view angle meets FOV ≥ 130°.

5. The visible light lens according to claim 1, characterized in that: Also included is a stop (100).

6. The visible light lens according to claim 5, characterized in that: The aperture (100) is arranged between the third lens (130) and the fourth lens (140).

7. The visible light lens according to claim 1, characterized in that: Also included is an optical filter (190).

8. The visible light lens according to claim 7, characterized in that: The filter (190) is arranged on a side of the seventh lens (170) close to the image plane.

9. A camera module, characterized in that: The camera module includes an image sensor and the visible light lens according to any one of claims 1 to 8, wherein the image sensor is arranged on the image side of the visible light lens.

10. A terminal device, characterized in that: Including the camera module described in claim 9.

Images