Lens and light-emitting device

Abstract

The utility model discloses a lens and a light-emitting device, and belongs to the technical field of optics. The lens comprises a light incident surface, a light emergent surface and a reflecting surface, the light incident surface is a concave surface used for forming a light source accommodating cavity, the light emergent surface is opposite to the light incident surface, the reflecting surface surrounds the light incident surface and the light emergent surface and is connected between the light incident surface and the light emergent surface, and the light incident surface, the light emergent surface and the reflecting surface are all curved surfaces. The light incident surface, the reflecting surface and the light emergent surface are configured to form light spots on the target surface based on light emitted by the light source, the light spots comprise a central area and a peripheral area, the peripheral area surrounds the central area, and the brightness of the central area is uniform and larger than that of the peripheral area. According to the lens, a light spot with a bright central area and a dark peripheral area can be obtained by adopting a simple structure.

Description

Technical Field

[0001] The present application relates to the field of optical technology, and in particular to a lens and a light-emitting device. Background Art

[0002] In different scenes, it is necessary to form light spots of different shapes based on the light source. Usually, a lens can be arranged in the light emitting direction of the light source to obtain a light spot of the desired shape through the lens.

[0003] In the related art, in some scenarios, a light spot with a brighter central area and a darker peripheral area is required, but the lens structure that forms such a light spot is relatively complex and difficult to process. Utility Model Content

[0004] The present application provides a lens and a light emitting device. The lens can obtain a light spot with a brighter central area and a darker peripheral area by using a simple structure and is easy to process.

[0005] In a first aspect, the present application provides a lens, which includes a light incident surface, a light emitting surface, and a reflective surface, wherein the light incident surface is a concave surface for forming a light source accommodating cavity, the light emitting surface is opposite to the light incident surface, the reflective surface surrounds the light incident surface and the light emitting surface, and is connected between the light incident surface and the light emitting surface, and the light incident surface, the light emitting surface, and the reflective surface are all curved surfaces. The light incident surface, the reflective surface, and the light emitting surface are configured to form a light spot on a target surface based on the light emitted by the light source, and the light spot includes a central area and a peripheral area, the peripheral area surrounds the central area, and the brightness of the central area is uniform and greater than the brightness of the peripheral area.

[0006] The lens uses the cooperation of the three curved surfaces of the light incident surface, the light emitting surface and the reflection surface to obtain a light spot with a brighter central area and a darker peripheral area. The three curved surfaces have a simple structure and are easy to form, thereby reducing the difficulty of processing the lens.

[0007] Optionally, the light incident surface is a spherical surface, and the reflection surface and the light emitting surface are both free-form surfaces. When the light incident surface is a spherical surface, the light emitted by the light source at the center of the sphere can be incident into the lens substantially along the radius direction of the spherical surface, and the optical path is relatively simple. On this basis, two free-form surfaces are designed as the reflection surface and the light emitting surface to form a light spot of desired brightness and shape, which is easy to implement.

[0008] Optionally, the light emitting surface is configured to emit the light propagated from the light incident surface to the light emitting surface to the central area, and to emit the light propagated from the reflecting surface to the light emitting surface to the peripheral area. By classifying the light propagated from the inside of the lens to the light emitting surface, different types of light are emitted to different areas. Since the light propagated from the light incident surface to the light emitting surface is emitted to the central area, the surface shape of the light emitting surface can be determined based on the surface shape of the light incident surface, the position of the target surface, and the brightness and size of the central area. And since the light propagated from the reflecting surface to the light emitting surface is emitted to the peripheral area, after the surface shape of the light emitting surface is determined, the surface shape of the reflecting surface can be determined based on the surface shape of the light emitting surface, the position of the target surface, and the brightness and size of the peripheral area.

[0009] Optionally, the surface shape of the light emitting surface is obtained by fitting a plurality of first discrete data points, and the plurality of first discrete data points are obtained by solving the following formula:

[0010]

[0011]

[0012] Among them, E (t x ,t y ) is the illumination distribution of the central area on the target surface, t x is the x coordinate of point T on the target surface, t y is the y coordinate of point T on the target surface, J(T) is the Jacobi matrix of the position vector T of point T, is the intensity distribution of the light source, where 0≤θ≤2π, θ represents the angle between the projection of point P in the xy plane and the line connecting the origin of the coordinate system and the x-axis. represents the angle between the line connecting point P and the origin of the coordinate system and the z-axis, and ρ represents the distance from point P to the origin of the coordinate system; θ represents the first-order partial derivative of ρ with respect to the angle θ, Denotes ρ with respect to the angle The first-order partial derivative of , point P is a point on the light-emitting surface; Ω1 represents the total solid angle of the light beam incident on the light-emitting surface, Ω2 represents the central area, and are the boundaries of regions Ω1 and Ω2 respectively.

[0013] Optionally, the surface shape of the reflecting surface is obtained by fitting a plurality of second discrete data points, and the plurality of second discrete data points are obtained by solving the following formula:

[0014]

[0015]

[0016] Among them, E(t x2 ,t y2 ) is the illumination distribution of the peripheral area on the target surface, t x2 is the x coordinate of point T2 on the target surface, t y2 is the y coordinate of point T2 on the target surface, J(T2) is the Jacobian matrix of the position vector T of point T2, is the intensity distribution of the light source, where 0≤θ≤2π, θ represents the angle between the projection of point Q in the xy plane and the line connecting the origin of the coordinate system and the x-axis. represents the angle between the line connecting point Q and the origin of the coordinate system and the z-axis, and ρ represents the distance from point Q to the origin of the coordinate system; θ represents the first-order partial derivative of ρ with respect to the angle θ, Denotes ρ with respect to the angle The first-order partial derivative of , point Q is a point on the reflection surface; Ω1 represents the total solid angle of the light beam incident on the reflection surface, Ω2 represents the peripheral area, and are the boundaries of regions Ω1 and Ω2 respectively.

[0017] Optionally, the central area and the peripheral area are both rectangular, and the centers of the central area and the peripheral area coincide with each other. In many scenarios, such as electronic police or gate vehicle identification, the area to be illuminated is rectangular, and the brightness of the central area needs to be higher than that of the peripheral area to meet the lighting requirements of different areas. In these scenarios, if a circular or elliptical light spot with uniform brightness is used, in order to completely cover the target area, the area of ​​the light spot must be larger than the area of ​​the target area, so that the light spot around the target area will cause light pollution. In the present application, a light spot with a rectangular shape in both the central area and the peripheral area is used, which can fit the shape of the target area and reduce light pollution.

[0018] Optionally, in the direction from the center of the peripheral area to the outside, the brightness of the peripheral area decreases monotonically from the brightness of the central area to a set percentage of the brightness of the central area. This monotonically decreasing brightness of the peripheral area is conducive to a smooth transition of the surface shape of the light emitting surface and / or the reflecting surface, so that the final surface shape is easy to process.

[0019] In a second aspect, the present application provides a light-emitting device, the light-emitting device comprises a first light-emitting unit, the first light-emitting unit comprises a first light source and a first lens, the first lens is any of the aforementioned lenses, and the first light source is located in a receiving cavity of the first lens. The light-emitting device has a simple structure and low cost.

[0020] Optionally, the first light source comprises a light-emitting diode (LED). LED has low power consumption and high brightness, which is conducive to reducing costs.

[0021] Optionally, the light emitting device is a fill light of a camera device. In various application scenarios of a camera device, it is necessary to shoot a target object in a dark environment. In order to ensure the shooting effect, the fill light can be used to fill light on the target object.

[0022] Optionally, the light emitting device further comprises a second light emitting unit, the second light emitting unit comprises a second light source and a second lens, the second lens is any of the aforementioned lenses, and the second light source is located in a receiving cavity of the second lens. The light spot formed by the first light emitting unit and the light spot formed by the second light emitting unit are arranged sequentially on the target surface.

[0023] When the target object passes through the illumination area of ​​the first light-emitting unit and the illumination area of ​​the second light-emitting unit in sequence, the first light-emitting unit and the second light-emitting unit can be controlled to emit light in sequence according to the position of the target object to avoid light pollution caused by the first light-emitting unit and the second light-emitting unit emitting light at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of a three-dimensional structure of a lens provided in an embodiment of the present application;

[0025] Figure 2 is a schematic diagram of a light spot provided in an embodiment of the present application;

[0026] Figure 3 yes Figure 2 Schematic diagram of brightness distribution of the middle light spot;

[0027] Figure 4 is a schematic diagram of the structure of a light-emitting device provided in an embodiment of the present application;

[0028] Figure 5 It is a schematic diagram of an application scenario of the light-emitting device provided in an embodiment of the present application.

[0029] Reference numerals

[0030] 1. Lens;

[0031] 10, light incident surface; 20, light exiting surface; 30, reflection surface; 40, target surface;

[0032] 2. Light source;

[0033] a. Central area; b. Peripheral area;

[0034] A. Electric poles; B. Vehicles; C. Camera equipment. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0036] The embodiment of the present application provides a lens and a light emitting device. The lens can form a light spot with a bright center area and a dark surrounding area, and has a simple structure and is easy to manufacture.

[0037] Figure 1 Schematic diagram of the structure of a lens provided in an embodiment of the present application. Figure 1 As shown, the lens includes a light incident surface 10, a light emitting surface 20 and a reflective surface 30. The light incident surface 10, the light emitting surface 20 and the reflective surface 30 are all curved surfaces. The light incident surface 10 is a concave surface for forming a light source accommodating cavity. The light emitting surface 20 is opposite to the light incident surface 10. The reflective surface 30 surrounds the light incident surface 10 and the light emitting surface 20 and is connected between the light incident surface 10 and the light emitting surface 20. The light incident surface 10, the light emitting surface 20 and the reflective surface 30 can form a light spot on the target surface based on the light emitted by the light source in the light source accommodating cavity.

[0038] Figure 2 Schematic diagram of a light spot provided in an embodiment of the present application. Figure 2 As shown, the light spot includes a central area a and a peripheral area b, the peripheral area b surrounds the central area a, and the brightness of the central area a is uniform and greater than the brightness of the peripheral area b. That is, the central area a of the light spot is brighter than the peripheral area b. When the central area covers the target object with a large illumination requirement and the peripheral area covers the target object with a small illumination requirement, different brightness can be used to illuminate different target objects to meet the different illumination requirements of different target objects.

[0039] Furthermore, the lens utilizes the cooperation of the three curved surfaces, namely, the light incident surface, the light emitting surface and the reflection surface, to obtain a light spot with a brighter central area and a darker peripheral area. The three curved surfaces have a simple structure and are easy to form, thereby reducing the difficulty of processing the lens.

[0040] For example, Figure 2 As shown, the central area a is rectangular, the peripheral area b is annular, the inner contour of the peripheral area b coincides with or is connected to the outer contour of the central area a, the outer contour of the peripheral area b is also rectangular, and includes four side edges connected end to end in sequence, and the four side edges of the outer contour of the peripheral area b are respectively parallel to the four side edges of the central area a. In other embodiments, the shape of the central area a and the shape of the outer contour of the peripheral area b can be selected according to actual needs.

[0041] Optionally, in the direction from the center of the peripheral area b to the outside, the brightness of the peripheral area b decreases monotonically from the brightness of the central area a to a set percentage of the brightness of the central area a. This monotonically decreasing brightness of the peripheral area b is conducive to a smooth transition of the surface shape of the light emitting surface and / or the reflecting surface, so that the final surface shape is easy to process.

[0042] Optionally, the range of the set percentage is 20% to 80%. Optionally, the range of the set percentage is 40% to 60%, for example 50%. The set percentage can be set according to the actual usage scenario, for example, according to the difference in illumination requirements of different parts of the target object in the central area and the peripheral area, and the embodiments of the present application are not limited to this. When the target object is a vehicle, the central area a needs to cover the window, and the peripheral area b needs to cover the license plate. Since the environment inside the window is dark and the face position is difficult to capture clearly, a higher illumination is required. Since the license plate is made of reflective material, if the brightness is too high, it is easy to produce overexposure, so the required illumination is lower.

[0043] Figure 3 yes Figure 2 Schematic diagram of the brightness distribution of the light spot in . Figure 3 As shown, the brightness of the peripheral area b gradually decreases in the direction from the central area a to the outside until the brightness becomes about 50% of the brightness of the central area a. This variation is more suitable for obtaining the required spot brightness using a continuous surface shape.

[0044] In the embodiment of the present application, the shape and size of the central area a and the shape and size of the peripheral area b can be determined according to the shape and size of the target object.

[0045] For example, if the target object is a car, the central area a needs to cover the car window, and the peripheral area b needs to cover the license plate, then the shape of the central area a is a rectangle, the length of the central area a is substantially equal to the length of the car window, and the width of the central area a is substantially equal to the width of the car window, that is, the central area a is a uniform light spot covering the car window. The peripheral area b is annular, the inner contour of the peripheral area b coincides with or connects with the outer contour of the central area a, the outer contour of the peripheral area b is also rectangular, and includes four side edges connected end to end in sequence, and the four side edges of the outer contour of the peripheral area b are respectively parallel to the four side edges of the central area a. The single-side width of the peripheral area b is related to the distance between the license plate and the car window and the width of the license plate, and it is sufficient to ensure that the area where the license plate is located can be covered. Exemplarily, the widths of different sides of the peripheral area b can be the same or different. For example, the upper side width of the peripheral area b can be smaller than the lower side width, and the left side width and the right side width of the peripheral area b are both equal to the upper side width. Here, the lower side width is the area used to cover the license plate.

[0046] For another example, if the target object is an exhibit (such as a painting, fabric, or sculpture, etc.), the shape of the central area a is rectangular, circular, or elliptical, the peripheral area b is annular, the inner contour of the peripheral area b coincides with or connects with the outer contour of the central area a, and the outer contour of the peripheral area b is the same as or different from the shape of the central area a. In some examples, the shape of the central area a is circular, and the outer contour of the peripheral area b is circular or rectangular. In other examples, the shape of the central area a is rectangular, and the outer contour of the peripheral area b is circular or rectangular, etc.

[0047] Optionally, the target plane is perpendicular to the optical axis of the light source, or the target plane and the optical axis of the light source are at an angle other than 90°. Depending on the installation position of the light emitting device in different scenarios, the target plane may be perpendicular to the optical axis of the light source or at an angle other than 90°.

[0048] In an embodiment of the present application, the light emitting surface 20 is configured to emit the light propagated from the light incident surface 10 to the light emitting surface 20 to the central area, and to emit the light propagated from the reflecting surface 30 to the light emitting surface 20 to the peripheral area. By classifying the light propagated from the inside of the lens to the light emitting surface, different types of light are emitted to different areas. Since the light propagated from the light incident surface to the light emitting surface is emitted to the central area, the surface shape of the light emitting surface can be determined based on the surface shape of the light incident surface, the position of the target surface, and the brightness and size of the central area. And since the light propagated from the reflecting surface to the light emitting surface is emitted to the peripheral area, after the surface shape of the light emitting surface is determined, the surface shape of the reflecting surface can be determined based on the surface shape of the light emitting surface, the position of the target surface, and the brightness and size of the peripheral area.

[0049] Optionally, at least one of the light incident surface 10, the light emitting surface 20 and the reflecting surface 30 is a free-form surface. By designing the free-form surface, a light spot of any shape can be obtained.

[0050] In a possible implementation, the light incident surface 10 is a hemispherical surface, and the light emitting surface 20 and the reflecting surface 30 are both free-form surfaces. When the light incident surface 10 is a spherical surface, the light emitted by the light source at the center of the sphere can be incident into the lens basically along the radius direction of the spherical surface, and the optical path is relatively simple. On this basis, two free-form surfaces are designed as the reflecting surface 30 and the light emitting surface 20 to form a light spot of the desired brightness and shape, which is easy to achieve. In this way, each surface of the lens adopts a continuous and easy-to-process surface shape for light distribution, which is easy to manufacture.

[0051] Figure 4 Schematic diagram of the cross-sectional structure of the lens provided in the embodiment of the present application. Figure 4 As shown, the light incident surface 10 is a hemispherical surface, and the light source 2 is arranged at the center of the hemispherical surface.

[0052] For example, the divergence angle of the light source 2 may be ±90°, and the light source intensity distribution obeys the Lambertian distribution. The emission angle of the light source 2 is less than or equal to the angle threshold. The light of light 2 directly exits from the light exiting surface 20 after passing through the light incident surface 10, and this part of the light exits to the target surface 40 to form the central area of ​​the light spot. The light passes through the light incident surface 10 and reaches the reflecting surface 20 first, and then is emitted from the light emitting surface 20 after being reflected by the reflecting surface 20. This part of the light is emitted to the peripheral area of ​​the target surface 40, thereby obtaining a light spot with a brighter central area and a darker peripheral area.

[0053] In some examples, the light source 2 may be a square LED surface light source, and the side length of the square may be set as required, such as 1.5 mm.

[0054] Figure 4 In the figure, the target plane 40 is perpendicular to the optical axis (coinciding with the z-axis) of the light source 2. Assuming that the target plane is the plane where the car window is located, and the size of the car window of a conventional car is about 1m, the light spot can be set to a square with a side length greater than 1m, for example, a square with a side length of 1.6m. Among them, the square with a side length of 1m in the middle is the central area, and the part outside the central area is the peripheral area.

[0055] The surface design process of the light emitting surface 20 and the reflecting surface 30 is described below.

[0056] Light emitting surface 20:

[0057] (1) Set the optical path structure of the free-form surface lens, the divergence angle and intensity distribution of the light source, the shape of the light spot, the illumination distribution, and the angle threshold

[0058] The optical path structure includes the following contents: the light incident surface 10 is a hemispherical surface, the light emitting surface 20 and the reflecting surface 30 are both free-form surfaces, the light source 2 is located at the center of the light incident surface 10, the initial vertex positions of the light emitting surface 10 and the reflecting surface 30, and the z-axis distance from the target surface 40 to the coordinate origin.

[0059] The light spot includes a central area and a peripheral area, the central area is rectangular, and the outer contour of the peripheral area is also rectangular. The center of the central area coincides with the center of the peripheral area, and the outer contour of the peripheral area is similar to that of the central area.

[0060] The size of is set manually according to the specific design. In the embodiment of the present application, Greater than 0° and less than 90°. In some examples, It can be 30°-70°, for example, 35°, 40°, 45°, 50°, 60°, 68°, etc. When the light emitted by the light source has an angle less than When the light emitted by the light source 2 has an angle greater than When , it is considered to be a light ray emitted at a larger angle, which is reflected by the reflection 30 and then emitted through the light emitting surface 20.

[0061] (2) Establish a rectangular coordinate system xyz with light source 2 as the coordinate origin.

[0062] Assume that vector P is the position vector of point P in the light-emitting surface 20; vector T is the position vector of point T in the target surface 40. According to the law of refraction O=n×I+P1×N, the unit direction vector O of the outgoing light is obtained. x ,O y ,O z ), and establish the coordinate relationship between point P and point T:

[0063]

[0064] Among them, t x ,t y and t z is the three-axis coordinate of point T; P x , P y and P z are the three components of the position vector P; x , O y and O z are the three components of the unit direction vector O of the outgoing light at point P; N is the unit normal (i.e., unit normal vector) of the free-form surface (i.e., the light-emitting surface 20) at point P, Angle α is the angle between vector I and vector N; n is the refractive index of the material used for the lens, and the medium surrounding the lens is air.

[0065] (3) According to formula (1), the following coordinate transformation relationship is obtained:

[0066]

[0067] In formula (2), J(T) is the Jacobi matrix of the position vector T; θ represents the angle between the projection of point P in the xy plane and the line connecting the origin of the coordinate system and the x-axis. Represents the angle between the line connecting point P and the coordinate origin and the z-axis.

[0068] (4) According to the law of conservation of local energy, if energy loss is not considered, then all the energy of any thin light beam emitted by the light source is transmitted to the target illumination area (here, the central area) on the target surface after being deflected by the free-form surface (light-emitting surface 20), and the following energy relationship exists:

[0069]

[0070] In formula (3), is the intensity distribution of the light source. After the light source is selected, It can be obtained by measurement; E(t x ,t y ) is the illumination distribution of the central area on the target surface, is the setting parameter; J(T) is the Jacobi matrix of the position vector T, obtained by formula (2); 0≤θ≤2π, in, is the angle of incidence of the light emitted from the light source.

[0071] (5) In order to ensure that the boundary light of the light beam is incident on the boundary of the illumination area on the target surface after being deflected by the free-form surface, the following boundary conditions must be met:

[0072]

[0073] Among them, Ω1 represents the total solid angle of the light beam incident on the light-emitting surface, Ω2 represents the central area, and are the boundaries of regions Ω1 and Ω2 respectively; ρ represents the distance from point P to the origin of the coordinate system; ρ θ represents the first-order partial derivative of ρ with respect to the angle θ, Denotes ρ with respect to the angle The first-order partial derivative of .

[0074] (6) Formulas (3) and (4) are solved jointly to obtain a set of first discrete data points. A free-form surface can be obtained by performing surface fitting on the set of first discrete data points. The free-form surface is the light incident surface 20.

[0075] When implementing, it is necessary to discretize the region Ω1 where the light beam incident on the light-emitting surface is located to obtain a set of discrete grid points, and each grid point corresponds to a partial differential equation; then, according to the partial differential equation, formulas (3) and (4) are converted into a nonlinear equation group; finally, the nonlinear equation group is solved using Newton's method to obtain the first discrete data point of the group.

[0076] That is, the surface shape of the light emitting surface 20 is obtained by fitting a plurality of first discrete data points, and the plurality of first discrete data points are obtained by solving the aforementioned formulas (3) and (4).

[0077] After obtaining the free-form surface corresponding to the light incident surface 20, the surface shape of the reflecting surface 30 is determined based on the surface shape of the light incident surface 20:

[0078] (1) Let vector is the position vector of point Q in the reflecting surface 20; vector T2(t x2 ,t y2 , t z ) is the position vector of point T2 in the target surface 40, I1 is the unit direction vector of the light emitted by the light source, and according to the reflection law in vector form -n×O1=n×I1+P1×N1, the unit direction vector O1=(O x1 ,O y1 ,O z1 ), where O x1 , O y1 and O z1 are the three components of the unit direction vector O1 of the outgoing light at point P; N1 is the unit normal (i.e., unit normal vector) of the free-form surface (i.e., the reflection surface 20) at point Q, Angle α is the included angle between vector I1 and vector N1; n is the refractive index of the material used for the lens, and the medium surrounding the lens is air.

[0079] Assume that N2 is the unit normal of the light emitting surface 20 at point M (i.e., the unit normal vector), and according to the law of refraction O2=n×O1+P1×N2, the unit direction vector O2=(O x2 ,O y2 ,O z2 ) and establish the coordinate relationship between point Q and point T2:

[0080]

[0081] (2) According to formula (5), the following coordinate transformation relationship is obtained:

[0082]

[0083] In formula (6), J(T2) is the Jacobi matrix of position vector T2.

[0084] (3) According to the law of conservation of local energy, if energy loss is not considered, then all the energy of any thin light beam emitted by the light source is transmitted to the target illumination area (here, the peripheral area) on the target surface after being deflected by the reflecting surface 20 and the light emitting surface 20, and the following energy relationship exists:

[0085]

[0086] In formula (7), is the intensity distribution of the light source, E(t x2 ,t y2 ) is the illumination distribution of the peripheral area on the target surface, J(T2) is the Jacobi matrix of the position vector T2; 0≤θ≤2π, in, is the light's angle of incidence, is the maximum divergence angle of the light source.

[0087] (4) In order to ensure that the boundary light of the light beam is incident on the boundary of the illumination area on the target surface after being deflected by the free-form surface, the following boundary conditions must be met:

[0088]

[0089] Among them, θ represents the angle between the projection of point Q in the xy plane and the line connecting the origin of the coordinate system and the x-axis, represents the angle between the line connecting point Q and the origin of the coordinate system and the z-axis, and ρ represents the distance from point Q to the origin of the coordinate system; θ represents the first-order partial derivative of ρ with respect to the angle θ, Denotes ρ with respect to the angle The first-order partial derivative of , point Q is a point on the reflection surface, Ω1 represents the total solid angle of the light beam incident on the reflection surface, Ω2 represents the peripheral area, and are the boundaries of regions Ω1 and Ω2 respectively.

[0090] (5) Formulas (7) and (8) are solved jointly to obtain a set of second discrete data points. A free-form surface can be obtained by performing surface fitting on the set of second discrete data points. The free-form surface is the reflection surface 20.

[0091] That is, the surface shape of the reflecting surface 20 is obtained by fitting a plurality of second discrete data points, and the plurality of second discrete data points are obtained by solving the aforementioned formulas (7) and (8).

[0092] Optionally, the lens 1 may be formed by injection molding or the like. Optionally, the material of the lens 1 includes but is not limited to polymethyl methacrylate (PMMA) or organic glass or the like.

[0093] The embodiment of the present application also provides a light emitting device. The light emitting device includes a first light emitting unit, the first light emitting unit includes a first light source and a first lens. The first lens is any of the above lenses, and the first light source is located in a light source accommodating cavity formed by a light incident surface of the first lens.

[0094] Optionally, the first light source includes but is not limited to LED, etc. LED has low power consumption and high brightness, which is conducive to reducing costs.

[0095] In some examples, the light emitting device may be a fill light of a camera device. Optionally, the fill light may be built into the camera device, or may be externally mounted near the camera device.

[0096] The embodiments of the present application do not limit the application scenarios of the light-emitting device. For example, it can be applied to scenarios such as electronic police, vehicle identification at barriers, or pedestrian identification; for another example, it can also be applied to exhibit lighting scenarios, etc.

[0097] Optionally, the light emitting device further comprises a second light emitting unit. The second light emitting unit comprises a second light source and a second lens, and the second lens is any of the aforementioned lenses. The second light source is located in a receiving cavity of the second lens. The light spot formed by the first light emitting unit and the light spot formed by the second light emitting unit are arranged sequentially on the target surface. Optionally, the second light source includes but is not limited to an LED, etc.

[0098] When the target object passes through the illumination area of ​​the first light-emitting unit and the illumination area of ​​the second light-emitting unit in sequence, the first light-emitting unit and the second light-emitting unit can be controlled to emit light in sequence according to the position of the target object to avoid light pollution caused by the first light-emitting unit and the second light-emitting unit emitting light at the same time.

[0099] Optionally, the light emitting device further comprises a third light emitting unit, the structure of the third light emitting unit is the same as that of the first light emitting unit, and the light spot formed by the third light emitting unit, the light spot formed by the first light emitting unit and the light spot formed by the second light emitting unit are arranged in sequence along the same direction on the target surface.

[0100] This lighting device including multiple light-emitting units is particularly suitable for electronic police scenarios. Figure 5 Schematic diagram of an application scenario of a light emitting device provided in an embodiment of the present application. Figure 5 As shown, the camera device C is set on the electric pole A. The camera device C includes the aforementioned light-emitting device including multiple light-emitting units. The light spots of the multiple light-emitting units are along the direction of vehicle travel (for example Figure 5 During the driving process of vehicle B, it will approach the electric pole A from far to near. In this case, each light-emitting unit is controlled to emit light in sequence according to the current position of the vehicle, and the camera device is controlled to shoot at the same time.

[0101] Unless otherwise defined, the technical or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which this application belongs. The words "first", "second", "third" and similar terms used in the patent application specification and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one" or "one" do not indicate a quantitative limitation, but indicate the existence of at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprises" include the elements or objects listed after "include" or "comprises" and their equivalents, and do not exclude other elements or objects. "A and / or B" means that there are the following three situations: the first, A; the second, B; the third, A and B.

[0102] The above is only an embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A lens, characterized in that: The lens comprises: a light incident surface, a light emitting surface and a reflective surface, wherein the light incident surface is a concave surface for forming a light source accommodating cavity, the light emitting surface is opposite to the light incident surface, the reflective surface surrounds the light incident surface and the light emitting surface, and is connected between the light incident surface and the light emitting surface, and the light incident surface, the light emitting surface and the reflective surface are all curved surfaces; The light incident surface, the reflection surface and the light emitting surface are configured to form a light spot on a target surface based on the light emitted by the light source, the light spot includes a central area and a peripheral area, the peripheral area surrounds the central area, and the brightness of the central area is uniform and greater than the brightness of the peripheral area.

2. The lens according to claim 1, characterized in that The light incident surface is a spherical surface, and the reflection surface and the light emitting surface are both free-form surfaces.

3. The lens according to claim 1 or 2, characterized in that: The light emitting surface is configured to emit the light propagating from the light incident surface to the light emitting surface to the central area, and to emit the light propagating from the reflection surface to the light emitting surface to the peripheral area.

4. The lens according to claim 3, characterized in that The surface shape of the light emitting surface is obtained by fitting a plurality of first discrete data points, and the plurality of first discrete data points are obtained by solving the following formula: Among them, E(tx,ty) is the illumination distribution of the central area on the target surface, tx is the x-coordinate of point T on the target surface, ty is the y-coordinate of point T on the target surface, J(T) is the Jacobian matrix of the position vector T of point T, is the intensity distribution of the light source, where 0≤θ≤2π, is the set angle threshold, θ represents the angle between the projection of point P in the xy plane and the line connecting the origin of the coordinate system and the x-axis, represents the angle between the line connecting point P and the origin of the coordinate system and the z-axis, ρ represents the distance from point P to the origin of the coordinate system; ρθ represents the first-order partial derivative of ρ with respect to the angle θ, Denotes ρ with respect to the angle The first-order partial derivative of , point P is a point on the light-emitting surface; Ω1 represents the total solid angle of the light beam incident on the light-emitting surface, Ω2 represents the central area, and are the boundaries of regions Ω1 and Ω2 respectively.

5. The lens according to claim 4, characterized in that: The surface shape of the reflecting surface is obtained by fitting a plurality of second discrete data points, and the plurality of second discrete data points are obtained by solving the following formula: Among them, E(tx2,ty2) is the illumination distribution of the peripheral area on the target surface, tx2 is the x-coordinate of point T2 on the target surface, ty2 is the y-coordinate of point T2 on the target surface, J(T2) is the Jacobian matrix of the position vector T of point T2, is the intensity distribution of the light source, where 0≤θ≤2π, is the set angle threshold, θ represents the angle between the projection of point Q in the xy plane and the line connecting the origin of the coordinate system and the x-axis, represents the angle between the line connecting point Q and the origin of the coordinate system and the z-axis, ρ represents the distance from point Q to the origin of the coordinate system; ρθ represents the first-order partial derivative of ρ with respect to the angle θ, Denotes ρ with respect to the angle The first-order partial derivative of , point Q is a point on the reflection surface; Ω1 represents the total solid angle of the light beam incident on the reflection surface, Ω2 represents the peripheral area, and are the boundaries of regions Ω1 and Ω2 respectively.

6. The lens according to any one of claims 1 to 2 and claims 4 to 5, characterized in that: The central area and the peripheral area are both rectangular, and the centers of the central area and the peripheral area coincide with each other.

7. The lens according to claim 6, characterized in that In a direction outward from the center of the peripheral area, the brightness of the peripheral area decreases monotonically from the brightness of the central area to a set percentage of the brightness of the central area.

8. A light emitting device, characterized in that: The light emitting device comprises a first light emitting unit, the first light emitting unit comprises a first light source and a first lens, the first lens is the lens as claimed in any one of claims 1 to 7, and the first light source is located in a receiving cavity of the first lens.

9. The light emitting device according to claim 8, characterized in that: The light source includes a light emitting diode.

10. The light emitting device according to claim 8, characterized in that: The light emitting device further comprises a second light emitting unit, the second light emitting unit comprises a second light source and a second lens, the second lens is the lens according to any one of claims 1 to 7, and the second light source is located in the accommodating cavity of the second lens; Wherein, the light spot formed by the first light emitting unit and the light spot formed by the second light emitting unit are arranged in sequence on the target surface.

11. The light emitting device according to claim 8, characterized in that: The light emitting device is a fill light of the camera equipment.

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