Projection welcome lamp based on super lens

Abstract

The invention relates to a projection welcome lamp based on a super lens, which belongs to the field of optical lenses and comprises a light source, an illumination lens, a projection sheet and a projection lens which are sequentially arranged from the light source to a projection surface along an optical axis, the illumination lens comprises a first lens and a second lens; the projection lens comprises a third lens, a fourth lens and a fifth lens; wherein at least one of the first lens, the second lens, the third lens, the fourth lens and the fifth lens is a metasurface lens, and the rest are aspheric lenses. According to the technical scheme of folding and super mixing, the five-piece type design is adopted, and the design of the greeting lamp with high-brightness projection is achieved through the combination of at least one super lens and a traditional aspheric lens.

Description

Technical Field

[0001] This invention belongs to the field of optical lenses, and specifically relates to a projection welcome light based on a superlens. Background Technology

[0002] Welcome lights are a type of lighting decoration equipment commonly used in hotels, shopping malls, automobiles, and other venues. They project logos, patterns, or text onto the ground through a light source and lens to illuminate paths or key areas and promote brand image.

[0003] Common welcome lights typically consist of several parts: a light source, an illumination lens, a slide, and a projection lens. The illumination lens and projection lens are often composed of plastic aspherical lenses, resulting in a long overall length, low projection brightness, and a tendency to deform at high temperatures, leading to performance degradation and a reduced lifespan. Summary of the Invention

[0004] This application provides a projection welcome light based on a superlens to at least solve the above-mentioned technical problems existing in the prior art.

[0005] This application provides a projection welcome light based on a superlens, including a light source, an illumination lens, a slide, and a projection lens arranged sequentially along the optical axis from the light source to the projection surface;

[0006] The illumination lens includes a first lens and a second lens, and the projection lens includes a third lens, a fourth lens, and a fifth lens;

[0007] Among them, at least one of the first lens, second lens, third lens, fourth lens and fifth lens is a metasurface lens, and the rest are aspherical lenses;

[0008] The projection welcome light design meets the following requirements:

[0009] 350mm≤L≤600mm

[0010] 45°≤α≤90°

[0011] Where L is the projection distance, defined as the distance from the center of the optical axis of the fifth lens away from the light source surface to the center of the projection surface, and α is the projection angle, defined as the angle between the center of the optical axis of the fifth lens away from the light source surface and the projection surface.

[0012] In one possible implementation, the illumination lens satisfies:

[0013]

[0014] Wherein, FOV1 is the divergence angle of the light source, TTL1 is the total length of the illumination lens, defined as the distance from the light source to the center of the optical axis of the second lens away from the light source surface, and D1 is the diameter of the light-emitting surface of the light source.

[0015] In one possible implementation, the projection lens satisfies:

[0016]

[0017] Where FOV2 is the field of view of the projection lens, TTL2 is the total length of the projection lens, defined as the distance from the projection sheet to the center of the optical axis of the fifth lens away from the light source surface, and D2 is the diameter of the projection sheet.

[0018] In one embodiment, the light source is an LED light source.

[0019] In one embodiment, the divergence angle of the light source satisfies FOV1 ≥ 80°.

[0020] In one embodiment, the field of view of the projection lens satisfies FOV2≤20°.

[0021] In one embodiment, the aperture number of the projection welcome light satisfies 1.6≤Fno≤2.4.

[0022] In one embodiment, the first lens is a metasurface lens, and the second, third, fourth, and fifth lenses are aspherical lenses.

[0023] In one embodiment, the first lens is a metasurface lens with positive optical power, having microstructures arranged near the light source and a flat surface away from the light source; the second lens is a lens with positive optical power, having a convex surface near the optical axis near the light source and a convex surface away from the light source; the third lens is a lens with negative optical power, having a concave surface near the optical axis near the light source and a convex surface away from the light source; the fourth lens is a lens with negative optical power, having a convex surface near the optical axis near the light source and a concave surface away from the light source; and the fifth lens is a lens with positive optical power, having a convex surface near the optical axis near the light source and a convex surface away from the light source.

[0024] In one embodiment, the aspherical lens is made of resin material, which has high transmittance of visible light.

[0025] This application adopts a hybrid technology solution to achieve a high-brightness projection welcome light design, while compressing the overall optical length, realizing miniaturization and thinning, and improving the service life of the welcome light design. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the projection welcome light based on a superlens in Embodiment 1 of this application;

[0027] Figure 2 This is a schematic diagram of the MTF of the projection welcome light based on the superlens in Embodiment 1 of this application;

[0028] Figure 3 This is a distortion diagram of the projection welcome light based on a superlens in Embodiment 1 of this application;

[0029] Figure 4 This is a schematic diagram of the projection spot of the projection welcome light based on the superlens in Embodiment 1 of this application;

[0030] Figure 5 These are schematic diagrams (left) and original images (right) of the projection welcome light based on a superlens in Embodiment 1 of this application;

[0031] Figure 6 This is a schematic diagram of the projection welcome light based on a superlens in Embodiment 2 of this application;

[0032] Figure 7 This is a schematic diagram of the MTF of the projection welcome light based on the superlens in Embodiment 2 of this application;

[0033] Figure 8 This is a distortion diagram of the projection welcome light based on a superlens in Embodiment 2 of this application;

[0034] Figure 9 This is a schematic diagram of the projection spot of the projection welcome light based on the superlens in Embodiment 2 of this application;

[0035] Figure 10 These are schematic diagrams (left) and original images (right) of the projection welcome light based on a superlens in Embodiment 2 of this application;

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Light source; 2. Illumination lens; 21. First lens; 22. Second lens; 3. Slide; 4. Projection lens; 41. Third lens; 42. Fourth lens; 43. Fifth lens. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings.

[0039] In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0040] The welcome light of this application adopts a super-refractive hybrid design. By utilizing the light intensity control capability of the super lens and combining it with a traditional lens, the super-refractive hybrid system can shorten the overall system length, improve projection brightness, and is more resistant to high temperatures and has a longer service life. It is more suitable for working in high-temperature scenarios where miniaturization and thinning of components are required.

[0041] This application discloses a projection welcome light based on a metalens, comprising a light source 1, an illumination lens 2, a slide 3, and a projection lens 4 arranged sequentially along the optical axis from the light source to the projection surface. The illumination lens 2 includes a first lens 21 and a second lens 22, and the projection lens 4 includes a third lens 41, a fourth lens 42, and a fifth lens 43. At least one of the first lens 21, second lens 22, third lens 41, fourth lens 42, and fifth lens 43 is a metasurface lens. The metasurface lens can replace an aspherical lens. By using at least one metasurface lens in the design of the projection welcome light based on a metalens, the projection brightness and clarity can be improved, the overall length shortened, and the service life increased.

[0042] Specifically, the working wavelength of the projection welcome light in this application is visible light. The aspherical lens is made of resin material, which has high transmittance in visible light, such as EP4000, EP5000, EP6000, EP7000, OKP4, APL5514, APL5014, etc. The metasurface lens can be made of materials such as Silica and D263TECO.

[0043] The metasurface lens consists of a substrate and micro / nanostructures disposed on the substrate. Each micro / nanostructure has a specific shape, size, and arrangement to achieve precise control over the phase, amplitude, or polarization state of the incident light wave. Through the design of the micro / nanostructures, the metalens can achieve optical performance comparable to or even better than that of traditional lenses while maintaining a thin and light volume, such as high transmittance, low chromatic aberration, and low distortion. The period of the micro / nanostructures of the first lens 21 ranges from 280 to 500 nm, and the optimal period is selected as 320 nm in this embodiment; the height of the micro / nanostructures ranges from 500 to 1500 nm, and the optimal height is selected as 1000 nm in this embodiment; the diameter of the micro / nanostructures covers 100 to 240 nm, the material is titanium dioxide, and they are arranged in square, regular hexagonal, and other shapes.

[0044] The design of the projection welcome light based on a superlens satisfies the following conditions: 350mm≤L≤600mm; 45°≤α≤90°, where L is the projection distance, defined as the distance from the center of the optical axis of the fifth lens 43 away from the light source surface to the center of the projection surface; α is the projection angle, defined as the angle between the center of the optical axis of the fifth lens 43 away from the light source surface and the projection surface; the illumination lens of the projection welcome light design based on a superlens satisfies the following conditions: Where FOV1 is the divergence angle of the light source, TTL1 is the total length of the illumination lens 2, defined as the distance from the light source to the center of the optical axis of the second lens 22 away from the light source surface, and D1 is the diameter of the light-emitting surface of the light source; the projection lens of the projection welcome light based on the superlens is designed to meet the following requirements: Wherein, FOV2 is the field of view of the projection lens, TTL2 is the total length of the projection lens, defined as the distance from the projection sheet to the center of the optical axis of the fifth lens 43 away from the light source surface, and D2 is the diameter of the projection sheet.

[0045] The projection welcome light design based on a superlens uses an LED light source, which can meet various color requirements and has an operating temperature of -40℃ to 85℃. The divergence angle of the light source 1 meets FOV1≥80°, and the field of view of the projection lens 4 meets FOV2≤20° to control the size of the projected pattern. The illumination lens 2 and the projection lens 4 are jointly optimized, and the aperture number of the projection welcome light meets 1.6≤Fno≤2.4, thereby ensuring the projection brightness.

[0046] As one feasible implementation, the first lens 21 is a metasurface lens, and the remaining lenses are aspherical lenses, as detailed below:

[0047] The first lens 21 is a superlens with positive optical power, having microstructures arranged near the light source and a flat surface away from the light source; the second lens 22 is a lens with positive optical power, having a convex surface near the optical axis near the light source and a convex surface away from the light source; the third lens 41 is a lens with negative optical power, having a concave surface near the optical axis near the light source and a convex surface away from the light source; the fourth lens 42 is a lens with negative optical power, having a convex surface near the optical axis near the light source and a concave surface away from the light source; the fifth lens 43 is a lens with positive optical power, having a convex surface near the optical axis near the light source and a convex surface away from the light source.

[0048] like Figure 1 As shown, the light emitted by the light source 1 passes through the first lens 21 and the second lens 22, illuminates the projection sheet 3, then passes through the third lens 41, the fourth lens 42 and the fifth lens 43, and is finally projected onto the projection surface at a specified distance and angle.

[0049] Example 1

[0050] For example, Table 1 details the specific optical data parameters of each lens in the projection welcome light design based on a superlens provided in the embodiments of the present invention, according to a feasible implementation. The optical data parameters in Table 1 correspond to... Figure 1 The image shows a projection welcome light design based on a superlens.

[0051] Among them, the first lens 21 is a superlens with positive optical power, which has microstructures arranged near the light source and is flat away from the light source; the second lens 22 is a lens with positive optical power, which is convex near the optical axis near the light source and convex away from the light source; the third lens 41 is a lens with negative optical power, which is concave near the optical axis near the light source and convex away from the light source; the fourth lens 42 is a lens with negative optical power, which is convex near the optical axis near the light source and concave away from the light source; and the fifth lens 43 is a lens with positive optical power, which is convex near the optical axis near the light source and convex away from the light source.

[0052] The parameters of each surface in the superlens-based projection welcome light design provided in Example 1 are shown in Table 1.

[0053] Table 1

[0054]

[0055] The surface numbers are assigned according to the order of the lenses. For example, surface number 1 represents the side of the first lens 21 closest to the light source, surface number 2 represents the side of the first lens 21 furthest from the light source, and so on. Surface number 0 represents the light source, surface number 5 represents the slide, and surface number 12 represents the projection surface. The radius of curvature represents the degree of curvature of the lens surface near the optical axis. A positive value indicates that the surface bends away from the light source, and a negative value indicates that the surface bends closer to the light source. "Infinity" indicates that the surface is flat. The spacing represents the axial distance between the current surface and the next surface. Both the radius of curvature and the spacing are in millimeters (mm). The angle represents the angle between the current surface and the previous surface, in degrees (°), with 0° indicating parallelism. The refractive index and Abbe number describe the material of each lens, and the focal length represents the effective focal length of each lens, in millimeters (mm).

[0056] Even-order aspherical surfaces satisfy the following equations:

[0057]

[0058] Where z is the distance from the even-order aspherical surface to its vertex along the optical axis, r is the height from the optical axis, c is the curvature, c = 1 / R, and R is the radius of curvature at the vertex of the lens; N is the number of polynomial coefficients in the series, k is the conic coefficient, and ai is the coefficient of the higher-order aspherical term.

[0059] For example, Table 2 details the conic coefficient k and higher-order coefficient ai of the aspherical lens surface in this embodiment with a feasible implementation.

[0060] Table 2

[0061]

[0062]

[0063] The phase of a binary surface is added by the following polynomial expansion:

[0064]

[0065] Where N is the number of polynomial coefficients in the series, Ai is the square coefficient of ρ, ρ is the normalized radial aperture coordinate, and M is the diffraction order.

[0066] For example, Table 3 details the binary surface coefficients of the superlens in this embodiment with a feasible implementation method.

[0067] Table 3

[0068]

[0069] Where R1 is the normalized radius of the binary surface.

[0070] In this embodiment, the projection distance L is 393mm, the projection angle α is 90°, the diameter D1 of the light-emitting surface of the light source is 1.46mm, the divergence angle FOV1 is 120°, the total length TTL1 of the illumination lens is 5.96mm, the diameter D2 of the slide is 4.4mm, the field of view FOV2 of the projection lens is 16.2°, and the total length TTL2 of the projection lens is 16.5mm.

[0071] Figure 2 This is a schematic diagram of the modulation transfer function (MTF) of the projection lens for a projection welcome light design based on a superlens provided in an embodiment of the present invention. The projection lens for a projection welcome light design based on a superlens provided in an embodiment of the present invention has an MTF value ≥ 0.45 in the entire field of view at 100 lp / mm, which meets the requirement of clear projection.

[0072] Figure 3 This is a distortion diagram of the projection lens for a projection welcome light design based on a superlens provided in an embodiment of the present invention. The projection lens for a projection welcome light design based on a superlens provided in an embodiment of the present invention has a distortion of less than 1.2% in the entire field of view in the working band, which meets the projection requirements.

[0073] Figure 4 The schematic diagram of the projection spot of the projection welcome light design based on the superlens provided in the embodiment of the present invention shows that the projection spot has uniform brightness and sharp edges.

[0074] Figure 5 The schematic diagram and original image of the projection image of the welcome light design based on the superlens provided in the embodiment of the present invention can be seen to show that the projection image is clear and has little distortion.

[0075] Example 2

[0076] For example, Table 4 details the specific optical data parameters of each lens in the projection welcome light design based on a superlens provided in the embodiments of the present invention, according to a feasible implementation. The optical data parameters in Table 4 correspond to... Figure 6 The image shows a projection welcome light design based on a superlens.

[0077] Among them, the first lens 21 is a superlens with positive optical power, which has microstructures arranged near the light source and is flat away from the light source; the second lens 22 is a lens with positive optical power, which is convex near the optical axis near the light source and convex away from the light source; the third lens 41 is a lens with negative optical power, which is concave near the optical axis near the light source and convex away from the light source; the fourth lens 42 is a lens with negative optical power, which is convex near the optical axis near the light source and concave away from the light source; and the fifth lens 43 is a lens with positive optical power, which is convex near the optical axis near the light source and convex away from the light source.

[0078] Table 4

[0079]

[0080] The surface numbers are assigned according to the order of the lenses. For example, surface number 1 represents the side of the first lens 21 closest to the light source, surface number 2 represents the side of the first lens 21 furthest from the light source, and so on. Surface number 0 represents the light source, surface number 5 represents the slide, and surface number 12 represents the projection surface. The radius of curvature represents the degree of curvature of the lens surface near the optical axis. A positive value indicates that the surface bends away from the light source, and a negative value indicates that the surface bends closer to the light source. "Infinity" indicates that the surface is flat. The spacing represents the axial distance between the current surface and the next surface. Both the radius of curvature and the spacing are in millimeters (mm). The angle represents the angle between the current surface and the previous surface, in degrees (°), with 0° indicating parallelism. The refractive index and Abbe number describe the material of each lens, and the focal length represents the effective focal length of each lens, in millimeters (mm).

[0081] Even-order aspherical surfaces satisfy the following equations:

[0082]

[0083] Where z is the distance from the even-order aspherical surface to its vertex along the optical axis, r is the height from the optical axis, c is the curvature, c = 1 / R, and R is the radius of curvature at the vertex of the lens; N is the number of polynomial coefficients in the series, k is the conic coefficient, and ai is the coefficient of the higher-order aspherical term.

[0084] For example, Table 5 details the conic coefficient k and higher-order coefficient ai of the aspherical lens surface in this embodiment with a feasible implementation.

[0085] Table 5

[0086]

[0087] The phase of a binary surface is added by the following polynomial expansion:

[0088]

[0089] Where N is the number of polynomial coefficients in the series, Ai is the square coefficient of ρ, ρ is the normalized radial aperture coordinate, and M is the diffraction order.

[0090] For example, Table 6 details the binary surface coefficients of the superlens in this embodiment with a feasible implementation.

[0091] Table 6

[0092]

[0093] Where R1 is the normalized radius of the binary surface.

[0094] In this embodiment, the projection distance L is 500mm, the projection angle α is 52°, the diameter D1 of the light-emitting surface of the light source is 1.2mm, the divergence angle FOV1 is 100°, the total length TTL1 of the illumination lens is 5.7mm, the diameter D2 of the slide is 4.2mm, the field of view FOV2 of the projection lens is 13.2°, and the total length TTL2 of the projection lens is 18.4mm.

[0095] Figure 7 This is a schematic diagram of the modulation transfer function (MTF) of the projection lens for a projection welcome light design based on a superlens provided in an embodiment of the present invention. The projection lens for a projection welcome light design based on a superlens provided in an embodiment of the present invention has an MTF value ≥ 0.35 in the entire field of view at 100 lp / mm, which meets the requirement of clear projection.

[0096] Figure 8 This is a distortion diagram of the projection lens for a projection welcome light design based on a superlens provided in an embodiment of the present invention. The projection lens for a projection welcome light design based on a superlens provided in an embodiment of the present invention has a distortion of less than 0.3% in the entire field of view in the working band, which meets the projection requirements.

[0097] Figure 9 The schematic diagram of the projection spot of the projection welcome light design based on the superlens provided in the embodiment of the present invention shows that the projection spot has uniform brightness and sharp edges.

[0098] Figure 10The schematic diagram and original image of the projection image of the welcome light design based on the superlens provided in the embodiment of the present invention can be seen to show that the projection image is clear and has little distortion.

[0099] The optical system parameters of Examples 1 and 2 satisfy the relationship shown in Table 7, as detailed below:

[0100] Table 7

[0101]

[0102] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. An ultralens-based projection welcome light, characterized in that, The projection welcome lamp comprises, in sequence along an optical axis from a light source to a projection plane, a light source, an illumination lens, a projection film and a projection lens; The illumination lens comprises a first lens and a second lens, and the projection lens comprises a third lens, a fourth lens and a fifth lens; At least one of the first lens, the second lens, the third lens, the fourth lens and the fifth lens is a super surface lens, and the rest are aspherical lenses; The projection welcome lamp satisfies: 350mm≤L≤600mm 45°≤α≤90° wherein L is a projection distance, defined as a distance from a center of an optical axis of a surface far from the light source to a center of the projection plane, and a is a projection angle, defined as an angle between the center of the optical axis of the surface far from the light source and the projection plane.

2. The superlens-based projection welcome light according to claim 1, wherein, The illumination lens satisfies: wherein FOV1 is a divergence angle of the light source, TTL1 is a total length of the illumination lens, defined as a distance from the light source to a center of an optical axis of the second lens far from the light source, and D1 is a diameter of a light emitting surface of the light source.

3. The superlens-based projection welcome light of claim 1, wherein, The projection lens satisfies: wherein FOV2 is a field of view angle of the projection lens, TTL2 is a total length of the projection lens, defined as a distance from the projection film to a center of an optical axis of the fifth lens far from the light source, and D2 is a diameter of the projection film.

4. The superlens-based projection welcome light of claim 1, wherein: The light source is an LED light source.

5. The superlens-based projection welcome light of claim 2, wherein: The divergence angle of the light source satisfies FOV1≥80°.

6. The superlens-based projection welcome light of claim 3, wherein: The field of view angle of the projection lens satisfies FOV2≤20°.

7. The superlens-based projection welcome light of claim 1, wherein: An aperture number of the projection welcome lamp satisfies 1.6≤Fno≤2.

4.

8. The superlens-based projection welcome light of claim 1, wherein: The first lens is a super surface lens, and the second lens, the third lens, the fourth lens and the fifth lens are aspherical lenses.

9. The superlens-based projection welcome light of claim 8, wherein: The first lens is a super surface lens with positive focal length, which has a microstructure arrangement on a side close to the light source and is a plane on a side far from the light source; The second lens is a lens with positive focal length, which is a convex surface near an optical axis on a side close to the light source and is a convex surface near an optical axis on a side far from the light source; The third lens is a lens with negative focal length, which is a concave surface near an optical axis on a side close to the light source and is a convex surface near an optical axis on a side far from the light source; The fourth lens is a lens with negative focal length, which is a convex surface near an optical axis on a side close to the light source and is a concave surface near an optical axis on a side far from the light source; The fifth lens is a lens with positive focal length, which is a convex surface near an optical axis on a side close to the light source and is a convex surface near an optical axis on a side far from the light source.

10. The superlens-based projection welcome light of claim 1, wherein: The material of the aspherical lens is selected from resin materials, which has high transparency in visible light.

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