Car lamp
By using a collimating module composed of spherical and aspherical lenses and a projection lens with a specific optical focal length distribution in car lights, the problems of low brightness and dark corners of DLP car lights are solved, achieving brightness improvement and cost optimization.
Patent Information
- Application Number
- CN202422630632.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-09-12
- Estimated Expiration
- 2034-10-30
AI Technical Summary
Existing headlights based on DLP technology have low brightness, obvious dark corners in the four corners of the projected image, and high development costs.
The collimation module consists of spherical and aspherical lenses, all of which are glass lenses. The specific optical focal length distribution and flip angle design of the reflector and projection lens are combined to increase the projection spot and reduce vignetting. The use of glass lenses improves transmittance, optimizes brightness and costs.
It improves the brightness of car lights, reduces dark corners, reduces development costs, and achieves more efficient light energy utilization and clearer projection effects.
Smart Images
Figure CN223331546U_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of projection lenses, and in particular relates to a vehicle lamp. Background Art
[0002] Common projection technologies mainly include Digital Light Processing (DLP) technology, Liquid Crystal on Silicon (LCOS) technology and Liquid Crystal Display (LCD) technology; among them, DLP technology is widely used in car lights, making the lighting of car lights more precise and controllable, and has obvious optimization in terms of reliability, brightness and number of pixels.
[0003] However, existing headlights based on DLP technology generally have problems such as low brightness, obvious dark corners in the four corners of the projected image, and high development costs. Utility Model Content
[0004] In view of this, an embodiment of the present application provides a car lamp, which aims to solve the problems of existing DLP technology-based car lamps, such as low brightness, obvious dark corners in the four corners of the projected image, and high development costs.
[0005] An embodiment of the present application provides a vehicle lamp, comprising a light source, a collimating module, a reflector, a digital micromirror array, and a projection lens arranged in sequence along a light path;
[0006] The collimating module is composed of a spherical lens and an aspherical lens, and all lenses in the collimating module and the projection lens are glass lenses;
[0007] The light beam emitted by the light source is sequentially converged and collimated by the collimation module, reflected by the reflector, and reflected by the digital micromirror array before being incident on the projection lens. The projection lens projects a pattern on the digital micromirror array to form a projection spot.
[0008] In one embodiment, the collimating module includes a first positive power spherical lens and a first positive power aspherical lens.
[0009] In one embodiment, the flip angle range of the normal of the reflector relative to the main optical axis of the collimating module is 27° to 33°, the flip angle range of the normal of the digital micromirror array relative to the main optical axis of the projection lens is -12° to +12°, and the aperture of the projection lens is 1.3.
[0010] In one embodiment, the optical power distribution of the projection lens is "positive-negative-positive", and all lenses in the projection lens are spherical lenses.
[0011] In one embodiment, at least one negative power lens in the projection lens has an Abbe number lower than or equal to 32.
[0012] In one embodiment, the projection lens includes a second positive power spherical lens, a third positive power spherical lens, a fourth negative power spherical lens, a fifth negative power spherical lens, a sixth positive power spherical lens, and a seventh positive power spherical lens.
[0013] In one embodiment, the fifth negative power spherical lens and the sixth positive power spherical lens are bonded together to form a doublet lens.
[0014] In one embodiment, the refractive index of the fifth negative power spherical lens is higher than or equal to the first refractive index, and the Abbe number is lower than or equal to the first Abbe number;
[0015] The refractive index of the sixth positive power spherical lens is lower than or equal to the second refractive index, and the Abbe number is higher than or equal to the second Abbe number;
[0016] The first refractive index is higher than the second refractive index, and the first Abbe number is lower than the second Abbe number.
[0017] In one embodiment, the first refractive index is equal to 1.65, and the second refractive index is equal to 1.80;
[0018] The first Abbe number is equal to 60, and the second Abbe number is equal to 32.
[0019] In one embodiment, the vehicle lamp is a car headlight.
[0020] In the vehicle lamp provided in the embodiment of the present application, the collimating module is composed of a spherical lens and an aspheric lens. Since the aspheric lens has multiple variables, it is beneficial to converge and collimate the light beam emitted by the light source; all lenses in the collimating module and the projection lens are made of glass lenses with high transmittance, which is beneficial to improve the brightness and achieve cost and brightness optimization. While improving the brightness, the light spot projected at the digital micromirror array can be enlarged to reduce dark corners. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0022] Figure 1 is a schematic structural diagram of a vehicle lamp provided in an embodiment of the present application;
[0023] Figure 2 Schematic diagram of the structure of the collimation module provided in an embodiment of the present application;
[0024] Figure 3 1 is a schematic structural diagram of a projection lens provided in an embodiment of the present application;
[0025] Figure 4 This is a schematic diagram of the light path of a vehicle lamp provided in an embodiment of the present application;
[0026] Figure 5 Schematic diagram of the modulation transfer function of the digital micromirror array of the projection lens provided by an embodiment of the present application at a working distance of 10m and an operating temperature of 20°C;
[0027] Figure 6 Schematic diagram of the modulation transfer function of the digital micromirror array of the projection lens provided by an embodiment of the present application at a working distance of 10m and an operating temperature of 60°C;
[0028] Figure 7 Schematic diagram of the modulation transfer function of the digital micromirror array of the projection lens provided by an embodiment of the present application at a working distance of 10m and an operating temperature of 100°C;
[0029] Figure 8 This is a simulated schematic diagram of the projection spot of the vehicle light provided by an embodiment of the present application at a working distance of 10m;
[0030] Figure Number:
[0031] 1- Light source;
[0032] 2-collimation module, 21-first positive optical power spherical lens, 22-first positive optical power aspherical lens;
[0033] 3-reflector;
[0034] 4-digital micromirror array;
[0035] 5-projection lens, 51-second positive power spherical lens, 52-third positive power spherical lens, 53-fourth negative power spherical lens, 54-fifth negative power spherical lens, 55-sixth positive power spherical lens, 56-seventh positive power spherical lens. DETAILED DESCRIPTION
[0036] In order to help those skilled in the art better understand the present invention, the following will clearly describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.
[0037] The terms "comprising" and "including" and any variations thereof in the specification and claims of this application and the accompanying drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to the process, method, product, or device. In addition, the terms "first," "second," and "third," etc. are used to distinguish different objects, not to describe a specific order.
[0038] like Figure 1 As shown, this embodiment provides a vehicle lamp, comprising a light source 1, a collimating module 2, a reflector 3, a digital micromirror array (DMD) 4, and a projection lens 5, which are sequentially arranged along the light path.
[0039] The collimating module 2 is composed of a spherical lens and an aspherical lens, and all lenses in the collimating module 2 are glass lenses;
[0040] The light beam emitted by the light source is converged and collimated by the collimation module 2, reflected by the reflector 3, and reflected by the digital micromirror array 4 before entering the projection lens 5. The projection lens 5 projects the pattern on the digital micromirror array 4 to form a projection spot.
[0041] In application, the headlights may be applied to any vehicle, such as a car, a railway train, etc. When the vehicle is a car, the headlights may specifically be car headlights.
[0042] In applications, the light source may include at least one of a light-emitting diode (LED) light source, a laser light source, a halogen light source, and a xenon light source.
[0043] In application, the collimation module 2 is composed of a spherical lens and an aspheric lens. Since the aspheric lens has multiple variables, it is beneficial to converge and collimate the light beam emitted by the light source 1; all lenses in the collimation module 2 are made of glass lenses with high transmittance, which is beneficial to improve the brightness and achieve cost and brightness optimization. While improving the brightness, the light spot projected at the digital micromirror array 4 can be enlarged to reduce dark corners.
[0044] like Figure 2 As shown, in one embodiment, the collimating module 2 includes a first positive power spherical lens 21 and a first positive power aspherical lens 22 .
[0045] In one embodiment, the flip angle range of the normal of the reflector 3 relative to the main optical axis of the collimating module 2 is 27° to 33°, the flip angle range of the normal of the digital micromirror array 4 relative to the main optical axis of the projection lens 5 is -12° to +12°, and the aperture of the projection lens 5 is 1.3.
[0046] In application, the flip angle range of the normal of the digital micromirror array 4 relative to the main optical axis of the projection lens 5 is -12° to +12°. In order to improve the brightness, it is necessary to adjust the flip angle of the normal of the reflector 3 relative to the main optical axis of the collimation module 2 within the range of 27° to 33°, so that the incident angle of the light beam incident on the digital micromirror array 4 after reflection by the reflector 3 is extended to the range of 12° to 48° relative to the normal of the digital micromirror array 4. In this way, the light beam emitted from the digital micromirror array 4 is tilted relative to the main optical axis of the projection lens 5, and the aperture F# of the projection lens 5 needs to be set to 1.3 to receive the tilted light beam.
[0047] In one embodiment, the optical power distribution of the projection lens is “positive-negative-positive”, and all lenses in the projection lens are spherical lenses.
[0048] In practice, the small F# of projection lens 5 results in significant aperture aberration, particularly spherical aberration. By configuring the power distribution of projection lens 5 in a symmetrical "positive-negative-positive" pattern, vertical aberration can be effectively corrected. This "positive-negative-positive" symmetrical power layout originates from the Cooke triplet and double-Gauss lens design. This symmetry minimizes the positive and negative vertical aberrations, ultimately achieving optimal aberration balance. All lenses in projection lens 5 are spherical, reducing development costs.
[0049] like Figure 3 As shown, in one embodiment, the projection lens 5 includes a second positive power spherical lens 51, a third positive power spherical lens 52, a fourth negative power spherical lens 53, a fifth negative power spherical lens 54, a sixth positive power spherical lens 55 and a seventh positive power spherical lens 56.
[0050] In application, the "positive-negative-positive" optical focal length layout of the projection lens 5 is borne by 6 lenses. The optical focal length of each group is split by the lens to bear the light deviation angle to reduce aberrations, which can avoid the generation of high-order aberrations.
[0051] In one embodiment, the Abbe number of at least one negative power lens in the projection lens 5 is lower than or equal to 32.
[0052] In application, the use of a low Abbe number negative power lens enables the projection lens 5 to have a more accurate and clear projection effect.
[0053] In one embodiment, the fifth negative power spherical lens 54 and the sixth positive power spherical lens 55 are cemented into a doublet lens.
[0054] In application, since the object and image sides of the projection lens 5 are not completely symmetrical, under the overall symmetrical pattern, local differentiation is achieved by lens splitting and gluing, which can better compensate for monochromatic aberration and chromatic aberration.
[0055] In application, each lens can also be split into two lenses with equivalent functions. The specific composition of each lens is not limited in the embodiments of the present application.
[0056] In one embodiment, the fifth negative-power spherical lens 54 has a refractive index (index of refraction, Nd) lower than or equal to the first refractive index and an Abbe number (Abbe, Vd) higher than or equal to the first Abbe number.
[0057] The refractive index of the sixth positive power spherical lens 55 is lower than or equal to the second refractive index, and the Abbe number is higher than or equal to the second Abbe number;
[0058] The first refractive index is lower than the second refractive index, and the first Abbe number is higher than the second Abbe number.
[0059] In practice, the fifth negative-power spherical lens 54 has a relatively high refractive index and a relatively low Abbe number, while the sixth positive-power spherical lens 55 has a relatively low refractive index and a relatively high Abbe number. The cemented structure of the two lens elements produces a significant achromatic effect, which helps reduce chromatic aberration in the projection lens 5. The first refractive index, second refractive index, first Abbe number, and second Abbe number can be set as needed, as long as the aforementioned relative size relationships are met.
[0060] In one embodiment, the first refractive index is equal to 1.65 and the second refractive index is equal to 1.80;
[0061] The first Abbe number is equal to 60, and the second Abbe number is equal to 32.
[0062] In one embodiment, the fifth negative-power spherical lens has a refractive index of 1.8052 and an Abbe number of 25.456.
[0063] The sixth positive power spherical lens has a refractive index of 1.603 and an Abbe number of 65.46.
[0064] like Figure 1 or Figure 4 As shown, in one embodiment, all lenses in the headlight are glass lenses;
[0065] The headlight includes, in order from the light source 1 side to the projection lens 5 side in the direction of the light path, a light source 1, a collimating module 2, a first positive power spherical lens 21, a first positive power aspherical lens 22, a reflector 3, a digital micromirror array 4, a projection lens 5, a second positive power spherical lens 51, a third positive power spherical lens 52, a fourth negative power spherical lens 53, a fifth negative power spherical lens 54, a sixth positive power spherical lens 55, and a seventh positive power spherical lens 56.
[0066] like Figures 5 to 7 , which exemplarily show the modulation transfer function (MTF) of the digital micromirror array of the projection lens at a working distance of 10m and operating temperatures of 20°C, 60°C, and 100°C; wherein the MTF observation line pair is 20lp / mm, the horizontal axis represents the spatial frequency in cycles per millimeter (cycles / mm), and the vertical axis represents the MTF value.
[0067] In applications, MTF represents the comprehensive resolving power of an optical system. The MTF value is used to evaluate the imaging quality of a lens, and its value range is 0 to 1. The higher and straighter the vertical axis of the MTF curve is, the better the imaging quality of the lens is, and the stronger its ability to restore the real image is. The better the degree of overlap of the curves of each field of view is, the better the consistency of the imaging quality is. Figures 5 to 7 It can be seen that in the visible light band, when the spatial frequency is 20lp / mm, the MTF of the entire field of view is ≥0.4, and the imaging quality is good.
[0068] In one embodiment, when the size of the digital micromirror array 4 is 0.55 inches and the aperture F# of the projection lens 5 is 1.3, the type, curvature radius, thickness, glass material, conic coefficient, and aspheric coefficient of each surface in the collimation module 2 are shown in Tables 1 and 2 below:
[0069] Table 1
[0070]
[0071]
[0072] Table 2
[0073] Aspheric coefficient a4 a6 a8 S5 1.53E-05 1.32E-06 -5.34E-10
[0074] In one embodiment, the size of the digital micromirror array 4 is 0.55 inches, and when the aperture F# of the projection lens 5 is 1.3, the type, curvature radius, thickness, and glass material of each surface of the projection lens 5 are shown in Table 3 below:
[0075] Table 3
[0076]
[0077]
[0078] like Figure 8 The figure shows a simulated schematic diagram of the projection spot of a headlight at a working distance of 10m. The numerical value in the figure is the intensity distribution of the light spot at the projection surface of 10m. By compromising the central illumination and the surrounding vignetting, and setting the low aperture F# of the projection lens 5, a headlight with high central brightness and no vignetting is finally obtained.
[0079] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.
Claims
1. A vehicle lamp, characterized in that: It includes a light source, a collimating module, a reflector, a digital micromirror array and a projection lens arranged in sequence along the optical path; The collimating module is composed of a spherical lens and an aspherical lens, and all lenses in the collimating module and the projection lens are glass lenses; The light beam emitted by the light source is sequentially converged and collimated by the collimation module, reflected by the reflector, and reflected by the digital micromirror array before being incident on the projection lens. The projection lens projects a pattern on the digital micromirror array to form a projection spot.
2. The vehicle lamp according to claim 1, wherein: The collimating module includes a first positive power spherical lens and a first positive power aspherical lens.
3. The vehicle lamp according to claim 1, wherein: The flip angle range of the normal line of the reflector relative to the main optical axis of the collimating module is 27° to 33°, the flip angle range of the normal line of the digital micromirror array relative to the main optical axis of the projection lens is -12° to +12°, and the aperture of the projection lens is 1.
3.
4. The vehicle lamp according to claim 1, wherein The optical power distribution of the projection lens is "positive-negative-positive", and all lenses in the projection lens are spherical lenses.
5. The vehicle lamp according to claim 4, wherein: At least one negative power lens in the projection lens has an Abbe number lower than or equal to 32.
6. The vehicle lamp according to claim 4, wherein: The projection lens includes a second positive power spherical lens, a third positive power spherical lens, a fourth negative power spherical lens, a fifth negative power spherical lens, a sixth positive power spherical lens and a seventh positive power spherical lens.
7. The vehicle lamp according to claim 6, wherein: The fifth negative power spherical lens and the sixth positive power spherical lens are bonded together to form a doublet lens.
8. The vehicle lamp according to claim 7, wherein: The refractive index of the fifth negative power spherical lens is higher than or equal to the first refractive index, and the Abbe number is lower than or equal to the first Abbe number; The refractive index of the sixth positive power spherical lens is lower than or equal to the second refractive index, and the Abbe number is higher than or equal to the second Abbe number; The first refractive index is lower than the second refractive index, and the first Abbe number is higher than the second Abbe number.
9. The vehicle lamp according to claim 8, wherein: The first refractive index is equal to 1.65, and the second refractive index is equal to 1.80; The first Abbe number is equal to 60, and the second Abbe number is equal to 32.
10. The vehicle lamp according to any one of claims 1 to 9, characterized in that: The vehicle lamp is a vehicle headlight.