A near-infrared low reflectance hud reflective film
Patent Information
- Application Number
- CN202522151872.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-11
- Publication Date
- 2026-08-28
- Estimated Expiration
- 2035-10-11
AI Technical Summary
[0004]然而，上述方案存在明显局限性，在镀膜工艺方面，冷光镜通常采用物理气相沉积(如磁控溅射或电子束蒸发)制备多层干涉膜系，其膜层数量多、厚度控制精度要求高，导致生产周期较长、能耗较大，多层膜结构在环境测试(如高温高湿、冷热冲击)中易因热膨胀系数不匹配出现附着力下降、膜裂或性能衰减问题
[0011]与现有技术相比，本实用新型包含6层膜层，结构简单实用，对可见光反射率高，同时在近红外波段(通常指800-2500nm)的光谱反射率被控制在20％以下；在HUD光学路径中，外界太阳光需依次经过两次反射后才能到达PGU，经此两次反射后，最终到达PGU的太阳光近红外能量将衰减至初始值的4％以下(计算方式：20％*20％＝4％)，这种对近红外能量的高效衰减能力，显著降低了因太阳光“倒灌”所引发的PGU温升效应，有效解决了PGU过热风险，提升了系统的热稳定性和可靠性；同时，镀有本实用新型反射膜的HUD反射镜能够满足在恒定湿热：温度设置85℃，湿度85％RH、保存1000H环测后百格不脱膜、膜裂，且能够满足在冷热冲击：-40℃、30min；105℃、30min(30S，500次)，环测后百格不脱膜、膜裂。
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Figure CN224696090U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of HUD technology, specifically to a near-infrared low-reflectivity HUD reflective film. Background Technology
[0002] In recent years, with the continuous improvement of automotive intelligence and digitalization, head-up display (HUD) systems have been increasingly widely used in vehicles. HUD systems effectively reduce driver eye movement and improve driving safety by projecting driving information onto a reflector in front of the driver's line of sight. As the core optical component of the HUD system, the reflector's performance directly affects the clarity, contrast, and environmental adaptability of the display.
[0003] Currently, the mainstream HUD reflector solution mainly adopts a composite scheme of AL reflector and cold mirror. AL reflector achieves high reflectivity through vacuum aluminum plating, but its high reflectivity in the near-infrared band can lead to heat accumulation in the projection system. Therefore, an additional cold mirror film layer is needed to suppress near-infrared light. Cold mirrors typically use multilayer dielectric film systems (such as TiO2 / SiO2) to achieve high visible light reflectivity and high near-infrared transmittance through interference effects.
[0004] However, the above-mentioned solutions have significant limitations. In terms of coating processes, cold optical mirrors typically use physical vapor deposition (such as magnetron sputtering or electron beam evaporation) to prepare multilayer interference films. This requires a large number of layers and high precision in thickness control, resulting in long production cycles and high energy consumption. Furthermore, multilayer film structures are prone to adhesion degradation, film cracking, or performance deterioration during environmental testing (such as high temperature and humidity, thermal shock), due to mismatched coefficients of thermal expansion. In addition, aluminum films are easily oxidized and corroded in humid and hot environments, leading to low performance in automotive-grade environmental resistance tests (such as high temperature and humidity, thermal shock, and salt spray resistance).
[0005] Therefore, there is an urgent need to develop a new type of reflective film for HUD mirrors that can further reduce near-infrared reflectivity while ensuring high visible light reflectivity, shorten coating time, improve environmental resistance, and control costs, so as to meet the demand of next-generation HUD systems for high-performance mirrors. Utility Model Content
[0006] The purpose of this invention is to provide a near-infrared low-reflectivity HUD reflective film.
[0007] This utility model provides the following technical solution:
[0008] This invention proposes a near-infrared low-reflectivity HUD reflective film, comprising a Cr film layer for coating on the HUD reflector, wherein a first SiO2 layer, a first Ti3O5 layer, a second SiO2 layer, a second Ti3O5 layer, and a third SiO2 layer are sequentially coated on the Cr film layer.
[0009] Furthermore, the thickness of the Cr film is 10 nm, the thickness of the first SiO2 layer is 70 nm, the thickness of the first Ti3O5 layer is 54 nm, the thickness of the second SiO2 layer is 100 nm, the thickness of the second Ti3O5 layer is 54 nm, and the thickness of the third SiO2 layer is 250 nm.
[0010] Furthermore, the refractive index of SiO2 in the HUD reflective film is 1.43-1.47; and the refractive index of Ti3O5 is 2.22-2.45.
[0011] Compared with existing technologies, this invention comprises six film layers, has a simple and practical structure, high visible light reflectivity, and its spectral reflectivity in the near-infrared band (typically 800-2500nm) is controlled below 20%. In the HUD optical path, external sunlight must undergo two reflections before reaching the PGU. After these two reflections, the near-infrared energy of the sunlight finally reaching the PGU will be attenuated to less than 4% of the initial value (calculated as 20% * 20% = 4%). This efficient attenuation of near-infrared energy... This significantly reduces the temperature rise effect of the PGU caused by the "backflow" of sunlight, effectively solving the risk of PGU overheating and improving the thermal stability and reliability of the system. At the same time, the HUD reflector coated with the reflective film of this invention can meet the requirements of constant humidity and heat: temperature setting 85℃, humidity 85%RH, storage for 1000 hours and 1000-grid test without film peeling or cracking. It can also meet the requirements of thermal shock: -40℃ for 30 minutes; 105℃ for 30 minutes (30 seconds, 500 times) and 1000-grid test without film peeling or cracking. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the film layer relationship of this utility model.
[0013] Figure 2 The reflectivity curve of this utility model is set at an incident angle of 8 degrees.
[0014] In the diagram, 00 is the HUD reflector; 1 is the Cr film layer; 2 is the first SiO2 layer; 3 is the first Ti3O5 layer; 4 is the second SiO2 layer; 5 is the second Ti3O5 layer; and 6 is the third SiO2 layer. Detailed Implementation
[0015] The following is in conjunction with the appendix Figure 1 The present invention will be further described below.
[0016] In one embodiment of this utility model, a near-infrared low-reflectivity HUD reflective film includes a Cr film layer 1 for deposition on a HUD reflector. The Cr film layer 1 is sequentially deposited with a first SiO2 layer 2, a first Ti3O5 layer 3, a second SiO2 layer 4, a second Ti3O5 layer 5, and a third SiO2 layer 6. This utility model contains 6 film layers. It eliminates the Al film design in the film system and introduces a metallic Cr film design. It uses high-refractive-index titanium pentoxide (Ti3O5) and low-refractive-index silicon dioxide (SiO2) to ensure high reflectivity for visible light and meet the requirements for low reflectivity in the near-infrared region.
[0017] In one embodiment of the present invention, the thickness of the Cr film layer 1 is 10 nm, the thickness of the first SiO2 layer 2 is 70 nm, the thickness of the first Ti3O5 layer 3 is 54 nm, the thickness of the second SiO2 layer 4 is 100 nm, the thickness of the second Ti3O5 layer 5 is 54 nm, and the thickness of the third SiO2 layer 6 is 250 nm.
[0018] Furthermore, the refractive index of SiO2 (layers 2, 4, and 6) in the HUD reflective film is 1.43-1.47; and the refractive index of Ti3O5 (layers 3 and 5) is 2.22-2.45.
[0019] The reflectivity results for this invention at an incident angle of 8 degrees are shown in the reference document. Figure 2 As shown, the average reflectance reaches 82.5% in the visible light (420-680nm) band and is less than 20% in the near-infrared (800-2500nm) band.
[0020] The reflective film of this invention is deposited on the HUD mirror using vacuum deposition. The parameters of the vacuum deposition are shown in Table 1 below. The HUD mirror coated with the reflective film of this invention can meet the requirements of constant temperature and humidity: temperature set at 85℃, humidity at 85%RH, stored for 1000 hours, and after 1000 cycles, the film does not peel off or crack. It can also meet the requirements of thermal shock: -40℃ for 30 minutes; 105℃ for 30 minutes (30 seconds, 500 cycles), and after 100 cycles, the film does not peel off or crack.
[0021] Table 1
[0022] 1 CR 10 20 1.5*E-3 0 150 25 2 <![CDATA[SIO2]]> 70 10 1.5*E-3 100 100 140 3 <![CDATA[TI3O5]]> 54 15 1.5*E-3 100 100 160 4 <![CDATA[SIO2]]> 100 10 1.5*E-3 100 100 200 5 <![CDATA[TI3O5]]> 54 15 1.5*E-3 100 100 160 6 <![CDATA[SIO2]]> 250 10 1.5*E-3 100 100 500
[0023] The embodiments of this utility model are given for the purpose of illustration and description. Although embodiments of this utility model have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this utility model. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this utility model.
Claims
1. A near-infrared low-reflectivity HUD reflective film, characterized in that: It includes a Cr film layer for deposition on a HUD reflector, wherein a first SiO2 layer, a first Ti3O5 layer, a second SiO2 layer, a second Ti3O5 layer, and a third SiO2 layer are sequentially deposited on the Cr film layer.
2. The near-infrared low-reflectivity HUD reflective film according to claim 1, characterized in that: The thickness of the Cr film is 10 nm, the thickness of the first SiO2 layer is 70 nm, the thickness of the first Ti3O5 layer is 54 nm, the thickness of the second SiO2 layer is 100 nm, the thickness of the second Ti3O5 layer is 54 nm, and the thickness of the third SiO2 layer is 250 nm.
3. The near-infrared low-reflectivity HUD reflective film according to claim 1, characterized in that: The refractive index of SiO2 in the HUD reflective film is 1.43-1.47; the refractive index of Ti3O5 is 2.22-2.45.