Electronic rearview mirror capable of improving antistatic performance

Abstract

The electronic rearview mirror capable of improving the antistatic performance comprises a reflection light valve and a protection lens, the protection lens is arranged on the front side of the reflection light valve, and an annular shielding layer is arranged in the peripheral area of the rear side face of the protection lens. The device is characterized in that the annular shielding layer is a semi-reflecting film, and the semi-reflecting film is formed by laminating a plurality of layers of insulating inorganic films with different refractive indexes; the electronic rearview mirror further comprises a conductor shell, the outer side of the reflection light valve is wrapped with the conductor shell, and the edge portion of the protection lens is in conductive connection with the conductor shell. The electronic rearview mirror not only can keep the integrity and aesthetic quality of the appearance of a product, but also can prevent electronic elements from being damaged, so that potential safety hazards are effectively eliminated.

Description

Technical Field

[0001] This utility model relates to the field of automotive rearview mirrors, specifically to an electronic rearview mirror that can improve antistatic performance. Background Technology

[0002] As an intelligent upgrade of traditional optical rearview mirrors, electronic rearview mirrors integrate electronic components such as cameras, displays, reflective light valves (e.g., liquid crystal light valves, electrochromic light valves), and photodiodes to achieve advanced functions such as automatic anti-glare and streaming video display. The core architecture of an electronic rearview mirror typically includes an optical reflective layer, a reflective light valve, and peripheral driving circuitry. The reflective light valve can adjust its transmittance through an electric field and, in conjunction with a light sensor, detects changes in ambient light intensity in real time, thereby achieving dynamic dimming to achieve an anti-glare effect. Compared to traditional mechanical anti-glare structures, it has advantages such as faster response speed and higher adjustment precision.

[0003] In the field of high-end electronic rearview mirror manufacturing, in order to improve the consistency of product appearance, existing electronic rearview mirrors usually adopt a composite protective lens structure. That is, a protective lens is set on the front side of the reflective light valve, and a metal coating layer is set on the rear edge of the protective lens to form a ring-shaped shielding layer (this ring-shaped shielding layer is generally formed on the glass substrate by vacuum sputtering process to form a chromium, aluminum or silver metal coating layer). This ring-shaped shielding layer has a dual function: first, the ring-shaped shielding layer can shield the peripheral wiring of the reflective light valve and the auxiliary electronic devices (such as light sensors) set on the edge of the mirror body; second, by presenting a uniform color between the metal coating layer and the central reflective mirror surface, the color difference problem of traditional ink shielding layers is eliminated, so that the electronic rearview mirror product presents a unified mirror visual effect.

[0004] However, due to the conductive properties of the metal coating layer and its conformal bonding with the circuit board, when the mirror surface is subjected to electrostatic discharge (ESD), the static charge will be rapidly conducted along the metal coating layer to the adjacent electronic components. Furthermore, critical components such as the peripheral circuitry of the reflective light valve and the light sensor are generally less than 2mm from the edge of the annular shielding layer. This compact layout easily leads to the electrostatic discharge path directly penetrating the sensitive electronic area (experimental data shows that when an 8kV contact discharge is applied, the transient potential at the edge of the annular shielding layer can reach over 1.5kV, far exceeding the level four immunity requirement specified in the IEC 61000-4-2 standard). Poor grounding of the metal coating layer and the FPC flexible circuit board exacerbates the risk of electrostatic damage, posing a significant safety hazard. In addition, in existing designs of electronic rearview mirrors, the metal coating layer is generally connected to the main grounding terminal at a single point via conductive silver paste. However, under temperature cycling conditions (-40℃ to 85℃), the paste layer is prone to micro-cracks, leading to an increase in grounding impedance. This prevents the electrostatic pulse from being effectively discharged, instead coupling to adjacent circuit nodes through distributed capacitance. Industry statistics show that camera module damage caused by this type of ESD problem accounts for 3%, and light valve driver IC failure accounts for 4%, seriously affecting product reliability.

[0005] To address the aforementioned technical issues, while some have proposed solutions focusing on adding TVS transient voltage suppressor diodes or improving PCB layout, these solutions only partially mitigate electrostatic discharge energy and do not fundamentally block the electrostatic conduction path formed by the metal coating layer. Especially at the chamfered edges of the mirror, the concentrated electric field causing point discharge still poses a potential threat to electronic components. Therefore, there is an urgent need to design an electronic rearview mirror that can maintain an aesthetically pleasing appearance while effectively blocking electrostatic conduction paths. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide an electronic rearview mirror that can improve anti-static performance. This electronic rearview mirror not only maintains the overall appearance and aesthetic quality of the product, but also prevents damage to electronic components, thereby effectively eliminating safety hazards. The technical solution adopted is as follows:

[0007] An electronic rearview mirror with improved antistatic performance includes a reflective light valve and a protective lens. The protective lens is disposed in front of the reflective light valve, and an annular shielding layer is provided on the peripheral area of ​​the rear side of the protective lens. The annular shielding layer is a semi-reflective film, which is composed of multiple layers of insulating inorganic thin films with different refractive indices. The electronic rearview mirror also includes a conductive shell, which covers the outside of the reflective light valve, and the edge of the protective lens is electrically connected to the conductive shell.

[0008] In this electronic rearview mirror structure, an annular shielding layer is placed on the peripheral area of ​​the rear side of the protective lens. It primarily shields the peripheral circuitry of the reflective light valve. This annular shielding layer is a distributed Bragg reflector (DBR) structure composed of multiple layers of insulating inorganic thin films with different refractive indices. By adjusting the structural parameters of each film layer, the transmittance and reflectance can be precisely controlled, forming a semi-reflective film with specific transmission / reflection characteristics. This not only achieves a perfectly matched mirror gloss effect between the edge and center areas of the electronic rearview mirror, significantly improving the overall appearance and aesthetic quality of the product, but also possesses excellent insulation properties, preventing the formation of a conductive path for electrostatic discharge. The conductive shell is conductive and can be grounded, acting as a channel for dissipating electrostatic current. When the mirror surface encounters electrostatic discharge (ESD), the annular shielding layer effectively blocks the electrostatic conduction path, allowing the static charge to be directly conducted to the conductive shell instead of being conducted along the annular shielding layer to adjacent electronic components. This prevents electrostatic current from being conducted to electronic components, thus preventing damage and effectively eliminating safety hazards.

[0009] Typically, the protective lens is made of glass, which combines internal structural protection with aesthetic enhancement.

[0010] Specifically, the conductor shell can be closed or semi-closed to cover the outside of the reflective light valve and the protective lens, and the conductor shell can be fixed by a certain structure (such as an adhesive structure) so that its inner wall is connected (such as in contact or close to) the edge of the protective lens and forms a conductive connection.

[0011] As a preferred embodiment of this utility model, the edge of the protective lens is bonded to the inner wall of the conductor shell through a conductive adhesive layer to form a conductive connection.

[0012] As a further preferred embodiment of this utility model, the edge and rear side of the annular shielding layer are bonded to the inner wall of the conductor shell by a conductive adhesive layer to form a conductive connection.

[0013] As a preferred embodiment of this utility model, the conductor shell is a metal shell. Specifically, the conductor shell can be an iron shell or an aluminum shell.

[0014] As a preferred embodiment of this utility model, the width of the annular shielding layer is 3-8mm.

[0015] As a preferred embodiment of this utility model, the annular shielding layer comprises multiple layers of first insulating inorganic film and multiple layers of second insulating inorganic film, with each layer of first insulating inorganic film and each layer of second insulating inorganic film alternately arranged from front to back. The refractive index of the first insulating inorganic film is greater than that of the second insulating inorganic film. The annular shielding layer can be prepared by magnetron sputtering, and the thickness tolerance of each film layer can be controlled within ±8%. Actual measurements show that the standard deviation of transmittance during mass production is less than 1.5%.

[0016] The refractive index of the first insulating inorganic film is 1.8 to 2.7, and its specific film material can be TiO2, Ti3O5, Nb2O5, Ta2O5, etc.; the refractive index of the second insulating inorganic film is 1.3 to 1.6, and its specific film material can be MgF2, SiO2, etc.

[0017] As a further preferred embodiment of this invention, the first insulating inorganic film is made of titanium dioxide (TiO2) with a refractive index of 2.4; the second insulating inorganic film is made of silicon dioxide (SiO2) with a refractive index of 1.46. This ensures that the overall reflectivity difference of the electronic rearview mirror is less than 2%, resulting in a visually uniform silver-gray mirror effect. Furthermore, both titanium dioxide (TiO2) and silicon dioxide (SiO2) possess excellent insulating properties, ensuring that the annular barrier layer effectively blocks electrostatic conduction paths.

[0018] As a further preferred embodiment of this utility model, the optical thickness of both the first insulating inorganic film and the second insulating inorganic film is λ / 4. By controlling the optical thickness to the order of λ / 4 wavelengths, semi-transmissive / semi-reflective light is achieved (achieving 45%±3% reflectivity and 55%±3% transmittance in the visible light band). The characteristics of this semi-reflective film are mainly determined by the number of film layers and the difference in refractive index.

[0019] As a preferred embodiment of this utility model, the electronic rearview mirror further includes a light sensor, which is integrated into the rear region of the annular shielding layer. Since the annular shielding layer is a semi-reflective film, after the light sensor is integrated into the rear region of the annular shielding layer and shielded by it, light from a rear light source can directly pass through the semi-reflective film to reach the light sensor. When the light sensor detects a light intensity exceeding 2000 lux, the control circuit automatically increases the driving voltage of the reflective light valve, reducing the reflectivity to below 15% to achieve the anti-glare function.

[0020] As a further preferred embodiment of this invention, the light sensor is an infrared sensor. This effectively eliminates interference from the visible light band on the light sensor.

[0021] As another preferred embodiment of this utility model, the light sensor is composed of a photodiode or a photoresistor.

[0022] The aforementioned light sensor can also employ a multi-channel optical detection component, which is used to monitor changes in the brightness of the rear light source in real time and feed the signal back to the control system to achieve dynamic anti-glare adjustment through a reflective light valve.

[0023] As a preferred embodiment of this utility model, the reflective light valve adopts a liquid crystal light valve structure, which includes a liquid crystal cell, a polarizer and a reflective layer. The polarizer is attached to the front side of the liquid crystal cell, and the reflective layer is disposed on the rear side of the liquid crystal cell.

[0024] As a further preferred embodiment of this utility model, the liquid crystal cell includes a first transparent plate, a second transparent plate, and a liquid crystal layer. The liquid crystal layer is sandwiched between the first and second transparent plates and is composed of nematic liquid crystal. A first transparent electrode and a first alignment layer are disposed on the side of the first transparent plate near the liquid crystal layer, and a second transparent electrode and a second alignment layer are disposed on the side of the second transparent plate near the liquid crystal layer. In reflection mode, the deflection angle of the liquid crystal molecules in the liquid crystal layer of the liquid crystal cell changes linearly with the driving voltage within the range of 0-5V, achieving dynamic adjustment of the reflectivity from 45% to 8%. Therefore, the reflective brightness can be dynamically adjusted by controlling the deflection angle of the liquid crystal molecules.

[0025] As a further preferred embodiment of this utility model, the reflective layer adopts a reflective polarizing film (such as a 3M RPM reflective polarizing film).

[0026] The aforementioned reflective light valve can also adopt an electrochromic (EC) light valve structure, which is based on the ion migration effect of electrochromic materials (such as WO2 / NiO) and controls the change of reflection intensity by voltage. The reflectivity of the rearview mirror can be directly controlled through its electrochromic layer.

[0027] The electronic rearview mirror can be expanded into a streaming media rearview mirror, realizing a dual mode of reflection function and image display. As a preferred embodiment of this invention, a liquid crystal display screen is provided on the rear side of the reflective light valve. The display screen can be a liquid crystal display screen or an OLED display screen, etc. Specifically, a 6.5-inch TFT liquid crystal display screen is provided on the rear side of the reflective light valve, and its display area coincides with the central optical control area of ​​the reflective light valve. In streaming media mode, the reflective light valve can be configured as semi-transparent to ensure the transmission of the display screen image.

[0028] Compared with the prior art, this utility model has the following advantages:

[0029] This electronic rearview mirror features a ring-shaped shielding layer on the periphery of the protective lens. This ring-shaped shielding layer is a semi-reflective film composed of multiple layers of insulating inorganic films with different refractive indices. It can shield the peripheral circuits of the reflective light valve and the light sensor, achieving a mirror-like gloss effect where the edge and center areas of the electronic rearview mirror are perfectly matched, thus significantly improving the overall appearance and aesthetic quality of the product. The conductor shell has conductive properties and can act as a channel for dissipating static current after being grounded. The ring-shaped shielding layer has good insulation properties and will not form a conductive channel for electrostatic damage. When the mirror surface is exposed to electrostatic discharge (ESD), the ring-shaped shielding layer can effectively block the electrostatic conduction path. The static charge is directly conducted to the conductor shell and will not be conducted along the ring-shaped shielding layer to the adjacent electronic components. This prevents the electrostatic current from being conducted from the electronic components, thus preventing damage to the electronic components and effectively eliminating safety hazards. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the electronic rearview mirror according to a preferred embodiment of the present invention.

[0031] Figure 2 yes Figure 1 The external view of the electronic rearview mirror shown.

[0032] Figure 3 yes Figure 2 The exploded view of the electronic rearview mirror shown.

[0033] Figure 4 yes Figure 1 A cross-sectional view of the annular shielding layer in the electronic rearview mirror shown. Detailed Implementation

[0034] like Figures 1-4 As shown, this electronic rearview mirror, which can improve anti-static performance, includes a reflective light valve 1, a protective lens 2, a conductor shell 3, and a light sensor 4. The protective lens 2 is located in front of the reflective light valve 1, and an annular shielding layer 5 is provided in the peripheral area of ​​the rear side of the protective lens 2. The annular shielding layer 5 is a semi-reflective film, which is composed of multiple layers of insulating inorganic thin films with different refractive indices. The light sensor 4 is integrated in the rear area of ​​the annular shielding layer 5. The conductor shell 3 covers the outside of the reflective light valve 1, and the edge of the protective lens 2 is electrically connected to the conductor shell 3.

[0035] In this embodiment, the reflective light valve 1 adopts a liquid crystal light valve structure, which includes a liquid crystal cell 11, a polarizer 12, and a reflective layer 13. The liquid crystal cell 11 includes a first transparent plate 111, a second transparent plate 112, and a liquid crystal layer 113. The liquid crystal layer 113 is sandwiched between the first transparent plate 111 and the second transparent plate 112, and it is composed of nematic liquid crystal. The first transparent plate 111 has a first transparent electrode and a first alignment layer (not shown in the figure) on the side near the liquid crystal layer 113. The second transparent plate 112 has a second transparent electrode and a second alignment layer (not shown in the figure) on the side near the liquid crystal layer 113. The polarizer 12 is attached to the front side of the liquid crystal cell 11, and the reflective layer 13 is disposed on the rear side of the liquid crystal cell 11. The reflective layer 13 adopts a reflective polarizing film (such as a 3M RPM reflective polarizing film). In reflection mode, the deflection angle of the liquid crystal molecules in the liquid crystal layer 113 of the liquid crystal cell 11 changes linearly with the driving voltage in the range of 0-5V, thereby achieving dynamic adjustment of the reflectivity from 45% to 8%. Thus, the dynamic adjustment of the reflected brightness can be achieved by controlling the deflection angle of the liquid crystal molecules.

[0036] In this embodiment, the protective lens 2 has a reinforced glass surface, which combines internal structural protection with aesthetic enhancement.

[0037] The conductor shell 3 can be closed or semi-closed, covering the outside of the reflective light valve 1 and the protective lens 2. The conductor shell 3 can be fixed by a certain structure (such as an adhesive structure) so that its inner wall connects (contacts or approaches) with the edge of the protective lens 2, forming a conductive connection. In this embodiment, the conductor shell 3 is a metal shell (such as an iron shell or an aluminum shell); the edge and rear side of the annular shielding layer 5 are bonded to the inner wall of the conductor shell 3 by a conductive adhesive layer 6 to form a conductive connection.

[0038] In this embodiment, the light sensor 4 is an infrared sensor. This effectively eliminates interference from the visible light band on the light sensor 4.

[0039] In this embodiment, the annular shielding layer 5 includes multiple layers of first insulating inorganic film 51 and multiple layers of second insulating inorganic film 52. The first insulating inorganic film 51 and the second insulating inorganic film 52 are alternately arranged from front to back. The optical thickness of the first insulating inorganic film 51 and the second insulating inorganic film 52 is λ / 4. The first insulating inorganic film 51 is made of titanium dioxide (TiO2) with a refractive index of 2.4. The second insulating inorganic film 52 is made of silicon dioxide (SiO2) with a refractive index of 1.46. The width of the annular shielding layer 5 is 3-8 mm. The annular shielding layer 5 adopts a distributed Bragg reflector (DBR) structure composed of multiple insulating inorganic thin films with different refractive indices and optical thicknesses of λ / 4. It can be fabricated by magnetron sputtering. By controlling the optical thickness on the order of λ / 4 wavelength, it achieves semi-transparency / semi-reflection of light (achieving 45%±3% reflectivity and 55%±3% transmittance in the visible light band). The characteristics of this semi-reflective film are mainly determined by the number of film layers and the difference in refractive index. The thickness tolerance of each film layer can be controlled within ±8%. According to actual measurements, the standard deviation of transmittance during mass production is less than 1.5%. This allows the overall reflectivity difference of the electronic rearview mirror to be less than 2%, resulting in a visually uniform silver-gray mirror effect. Moreover, titanium dioxide (TiO2) and silicon dioxide (SiO2) both have good insulation properties, which can ensure that the annular blocking layer can effectively block the electrostatic conduction path.

[0040] In this embodiment, the protective lens 2 and the annular shielding layer 5 are bonded to the front side of the reflective light valve 1 by an adhesive layer 7.

[0041] In this embodiment, a liquid crystal display screen 8 is disposed on the rear side of the reflective light valve 1, and the liquid crystal display screen 8 is installed inside the conductor housing 3. Specifically, the liquid crystal display screen 8 is a 6.5-inch TFT liquid crystal display screen, and its display area coincides with the central optical control area of ​​the reflective light valve 1. Thus, this electronic rearview mirror can be extended into a streaming media rearview mirror, realizing a dual mode of reflection function and image display. In streaming media mode, the reflective light valve 1 can be configured as semi-transparent to ensure the transmission of the display screen image.

[0042] In this electronic rearview mirror structure, an annular shielding layer 5 is placed on the peripheral area of ​​the rear side of the protective lens 2. It is mainly used to shield the peripheral circuitry of the reflective light valve 1. The annular shielding layer 5 is a distributed Bragg reflector (DBR) structure composed of multiple layers of insulating inorganic thin films with different refractive indices. Its transmittance and reflectance can be precisely controlled by adjusting the structural parameters of each film layer, forming a semi-reflective film with specific transmission / reflection characteristics. Because the annular shielding layer 5 is a semi-reflective film, after the light sensor 4 is integrated into the rear area of ​​the annular shielding layer 5 and shielded by it, the light from the rear light source can be... The light can pass directly through the semi-reflective film to the light sensor 4. When the light sensor 4 detects a light intensity exceeding 2000 lux, the control circuit automatically increases the driving voltage of the reflective light valve 1, reducing the reflectivity to below 15% to achieve the anti-glare function. The conductor shell 3 is grounded. When the surface of the mirror is exposed to electrostatic discharge (ESD), the annular shielding layer 5 can effectively block the electrostatic conduction path. The static charge is directly conducted to the conductor shell 3, and will not be conducted along the annular shielding layer 5 to the adjacent electronic components. This can prevent the electrostatic current from being conducted from the electronic components, prevent damage to the electronic components, and effectively eliminate safety hazards.

[0043] Furthermore, it should be noted that the names of the various parts of the specific embodiments described in this specification may differ. All equivalent or simple variations made to the structure, features, and principles of this utility model patent are included within the protection scope of this utility model patent. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this utility model or exceed the scope defined by the claims, they should all fall within the protection scope of this utility model.

Claims

1. An electronic rearview mirror capable of improving antistatic performance, comprising a reflective light valve and a protective lens, wherein the protective lens is disposed in front of the reflective light valve, and an annular shielding layer is provided on the peripheral area of ​​the rear side of the protective lens; characterized in that: The annular shielding layer is a semi-reflective film, which is composed of multiple layers of insulating inorganic thin films with different refractive indices; the electronic rearview mirror also includes a conductor shell, which covers the outside of the reflective light valve and protects the edge of the lens from forming a conductive connection with the conductor shell.

2. The electronic rearview mirror with improved antistatic performance according to claim 1, characterized in that: The edge of the protective lens is bonded to the inner wall of the conductor shell through a conductive adhesive layer to form a conductive connection.

3. The electronic rearview mirror with improved antistatic performance according to claim 2, characterized in that: The edges and rear sides of the annular shielding layer are bonded to the inner wall of the conductor shell through a conductive adhesive layer to form a conductive connection.

4. The electronic rearview mirror with improved antistatic performance according to claim 1, characterized in that: The conductor shell is a metal shell.

5. An electronic rearview mirror with improved antistatic performance according to claim 1, characterized in that: The annular shielding layer comprises multiple layers of first insulating inorganic film and multiple layers of second insulating inorganic film, with each layer of first insulating inorganic film and each layer of second insulating inorganic film alternately arranged from front to back, and the refractive index of the first insulating inorganic film being greater than that of the second insulating inorganic film.

6. An electronic rearview mirror with improved antistatic performance according to claim 5, characterized in that: The first insulating inorganic film is made of titanium dioxide with a refractive index of 2.4; the second insulating inorganic film is made of silicon dioxide with a refractive index of 1.46; the optical thickness of both the first and second insulating inorganic films is λ / 4.

7. An electronic rearview mirror with improved antistatic performance according to any one of claims 1-6, characterized in that: The electronic rearview mirror also includes a light sensor, which is integrated into the rear region of the annular shielding layer.

8. An electronic rearview mirror with improved antistatic performance according to claim 7, characterized in that: The light sensor is composed of a photodiode or a photoresistor; or, the light sensor is an infrared sensor.

9. An electronic rearview mirror with improved antistatic performance according to any one of claims 1-6, characterized in that: The reflected light valve adopts a liquid crystal light valve structure, which includes a liquid crystal cell, a polarizer and a reflective layer. The polarizer is attached to the front side of the liquid crystal cell, and the reflective layer is located on the rear side of the liquid crystal cell. The reflective layer adopts a reflective polarizing film.

10. An electronic rearview mirror with improved antistatic performance according to any one of claims 1-6, characterized in that: An LCD screen is provided on the rear side of the reflective light valve.

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