For: multi-functional device with adjustable reflectivity

• US 20130148063A1
• Filed: 12/13/2011
• Published: 06/13/2013
• Est. Priority Date: 12/13/2011
• Status: Active Grant

• Current Assignee: Philip Maeda
• Original Assignee: Philip Maeda
• Inventors: Maeda, Philip
• Granted Patent: US 8,717,521 B2
• Time in Patent Office: Days
• US Class Current: 349/114
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors
• CPC Class Codes: B60R 1/12 Mirror assemblies combined with other articles, e.g. clocks
• CPC Class Codes: B60R 2001/1253 with cameras, video cameras or video screens
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence
• CPC Class Codes: G02F 1/1396 the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell G02F1/141 takes precedence

Abstract

A reflective device wherein the device reflectivity is adjustable via automatic or manual means. The variable reflectance element includes a metallic mirror reflector on one side of a substrate and additional substrate layers consisting of a polarizer and a LCD whose material characteristics have been optimized for dimming. The mirror assembly provides alternate trigger mechanisms for initiating the dimming function, the dimming function being automatically referenced to ambient light levels (day or night) or manually adjusted or selected. In the automatic mode the dimming mirror assembly provides the user immediate eye protection from reflected high intensity glare by effecting near instantaneous adjustment in mirror reflectivity, such that the intensity of the reflected light impinging on the eyes is automatically adjusted so as to be at comfortable levels. The mirror assembly construction is in one piece, and allows the viewing of a display or TFT monitor located adjacent to the mirror.

Claims

1. A reflective mirror system comprising:

an interior assembly having a variable reflectance element, said variable reflectance element including an optimized rearview mirror LCD electro-optic medium disposed between a first substrate and a second substrate, said first substrate contacted by a polarizing film on its exterior side and said LCD electro-optic medium on the interior side of said first substrate, said second substrate having a metallic mirror reflector at its side contacted by said electro-optic medium, wherein said metallic mirror reflector comprises a reflecting metal film wherein said interior mirror assembly comprises at least one light sensor; and

a control system wherein responsive to a light level sensed by at least said one light sensor, the mirror reflectance is adjustable by said control system when said interior rearview mirror assembly is normally mounted in an installation, said interior mirror assembly being constructed as a single component.

2. The mirror system of claim 1, wherein said reflective element is at least about 60 percent reflective to visible light incident thereon.

3. The mirror system of claim 1, further including circuitry associated with said light sensor, said circuitry comprising a current to frequency converter.

4. The mirror system of claim 1 wherein said light sensor comprises a silicon photo-sensor and associated circuitry commonly formed as a monolithic CMOS integrated circuit.

5. The mirror system of claim 1 wherein said control circuit comprises a charge accumulation device, a comparison function and a controller, said comparison function comparing an output of said charge accumulation device with a reference, said controller selectively connecting said ambient light sensor with said charge accumulation device.

6. The mirror system of claim 1 wherein said control circuit establishes a reflectance level of said reflective element responsive to a ratio of a glare light value to an ambient light value.

7. The mirror system of claim 6, wherein said ratio of glare light value to ambient value is from about 0.01 to at least about 100, the mirror system reflectivity being programmable to all ratios of the glare light value between 0.01 and 100.

8. The mirror system of claim 6, wherein said control circuit establishes said reflectance level within a relatively linear value of said ratio of glare light value to ambient light value, said reflectance level being adjustable.

9. The mirror system of claim 1 wherein the mirror dimming function is initiated and adjusted by touch screen, toggle switch or said photo sensor system.

10. A reflective mirror system comprising a mirror assembly having a variable reflectance element, said reflective element having a front surface and a rear surface, said front surface being closer to a user than said rear surface;

wherein said reflective element comprises a mirror reflector that partially reflects light incident thereon;

an ambient light sensor system operable to sense ambient light;

a glare light sensor system operable to sense light incident at or near said reflective element;

wherein said ambient light sensor comprises a silicon photo-sensor and associated circuitry formed as an integrated circuit and wherein said glare light sensor comprises a silicon photo-sensor and associated circuitry formed as an integrated circuit and wherein said glare light sensor converts incident light to a signal processed by a microprocessor;

a control circuit operable to establish a reflectance level of said reflective element, wherein said control circuit is responsive to light detection by at least one of said ambient light sensors as well as said glare light sensor;

wherein said mirror system further comprises temperature compensation of at least one of said glare light sensors and said ambient light sensors, and wherein said temperature compensation is responsive to a reference sensor not exposed to light; and

wherein said control circuit establishes a reflectance level of said reflective element responsive to a ratio of a glare light value to a preselected ambient light value.

11. The mirror system of claim 10, wherein said control circuit establishes said reflectance level within a relatively linear value of said ratio of glare light value to ambient light value, said reflectance level being a programmable function of said ratio of glare light to ambient light value.

12. The rearview mirror system of claim 11, comprising means for compensating for temperature of at least one of said glare light sensors and said ambient light sensors, wherein said temperature compensation is responsive to a reference sensor not exposed to light.