Mirror with dazzle light attenuation zone

• US 5,168,378 A
• Filed: 02/10/1992
• Issued: 12/01/1992
• Est. Priority Date: 02/10/1992
• Status: Expired due to Fees

• Current Assignee: Reliant Technologies, Inc. (Bausch Health Cos., Inc.)
• Original Assignee: Reliant Laser Corporation
• Inventors: Black, Michael, Kupershmidt, Vladimir
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): MAI, HUY KIM
• Application Number:
  US07/833,010
• Time in Patent Office: 295 Days
• Field of Search: 359/38, 359/54, 359/63, 359/70, 359/72, 359/79, 359/85
• US Class Current: 349/195
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors
• CPC Class Codes: G02F 1/135 Liquid crystal cells structurally associated with a photoconducting or a ferro-electric layer, the properties of which can be optically or electrically varied G02F1/133348 takes precedence
• CPC Class Codes: G02F 2203/02 reflective

Abstract

A liquid-crystal matrix-type reflection mirror (10) with a localized dazzle light attenuation zone. The mirror has a multilayered structure and consists of a broadband reflective base mirror (12) having maximum reflectivity in the range corresponding to spectral range of halogen lamps of automobile headlights. Deposited on the base mirror are a matrix transparent electrode (14) and a photoconductive layer (20) placed on the matrix transparent electrode. The photoconductive layer (20) and the matrix transparent electrode (14) have a matrix-type structure formed as a pixel array. Each pixel of the matrix transparent electrode (14) is a projection of an overlaid pixel of the photoconductive layer (20). The multilayered structure further includes the following subsequent layers: a rear polarizer (22) which has a predetermined axis of polarization and is placed on the photoconductive layer, a common transparent electrode (36), a liquid crystal (25) sandwiched and sealed between the rear polarizer (22) and the common transparent electrode (36), a front polarizer (42), and an antireflection coating (44). The mirror (10) has a control circuit connected between the common transparent electrode (36) and the matrix transparent electrode. The control circuit applies a control voltage to the liquid crystal in accordance with the incident light. The pixel enabling just the dazzle light zone to be attenuating.

Claims

1. A liquid-crystal matrix-type reflection mirror with a localized dazzle light attenuation zone, said mirror having a multilayered structure and comprising:

a base mirror having a broadband spectral reflectivity;

a matrix transparent electrode on one side of said base mirror;

a photoconductive layer on said matrix transparent electrode;

a rear polarizer placed on said photoconductive layer and having a predetermined axis of polarization;

a common transparent electrode above said rear polarizer;

a liquid crystal sandwiched and sealed between said rear polarizer and said common transparent electrode;

a front polarizer on said common electrode, said front polarizer having an outer surface and an axis of polarization parallel to said predetermined axis of polarization; and

a control circuit connected between said common transparent electrode and said matrix transparent electrode, said control circuit having means for applying a voltage to said common transparent electrode and said matrix transparent electrode.

2. The liquid-crystal matrix-type reflection mirror of claim 1 wherein said base mirror has maximum reflectivity in the range corresponding to the spectral range of halogen lamps of motor vehicle headlights.

3. The liquid-crystal matrix-type reflection mirror of claim 2 wherein said photoconductive layer and said matrix transparent electrode have a matrix-type structure formed as a pixel array, each pixel of said matrix transparent electrode being a projection of an overlaid pixel of said photoconductive layer.

4. The liquid-crystal matrix-type reflection mirror of claim 3, further including a first insulation layer between said liquid crystal and said rear polarizer, a second insulation layer between said liquid crystal and said front polarizer, a first orientation layer between said first insulation layer and said rear polarizer, and a second orientation layer between said second insulation layer and said front polarizer.

5. The liquid-crystal matrix-type reflection mirror of claim 4, further including an antireflection coating on said outer surface of said front polarizer.

6. The liquid-crystal matrix-type reflection mirror of claim 5 wherein said mirror is a rearview mirror of an automobile.

7. The liquid-crystal matrix-type reflection mirror of claim 2 wherein said common transparent electrode, and said matrix transparent electrode are made of indium tin oxide, and said photoconductive layer is made of a material selected from the group consisting of cadmium selenide and cadmium sulfide.

8. The liquid-crystal matrix-type reflection mirror of claim 1, further including a photoconductive layer on said matrix transparent electrode, said photoconductive layer and said matrix transparent electrode having a matrix-type structure formed of an array of pixels, each pixel of said matrix transparent electrode being a projection of and aligned with a corresponding pixel of said photoconductive layer.

9. A liquid-crystal matrix-type reflection mirror with a localized dazzle light attenuation zone, said mirror having a multilayered structure and comprising:

a broadband reflective base mirror having maximum reflectivity in the range corresponding to spectral range of halogen lamps of automobile headlights;

a matrix transparent electrode on said broadband reflective base mirror;

a photoconductive layer on said matrix transparent electrode, said photoconductive layer and said matrix transparent electrode having a matrix-type structure formed as a pixel array, each pixel of said matrix transparent electrode being a projection of an overlaid pixel of said photoconductive layer;

a rear polarizer on said photoconductive layer, said rear polarizer having a predetermined axis of polarization;

a common transparent electrode above said rear polarizer;

a liquid crystal sandwiched and sealed between said rear polarizer and said common transparent electrode;

a front polarizer on said common electrode and having an outer surface, and an axis of polarization parallel to said predetermined axis of polarization; and

a control circuit connected between said common transparent electrode and said matrix transparent electrode, said control circuit having means for applying a voltage to said common transparent electrode and said matrix transparent electrode.

10. The liquid-crystal matrix-type reflection mirror of claim 9, further including a first insulation layer between said liquid crystal and said rear polarizer, a second insulation layer between said liquid crystal and said front polarizer, a first orientation layer between said first insulation layer and said rear polarizer, and a second orientation layer between said second insulation layer and said front polarizer.

11. The liquid-crystal matrix-type reflection mirror of claim 10, further including an antireflection coating on said outer surface of said front polarizer.

12. The liquid-crystal matrix-type reflection mirror of claim 9 wherein said common transparent electrode, said matrix transparent electrode are made of indium tin oxide, and said photoconductive layer is made of a material selected from the group consisting of cadmium selenide and cadmium sulfide.

13. The liquid-crystal matrix-type reflection mirror of claim 9 wherein each said pixel has its individually addressed electrode, said control circuit having a threshold device, said electrodes being connected to said means for applying a voltage through said threshold device.

14. The liquid-crystal matrix-type reflection mirror of claim 13 wherein said threshold device has a threshold value which corresponds to a predetermined intensity of dazzling light.

15. A liquid-crystal matrix-type reflection mirror with a localized dazzle light attenuation zone, said mirror having a multilayered structure and comprising:

a broadband reflective base mirror having maximum reflectivity in the range corresponding to spectral range of halogen lamps of automobile headlights;

a matrix transparent electrode on said broad band reflective base mirror;

a photoconductive layer on said matrix transparent electrode, said photoconductive layer and said matrix transparent electrode having a matrix-type structure formed of an array of pixels, each pixel of said matrix transparent electrode being a projection of and aligned with a corresponding pixel of said photoconductive layer;

a rear polarizer on said photoconductive layer, said rear polarizer having a predetermined axis of polarization;

a common transparent electrode above said rear polarizer;

a liquid crystal sandwiched and sealed between said rear polarizer and said common transparent electrode;

a front polarizer placed on said common electrode and having an outer surface, which faces an incident light, and an axis of polarization parallel to said predetermined axis of polarization;

a control circuit connected between said common transparent electrode and said matrix transparent electrode, said control circuit having means for applying a voltage to said common transparent electrode and said matrix transparent electrode;

a first insulation layer between said liquid crystal and said rear polarizer;

a second insulation layer between said liquid crystal and said front polarizer;

a first orientation layer between said first insulation layer and said rear polarizer, and

a second orientation layer between said second insulation layer and said front polarizer.

16. The liquid-crystal matrix-type reflection mirror of claim 15, further including an antireflection coating on said outer surface of said front polarizer.

17. The liquid-crystal matrix-type reflection mirror of claim 15 wherein said mirror is a rearview mirror of a motor vehicle.

18. The liquid-crystal matrix-type reflection mirror of claim 17 wherein said common transparent electrode and said matrix transparent electrode are made of indium tin oxide, and said photoconductive layer is made of a material selected from the group consisting of cadmium selenide and cadmium sulfide.

19. The liquid-crystal matrix-type reflection mirror of claim 16 wherein each pixel of said array of pixels has a respective addressing electrode, said control circuit having a threshold device, said electrodes being connected to said means for applying a voltage through said threshold device.

20. The liquid-crystal matrix-type reflection mirror of claim 19 wherein said threshold device has a threshold value which corresponds to a predetermined intensity of dazzling light.