LIQUID CRYSTAL GLARE-PROOF MIRROR

• US 20090002576A1
• Filed: 04/30/2008
• Published: 01/01/2009
• Est. Priority Date: 06/28/2007
• Status: Abandoned Application

• Current Assignee: Murakami Corporation
• Original Assignee: Murakami Corporation
• Inventors: Sato, Hidenori, Suzuki, Norihiro, Unno, Noriyuki
• Application Number:
  US12/112,133
• Publication Number:
  US 20090002576A1
• Time in Patent Office: Days
• US Class Current: 349/1
• 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 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133545 Dielectric stack polarisers
• CPC Class Codes: G02F 2201/34 reflector

Abstract

Disclosed is a liquid crystal glare-proof mirror including a first polarizing plate and a second polarizing plate formed of resin layers having refractive index anisotropy. The refractive index anisotropy of the first polarizing plate and the second polarizing plate allows an ordinary ray to be separated from an extraordinary ray in which the incident light is refracted in different directions depending on an angle at which the incident light comes into the one of the first polarizing plate and the second polarizing plate.

Claims

1. A liquid crystal glare-proof mirror comprising:

a first polarizing plate for transmitting a first polarization component of incident light;

a second polarizing plate for transmitting a second polarization component of the incident light; and

a liquid crystal cell disposed between the first polarizing plate and the second polarizing plate,

at least either one of the first polarizing plate and the second polarizing plate being formed of material having refractive index anisotropy exhibiting a different refraction of the incident light that varies depending on an angle at which the incident light comes into the either one of the first polarizing plate and the second polarizing plate.

2. The liquid crystal glare-proof mirror according to claim 1, wherein

the second polarizing plate reflects a third polarization component perpendicular to the second polarizing component,

liquid crystal molecules in the liquid crystal cell are aligned in such a manner that the liquid crystal cell exhibits polarization rotatory power on the incident light when voltage is not applied to the liquid crystal molecules and the liquid crystal cell does not exhibit the polarization rotatory power on the incident light when voltage is applied to the liquid crystal molecules, and

the first polarizing plate and the second polarizing plate are disposed in such a manner that the first polarization component is perpendicular to the third polarization component and the first polarization component is parallel to the second polarization component.

3. The liquid crystal glare-proof mirror according to claim 1, wherein an optical absorption member for absorbing the second polarization component transmitted through the second polarizing plate is disposed opposite to the side of the second polarizing plate on which the liquid crystal cell is disposed.

4. The liquid crystal glare-proof mirror according to claim 2, wherein an optical absorption member for absorbing the second polarization component transmitted through the second polarizing plate is disposed opposite to the side of the second polarizing plate on which the liquid crystal cell is disposed.

5. The liquid crystal glare-proof mirror according to claim 1, further comprising:

a surrounding light detection device for detecting a quantity of light around a vehicle;

a back light detection device for detecting a quantity of light coming from a rear side of the vehicle;

a liquid crystal cell control device for

comparing the quantity of light around the vehicle detected by the surrounding light detection device and the quantity of light coming from the rear side of the vehicle detected by the back light detection device,

controlling the liquid crystal glare-proof mirror to be glare-proofed when the quantity of the light coming from the rear side of the vehicle is greater than the quantity of light around the vehicle at not less than a predetermined value, and

controlling the liquid crystal glare-proof mirror not to be glare-proofed when the quantity of the light coming from the rear side of the vehicle is smaller than or equal to the quantity of the light around the vehicle, or when the quantity of light coming from the rear side of the vehicle is greater than the quantity of the light around the vehicle in less than the predetermined value.

6. The liquid crystal glare-proof mirror according to claim 2, further comprising:

a surrounding light detection device for detecting a quantity of light around a vehicle;

a back light detection device for detecting a quantity of light coming from a rear side of the vehicle;

a liquid crystal cell control device for

comparing the quantity of the light around the vehicle detected by the surrounding light detection device and the quantity of the light coming from the rear side of the vehicle detected by the back light detection device,

controlling the liquid crystal glare-proof mirror to be glare-proofed when the quantity of light coming from the rear of the vehicle is greater than the quantity of the light around the vehicle at not less than a predetermined value, and

controlling the liquid crystal glare-proof mirror not to be glare-proofed when the quantity of the light coming from the rear side of the vehicle is smaller than or equal to the quantity of the light around the vehicle or the quantity of the light coming from the rear side of the vehicle is greater than the quantity of the light around the vehicle in less than the predetermined value.

7. The liquid crystal glare-proof mirror according to claim 3, further comprising:

a surrounding light detection device for detecting a quantity of light around a vehicle;

a back light detection device for detecting a quantity of light coming from a rear side of the vehicle;

a liquid crystal cell control device for

comparing the quantity of the light around the vehicle detected by the surrounding light detection device and the quantity of the light coming from the rear side of the vehicle detected by the back light detection device,

controlling the liquid crystal glare-proof mirror to be glare-proofed when the quantity of the light coming from the rear side of the vehicle is greater than the quantity of the light around the vehicle at not less than a predetermined value, and

controlling the liquid crystal glare-proof mirror not to be glare-proofed when the quantity of the light coming from the rear side of the vehicle is smaller than or equal to the quantity of the light around the vehicle or the quantity of the light coming from the rear side of the vehicle is greater than the quantity of the light around the vehicle in less than the predetermined value.

8. The liquid crystal glare-proof mirror according to claim 4, further comprising:

a surrounding light detection device for detecting a quantity of light around a vehicle;

a back light detection device for detecting a quantity of light coming from a rear side of the vehicle;

a liquid crystal cell control device for

comparing the quantity of the light around the vehicle detected by the surrounding light detection device and the quantity of the light coming from the rear side of the vehicle detected by the back light detection device,

controlling the liquid crystal glare-proof mirror to be glare-proofed when the quantity of the light coming from the rear side of the vehicle is greater than the quantity of the light around the vehicle at not less than a predetermined value, and

controlling the liquid crystal glare-proof mirror not to be glare-proofed when the quantity of the light coming from the rear side of the vehicle is smaller than or equal to the quantity of the light around the vehicle or the quantity of the light coming from the rear side of the vehicle is greater than the quantity of the light around the vehicle in less than the predetermined value.

9. The liquid crystal glare-proof mirror according to claim 5, further comprising a delay unit for delaying a timing at which a detection signal output from the surrounding light detection device and a detection signal output from the back light detection device are input to the liquid crystal cell control device.

10. The liquid crystal glare-proof mirror according to claim 6, further comprising a delay unit for delaying a timing at which a detection signal output from the surrounding light detection device and a detection signal output from the back light detection device are input to the liquid crystal cell control device.

11. The liquid crystal glare-proof mirror according to claim 7, further comprising a delay unit for delaying a timing at which a detection signal output from the surrounding light detection device and a detection signal output from the back light detection device are input to the liquid crystal cell control device.

12. The liquid crystal glare-proof mirror according to claim 8, further comprising a delay unit for delaying a timing at which a detection signal output from the surrounding light detection device and a detection signal output from the back light detection device are input to the liquid crystal cell control device.

13. The liquid crystal glare-proof mirror according to claim 5, wherein the liquid crystal cell control device comprises an oscillation unit for oscillating a control signal which controls the liquid crystal cell.

14. The liquid crystal glare-proof mirror according to claim 6, wherein the liquid crystal cell control device comprises an oscillation unit for oscillating a control signal which controls the liquid crystal cell.

15. The liquid crystal glare-proof mirror according to claim 7, wherein the liquid crystal cell control device comprises an oscillation unit for oscillating a control signal which controls the liquid crystal cell.

17. The liquid crystal glare-proof mirror according to claim 8, wherein the liquid crystal cell control device comprises an oscillation unit for oscillating a control signal which controls the liquid crystal cell.

18. The liquid crystal glare-proof mirror according to claim 9, wherein the liquid crystal cell control device comprises an oscillation unit for oscillating a control signal which controls the liquid crystal cell.

19. The liquid crystal glare-proof mirror according to claim 10, wherein the liquid crystal cell control device comprises an oscillation unit for oscillating a control signal which controls the liquid crystal cell.

20. The liquid crystal glare-proof mirror according to claim 12, wherein the liquid crystal cell control device comprises an oscillation unit for oscillating a control signal which controls the liquid crystal cell.

21. The liquid crystal glare-proof mirror according to claim 11, wherein the liquid crystal cell control device comprises an oscillation unit for oscillating a control signal which controls the liquid crystal cell.