Variable reflectance mirrors and windows

• US 7,916,380 B2
• Filed: 01/22/2010
• Issued: 03/29/2011
• Est. Priority Date: 07/12/2004
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Bauer, Frederick T., Watson, Alan R., Tonar, William L.
• Primary Examiner(s): Pritchett; Joshua L
• Application Number:
  US12/691,990
• Publication Number:
  US 20100165437A1
• Time in Patent Office: 431 Days
• Field of Search: 359/267, 359/265, 359/604
• US Class Current: 359/267
• CPC Class Codes: B60R 1/088 using a cell of electrically changeable optical characteristic, e.g. liquid-crystal or electrochromic mirrors

Abstract

Various structures for variable reflectance rearview mirrors and variable transmittance windows are disclosed. One embodiment pertains to the provision of a polarized reflector in a rearview mirror. Another embodiment pertains to the provision of a switchable cholesteric liquid crystal element in a window. Yet another embodiment pertains to the provision of a plurality of apertures in a reflector layer of a rearview mirror where the apertures are sized and positioned in alignment with light emitting areas of a display positioned behind the reflector layer. In another embodiment, a moveable display or mirror element is attached to a rearview mirror housing.

Claims

1. An automotive rearview assembly having a front, the assembly comprising a switchable mirror system configured to have a non-transitory changeable reflectance, the switchable mirror system including

a plurality of substrates disposed sequentially in parallel and spaced-apart relationship so as to form a plurality of chambers, each chamber defined by opposing surfaces of two sequentially disposed substrates and a seal disposed therebetween, each of the opposing surfaces having an electrically conductive layer deposited thereon, each chamber containing a corresponding electro-optical medium that is in electrical communication with adjacent electrically conductive layers,

wherein at least one chamber is configured to define a voltage-switchable reflective polarizer, and

wherein the changeable reflectance includes at least three levels of reflectance respectively corresponding to at least three reflectance modes of operation of the switchable mirror system.

2. An assembly according to claim 1, wherein two chambers have a common substrate from the plurality of substrates.

3. An assembly according to claim 1, wherein at least one chamber is configured to define an electrochromic element.

4. An assembly according to claim 1, further comprising molecule orientation layers disposed on the conductive layers of at least one chamber from the plurality of chambers.

5. An assembly according to claim 1, wherein the reflectance of the switchable mirror system is continuously variable.

6. An assembly according to claim 1, wherein the switchable mirror system contains a reflective polarizer configured to substantially transmit light of a first polarization and substantially reflect light of a second polarization, the second polarization being orthogonal to the first polarization.

7. An assembly according to claim 6, wherein the reflective polarizer includes multiple layers of plastic film.

8. An assembly according to claim 7, wherein the reflective polarizer is laminated to a substrate from the plurality of substrates.

9. An assembly according to claim 1, further comprising at least one additional device selected from the group consisting of an illumination assembly, a display, a voice activated system, a compass system, a telephone system, a highway toll booth interface, a telemetry system, a headlight controller, a rain sensor, a tire pressure monitoring system, a navigation system, a lane departure warning system, and an adaptive cruise control system.

10. An automotive rearview assembly according to claim 1, wherein the switchable mirror system is configured to reflect light having, at the at least three levels of reflectance, different polarizations.

11. An automotive rearview assembly having a front, the assembly comprising a switchable mirror system configured to have a non-transitory changeable reflectance, the switchable mirror system including

a plurality of substrates disposed sequentially in parallel and spaced-apart relationship so as to form a plurality of chambers, each chamber defined by opposing surfaces of two sequentially disposed substrates and a seal disposed therebetween, each of the opposing surfaces having an electrically conductive layer deposited thereon, each chamber containing a corresponding electro-optical medium that is in electrical communication with adjacent electrically conductive layers,

wherein one chamber defines an electrochromic (EC) element corresponding to the front of the rearview assembly and at least one chamber is configured to define a voltage-switchable polarizer disposed behind the EC element, and

wherein the changeable reflectance includes at least three levels of reflectance respectively corresponding to at least three reflectance modes of operation of the switchable mirror system.

12. An assembly according to claim 11, wherein the switchable mirror system contains a reflective polarizer.

13. An assembly according to claim 11, wherein the switchable mirror system is configured to reflect light at the at least three levels of reflectance wherein polarization states of light reflected at said levels of reflectance differ from one another.

14. An assembly according to claim 13, further comprising at least one additional device selected from the group consisting of an illumination assembly, a display, a voice activated system, a compass system, a telephone system, a highway toll booth interface, a telemetry system, a headlight controller, a rain sensor, a tire pressure monitoring system, a navigation system, a lane departure warning system, and an adaptive cruise control system.

15. An assembly according to claim 11, further comprising molecule orientation layers disposed on the conductive layers of at least one chamber from the plurality of chambers.

16. An automotive rearview assembly having a front, the assembly comprising a switchable mirror system configured to have a non-transitory changeable reflectance, the switchable mirror system including

a plurality of substrates disposed sequentially in parallel and spaced-apart relationship so as to form a plurality of chambers, each chamber defined by opposing surfaces of two sequentially disposed substrates and a seal disposed therebetween, each of the opposing surfaces having an electrically conductive layer deposited thereon, each chamber containing a corresponding electro-optical medium that is in electrical communication with adjacent electrically conductive layers,

wherein at least one chamber is configured to define a cholesteric liquid-crystal element,

wherein one chamber is configured to define and electrochromic (EC) element corresponding to the front of the rearview assembly and disposed in front of the at least one chamber that is configured to define a cholesteric liquid-crystal medium, and wherein the changeable reflectance of the switchable mirror includes at least three levels of reflectance respectively corresponding to at least three reflectance modes of operation of the switchable mirror system.

17. An assembly according to claim 16, further comprising at least one additional device selected from the group consisting of an illumination assembly, a display, a voice activated system, a compass system, a telephone system, a highway toll booth interface, a telemetry system, a headlight controller, a rain sensor, a tire pressure monitoring system, a navigation system, a lane departure warning system, and an adaptive cruise control system.

18. An assembly according to claim 16, wherein the switchable mirror system contains a reflective polarizer including multiple layers of plastic film and configured to substantially transmit light of a first polarization and substantially reflect light of a second polarization, the second polarization being orthogonal to the first polarization.

19. An assembly according to claim 16, wherein a first light reflected by the switchable mirror system in one of the at least three reflectance modes of operation and a second light reflected by the switchable mirror system in another of the at least three reflectance modes of operation have different polarizations.