Electrochromic rearview mirror assembly incorporating a display/signal light

• US 20020154379A1
• Filed: 04/03/2002
• Published: 10/24/2002
• Est. Priority Date: 04/02/1997
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Cammenga, David J., Tonar, William L., Anderson, John S., Watson, Alan R., Forgette, Jeffrey A., Turnbull, Robert R., Bugno, Mark D., Hall, Philip B.
• Granted Patent: US 6,700,692 B2
• Time in Patent Office: Days
• US Class Current: 359/267
• CPC Class Codes: B60Q 1/2665 on rear-view mirrors lighting devices for vehicle interior on or for rear-view mirrors B60Q3/258
• CPC Class Codes: B60Q 1/2669 on door or boot handles lighting devices for vehicle interior on door handles B60Q3/267
• 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 1/1207 with lamps; with turn indicators
• CPC Class Codes: B60R 2001/1215 with information displays
• CPC Class Codes: B60R 2001/1223 with sensors or transducers
• CPC Class Codes: C09K 9/02 Organic tenebrescent materials
• CPC Class Codes: F21S 43/14 Light emitting diodes [LED]
• CPC Class Codes: F21S 45/47 Passive cooling, e.g. using fins, thermal conductive elements or openings
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/85 characterised by the material liquid coolants F21V29/56
• CPC Class Codes: F21V 29/89 Metals
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 2027/0114 comprising dichroic elements
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G02F 1/155 Electrodes
• CPC Class Codes: G02F 1/157 Structural association of cells with optical devices, e.g. reflectors or illuminating devices
• CPC Class Codes: G02F 1/163 Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor
• CPC Class Codes: G02F 2001/1502 complementary cell
• CPC Class Codes: G02F 2001/15145 : the electrochromic layer comprises a mixture of anodic and cathodic compounds
• CPC Class Codes: G02F 2201/58 : Arrangements comprising a monitoring photodetector
• CPC Class Codes: G02F 2203/09 : transflective
• CPC Class Codes: H01L 23/49562 : for devices being provided for in H01L29/00
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12044 : OLED
• CPC Class Codes: H04R 1/08 : Mouthpieces; Microphones; Attachments therefor
• CPC Class Codes: H10K 50/84 : Passivation; Containers; Encapsulations
• CPC Class Codes: H10K 50/85 : Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/87 : Arrangements for heating or cooling

Abstract

According to one embodiment of the present invention, an electrochromic rearview mirror assembly for a vehicle includes an electrochromic mirror having a variable reflectivity, a glare sensor for sensing levels of light directed towards the front element from the rear of the vehicle, an ambient sensor for sensing levels of ambient light, a display positioned behind the partially transmissive, partially reflective portion of the reflector for displaying information therethrough; and a control circuit coupled to the sensors and the display. The control circuit determines whether daytime or nighttime conditions are present as a function of the ambient light level sensed by the ambient sensor. During daytime conditions, the control circuit responds to light levels sensed by the glare sensor to control a contrast ratio of light originating from the display and light reflecting from the partially transmissive, partially reflective area of the reflector.

Claims

1. A rearview mirror assembly for a vehicle comprising:

a mirror comprising a reflector having a partially transmissive, partially reflective area;

a first sensor for sensing light levels;

a display positioned behind the partially transmissive, partially reflective portion of said reflector for displaying information therethrough; and

a control circuit coupled to said first sensor and said display, said control circuit determines whether daytime or nighttime conditions are present, and, during daytime conditions, said control circuit responds to light levels sensed by said first sensor to control a contrast ratio of light originating from said display and light reflecting from said partially transmissive, partially reflective area of said reflector.

2. The rearview mirror assembly of claim 1, wherein said mirror is an electrochromic mirror having a variable reflectivity, said electrochromic mirror comprising:

front and rear elements each having front and rear surfaces;

a transparent first electrode including a layer of conductive material carried on a surface of one of said elements;

a second electrode carried on a surface of one of said elements;

an electrochromic material contained between said elements and having a variable transmissivity; and

a second sensor for sensing levels of ambient light,

wherein said first sensor is a glare sensor for sensing levels of light directed at said mirror from the rear of the vehicle,

wherein said reflector is carried on a surface of said rear element, wherein said second electrode is integrated with said reflector when said reflector is carried on the front surface of said rear element, and

wherein said control circuit is coupled to said first and second electrodes for controlling the reflectivity of said electrochromic mirror in response to light levels sensed by said sensors.

3. The rearview mirror assembly of claim 2, wherein said control circuit controls the contrast ratio by reducing the reflectivity of at least a portion of said electrochromic mirror.

4. The rearview mirror assembly of claim 3, wherein said control circuit controls the contrast ratio by additionally increasing the brightness level of said display.

5. The rearview mirror assembly of claim 1, wherein said control circuit controls the contrast ratio by increasing the brightness level of said display.

6. The rearview mirror assembly of claim 2, wherein during nighttime conditions, said control circuit controls the reflectivity of said electrochromic mirror in response to light levels sensed by said sensors, and reduces the brightness level of said display relative to the display brightness levels during daytime conditions.

7. The rearview mirror assembly of claim 6, wherein said control circuit transmits a display brightness control signal to at least one additional display remote from the rearview mirror assembly to which the at least one additional display responds by varying its brightness level.

8. The rearview mirror assembly of claim 7, wherein said control circuit transmits a display brightness control signal that varies the brightness level of the at least one additional display between two different brightness levels.

9. The rearview mirror assembly of claim 7, wherein said control circuit transmits a display brightness control signal that varies the brightness level of the at least one additional display throughout a range of different brightness levels.

10. The rearview mirror assembly of claim 1, wherein said control circuit varies the brightness level of said display during nighttime conditions.

11. The rearview mirror assembly of claim 1, wherein said control circuit determines whether daytime or nighttime conditions are present by comparing light levels sensed by said first sensor to a threshold.

12. The rearview mirror assembly of claim 1 and further including a second sensor for sensing ambient light levels, wherein said control circuit determines whether daytime or nighttime conditions are present by comparing ambient light levels sensed by said second sensor to a threshold.

13. The rearview mirror assembly of claim 12, wherein said first sensor is a rearward facing sensor for sensing the level of light directed at the mirror from the rear of the vehicle.

14. The rearview mirror assembly of claim 1, wherein said control circuit determines whether daytime or nighttime conditions are present in response to a signal representing the status of the vehicle'"'"'s headlamps.

16. The display device of claim 15, wherein said first and second ranges of brightness levels are disjoint.

17. The display device of claim 16, wherein said first and second ranges of brightness levels represent separate portions of a wider continuous range.

18. The display device of claim 15, wherein said first and second ranges of brightness levels overlap.

19. The display device of claim 15, wherein one of said first and second ranges of brightness levels is a subset of the other.

15. A display device for a vehicle comprising:

a light sensor for sensing ambient light levels;

a display for displaying information to an occupant of the vehicle; and

a control circuit coupled to said display and said light sensor, said control circuit determines whether daytime or nighttime conditions are present as a function of the ambient light level sensed by said light sensor, and, during daytime conditions, said control circuit varies the brightness level of said display within a first range of brightness levels, and, during nighttime conditions, said control circuit varies the brightness level of said display within a second range of brightness levels, which is different from the first range of brightness levels.

20. A rearview mirror assembly for a vehicle comprising:

a housing;

a mirror supported by said housing;

an ambient sensor supported by said housing for sensing levels of ambient light; and

a control circuit supported by said housing and coupled to said ambient sensor and coupled to a display device remote from the rearview mirror assembly, said control circuit determines whether daytime or nighttime conditions are present as a function of the ambient light level sensed by said ambient sensor, generates a display brightness control signal based upon the determination of daytime/nighttime condition and transmits the display brightness control signal to the remote display device to which the remote display device responds by varying its brightness level.

21. The rearview mirror assembly of claim 20, wherein said housing is configured for mounting to the inside of the vehicle.

22. The rearview mirror assembly of claim 20 and further comprising a display supported by said housing and coupled to said control circuit, wherein said control circuit controls the brightness level of said display as a function of ambient light levels sensed by said ambient sensor.

23. The rearview mirror assembly of claim 22, wherein said mirror is an electrochromic mirror.

24. The rearview mirror assembly of claim 23 and further comprising:

a glare sensor for sensing levels of light directed towards said electrochromic mirror from the rear of the vehicle;

an ambient sensor for sensing levels of ambient light;

a display positioned behind said electrochromic mirror for displaying information therethrough; and

a control circuit coupled to said sensors and said display, wherein, during daytime conditions, said control circuit responds to light levels sensed by said glare sensor to control a contrast ratio of light originating from said display and light reflecting from said electrochromic mirror.

26. The rearview mirror assembly of claim 25, wherein said second electrode is a reflective electrode being partially transmissive and partially reflective over substantially all of said front surface of said rear element.

27. The rearview mirror assembly of claim 26, wherein said reflective electrode is formed over substantially all of said front surface of said rear element, said reflective electrode including a transparent electrically conductive coating, and a thin reflective layer of silver or silver alloy applied over said transparent electrically conductive coating.

28. The rearview mirror assembly of claim 26, wherein said reflective electrode is partially transmissive and partially reflective with a reflectance of at least about 50 percent and a transmittance of at least about 10 percent in at least portions of the visible spectrum.

29. The rearview mirror assembly of claim 25, wherein said anti-reflective structure is an anti-reflective coating applied to a surface of said display assembly.

30. The rearview mirror assembly of claim 25, wherein said anti-reflective structure is an anti-reflective treatment applied to a surface of said display assembly.

25. A rearview mirror assembly for a vehicle comprising:

a housing adapted to be mounted to the vehicle;

front and rear elements mounted in said housing, said elements each having front and rear surfaces;

an electrochromic material contained between said elements;

a transparent first electrode including a layer of conductive material carried on a surface of one of said elements;

a second electrode disposed on said front surface of said rear element;

a light emitting display assembly mounted in said housing, said display assembly having a cover having a rear surface and a front surface that is mounted adjacent said rear surface of said rear element; and

an anti-reflective structure applied to a surface of said display assembly,

wherein either said second electrode is a reflective electrode or a separate reflector is disposed over substantially all of said rear surface of said rear element, said reflective electrode/reflector being partially transmissive and partially reflective in at least a location in front of said display assembly.

31. A rearview mirror assembly for a vehicle comprising:

a housing adapted to be mounted to the vehicle;

front and rear elements mounted in said housing, said elements each having front and rear surfaces;

a transparent first electrode including a layer of conductive material carried on a surface of one of said elements;

a second electrode disposed on said front surface of said rear element; and

an electrochromic material contained between said elements,

wherein one of said front and rear elements comprises an organic light emitting diode display, and

wherein either said second electrode is a reflective electrode or a separate reflector is disposed over substantially all of said rear surface of said rear element.

32. A rearview mirror assembly for a vehicle comprising:

front and rear elements each having front and rear surfaces;

a transparent first electrode including a layer of conductive material carried on a surface of one of said elements;

a second electrode carried on a surface of one of said elements;

an electrochromic material contained between said elements and having a variable transmissivity;

a reflector carried on a surface of said rear element, wherein said second electrode is integrated with said reflector when said reflector is carried on the front surface of said rear element, at least a portion of said reflector is partially transmissive and partially reflective; and

a light emitting display assembly mounted in said housing, said display assembly is mounted adjacent said rear surface of said rear element,

wherein a region of said reflector in front of said display assembly exhibits a reflective gradient whereby the reflectivity of the reflector gradually decreases throughout at least a portion of the region in front of said display assembly.

33. An electrochromic device comprising:

front and rear elements each having front and rear surfaces;

a transparent first electrode including a layer of conductive material carried on a surface of one of said elements;

a second electrode carried on a surface of one of said elements;

an electrochromic material contained between said elements and having a variable transmissivity; and

a reflector carried on a surface of said rear element, wherein said second electrode is integrated with said reflector when said reflector is carried on the front surface of said rear element, at least a portion of said reflector is partially transmissive and partially reflective,

wherein said reflector is a diffuse reflector for diffusing and reflecting light incident thereon.

34. A display device comprising the electrochromic device of claim 33.

36. The electrochromic mirror of claim 35, wherein said transparent electrically conductive material is indium tin oxide.

37. The electrochromic mirror of claim 36, wherein said first reflective coating comprises a first layer of a first reflective material and a second layer of second reflective material.

38. The electrochromic mirror of claim 37, wherein said first reflective material is a silver alloy.

39. The electrochromic mirror of claim 38, wherein said second reflective material is chrome.

40. The electrochromic mirror of claim 39, wherein said second layer is masked in the region in front of the light source.

41. The electrochromic mirror of claim 40, wherein said first layer is masked in the region in front of the light source.

42. The electrochromic mirror of claim 35, wherein said first reflective coating comprises a first layer of a first reflective material and a second layer of second reflective material.

43. The electrochromic mirror of claim 42, wherein said second reflective material is chrome.

44. The electrochromic mirror of claim 42, wherein said first reflective material is a silver alloy.

45. The electrochromic mirror of claim 42, wherein at least one of said first and second layers is masked in the region in front of the light source.

49. The electrochromic mirror of claim 48, wherein both said front and rear elements have a thickness ranging from about 0.5 mm to about 1.8 mm.

50. The electrochromic mirror of claim 48, wherein:

said chamber contains a free-standing gel comprising a solvent and a cross-linked polymer matrix,

said chamber further contains at least one electrochromic material; and

said polymer matrix cooperatively interacts with said front and rear elements.

51. The electrochromic mirror of claim 48, wherein said at least one electrochromic material is in solution with said solvent and, as part of said solution, interspersed in said cross-linked polymer matrix.

52. The electrochromic mirror of claim 48, wherein said front and rear elements each have a thickness ranging from about 0.8 mm to about 1.2 mm.

53. The electrochromic mirror of claim 48, wherein said front and rear elements are bent to a convex shape.

54. The electrochromic mirror of claim 48, wherein said front and rear elements are bent to an aspheric shape.

55. The electrochromic mirror of claim 48, wherein at least one of said front and rear elements have a thickness ranging from about 0.5 mm to about 1.6 mm.

56. The electrochromic mirror of claim 48, wherein at least one of said front and rear elements have a thickness ranging from about 0.5 mm to about 1.5 mm.

57. The electrochromic mirror of claim 48, wherein at least one of said front and rear elements have a thickness ranging from about 0.5 mm to about 1.2 mm.

59. The electrochromic mirror of claim 58, wherein the electrochromic mirror is adapted for use in a rearview mirror assembly having a light source positioned behind the electrochromic mirror for selectively projecting light therethrough, said electrochromic mirror said second electrode includes a region in front of the light source that is at least partially transmissive.

35. An electrochromic mirror for use in a rearview mirror assembly having a light source positioned behind the electrochromic mirror for selectively projecting light therethrough, said electrochromic mirror comprising:

front and rear spaced elements, each having front and rear surfaces;

a transparent first electrode including a layer of conductive material disposed on said rear surface of said front element;

an electrochromic medium contained between said elements; and

a second electrode overlying said front surface of said rear element, said second electrode including a first reflective coating and a second coating of transparent electrically conductive material, wherein said second electrode includes a region in front of the light source that is at least partially transmissive.

46. A rearview mirror assembly for a vehicle comprising:

a housing adapted to be mounted to the vehicle;

,

front and rear elements mounted in said housing, said elements each having front and rear surfaces;

a transparent first electrode including a layer of conductive material carried on a surface of one of said elements;

a second electrode disposed on said front surface of said rear element;

an electrochromic material contained between said elements; and

a computer video monitor disposed over a surface of one of said front and rear elements and coupled to a computer for displaying information provided from the computer,

wherein either said second electrode is a reflective electrode or a separate reflector is disposed over substantially all of said rear surface of said rear element.

47. A rearview mirror assembly for a vehicle comprising:

a housing adapted to be mounted to the vehicle;

front and rear elements mounted in said housing, said elements each having front and rear surfaces;

a transparent first electrode including a layer of conductive material carried on a surface of one of said elements;

a second electrode disposed on said front surface of said rear element;

an electrochromic material contained between said elements; and

an electroluminescent display disposed over a surface of one of said front and rear elements,

wherein either said second electrode is a reflective electrode or a separate reflector is disposed over substantially all of said rear surface of said rear element.

48. An electrochromic mirror comprising:

front and rear elements each having front and rear surfaces, wherein at least one of said front and rear elements has a thickness ranging from about 0.5 mm to about 1.8 mm;

a transparent first electrode including a layer of conductive material carried on a surface of one of said elements;

a second electrode carried on a surface of one of said elements;

an electrochromic material contained between said elements and having a variable transmissivity; and

a reflector carried on a surface of said rear element, wherein said second electrode is integrated with said reflector when said reflector is carried on the front surface of said rear element, at least a portion of said reflector is partially transmissive and partially reflective.

58. An electrochromic mirror comprising:

front and rear spaced elements, each having front and rear surfaces;

a transparent first electrode including a layer of conductive material disposed on said rear surface of said front element;

an electrochromic medium contained between said elements; and

a second electrode overlying said front surface of said rear element, said second electrode includes a layer of white gold.

60. An electrochromic rearview mirror assembly comprising:

an electrochromic mirror element having a variable reflectivity; and

a display device positioned behind said electrochromic mirror element for displaying information in a first color through said electrochromic mirror element, said display device comprising at least one first light source for emitting light of a second color and at least one second light source for emitting light of a third color, the second and third colors being different from each other and from the first color while mixing together to form light of the first color.

61. The electrochromic rearview mirror assembly of claim 60, wherein said light sources each comprising at least one LED chip.

62. The electrochromic rearview mirror assembly of claim 60, wherein said first light source is a first LED that emits red light, said second light source is a second LED that emits green light, and wherein the first color is amber.

63. The electrochromic rearview mirror assembly of claim 60, wherein said electrochromic mirror element attenuates light of the first color.

64. The electrochromic rearview mirror assembly of claim 60, wherein said display device further comprising a liquid crystal display element, wherein said light sources are arranged to transmit light through said liquid crystal display element.

65. The electrochromic rearview mirror assembly of claim 64, wherein said light sources are arranged to provide backlighting for said liquid crystal display element.

66. The electrochromic rearview mirror assembly of claim 60, wherein said display device further comprises an indicia etched in a reflective layer of said electrochromic mirror.

67. The electrochromic rearview mirror assembly of claim 60, wherein said display device further comprises an indicia formed in an applique panel.