Reflective display device having viewable display on both sides

• US 7,999,993 B2
• Filed: 11/08/2007
• Issued: 08/16/2011
• Est. Priority Date: 09/27/2004
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Miles, Mark W, Chui, Clarence
• Primary Examiner(s): Lester; Evelyn A.
• Application Number:
  US11/937,437
• Publication Number:
  US 20080055706A1
• Time in Patent Office: 1,377 Days
• Field of Search: 359/223, 359/224, 359290-292, 359/295, 359/298, 359/318, 345/85, 345/108
• US Class Current: 359/290
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26

Abstract

An interferometric light modulating device having two viewing surfaces is provided. In some embodiments, the device can generate two distinct images, one on each side of the device, simultaneously.

Claims

1. A light modulating device comprising:

a first layer partially reflective and partially transmissive to light;

a second layer partially reflective and partially transmissive to light, the second layer substantially parallel to the first layer and spaced from the first layer;

a cavity between the first layer and the second layer;

a first reflective surface moveable within the cavity; and

a second reflective surface moveable within the cavity.

2. The light modulating device of claim 1, wherein the first reflective surface and the first layer have a first sub-cavity therebetween, and wherein the second reflective surface and the second layer have a second sub-cavity therebetween.

3. The light modulating device of claim 2, wherein the first reflective surface and the second reflective surface have a third sub-cavity therebetween.

4. The light modulating device of claim 2, wherein, upon movement of the first reflective surface towards the first layer, the first sub-cavity decreases in size and the second sub-cavity does not necessarily change in size, and wherein, upon movement of the second reflective surface towards the second layer, the second sub-cavity decreases in size and the first sub-cavity does not necessarily change in size.

5. The light modulating device of claim 1, wherein the first reflective surface is moveable in a direction generally perpendicular to the first layer and the second reflective surface is moveable in a direction generally perpendicular to the second layer.

6. The light modulating device of claim 1, wherein the first reflective surface is movable independently with respect to the second reflective surface.

7. The light modulating device of claim 1, wherein the first reflective surface and the second reflective surface are surfaces of an element configured to move within the cavity.

8. The light modulating device of claim 7, wherein the moveable element comprises a deformable layer spaced from the first reflective surface.

9. The light modulating device of claim 8, wherein the deformable layer is spaced from the second reflective surface.

10. The light modulating device of claim 1, wherein the first reflective surface is a surface of a first element and the second reflective surface is a surface of a second element configured to move within the cavity.

11. The light modulating device of claim 10, wherein the first element comprises a deformable layer spaced from the first reflective surface.

12. The light modulating device of claim 11, wherein the second element comprises a deformable layer spaced from the second reflective surface.

13. A display system comprising:

a plurality of light modulating devices viewable from a first side and a second side, the first side viewable from a first direction, the second side viewable from a second direction substantially opposite the first direction, each light modulating device comprising;

a first layer partially reflective and partially transmissive to light;

a second layer partially reflective and partially transmissive to light, the second layer substantially parallel to the first layer and spaced from the first layer;

a cavity between the first layer and the second layer;

a first reflective surface moveable within the cavity; and

a second reflective surface moveable within the cavity;

a first electronic display comprising the first side of the plurality of light modulating devices;

a second electronic display comprising the second side of the plurality of light modulating devices;

a processor in electrical communication with the plurality of light modulating devices, the processor configured to process image data; and

a memory device in electrical communication with the processor.

14. The display system of claim 13, wherein the display system is configured to produce an image on either the first display or the second display at separate times.

15. The display system of claim 13, wherein the display system comprises a housing positionable in a plurality of configurations, the display system configured to produce an image on the first display, on the second display, or on both the first display and the second display simultaneously, depending on a configuration of the housing.

16. The display system of claim 15, wherein the display system comprises a portion of a clam shell cellular phone.

17. The display system of claim 15, wherein the display system comprises a housing positionable in an open configuration or a closed configuration, the first display viewable when the housing is in the closed configuration and the second display viewable when the housing is in the open configuration.

18. The display system of claim 13, wherein the first reflective surface and the second reflective surface are surfaces of a single layer moveable to produce an image on the first display and an image on the second display.

19. The display system of claim 18, further comprising a source of illumination configured to illuminate the first display and the second display.

20. The display system of claim 19, wherein the source of illumination is configured to illuminate the first display with a first frequency of light and to illuminate the second display with a second frequency of light, wherein the first and second frequencies are offset from one another.

21. The display system of claim 13, wherein the first reflective surface is a surface of a first layer moveable to produce an image on the first display and the second reflective surface is a surface of a second layer movable to produce an image on the second display.

22. A method of creating two oppositely facing images, the method comprising:

providing a light modulating device comprising;

a first layer partially reflective and partially transmissive to light;

a second layer partially reflective and partially transmissive to light, the second layer substantially parallel to the first layer and spaced from the first layer;

a cavity between the first layer and the second layer;

a first reflective surface moveable within the cavity; and

a second reflective surface moveable within the cavity;

moving the first reflective surface in a direction generally perpendicular to the first and second layers, thereby creating a first image viewable from a first side of the light modulating device; and

moving the second reflective surface in a direction generally perpendicular to the first and second layers, thereby creating a second image viewable from a second side of the light modulating device, the second side opposite to the first side.

23. The method of claim 22, wherein the first image is created at a first point in time and the second image is created at a different point in time.

24. The method of claim 22, wherein the first image and the second image are created simultaneously.

25. The method of claim 22, wherein the first reflective surface and the second reflective surface are surfaces of a single layer, the first and second images created by moving the single layer.

26. The method of claim 25, further comprising providing a source of illumination to illuminate the first reflective surface and the second reflective surface.

27. The method of claim 26, wherein the source of illumination illuminates the first reflective surface with light having a first frequency and illuminates the second reflective surface with light having a second frequency, wherein the first and second frequencies are offset from one another.

28. The method of claim 22, wherein the first reflective surface is a surface of a first layer moveable to produce an image on the first display and the second reflective surface is a surface of a second layer movable to produce an image on the second display.

29. A light modulating device comprising:

a first layer partially reflective and partially transmissive to light;

a second layer partially reflective and partially transmissive to light, the second layer substantially parallel to the first layer and spaced from the first layer;

a single first substrate between the first layer and the second layer;

a first reflective surface moveable within a first region between the first layer and the first substrate; and

a second reflective surface moveable within a second region between the second layer and the first substrate.

30. The light modulating device of claim 29, wherein the first substrate is not transparent to light.

31. The light modulating device of claim 29, wherein the first substrate is solid.

32. The light modulating device of claim 29, wherein the first substrate comprises glass.

33. The light modulating device of claim 29, further comprising a second substrate that is substantially transparent, wherein the second substrate is positioned such that the first layer is between the first substrate and the second substrate.

34. The light modulating device of claim 33, further comprising a third substrate that is substantially transparent, wherein the third substrate is positioned such that the second layer is between the first substrate and the third substrate.

35. The light modulating device of claim 29, wherein the first reflective surface is configured to move towards the first substrate when actuated.

36. The light modulating device of claim 35, wherein the second reflective surface is configured to move towards the first substrate when actuated.

37. A display system comprising:

a plurality of light modulating devices, each light modulating device comprising;

a first layer partially reflective and partially transmissive to light;

a second layer partially reflective and partially transmissive to light, the second layer substantially parallel to the first layer and spaced from the first layer;

a single first substrate between the first layer and the second layer;

a first reflective surface moveable within a first region between the first layer and the first substrate; and

a second reflective surface moveable within a second region between the second layer and the first substrate;

a first electronic display comprising a first side of the plurality of light modulating devices;

a second electronic display comprising a second side of the plurality of light modulating devices;

a processor that is in electrical communication with the plurality of light modulating devices, the processor configured to process image data; and

a memory device in electrical communication with the processor.

38. The display system of claim 37, wherein the first substrate is solid.

39. The display system of claim 37, wherein the first substrate comprises glass.

40. The display system of claim 37, further comprising a second substrate that is substantially transparent, wherein the second substrate is positioned such that the first layer is between the first substrate and the second substrate.

41. The display system of claim 40, further comprising a third substrate that is substantially transparent, wherein the third substrate is positioned such that the second layer is between the first substrate and the third substrate.

42. The display system of claim 37, wherein the first reflective surface is configured to move towards the first substrate when actuated and wherein the second reflective surface is configured to move towards the first substrate when actuated.

43. The display system of claim 37, wherein the display system is configured to produce an image on either the first display or the second display at separate times.

44. The display system of claim 37, wherein the display system comprises a housing positionable in a plurality of configurations, the display system configured to produce an image on the first display, the second display, or both the first display and the second display simultaneously, depending on a configuration of the housing.

45. The display system of claim 44, wherein the display system comprises a portion of a clam shell cellular phone.

46. The display system of claim 44, wherein the display system comprises a housing positionable in an open configuration or a closed configuration, the first display viewable when the housing is in the closed configuration and the second display viewable when the housing is in the open configuration.

47. The display system of claim 37, wherein the first reflective surface and the second reflective surface are surfaces of a single layer moveable to produce an image on the first display and an image on the second display.

48. A method of creating two oppositely facing images, the method comprising:

providing a light modulating device comprising;

a first layer partially reflective and partially transmissive to light;

a second layer partially reflective and partially transmissive to light, the second layer substantially parallel to the first layer and spaced from the first layer;

a single substrate between the first layer and the second layer;

a first reflective surface moveable within a first region between the first layer and the substrate; and

a second reflective surface moveable within a second region between the second layer and the substrate;

moving the first reflective surface in a direction generally perpendicular to the first and second layers, thereby creating a first image viewable from a first side of the light modulating device; and

moving the second reflective surface in a direction generally perpendicular to the first and second layers, thereby creating a second image viewable from a second side of the light modulating device, the second side opposite to the first side.

49. The method of claim 48, wherein the first image is created at a first point in time and the second image is created at a different point in time.

50. The method of claim 48, wherein the first image and the second image are created simultaneously.

51. The method of claim 48, wherein the first reflective surface and the second reflective surface are surfaces of a single layer, the first and second images created by moving the single layer.

52. The method of claim 51, further comprising providing a source of illumination to illuminate the first reflective surface and the second reflective surface.

53. The method of claim 52, wherein the source of illumination illuminates the first reflective surface with light having a first frequency and illuminates the second reflective surface with light having a second frequency, wherein the first and second frequencies are offset from one another.

54. The method of claim 48, wherein the first reflective surface is a surface of a first layer moveable to produce an image on the first display and the second reflective surface is a surface of a second layer movable to produce an image on the second display.

55. A method of manufacturing an interferometric modulator device with two viewable sides, said method comprising:

providing a first substrate;

forming a first partially reflective layer;

forming a first support portion;

forming a moveable layer;

forming a reflective layer, wherein said first support portion supports said reflective layer;

forming a second support portion;

forming a second partially reflective layer, wherein said first and second partially reflective layers are coupled to said support portions; and

applying a second substrate to the second partially reflective layer.

56. The method of claim 55, further comprising providing a sacrificial layer and etching said sacrificial layer away to create cavities.

57. The method of claim 56, further comprising providing holes to the partially reflective layers and the second substrate and using said holes to administer an etchant to the sacrificial layer.

58. The method of claim 55, further comprising:

forming a third support portion;

forming a movable layer; and

forming a second reflective layer.

59. A light modulating device created according to the method of claim 55.

60. The light modulating device of claim 59, created by the further step of forming a second movable layer, wherein said second movable layer is positioned between the first and second partially reflective layers and is further supported by said support portions.