BACKLIGHT DISPLAYS

• US 20090323154A1
• Filed: 06/25/2008
• Published: 12/31/2009
• Est. Priority Date: 06/25/2008
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Sampsell, Jeffrey B.
• Granted Patent: US 7,791,783 B2
• Time in Patent Office: Days
• US Class Current: 359/247
• 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

A transmissive backlit display is disclosed. In one aspect, the backlit display comprises a backlight and an array of transmissive interferometric modulators. Each interferometric modulator comprises a fixed and moving dielectric mirror stack. The interferometric modulators cause light within the desired wavelength range to be transmitted while reflecting at least a portion of the remaining light.

Claims

1. A transmissive display device, comprising:

an array of transmissive interferometric modulators deposited on a back side of a substrate;

a back plate having a front side and a back side, the front side of the back plate being sealed to the back side of the substrate; and

a reflective black mask located between the front side of the back plate and the substrate and patterned to cover at least the non-active areas of the array of interferometric modulators.

2. The device of claim 1, wherein the reflective black mask is deposited on the front side of the back plate.

3. The device of claim 1, wherein the reflective black mask is located between the back side of the substrate and the array.

4. The device of claim 1, further comprising a light source behind the back side of the back plate, the light source being configured to illuminate the array.

5. The device of claim 1, further comprising:

an absorbing black mask deposited on the front side of the substrate and patterned to cover at least the non-active areas.

6. The device of claim 1, wherein each interferometric modulator comprises:

a cavity defined by a fixed first layer deposited on the substrate and a movable second layer connected to the substrate, the first and second layers being partially transparent;

wherein light incident to the interferometric modulator is interferometrically modulated by the first and second layer.

7. The device of claim 6, wherein each of the first and second layers comprises dielectric material.

8. The device of claim 6, wherein each of the first and second layers comprises metal or metal oxide.

9. The device of claim 6, wherein the second layer is movable between a first and a second position.

10. The device of claim 9, wherein each interferometric modulator is configured to block out a substantial amount of visible light while the second layer is in a second position.

11. The device of claim 9, wherein each interferometric modulator is configured to pass through light of a particular wavelength range while the second layer is in a first position.

12. The device of claim 1, wherein the reflective black mask is configured to reflect light coming from the back of the display.

48. The device of claim 1, wherein the array is enclosed by the back plate and the substrate.

13. A transmissive display device, comprising:

an array of interferometric modulators deposited on a back side of a substrate; and

a collimated light source located on the back side of the substrate and configured to illuminate through the array,

wherein each interferometric modulator comprises a cavity defined by a fixed first layer deposited on the substrate and a movable second layer connected to the substrate, the first and second layers being partially transparent, wherein light incident to the interferometric modulator is interferometrically modulated by the first and second layer.

14. The device of claim 13, further comprising:

an array of lenslets with each lenslet aligning with one interferometric modulator to converge incidental light into the active area of the interferometric modulator.

16. The device of claim 13, wherein each of the first and second layers comprises dielectric material.

17. The device of claim 13, wherein each of the first and second layers comprises metal or metal oxide.

18. The device of claim 13, wherein the second layer is movable between a first and a second position.

19. The device of claim 18, wherein each interferometric modulator is configured to block out a substantial amount of visible light while the second layer is in a second position.

20. The device of claim 18, wherein each interferometric modulator is configured to pass through light of a particular wavelength range while the second layer is in a first position.

15. (canceled)

21. A transmissive display device, comprising:

an array of interferometric modulators positioned on a back side of a substrate; and

an angle converter positioned on a front side of the substrate and configured to change angular distribution of incoming light based on the direction of the light when the light passes through the angle converter, wherein the angle converter broadens angular distribution of the light passing through the array.

22. The device of claim 21, wherein the angle converter is configured to reduce reflection of light coming from the front side of the substrate.

24. The device of claim 21, further comprising a light source located on the back side of the substrate, the light source being configured to illuminate the array.

25. The device of claim 24, wherein the light source is substantially collimated.

26. The device of claim 21, wherein each interferometric modulator comprises:

a cavity defined by a fixed first layer deposited on the substrate and a movable second layer connected to the substrate, the first and second layers being partially transparent;

wherein light incident to the interferometric modulator is interferometrically modulated by the first and second layer.

27. The device of claim 26, wherein each of the first and second layers comprises dielectric material.

28. The device of claim 26, wherein each of the first and second layers comprises metal or metal oxide.

29. The device of claim 26, wherein the second layer is movable between a first and a second position.

30. The device of claim 29, wherein each interferometric modulator is configured to block out a substantial amount of visible light while the second layer is in a second position.

31. The device of claim 29, wherein each interferometric modulator is configured to pass through light of a particular wavelength range while the second layer is in a first position.

32. The device of claim 21, further comprising:

a display;

a processor that is configured to communicate with said display, said processor being configured to process image data; and

a memory device that is configured to communicate with said processor.

33. The device of claim 32, further comprising a driver circuit configured to send at least one signal to the display.

34. The device of claim 33, further comprising a controller configured to send at least a portion of the image data to the driver circuit.

35. The device of claim 32, further comprising an image source module configured to send said image data to said processor.

36. The device of claim 35, wherein the image source module comprises at least one of a receiver, transceiver, and transmitter.

37. The device of claim 32, further comprising an input device configured to receive input data and to communicate said input data to said processor.

50. The device of claim 21, wherein the angle converter is fixed.

51. The device of claim 21, wherein the angle converter comprises at lest two black masks separated by a gap.

52. The device of claim 51, wherein the two black mask form an approximately semi-parabolic cavity over an interferometric modulator.

23. (canceled)

38. A transmissive display device, comprising:

means for transmissively and interferometrically modulating light, the modulating means being deposited on a first side of a substrate distal from a user;

means for enclosing the modulating means, the enclosing means being sealed to the first side of the substrate; and

means for covering at least the non-active areas of the modulating means and reflecting light coming from a side near the enclosing means, the covering means being located between the enclosing means and the substrate.

39. The device of claim 38, wherein the modulating means comprises an array of interferometric modulators.

40. The device of claim 38, wherein the enclosing means comprises a back plate.

41. The device of claim 38, wherein the covering means comprises a reflective black mask.

49. The device of claim 38, wherein the modulating means is enclosed by the enclosing means and the substrate.

42. A transmissive display device, comprising:

means for transmissively and interferometrically modulating light, the modulating means being deposited on a back side of a substrate, the modulating means comprising an array of interferometric modulators, wherein each interferometric modulator comprises a cavity defined by a fixed first layer deposited on the substrate and a movable second layer connected to the substrate, the first and second layers being partially transparent, wherein light incident to the interferometric modulator is interferometrically modulated by the first and second layer; and

means for illuminating the modulating means with substantially collimated light.

44. The device of claim 42, wherein the illuminating means comprises a collimated light source.

43. (canceled)

45. A transmissive display device, comprising:

transmissive means for interferometrically modulating light, the modulating means being deposited on a back side of a substrate; and

means for changing angular distribution of incoming light based on the direction of the light when the light passes through the changing means, the changing means being positioned on a front side of the substrate, the changing means being configured to broaden angular distribution of the light passing through the modulating means.

46. The device of claim 45, wherein the modulating means comprises an array of interferometric modulators.

47. The device of claim 45, wherein the changing means comprises an angle converter.

53. The device of claim 45, wherein the changing means is fixed.

54. The device of claim 46, wherein the changing means comprises at lest two black masks separated by a gap.

55. The device of claim 54, wherein the two black mask form an approximately semi-parabolic cavity over an interferometric modulator.