SIMULTANEOUS LIGHT COLLECTION AND ILLUMINATION ON AN ACTIVE DISPLAY

• US 20090126777A1
• Filed: 11/14/2008
• Published: 05/21/2009
• Est. Priority Date: 11/16/2007
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Khazeni, Kasra, Kothari, Manish
• Granted Patent: US 8,941,631 B2
• Time in Patent Office: Days
• US Class Current: 136/246
• 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
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G09G 2330/023 using energy recovery or conservation
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/3466 based on interferometric effect
• CPC Class Codes: H01L 31/052 Cooling means directly associated or integrated with the PV cell, e.g. integrated Peltier elements for active cooling or heat sinks directly associated with the PV cells cooling means in combination with the PV module H02S40/42
• CPC Class Codes: H01L 31/0547 comprising light concentrating means of the reflecting type, e.g. parabolic mirrors, concentrators using total internal reflection
• CPC Class Codes: Y02E 10/52 PV systems with concentrators

Abstract

In various embodiments described herein, a display device comprising a light collection film and a photovoltaic device disposed on an edge of the collection film. The collection film has a plurality of light-turning features for redirecting light between the front and back surface of the collection film and the photovoltaic device. In some embodiments, a light source is also disposed on an edge of the collection film and emits light which is turned by the light-turning features toward the display.

Claims

1. A display device comprising:

an active array of display pixels having a front display surface for facing a viewer and a back display surface;

at least one collection film adjacent to one of the front or back display surfaces, the collection film having a front collection film surface, a back collection film surface, at least one edge, and a plurality of light-turning features, wherein the light-turning features are configured to redirect light between the front or back collection film surface and an edge of the collection film; and

a photovoltaic device disposed on the edge of the collection film and oriented to receive light laterally transmitted from the light-turning features through the collection film surface.

2. The display device of claim 1, further comprising a light source disposed on an edge of the collection film.

3. The display device of claim 2, wherein the light source comprises a light-emitting diode (LED).

4. The display device of claim 1, wherein the light source is disposed on the same edge as the photovoltaic device.

5. The display device of claim 1, wherein the light source is disposed at a different location from the photovoltaic device.

6. The display device of claim 1, wherein the collection film comprises a thin film having a thickness between about 0.5 mm to 10 mm.

7. The display device of claim 1, further comprising a plurality of collection films disposed in a stack structure, each collection film having a front collection film surface, a back collection film surface, at least one edge, and a plurality of light-turning features, wherein the light-turning features are configured to redirect light between the front or back collection film surface and an edge of the collection film.

8. The display device of claim 1, wherein the light-turning features of the collection film comprise prismatic features.

9. The display device of claim 8, wherein the prismatic features are symmetrical.

10. The display device of claim 8, wherein the prismatic features are asymmetrical.

11. The display device of claim 10, wherein the prismatic features comprise slits.

12. The display device of claims 10, wherein the photovoltaic device and a light source are disposed on opposite edges of the collection film and the asymmetric prismatic features of the collection film are configured to redirect ambient light from the front collection film surface to the photovoltaic device and to redirect emitted light from the light source to the back collection film surface.

13. The display device of claim 1, wherein the light-turning features comprise diffractive features.

14. The display device of claim 1, wherein the light-turning features comprise holographic features.

15. The display device of claim 1, wherein the pixels of the active array of display pixels employ a reflective display technology.

16. The display device of claim 15, wherein the pixels of the active array of display pixels incorporate microelectromechanical systems (MEMS) devices.

17. The display device of claim 16, wherein the MEMS devices are interferometric modulators (IMODs).

18. The display device of claim 15, wherein the pixels of the active array of display pixels incorporate liquid crystal display (LCD) devices.

19. The display device of claim 15, wherein the collection film is disposed on the front display surface of the active array of display pixels.

20. The display device of claim 15, wherein the collection film is disposed on the back display surface of the active array of display pixels.

21. The display device of claim 20, wherein a second collection film is disposed on the front display surface of the active array of display pixels.

22. This display device of claim 20, wherein ambient light can pass through at least one inactive region between active pixel regions of the array.

23. The display device of claim 22, wherein the pixels of the active array of display pixels are transflective, wherein a portion of ambient light passes through active pixel regions to reach the collection film.

24. The display device of claim 22, wherein the inactive region comprises areas between pixels.

25. The display device of claim 22, wherein a percentage of about 5% to about 50% of visible light is allowed to pass through the active array of display pixels.

26. The display device of claim 1, wherein the pixels of the active array of display pixels employ an emissive display technology.

27. The display device of claim 26, wherein the pixels of the active array of display pixels employ a display technology chosen from a group consisting of LED, OLED, FED, and backlit reflective technologies.

28. The display device of claim 27, wherein the pixels of the active array of display pixels incorporate organic light emitting diode (OLED) devices.

29. The display device of claim 26, wherein the pixels of the active array of display pixels incorporate liquid crystal display (LCD) devices.

30. The display device of claim 26, wherein the collection film is disposed on the front display surface of the active array of display pixels.

31. The display device of claim 26, wherein the collection film is disposed on the back display surface of the active array of display pixels.

32. The display device of claim 31, wherein a second collection film is disposed on the front display surface of the active array of display pixels.

33. A display device comprising:

an array of display pixels;

at least one collection film disposed next to the array of display pixels, the collection film having a plurality of light-turning features, wherein the light-turning features are configured to redirect light between a front or back collection film surface and edges of the collection film;

at least one photovoltaic device disposed at a first edge of the collection film, wherein the photovoltaic device is oriented to receive light laterally transmitted from the light-turning features through the collection film; and

at least one light source disposed at a second edge, wherein the light source emits light laterally through the collection film to be turned by the light-turning features toward the array of display pixels.

34. A display device comprising:

a means for displaying and altering images;

a means for converting light energy into an alternate form of energy; and

a means for turning light from a direction incident on the means for displaying images to a lateral direction along the display surface toward the means for converting light energy into an alternate form of energy.

35. The display device of claim 34, further comprising a means for emitting light.

36. The display device of claim 34, wherein the means for displaying images comprises an active array of display pixels having a front display surface, a back display surface, and at least one edge.

37. The display device of claim 34, wherein the means for converting light energy into an alternate form of energy comprises a photovoltaic device.

38. The display device of claim 34, wherein the means for turning light comprises a collection film having a front collection film surface, a back collection film surface, and a plurality of light-turning features, wherein the light-turning features are configured to redirect light between the front or back collection film surface and an edge of the collection film.

39. A method of light collection and image display comprising:

actively displaying images in an image area;

collecting light from the image area;

turning the light from the image area to at least one edge of the image area; and

converting the light to an electrical current.

40. The method of claim 39, further comprising emitting light from an edge of the image area and turning the light to the image area.

41. The method of claim 39, wherein actively displaying comprises moving a microelectromechanical systems (MEMS) mirror.

42. The method of claim 39, wherein the image area comprises an array of display pixels operatively coupled to at least one collection film.

43. A method of manufacturing a display device comprising:

operatively coupling a collection film to a front or back display surface of an active array of display pixels, the collection film having a front collection film surface, a back collection film surface, at least one edge, and a plurality of light-turning features; and

aligning a photovoltaic device with the edge of the collection film, such that ambient light is re-directed by the light-turning features from the front collection film surface to the photovoltaic device at the edge of the collection film to be converted into electrical energy.

44. The method of claim 43, further comprising disposing a light source on an edge of the collection film to emit light.