DISPLAY WITH INTEGRATED PHOTOVOLTAIC DEVICE

• US 20090103161A1
• Filed: 10/20/2008
• Published: 04/23/2009
• Est. Priority Date: 10/19/2007
• 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 8,130,440 B2
• Time in Patent Office: Days
• US Class Current: 359/245
• 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 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence
• CPC Class Codes: G02F 1/13324 Circuits comprising solar cells
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: H01L 31/043 Mechanically stacked PV cells
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

A display with a photovoltaic (PV) cells integrated as the front side and/or back side of the display is disclosed. Ambient light may reach a PV cell situated behind a display through fully or partially transmissive features within the display. Display-generated light may also reach a PV cell behind a display. A transmissive PV material situated in front of a display may collect both ambient light as well as display-generated light.

Claims

1. A display device displaying an image toward a front side, with a back side opposite the front side, the display device comprising:

a display comprising an array of active pixels in an image region; and

a photovoltaic cell comprising a photovoltaic material formed over one of the front side and the back side of the display in the image region, wherein the photovoltaic cell is oriented to be capable of receiving light.

2. The device of claim 1, wherein the photovoltaic material is a blanket layer.

3. The device of claim 1, wherein the photovoltaic cell is oriented to be capable of receiving ambient light.

4. The device of claim 1, the display further comprising a light source, wherein the photovoltaic cell is oriented to be capable of receiving light emitted by the light source.

5. The device of claim 1, further comprising:

a front photovoltaic cell comprising a photovoltaic material formed over the front side of the display in the image region; and

a back photovoltaic cell comprising a photovoltaic material formed over the back side of the display in the image region.

6. The device of claim 1, wherein the photovoltaic material comprises a deposited thin film photovoltaic material.

7. The device of claim 1, wherein the photovoltaic material comprises a single crystal photovoltaic material.

8. The device of claim 2, wherein the photovoltaic material is formed over the front side of the display in the image region.

9. The device of claim 8, wherein the photovoltaic cell is capable of receiving and converting to electricity both ambient light as well as light generated by the display.

10. The device of claim 9, wherein the photovoltaic cell comprises a transparent conducting film in electrical contact with the photovoltaic material on the front side and back side of the photovoltaic material.

11. The device of claim 8, wherein the photovoltaic material has a transmittance of greater than 65% of visible light incident on the photovoltaic material.

12. The device of claim 8, wherein the display comprises a microelectromechanical system (MEMS) device.

13. The device of claim 12, wherein the active pixels comprise interferometric modulators each comprising an optical absorber, a reflector, and a variable gap between the absorber and the reflector.

14. The device of claim 8, the display further comprising a light source, wherein the photovoltaic cell is oriented to be capable of receiving and converting to electricity light from the light source.

15. The device of claim 14, wherein the light source comprises a light source behind of the array of active pixels.

16. The device of claim 15, wherein the active pixels comprise liquid crystal display pixels.

17. The device of claim 8, wherein the active pixels are light-emissive active pixels.

18. The device of claim 17, wherein the light-emissive active pixels are selected from the group consisting of light-emitting diodes, organic light-emitting diodes, field emission displays, and liquid crystal displays.

19. The device of claim 2, wherein the photovoltaic material is formed over the back side of the display in the image region.

20. The device of claim 19, wherein the display comprises gaps between the active pixels capable of allowing ambient light to reach the photovoltaic material.

21. The device of claim 19, the display further comprising inactive structures within the array region, wherein the inactive structures are at least partially transparent and capable of allowing ambient light to reach the photovoltaic material.

22. The device of claim 19, wherein the display is primarily reflective.

23. The device of claim 19, wherein the active pixels are configured to be partially transmissive, wherein the partially transmissive active pixels are capable of allowing ambient light to pass through and reach the photovoltaic material.

24. The device of claim 19, wherein the active pixels comprise microelectromechanical systems (MEMS) devices.

25. The device of claim 24, wherein the active pixels comprise interferometric modulators, each interferometric modulator comprising an optical absorber, a reflector, and a variable gap between the absorber and the reflector.

26. The device of claim 25, wherein the reflector is configured to allow up to about 50% of visible light incident upon the reflector to reach the photovoltaic material.

27. The device of claim 25, wherein the reflector is a metal layer with a thickness of less than 225 Å

.

28. The device of claim 19, the display further comprising a light source, wherein the photovoltaic cell is oriented to be capable of receiving and converting to electricity light from the light source.

29. The device of claim 28, wherein the light source comprises a light source behind the array of active pixels.

30. The device of claim 29, wherein the active pixels comprise liquid crystal display pixels.

31. The device of claim 1, further comprising:

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

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

32. The device of claim 31, further comprising a driver circuit configured to send at least one signal to the display.

33. The device of claim 31, further comprising an input device configured to receive input data and to communicate the input data to the processor.

34. A method of manufacturing a display device, the display device configured to display an image toward a front side, with a back side opposite the front side, the method comprising:

providing a display comprising an array of active pixels in an image region; and

disposing a photovoltaic material over one of a front and a back side of the display in the image region.

35. The method of claim 34, further comprising forming a transparent conducting film in electrical contact with the photovoltaic material on the back side of the photovoltaic material.

36. The method of claim 34, wherein disposing the photovoltaic material comprises laminating the photovoltaic material over a front or back side of the array region.

37. The method of claim 36, further comprising forming a thin film photovoltaic material onto an optically suitable substrate and laminating the substrate over a front or back side of the array region.

38. A method of operating a display, the method comprising:

receiving light in a photovoltaic material at one of a front side and a back side of a display element in an image region; and

converting the light into electricity.

39. The method of claim 38, further comprising storing the electricity for later use.

40. The method of claim 38, further comprising using the electricity to power one of the display and an electrical device associated with the display.

41. The method of claim 40, wherein the electricity is used to power both the display and the electrical device.

42. The method of claim 38, further comprising passing the light through the photovoltaic material, receiving and converting a portion of the light to electricity in the photovoltaic material and passing another portion of the light to be incident upon the display element.

43. The method of claim 38, further comprising passing the light through the display element and receiving and converting a portion of the light to electricity in the photovoltaic material.

44. A display device displaying an image toward a front side, with a back side opposite the front side, the display device comprising:

means for displaying a pixilated image; and

means for converting light into electricity, wherein the converting means is positioned over one of a front side and a back side of the displaying means.