Method and apparatus for providing back-lighting in a display device

• US 7,933,475 B2
• Filed: 08/19/2009
• Issued: 04/26/2011
• Est. Priority Date: 02/17/2006
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Wang, Chun-Ming, Tung, Ming-Hau, Ganti, Surya Prakash
• Primary Examiner(s): WONG, TINA MEI SENG
• Application Number:
  US12/544,184
• Publication Number:
  US 20090310208A1
• Time in Patent Office: 615 Days
• Field of Search: None
• US Class Current: 385/1
• 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

Methods and apparatus for providing lighting in a display are provided. In one embodiment, a microelectromechanical system (MEMS) is provided that includes a transparent substrate and a plurality of interferometric modulators. The interferometric modulators include an optical stack coupled to the transparent substrate, a reflective layer over the optical stack, and one or more posts to support the reflective layer and to provide a path for light from a backlight for lighting the display.

Claims

1. A display comprising:

a plurality of display elements supported by a transparent substrate, the plurality of display elements having a viewing side;

a backlight positioned on a side of the plurality of display elements opposite the viewing side;

one or more waveguides positioned between the display elements, the one or more waveguides configured to provide a path for light emitted by the backlight to illuminate the display elements, wherein the one or more waveguides comprise one or more posts configured to support at least a portion of the display elements; and

a plurality of light scatterers or reflectors disposed between the transparent substrate and the plurality of display elements.

2. The display of claim 1, wherein the one or more waveguides are configured to direct the light emitted by the backlight to the viewing side of the display elements.

3. The display of claim 1, wherein the display elements are reflective display elements.

4. The display of claim 1, where in the display elements are micro electromechanical display elements.

5. The display of claim 4, wherein the display elements comprise interferometric modulators.

6. The display of claim 1, further comprising:

a processor in electrical communication with the display elements, the processor configured to process image data; and

a memory device in electrical communication with the processor.

7. The display of claim 1, wherein the plurality of light scatterers or reflectors are configured to redirect the light passing through the one or more waveguides to the display elements.

8. A display comprising:

a plurality of display elements having a viewing side, the plurality of display elements comprising interferometric modulators that comprise;

an optical stack coupled to a transparent substrate;

a reflective layer over the optical stack, forming a gap between the optical stack and the reflective layer; and

one or more posts wherein at least a portion of the one or more posts is disposed directly vertically between the optical stack and the reflective layer to support the reflective layer, the one or more posts comprising one or more waveguides; and

a backlight positioned on a side of the plurality of display elements opposite the viewing side, wherein the one or more waveguides are configured to provide a path for light emitted by the backlight to illuminate the display elements.

9. The display of claim 8, further comprising a plurality of light scatterers or reflectors disposed on the same side of the transparent substrate as the optical stack, wherein the plurality of light scatterers or reflectors are configured to redirect the light passing through the one or more waveguides to the display elements.

10. The display of claim 9, further comprising a glass layer on the viewing side of the display elements, the glass layer including the plurality of light scatterers or reflectors.

11. A display comprising:

a plurality of display elements having a viewing side;

a backlight positioned on a side of the plurality of display elements opposite the viewing side;

one or more waveguides positioned between the display elements, the one or more waveguides configured to provide a path for light emitted by the backlight to illuminate the display elements;

a plurality of light scatterers or reflectors configured to redirect the light passing through the one or more waveguides to the display elements; and

one or more reflecting surfaces arranged to direct light emitted by the one or more waveguides to the plurality of light scatterers or reflectors.

12. The Display of claim 11, further comprising a transparent substrate supporting the plurality of display elements, wherein the plurality of light scatterers or reflectors are disposed between the transparent substrate and the plurality of display elements.

13. A display comprising:

a plurality of means for modulating light formed on a substrate means, the plurality of light modulating means having a viewing side;

a means for emitting light positioned on a side of the plurality of light modulating means opposite the viewing side;

one or more means for guiding light positioned between the plurality of light modulating means, the one or more light guiding means configured to provide a path for light emitted by the light emitting means to illuminate the plurality of light modulating means, wherein the one or more light guiding means comprise one or more means for supporting at least a portion of the light modulating means; and

a plurality of means for scattering or reflecting light configured to redirect the light passing through the one or more light guiding means to the plurality of light modulating means, wherein the plurality of scattering or reflecting means are disposed on the same side of the substrate means as the plurality of light modulating means.

14. The display of claim 13, wherein the one or more light guiding means are configured to direct the light emitted by the light emitting means to the viewing side of the plurality of light modulating means.

15. A display comprising:

a plurality of means for modulating light having a viewing side, one or more of the plurality of light modulating means comprising;

a first means for reflecting coupled to a substrate means;

a second means for reflecting, said second reflecting means being movable and positioned over the first reflecting means forming a gap between the first reflecting means and the second reflecting means; and

means for supporting the second reflecting means, wherein at least a portion of the supporting means is disposed directly between the first reflecting means and the second reflecting means, wherein the supporting means comprises one or more means for guiding light; and

a means for emitting light positioned on a side of the plurality of light modulating means opposite the viewing side, wherein the one or more light guiding means are configured to provide a path for light emitted by the light emitting means to illuminate the plurality of light modulating means.

16. The display of claim 15, further comprising a plurality of means for scattering or reflecting light configured to redirect the light passing through the light guiding means to the light modulating means.

17. A display comprising:

a plurality of means for modulating light, the plurality of light modulating means having a viewing side;

a means for emitting light positioned on a side of the plurality of light modulating means opposite the viewing side;

one or more means for guiding light positioned between the plurality of light modulating means, the one or more light guiding means configured to provide a path for light emitted by the light emitting means to illuminate the plurality of light modulating means;

a plurality of means for scattering or reflecting light configured to redirect the light passing through the one or more light guiding means to the plurality of light modulating means; and

a means for reflecting arranged to direct light from the light guiding means to the plurality of light scattering or reflecting means.

18. The display of claim 17, wherein the plurality of light modulating means comprises a plurality of display elements, or wherein the light emitting means comprises a backlight, or wherein the one or more light guiding means comprises one or more light guides, or wherein the plurality of scattering or reflecting means comprises a plurality of scatterers or reflectors dispersed in a glass layer, or wherein the reflecting means comprises a reflective surface.

19. The Display of claim 17, further comprising a substrate means for supporting the plurality of light modulating means, wherein the plurality of scattering or reflecting means are disposed between the substrate means and the light modulating means.

20. A method for providing a display, the method comprising:

providing a plurality of display elements supported by a transparent substrate, the plurality of display elements having a viewing side;

positioning a backlight on a side of the plurality of display elements opposite the viewing side;

forming one or more waveguides between the display elements, wherein the one or more waveguides are configured to provide a path for light emitted by the backlight to illuminate the display elements, wherein the one or more waveguides comprise one or more posts configured to support at least a portion of the display elements; and

forming a plurality of light scatterers or reflectors on the same side of the transparent substrate as the display elements.

21. The method of claim 20, wherein the plurality of light scatterers or reflectors are configured to redirect the light passing through the one or more waveguides to the display elements.

22. A method for providing a display, the method comprising:

providing a transparent substrate;

forming a plurality of interferometric modulators having a viewing side including;

coupling an optical stack to the transparent substrate;

forming a reflective layer over the optical stack forming a gap between the optical stack and the reflective layer; and

forming one or more posts wherein at least a portion of the one or more posts is disposed between the optical stack and the reflective layer to support the reflective layer, the one or more posts comprising one or more waveguides; and

positioning a backlight on a side of the interferometric modulators opposite the viewing side, wherein the one or more waveguides are configured to provide a path for light emitted by the backlight to illuminate the interferometric modulators.

23. A method for providing a display, the method comprising:

providing a plurality of display elements having a viewing side;

positioning a backlight on a side of the plurality of display elements opposite the viewing side;

forming one or more waveguides between the display elements, wherein the one or more waveguides are configured to provide a path for light emitted by the backlight to illuminate the display elements;

forming a plurality of light scatterers or reflectors configured to redirect the light passing through the one or more waveguides to the display elements; and

forming one or more reflective surfaces arranged to direct the light from the one or more waveguides toward the plurality of light scatterers or reflectors.