Method and apparatus for providing back-lighting in an interferometric modulator display device

• US 7,603,001 B2
• Filed: 02/17/2006
• Issued: 10/13/2009
• 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: Ganti, Surya Prakash, Wang, Chun-Ming, Tung, Ming-Hau
• Primary Examiner(s): WONG, TINA MEI SENG
• Application Number:
  US11/357,702
• Publication Number:
  US 20070196040A1
• Time in Patent Office: 1,334 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 light in an interferometric modulator device 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 and to provide a path for light from a backlight for lighting the interferometric modulators.

Claims

1. A micro electromechanical system (MEMS) comprising:

a transparent substrate; and

a plurality of interferometric modulators comprising;

an optical stack coupled to the transparent substrate;

a reflective layer over the optical stack;

one or more posts to support the reflective layer and to provide a path for light to pass through the one or more posts for lighting the interferometric modulators;

one or more mirrors arranged to direct the light from the one or more posts toward a layer of transparent or translucent material disposed beneath the optical stack; and

a plurality of light scatterers or reflectors disposed with respect to said layer of transparent or translucent material beneath the optical stack to redirect the light passing through the one or more posts into the optical stack and the reflective layer.

2. The MEMS of claim 1, wherein the layer of transparent or translucent material disposed beneath the optical stack comprises a glass layer between the transparent substrate and the optical stack.

3. The MEMS of claim 2, wherein the glass layer comprises first spin-on glass (SOG) including the plurality of scatterers or reflectors.

4. The MEMS of claim 3, wherein the one or more posts comprise a transparent polymer or second spin-on glass (SOG).

5. The MEMS of claim 1, wherein the one or more posts extend from the substrate through the reflective layer.

6. The MEMS of claim 1, as a display system, further comprising:

a display including the MEMS;

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

a memory device in electrical communication with the processor.

7. The display system of claim 6, further comprising:

a backlight coupled to the display for providing light to the interferometric modulators, the backlight being located on a side of the reflective layer opposite of the transparent substrate.

8. The display system of claim 6, further comprising:

a first controller configured to send at least one signal to the display; and

a second controller configured to send at least a portion of the image data to the first controller.

9. The display system of claim 6, further comprising an image source module configured to send the image data to the processor.

10. The display system of claim 9, wherein the image source module comprises at least one of a receiver, transceiver, and transmitter.

11. The display system of claim 6, further comprising an input device configured to receive input data and to communicate the input data to the processor.

12. The MEMS of claim 1, wherein the one or more mirrors are disposed at a lower end of said one or more posts.

13. The MEMS of claim 12, wherein the one or more mirrors comprises a sloped surface.

14. The MEMS of claim 12, wherein the one or more mirrors is arranged such that light can pass through the one or more posts in a first direction generally perpendicular to the substrate and be reflected by the one or more mirrors in a second direction generally parallel to the substrate beneath the optical stack.

15. The MEMS of claim 1, wherein the layer of light transparent or translucent material comprises the plurality of scatterers or reflectors therein.

16. The method of claim 15, wherein the one or more mirrors are formed at a lower end of said one or more posts.

17. The method of claim 15, wherein the one or more mirrors are formed to include a sloped surface.

18. The method of claim 15, wherein the one or more mirrors are formed such that light can pass through the one or more posts in a first direction generally perpendicular to the substrate and be reflected by the one or more mirrors in a second direction generally parallel to the substrate beneath the optical stack.

19. A micromechanical system (MEMS) comprising:

a transparent substrate means; and

a plurality of means for interferometrically modulating light comprising;

an optical stack means coupled to the transparent substrate means;

a moveable means for reflecting over the optical stack means;

means for supporting the moveable reflecting means and for providing a path for light through the supporting means for lighting the interferometric modulator means;

one or more mirror means arranged to direct the light from supporting means toward a region disposed beneath the optical stack means; and

a plurality of means for scattering or reflecting disposed in said region beneath the optical stack means to direct the light passing through the supporting means into the optical stack means and the moveable reflecting means.

20. The MEMS of claim 19, wherein the region disposed beneath the optical stack means comprises a glass layer between the transparent substrate means and the optical stack means, the glass layer comprising the plurality of scattering or reflecting means.

21. The MEMS of claim 20, wherein the glass layer comprises first spin-on glass (SOG) including the plurality of scattering or reflecting means.

22. The MEMS of claim 21, wherein the supporting means comprises a transparent polymer or second spin-on glass (SOG).

23. The MEMS of claim 20, wherein the supporting means extends from the optical stack means through the moveable reflecting means.

24. A method for providing light in a microelectromechanical system (MEMS), the method comprising:

providing a transparent substrate; and

forming a plurality of interferometric modulators including;

coupling an optical stack to the transparent substrate;

forming a reflective layer over the optical stack;

forming one or more posts to support the reflective layer and to provide a path for light to pass through the one or more posts for lighting the interferometric modulators;

forming one or more mirrors arranged to direct the light from the one or more posts toward a region disposed beneath the optical stack; and

forming a plurality of scatterers or reflectors disposed in said region beneath the optical stack to redirect the light passing through the one or more posts into the optical stack and the reflective layer.

25. The method of claim 24, further comprising forming a glass layer between the transparent substrate and the optical stack so as to define the region disposed beneath the optical stack, the glass layer including the plurality of scatterers or reflectors.

26. The method of claim 25, wherein the glass layer comprises first spin-on glass (SOG) including the plurality of scatterers.

27. The method of claim 25, wherein the one or more posts extend from the optical stack through the reflective layer.

28. An interferometric modulator display device manufactured in accordance with the method of claim 24.

29. The method of claim 24, wherein a layer of light transparent or translucent material is formed to include the plurality of scatterers or reflectors therein.