Method and apparatus for providing brightness control in an interferometric modulator (IMOD) display

• US 20070247704A1
• Filed: 04/21/2006
• Published: 10/25/2007
• Est. Priority Date: 04/21/2006
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Mignard, Marc
• Granted Patent: US 8,004,743 B2
• Time in Patent Office: Days
• US Class Current: 359/365
• 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: G09G 2320/0242 Compensation of deficiencies in the appearance of colours
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 3/3466 based on interferometric effect
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

Methods and systems for providing brightness control in an interferometric modulator (IMOD) display are provided. In one embodiment, an interferometric modulator display pixel is provided that includes a microelectromechanical systems (MEMS) interferometric modulator having an associated first color spectrum, and a color absorber located substantially in front of the interferometric modulator display pixel, in which the color absorber has an associated second color spectrum. The microelectromechanical systems (MEMS) interferometric modulator is operable to shift the first color spectrum relative to the second color spectrum to control a visual brightness of the interferometric modulator display pixel independent of a color of the interferometric modulator display pixel.

Claims

1. An interferometric modulator display pixel comprising:

a microelectromechanical systems (MEMS) interferometric modulator having an associated first color spectrum indicating a reflectance of light at a first pre-determined peak wavelength,

wherein the microelectromechanical systems (MEMS) interferometric modulator is operable to shift the first color spectrum relative to a second color spectrum to control a visual brightness of the interferometric modulator display pixel independent of a color of the interferometric modulator display pixel, the second color spectrum indicating absorption of light except at a second pre-determined peak wavelength that is different from the first pre-determined wavelength.

2. The interferometric modular display pixel of claim 1, further comprising a color absorber located substantially in front of the interferometric modulator, wherein the color absorber has the second color spectrum.

3. The interferometric modulator display pixel of claim 1, wherein the visual brightness of the interferometric modulator display pixel increases with greater overlap between the first color spectrum and the second color spectrum, and decreases with less overlap between the first color spectrum and the second color spectrum.

4. The interferometric modulator display pixel of claim 1, further comprising a light source.

5. The interferometric modulator display pixel of claim 1, wherein:

the interferometric modulator display pixel comprises a plurality of color space regions, each color space region having a corresponding color spectrum associated therewith; and

the interferometric modulator display pixel further comprises a color absorber located substantially in front of each color space region, each color absorber having an associated color spectrum,

wherein the microelectromechanical systems (MEMS) interferometric modulator is operable to shift the color spectrum of each color space region relative to a color spectrum of a corresponding color absorber to control a visual brightness of a color associated with each color space region.

6. The interferometric modulator display pixel of claim 5, wherein the plurality of color space regions comprises one or more of a red color space region, a green color space region, or a blue color space region.

7. The interferometric modulator display pixel of claim 1, wherein one or more light sources provides light at the second color spectrum associated with the color absorber.

8. The interferometric modulator display pixel of claim 7, wherein the one or more light sources comprise a narrow spectrum light source or a broad spectrum light source.

9. The interferometric modulator display pixel of claim 8, wherein the narrow spectrum light source comprises a laser or a light-emitting diode (LED).

10. The interferometric modulator display pixel of claim 8, wherein the broad spectrum light source comprises a mercury lamp or a carbon arc lamp.

11. The interferometric modulator display pixel of claim 1, wherein the microelectromechanical systems (MEMS) interferometric modulator comprises:

a first electrode layer;

a second electrode layer;

a support structure which separates the first electrode from the second electrode layer; and

a reflective element located and movable between a first position and a second position located between the first and second electrode layers, wherein movement of the reflective element between the first position and the second position shifts the first color spectrum relative to the second color spectrum.

12. The interferometric modulator display pixel of claim 11 wherein the reflective element is coupled to the second electrode layer.

13. The interferometric modulator display pixel of claim 11 wherein the reflective element is the second electrode layer.

14. A display comprising the interferometric modulator display pixel of claim 1.

15. The display of claim 14, further comprising:

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

a memory device in electrical communication with the processor.

16. The display of claim 15, further comprising:

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

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

17. The display of claim 15, further comprising an image source module configured to send the image data to the processor.

18. The display of claim 17, wherein the image source module comprises at least one of a receiver, transceiver, and transmitter.

19. The display of claim 15, further comprising an input device configured to receive input data and to communicate the input data to the processor.

20. An interferometric modulator display pixel comprising:

a microelectromechanical systems (MEMS) interferometric modulator means having an associated first color spectrum indicating a reflectance of light at a first pre-determined peak wavelength; and

a color absorber means located substantially in front of the interferometric modulator display pixel, the color absorber means having an associated second color spectrum indicating absorption of light except at a second pre-determined peak wavelength that is different from the first pre-determined wavelength,

wherein the microelectromechanical systems (MEMS) interferometric modulator means is operable to shift the first color spectrum relative to the second color spectrum to control a visual brightness of the interferometric modulator display pixel independent of a color of the interferometric modulator display pixel.

21. A method of manufacturing an interferometric modulator display device, the method comprising:

providing a substrate;

forming an optical stack on the substrate;

forming a moveable reflective layer over the optical stack; and

providing a color absorber on a surface of the substrate, the color absorber absorbing light except light within a pre-determined range of wavelengths.

22. The method of claim 21, wherein the color absorber is formed on the surface of the substrate opposite of the optical stack.

23. The method of claim 21, wherein the color absorber is formed on the surface of the substrate on a same side as the optical stack.

24. The method of claim 21, wherein forming an optical stack on the substrate and forming a moveable reflective layer over the optical stack comprises:

forming a first conductive plate on the substrate;

depositing an oxide layer over the first conductive plate;

depositing a sacrificial layer over the oxide layer;

forming a plurality of first support posts to support a second conductive plate;

forming the second conductive plate over the sacrificial layer and the plurality of first support posts; and

etching away the sacrificial layer.

25. An interferometric modulator display device manufactured in accordance with the method of claim 21.