System and method for multi-level brightness in interferometric modulation

• US 20060067643A1
• Filed: 04/01/2005
• Published: 03/30/2006
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Chui, Clarence
• Granted Patent: US 7,302,157 B2
• Time in Patent Office: Days
• US Class Current: 385/147
• 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 2300/0439 Pixel structures
• CPC Class Codes: G09G 3/2011 by amplitude modulation
• CPC Class Codes: G09G 3/207 by domain size control G09G3/3637 takes precedence
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/3466 based on interferometric effect
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

A display having a plurality of reflective display elements. In one embodiment, the display elements comprise at least one electrode having a plurality of active areas. In one embodiment, at least two of the sizes of the active areas are different with respect to each other, e.g., they are non-uniform in size. The interferometric modulators have a plurality of states, wherein selected ones of the interferometric modulators are configured to be actuated depending differing electrostatic forces in the interferometric modulators. The electrostatic forces in the interferometric modulators are different at least in part due to variations in the sizes of the active areas of the electrodes.

Claims

1. A display element, comprising:

at least one electrode having a plurality of active areas, at least two of the sizes of the active areas being different with respect to each other; and

at least one array of interferometric modulators, selected ones of the interferometric modulators being configured to be actuated depending varying electrostatic forces in the interferometric modulators, the electrostatic forces in the interferometric modulators varying at least in part due to variations in the sizes of the active areas of electrodes in the interferometric modulators.

2. The display element of claim 1, wherein the electrodes have a substantially staircase shape from a viewing perspective of the display element.

3. The display element of claim 1, wherein the electrodes have a pyramidal shape from a viewing perspective of the display element.

4. The display element of claim 1, additionally comprising a latch electrode for modifying an activation voltage threshold of at least one of the interferometric modulators.

5. The display element of claim 1, wherein the latch electrode is placed proximate to an end of an active area of the interferometric modulators.

19. The display element of claim 1, additionally comprising a latch electrode for modifying an activation voltage threshold of at least one of the reflective display elements.

6. A display comprising:

a plurality of reflective display elements, each of the display elements having;

a first electrode; and

a second electrode having a substantially non-uniform width, wherein the second electrode spans at least two display elements.

7. The display of claim 6, wherein the first electrode is perpendicular to the second electrode.

8. The display element of claim 6, wherein the display element has a first optical property when the second electrode is in an non-activated state with respect to the first electrode, and wherein the display element has a second optical property when the second electrode is in an activated state with respect to the first electrode.

9. The display of claim 6, wherein second electrode has a substantially staircase shape from a viewing perspective of the display.

10. The display of claim 6, wherein the second electrode has a pyramidal shape from a viewing perspective of the display.

11. The display of claim 6, additionally comprising a latch electrode for modifying an activation voltage threshold of at least one of the reflective display elements.

12. The display of claim 6, wherein the latch electrode is placed proximate to an end of an active area of the reflective display elements.

13. A method comprising:

providing a voltage to an electrode having a substantially non-uniform width; and

in response to the provided voltage, activating selected ones of a plurality of reflective display elements.

14. The method of claim 13, additionally comprising providing a latch voltage so to modify an activation voltage threshold of at least one of the reflective display elements.

15. The method of claim 13, wherein the electrode has a substantially staircase shape from a viewing perspective of the display.

16. The method of claim 13, wherein the electrode has a pyramidal shape from a viewing perspective of the display.

17. A reflective display element comprising:

a first electrode having a non-uniform width; and

a second electrode, wherein the first electrode is configured to activate selected portions of the first electrode in response to varying a difference in the voltage between the first electrode and the second electrode.

18. The reflective display element of claim 17, wherein the first electrode is positioned substantially perpendicular to the second electrode.

20. A method comprising:

varying a difference in voltage between a first electrode and a second electrode, wherein the first electrode has a non-uniform shape, and wherein the varied voltage results in a change in an optical characteristic of an interferometric modulator; and

in response to the varied voltage, selectively activating or deactivating fractional portions of the second electrode.

21. The method of claim 20, additionally comprising providing a latch voltage to maintain the actuated portion of the second electrode in an actuated state.