System and method for addressing a MEMS display

• US 7,388,697 B2
• Filed: 10/25/2006
• Issued: 06/17/2008
• Est. Priority Date: 12/09/2003
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Chui, Clarence, Mignard, Marc, Mathew, Mithran C.
• Primary Examiner(s): Choi; William C
• Application Number:
  US11/586,179
• Publication Number:
  US 20070035804A1
• Time in Patent Office: 601 Days
• Field of Search: 359/198, 359/247, 359/290, 359/291, 359/302
• US Class Current: 359/198.1
• 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
• CPC Class Codes: G09G 2300/06 Passive matrix structure, i.e. with direct application of both column and row voltages to the light emitting or modulating elements, other than LCD or OLED
• 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

Abstract

A system and method for addressing an array of MEMS display elements, such as interferometric modulators, from a drive control. A display includes groups of display elements that are addressed with a commonly applied drive signal. In one embodiment, the groups of display elements are configured to have different response times and are driven by pulses of varying length indicative of those response times. In another embodiment, the groups of display elements are configured to have different actuation voltages and are driven by pulses of varying voltage indicative of those actuation voltages.

Claims

1. A method of addressing a plurality of display elements having at least a first and second display element and characterized by respective response thresholds, the method comprising:

generating a first pulse characterized by a parameter having a value greater than the response threshold of the first display element and less than the response threshold of the second display element; and

applying the first pulse to the plurality of display elements.

2. The method of claim 1, wherein the parameter comprises a pulse duration and the response threshold comprises a response time of the respective display element.

3. The method of claim 1, wherein the parameter comprises a voltage magnitude and the response threshold comprises an actuation voltage of the respective display element.

4. The method of claim 1, wherein the state of the second element is maintained.

5. The method of claim 1, further comprising:

receiving an image data signal; and

setting the state of each of the first and second display elements based, at least in part, on the image data signal.

6. The method of claim 1, further comprising:

generating a second pulse of a second value of the parameter that is greater than the response threshold of a third display element, wherein the second value is less than the response threshold of the first display element; and

applying the second pulse to the plurality of display elements.

7. The method of claim 1, wherein applying the first pulse to the plurality of display elements comprises applying the first pulse to a plurality of interferometric modulators.

8. The method of claim 7, wherein each of the plurality of interferometric modulators comprises a movable mirror characterized by a respective resistance when moving through air.

9. The method of claim 8, wherein the respective response times of the plurality of interferometric modulators are based, at least in part, on the respective air resistance of the movable mirror, and wherein the first and second display elements are characterized by different resistances to movement through air.

10. The method of claim 1, wherein the plurality of display elements is characterized by respective resistor-capacitor (RC) time constants.

11. The method of claim 10, wherein the respective response times of the plurality of display elements are based, at least in part, on the respective RC time constants, and wherein the first and second display elements are characterized by different RC time constants.

12. The method of claim 1, wherein the plurality of display elements is characterized by respective physical properties.

13. The method of claim 12, wherein the respective response times of the plurality of display elements are based, at least in part, on the respective spring constants, and wherein the first and second display elements are characterized by different spring constants.

14. The method of claim 1, wherein applying the first pulse to the plurality of display elements comprises applying the first pulse to a pixel of a visual display.

15. The method of claim 14, wherein the pixel comprises the plurality of display elements.

16. The method of claim 1, wherein applying the first pulse to the plurality of display elements comprises applying a voltage pulse.

17. The method of claim 1, wherein applying the first pulse to the plurality of display elements comprises applying a first voltage pulse to a row of the display elements and applying a second voltage pulse to a column of the display elements, and wherein each of the first and second display elements is associated with the row and the column.

18. A driver circuit for addressing a plurality of display elements having at least a first and second display element and characterized by respective response thresholds, the driver circuit comprising:

means for generating a first pulse characterized by a parameter having a value greater than the response threshold of the first display element and less than the response threshold of the second display element; and

means for applying the first pulse to the plurality of display elements.

19. The driver circuit of claim 18, wherein the parameter comprises a pulse duration and the response threshold comprises a response time of the respective display element.

20. The driver circuit of claim 18, wherein the parameter comprises a voltage magnitude and the response threshold comprises an actuation voltage of the respective display element.

21. The driver circuit of claim 18, wherein the state of the second element is maintained.

22. The driver circuit of claim 18, further comprising:

means for receiving an image data signal; and

means for setting the state of each of the first and second display elements based, at least in part, on the image data signal.

23. The driver circuit of claim 18, further comprising:

means for generating a second pulse of a second value of the parameter that is greater than the response threshold of a third display element, wherein the second value is less than the response threshold of the first display element; and

means for applying the second pulse to the plurality of display elements.

24. The driver circuit of claim 18, wherein the means for applying the first pulse to the plurality of display elements comprises means for applying the first pulse to a plurality of interferometric modulators.

25. The driver circuit of claim 18, wherein the means for applying the first pulse to the plurality of display elements comprises means for applying the first pulse to a pixel of a visual display.

26. The driver circuit of claim 18, wherein the means for applying the first pulse to the plurality of display elements comprises means for applying a voltage pulse.

27. The driver circuit of claim 18, wherein the means for applying the first pulse to the plurality of display elements comprises means for applying a first voltage pulse to a row of the display elements and applying a second voltage pulse to a column of the display elements, and wherein each of the first and second display elements is associated with the row and the column.