Method and system for driving MEMS display elements

• US 7,355,779 B2
• Filed: 01/06/2006
• Issued: 04/08/2008
• Est. Priority Date: 09/02/2005
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Gally, Brian J., Mignard, Marc, Cummings, William J.
• Primary Examiner(s): Schwartz; Jordan
• Assistant Examiner(s): JONES, JAMES
• Application Number:
  US11/327,191
• Publication Number:
  US 20070053652A1
• Time in Patent Office: 823 Days
• Field of Search: 359/288
• US Class Current: 359/288
• 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 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 3/3466 based on interferometric effect

Abstract

Systems and methods for driving MEMS display elements are disclosed. In one embodiment, a display comprises an array of MEMS display elements, and a driving circuit coupled to said array, wherein said driving circuit configured to provide at lease a row signal and a column signal to drive said array, and only one of said row and column signals is adjusted for temperature change. In another embodiment, a method of driving an array of MEMS display elements is disclosed, where the method comprises sensing a temperature at a predetermined location, generating one of a row signal and a column signal having a level based at least in part on the sensed temperature and the other not based on the sensed temperature, and providing said row and column signals to said array.

Claims

1. A display, comprising:

an array of microelectromechanical system (MEMS) display elements; and

a driving circuit coupled to said array and configured to provide actuation signals to drive said array, wherein said actuation signals comprise at lease a row signal and a column signal, and wherein only one of said row and column signals is adjusted for temperature change.

2. The display of claim 1, wherein only one of said row and column signals comprises a data signal representing images to be displayed in said array, and wherein only said signal comprising a data signal is adjusted for temperature change.

3. The display of claim 2, wherein at least one of the MEMS display elements comprises an interferometric modulator.

4. The display of claim 3, wherein said row and column signals comprise voltage signals.

5. The display of claim 4, wherein said row or column voltage signal to be adjusted for temperature change is designed to take one of two values, V_high and V_low, at a temperature T, which can be calculated by the following equations:

V_high=V_bias0+K_t*(T −

T₀)

V_low=−

V_bias0−

K_t*(T−

T₀)

where V_bias0 and −

V_bias0 are the voltage values chosen to drive the array at a reference temperature T₀, and K_t is a negative constant.

6. The display of claim 1, further comprising:

a processor that is configured to communicate with said display, said processor being configured to process image data; and

a memory device that is configured to communicate with said processor.

7. The display of claim 6, further comprising a controller configured to send at least a portion of said image data to said driver circuit.

8. The display of claim 6, further comprising an image source module configured to send said image data to said processor.

9. The display of claim 8, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

10. The display of claim 6, further comprising an input device configured to receive input data and to communicate said input data to said processor.

11. A method of driving an array of microelectromechanical system (MEMS) display elements, the method comprising:

sensing a temperature at a predetermined location;

generating one of a row signal and a column signal having a level based at least in part on the sensed temperature and the other of the row and column signals not based on the sensed temperature; and

providing said row and column signals to said array.

12. The method of claim 11, wherein only one of said row and column signals comprises a data signal representing images to be displayed in said array, and wherein only said signal comprising a data signal is generated based on the sensed temperature.

13. The method of claim 12, wherein at least one of the MEMS display elements comprises an interferometric modulator.

14. The method of claim 13, wherein said row and column signals comprise voltage signals.

15. The method of claim 14, wherein generating one of said row or column voltage signals based on temperature further comprises calculating at least one of two values, V_high and V_low, at a sensed temperature T, by the following equations:

V_high=V_bias0+K_t*(T−

T₀)

V_low=−

V_bias0−

K_t*(T−

T₀)

where V_bias0 and −

V_bias0 are the voltage values chosen to drive the array at a reference temperature T₀, and K_t is a negative constant.

16. A display, comprising:

means for sensing a temperature at a predetermined location;

means for generating one of a row signal and a column signal having a level based at least in part on the sensed temperature and the other of the row and column signals not based on the sensed temperature;

means for displaying image data; and

means for providing said row and column signals to said displaying means.

17. The display of claim 16, wherein only one of said row and column signals comprises a data signal representing images to be displayed in said displaying means, and wherein only said signal comprising a data signal is generated based on the sensed temperature.

18. The display of claim 17, wherein the displaying means comprises an interferometric modulator.

19. The display of claim 18, wherein said row and column signals comprise voltage signals.

20. The display of claim 19, wherein means for generating one of said row or column voltage signals based on temperature further comprises means for calculating at least one of two values, V_high and V_low, at a sensed temperature T, by the following equations:

V_high=V_bias0+K_t*(T−

T₀)

V_low=−

V_bias0−

K_t*(T−

T₀)

where V_bias0 and −

V_bias0 are the voltage values chosen to drive the array at a reference temperature T₀, and K_t is a negative constant.