SYSTEMS AND METHODS OF ACTUATING MEMS DISPLAY ELEMENTS

• US 20090273596A1
• Filed: 07/10/2009
• Published: 11/05/2009
• Est. Priority Date: 08/27/2004
• Status: Abandoned Application

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Cummings, William J.
• Application Number:
  US12/501,338
• Publication Number:
  US 20090273596A1
• Time in Patent Office: Days
• US Class Current: 345/214
• 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 2310/0254 Control of polarity reversal in general, other than for liquid crystal displays
• CPC Class Codes: G09G 2320/0204 Compensation of DC component across the pixels in flat panels
• CPC Class Codes: G09G 2320/0257 Reduction of after-image effects
• CPC Class Codes: G09G 3/3466 based on interferometric effect

Abstract

Methods of writing display data to MEMS display elements are configured to minimize charge buildup and differential aging. The methods may include writing data with opposite polarities, and periodically releasing and/or actuating MEMS elements during the display updating process. Actuating MEMS elements with potential differences higher than those used during normal display data writing may also be utilized.

Claims

1. A method of writing display data to an array of MEMS display elements, comprising:

periodically writing display data to MEMS elements in a portion of said array; and

actuating all MEMS elements in said portion of said array prior to each periodic writing of said display data.

2. The method of claim 1, wherein said portion of said array comprises a row of MEMS elements of said array.

3. The method of claim 1, wherein said portion of said array comprises said entire array.

4. The method of claim 1, comprising releasing all MEMS elements in said portion of said array prior to writing display data to said portion of said array.

5. The method of claim 1, wherein the array comprises a plurality of rows of the MEMS display elements and a plurality of columns of the MEMS display elements, and wherein the portion of the array comprises at least a plurality of aligned MEMS elements.

6. The method of claim 5, wherein the portion comprises a plurality of MEMS elements in each of a plurality of rows of the array.

7. The method of claim 1, comprising:

placing substantially all MEMS elements in a row of said array in an actuated state a first time;

writing a first set of display data to said row of said array with a potential difference of a first polarity;

placing substantially all MEMS elements in said row of said array in an actuated state a second time; and

writing a second set of display data to said row of said array with a potential difference of a polarity opposite said first polarity.

8. The method of claim 7, wherein said first set of display data and said second set of display data comprise identical data.

9. The method of claim 7, wherein said first set of display data and said second set of display data comprise different data.

10. The method of claim 7, wherein said writing a first set or said writing a second set comprises releasing certain of said MEMS display elements in said row.

11. The method of claim 7, further comprising releasing substantially all MEMS elements in said row of said array, and wherein said writing a first set or said writing a second set comprises actuating certain of said MEMS display elements in said row.

12. The method of claim 1, wherein said actuating all MEMS elements in said portion comprises actuating at least some of said MEMS elements in said portion with a potential difference greater than a potential difference used when writing said display data to said at least some MEMS elements.

13. The method of claim 12, wherein said actuating at least some of said MEMS elements comprises actuating said at least some of said MEMS elements with a potential difference that is approximately twice the potential difference used when writing said display data.

14. The method of claim 12, wherein said potential difference used when writing said display data is approximately 5 volts, and wherein said actuating at least some of said MEMS elements comprises actuating said at least some of said MEMS elements with a potential difference of approximately 7 volts or approximately 10 volts.

15. A system for writing display data to an array of MEMS display elements, comprising:

a column driver configured to apply a first voltage to one or more columns of the MEMS display elements; and

a row driver configured to apply a second voltage to one or more rows of the MEMS display elements so as to create a potential difference between the first voltage and the second voltage across a plurality of MEMS elements,

wherein said column and row drivers are configured to periodically apply said first and second voltages so as to write display data to all MEMS elements in said plurality, and

wherein said column and row drivers are further configured to apply said first and second voltages so as to actuate all MEMS elements in said plurality prior to each said periodic application of said first and second voltages.

16. The system of claim 15, wherein said MEMS elements in said plurality comprise a row of MEMS elements of said array.

17. The system of claim 15, wherein said MEMS elements in said plurality comprise said entire array.

18. The system of claim 15, wherein said column and row drivers are configured to release all MEMS elements in said plurality prior to writing display data to said MEMS elements in said plurality.

19. The system of claim 15, wherein said column and row drives are configured to:

place substantially all MEMS elements in a row of said array in an actuated state a first time;

write a first set of display data to said row of said array with a potential difference of a first polarity;

place substantially all MEMS elements in said row of said array in an actuated state a second time; and

write a second set of display data to said row of said array with a potential difference of a polarity opposite said first polarity.

20. The system of claim 19, wherein said first set of display data and said second set of display data comprise identical data.

21. The system of claim 15, wherein a potential difference created across at least some of the MEMS elements in said plurality during said actuating all MEMS elements in said plurality is greater than a potential difference created across said at least some MEMS elements when writing said display data to all MEMS elements in said plurality.

22. A method of writing display data to an array of MEMS display elements, comprising:

setting substantially all MEMS elements in the array to a common state; and

writing display data to said substantially all elements in the array.

23. The method of claim 22, comprising:

actuating substantially all elements in the array; and

releasing substantially all elements in the array after said actuating.

24. The method of claim 23, wherein said actuating and releasing is performed between writing frames comprising different display data.

25. The method of claim 23, wherein said actuating and releasing is performed between writing frames comprising display data that is the same.

26. The method of claim 22, comprising:

releasing substantially all elements in the array; and

actuating substantially all elements in the array after said releasing.

27. The method of claim 26, wherein said releasing and actuating is performed between writing frames of display data.

28. The method of claim 22, wherein said setting comprises:

applying a first voltage to substantially all columns in the array; and

scanning substantially all rows in the array simultaneously with a second voltage.

29. The method of claim 22, wherein said array comprises a plurality of rows of the MEMS display elements and a plurality of columns of the MEMS display elements.