FRAME RATES IN A MEMS DISPLAY BY SELECTIVE LINE SKIPPING

• US 20100245338A1
• Filed: 03/27/2009
• Published: 09/30/2010
• Est. Priority Date: 03/27/2009
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Todorovich, Mark M.
• Granted Patent: US 8,248,358 B2
• Time in Patent Office: Days
• US Class Current: 345/214
• CPC Class Codes: G09G 2310/0213 controlling the sequence of the scanning lines with respect to the patterns to be displayed, e.g. to save power
• CPC Class Codes: G09G 2310/0267 Details of drivers for scan electrodes, other than drivers for liquid crystal, plasma or OLED displays
• CPC Class Codes: G09G 2310/0278 Details of driving circuits arranged to drive both scan and data electrodes
• CPC Class Codes: G09G 2310/04 Partial updating of the display screen
• 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 improving frame rate in MEMS display devices are disclosed. Lines are selected for skipping during updates based on the desired frame rate and the visual effect of skipping the particular line.

Claims

1. A method of operating a bi-stable display, the method comprising:

determining a drive schedule for a plurality of bi-stable display elements arranged in a plurality of rows and columns; and

during a display update, skipping at least one of the rows or columns based upon the determined drive schedule.

2. The method of claim 1, wherein determining the drive schedule comprises

determining a desired display update rate.

3. The method of claim 2, wherein determining the drive schedule further comprises:

determining an actual display update rate capability; and

comparing the actual display update rate capability to the desired display update rate.

4. The method of claim 3, further comprising determining a number of the rows or columns, which, when skipped, cause the actual display rate capability to be equal to or exceed the desired display update rate.

5. The method of claim 3, wherein determining the actual display update rate capability comprises determining an amount of time required to update a row or column.

6. The method of claim 5, wherein determining the amount of time required to update the row or column further comprises:

detecting a physical parameter; and

estimating the amount of time required to update the row or column based, at least in part, on the physical parameter.

7. The method of claim 6, wherein the physical parameter is a temperature.

8. The method of claim 6, wherein the physical parameter is an actuation voltage of one or more of the plurality of bi-stable display elements.

9. The method of claim 5, wherein determining the amount of time required to update the row or column further comprises:

measuring an accumulated charge applied to the row or column over a known period of time; and

comparing the accumulated charge to a known quantity of charge required to actuate the row or column.

10. The method of claim 5, wherein determining the amount of time required to update the row or column further comprises accessing a fixed time value associated with one or more of the plurality of bi-stable display elements.

11. The method of claim 1, further comprising determining a number of rows or columns to skip.

12. The method of claim 11, further comprising:

dividing the plurality of rows and columns into a plurality of groups; and

dividing the number of the rows or columns to skip among the plurality of groups.

13. The method of claim 12, wherein the number of the rows or columns allotted to each group is approximately even.

14. The method of claim 1, wherein determining the drive schedule comprises associating a priority value with the at least one of the rows or columns.

15. The method of claim 14, wherein the priority value is determined based, at least in part, on a number of times the at least one of the rows or columns has been skipped during one or more previous display updates.

16. The method of claim 14, wherein the priority value is determined based, at least in part, on a color of light associated with the at least one of the rows or columns.

17. The method of claim 14, wherein the priority value is determined based, at least in part, on a priority value associated with another row or column that is adjacent to the at least one of the rows or columns.

18. A bi-stable display system, the system comprising:

a display comprising a plurality bi-stable elements arranged in a plurality of rows and columns; and

a processor configured to communicate with said display, said processor being configured to determine a drive schedule and skip at least one of the rows or columns during an update of the display based upon the determined drive schedule.

19. The system of claim 18, wherein the processor is further configured to determine a desired display update rate.

20. The system of claim 19, wherein the processor is further configured to:

determine an actual display update rate capability; and

compare the actual display update rate capability to the desired display update rate.

21. The system of claim 18, wherein the processor is further configured to determine a number of the rows or columns, which, when skipped, cause the actual display rate capability to be equal to or exceed the desired display update rate.

22. The system of claim 20, wherein the processor is further configured to determine an amount of time required to update a row or column.

23. The system of claim 22, wherein the processor is further configured to:

detect a physical parameter; and

estimate the amount of time required to update the row or column based, at least in part, on the physical parameter.

24. The system of claim 23, wherein the physical parameter is a temperature.

25. The system of claim 23, wherein the physical parameter is an actuation voltage of one or more of the plurality of bi-stable display elements.

26. The system of claim 22, wherein the processor is further configured to:

measure an accumulated charge applied to the row or column over a known period of time; and

compare the accumulated charge to a known quantity of charge required to actuate the row or column.

27. The system of claim 22, wherein the processor is further configured to access a fixed time value associated with one or more of the plurality of bi-stable display elements.

28. The system of claim 18, wherein the processor is further configured to determine a number of rows or columns to skip.

29. The system of claim 28, wherein the processor is further configured to:

divide the plurality of rows and columns into a plurality of groups; and

divide the number of the rows or columns to skip among the plurality of groups.

30. The system of claim 29, wherein the number of the rows or columns allotted to each group is approximately even.

31. The system of claim 18, wherein determining the drive schedule comprises associating a priority value with the at least one of the rows or columns.

32. The system of claim 31, wherein the priority value is determined based, at least in part, on a number of times the at least one of the rows or columns has been skipped during one or more previous display updates.

33. The system of claim 31, wherein the priority value is determined based, at least in part, on a color of light associated with the at least one of the rows or columns.

34. The system of claim 31, wherein the priority value is determined based, at least in part, on a priority value associated with another row or column that is adjacent to the at least one of the rows or columns.

35. The system of claim 18, further comprising:

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

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

36. The system of claim 35, further comprising a driver circuit configured to send at least one signal to said display.

37. The system of claim 36, further comprising a controller configured to send at least a portion of said image data to said driver circuit.

38. The system of claim 35, further comprising an image source module configured to send said image data to said second processor.

39. The system of claim 38, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

40. The system of claim 35, further comprising an input device configured to receive input data and to communicate said input data to said second processor.

41. A bi-stable display system, the system comprising:

means for displaying display data; and

means for determining a drive schedule for updating the display means and skipping at least one of the rows or columns during an update of the display means based upon the determined drive schedule.

42. The system of claim 41, wherein:

the display means comprises a plurality of bi-stable elements arranged in a plurality of rows and columns; and

the determining means comprises a processor.