Drive scheme for a display

• US 8,669,926 B2
• Filed: 11/30/2011
• Issued: 03/11/2014
• Est. Priority Date: 11/30/2011
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Mignard, Marc M., Chui, Clarence, Lewis, Alan G.
• Primary Examiner(s): Nguyen, Jennifer
• Application Number:
  US13/308,427
• Publication Number:
  US 20130135271A1
• Time in Patent Office: 832 Days
• Field of Search: 345/55, 345/85, 345/108, 345/204, 359237-275, 359290-295, 359/316
• US Class Current: 345/85
• 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 2300/0473 Use of light emitting or modulating elements having two or more stable states when no power is applied
• 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 2340/16 Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 3/2014 by modulation of the duration of a single pulse during which the logic level remains constant
• CPC Class Codes: G09G 3/2081 with combination of amplitude modulation and time modulation space and time error diffusion G09G3/2066
• CPC Class Codes: G09G 3/3466 based on interferometric effect

Abstract

This disclosure provides systems, methods and apparatus for writing a display image to a display having an array of pixels according to a selected driving sequence. In one aspect, display elements in a row are driven using a tall and narrow voltage pulse. This allows display elements of a row to be driven in a shorter line time.

Claims

1. A method for addressing a plurality of display elements comprising:

applying a first potential to a segment electrode of a first display element;

applying a second potential different from the first potential to a segment electrode of a second display element;

applying a third potential to a common electrode of both display elements for a selected duration;

wherein a potential difference produced across the first and second display elements during the selected duration has an amplitude and duration greater than a response threshold of the first display element and less than a response threshold of the second display element, wherein the response threshold of the first display element is based at least in part on the first potential applied to the segment electrode of the first display element, and wherein the response threshold of the second display element is based at least in part on the second potential applied to the segment electrode of the second display element; and

wherein the potential difference across the first display element during the selected duration has an amplitude outside of a first hysteresis window of the first display element and wherein the potential difference across the second display element during the selected duration has an amplitude outside a second hysteresis window of the second display element.

2. The method of claim 1, wherein a gap between the common electrode and the segment electrode of the first display element is based at least in part on the first potential applied to the segment electrode of the first display element, and wherein a gap between the common electrode and segment electrode of the second display element is based at least in part on the second potential applied to the segment electrode of the second display element, and wherein both the first display element and the second display element are in a relaxed state prior to applying the third potential to the common electrodes of both the first and second display elements.

3. The method of claim 1, wherein the first hysteresis window is approximately equal to the second hysteresis window.

4. The method of claim 1, wherein the response threshold of the first display element is a first mechanical response time and the response threshold of the second display element is a second mechanical response time.

5. The method of claim 1, wherein a state of the second display element is maintained, and wherein a state of the first display element is changed.

6. 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.

7. A display apparatus comprising:

a plurality of display elements including at least a first and second display element; and

a driver circuit configured to;

generate a first pulse characterized by a parameter having a value greater than a response threshold of the first display element and less than a response threshold of the second display element, wherein the response threshold of the first display element is based at least in part on a first hold voltage applied to the first display element, and wherein the response threshold of the second display element is based at least in part on a second hold voltage applied to the second display element; and

apply the first pulse to the plurality of display elements, wherein the pulse has an amplitude outside of a first hysteresis window of the first display element and outside a second hysteresis window of the second display element.

8. The display apparatus of claim 7, wherein the driver circuit is configured to apply the first pulse to the plurality of display elements by applying the pulse having the pulse voltage at an electrode of the first display element and the second display element.

9. The display apparatus of claim 7, wherein the first display element comprises a first electrode and a second electrode, wherein a gap between the first electrode and the second electrode is based at least in part on the first hold voltage applied to the first display element, wherein the second display element comprises a third electrode and a fourth electrode, wherein a gap between the third electrode and the fourth electrode is based at least in part on the second hold voltage applied to the second display element, and wherein both the first display element and the second display element are in a relaxed state prior to applying the first pulse.

10. The display apparatus of claim 7, wherein the first hysteresis window is approximately equal to the second hysteresis window.

11. The display apparatus of claim 7, wherein the parameter comprises a duration of the pulse, and wherein the response threshold of the first display element is a first mechanical response time and the response threshold of the second display element is a second mechanical response time.

12. The display apparatus of claim 7, wherein a state of the second display element is maintained, and wherein a state of the first display element is changed.

13. The display apparatus of claim 7, wherein the driver circuit is further configured to:

receive an image data signal; and

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

14. A display apparatus comprising:

means for generating a first pulse characterized by a parameter having a value greater than a response threshold of a first display element and less than a response threshold of a second display element, wherein the response threshold of the first display element is based at least in part on a first hold voltage applied to the first display element, and wherein the response threshold of the second display element is based at least in part on a second hold voltage applied to the second display element; and

means for applying the first pulse to the first display element and the second display element, wherein the pulse has an amplitude outside of a first hysteresis window of the first display element and outside a second hysteresis window of the second display element.

15. The display apparatus of claim 14, further comprising means for applying the pulse having the pulse voltage at an electrode of the first display element and the second display element.

16. The display apparatus of claim 14, wherein the first display element comprises a first electrode and a second electrode, wherein a gap between the first electrode and the second electrode is based at least in part on the first hold voltage applied to the first display element, wherein the second display element comprises a third electrode and a fourth electrode, wherein a gap between the third electrode and the fourth electrode is based at least in part on the second hold voltage applied to the second display element, and wherein both the first display element and the second display element are in a relaxed state prior to applying the first pulse.

17. The display apparatus of claim 14, wherein the first hysteresis window is approximately equal to the second hysteresis window.

18. The display apparatus of claim 14, wherein the parameter comprises a duration of the pulse, and wherein the response threshold of the first display element is a first mechanical response time and the response threshold of the second display element is a second mechanical response time.

19. The display apparatus of claim 14, wherein a state of the second display element is maintained, and wherein a state of the first display element is changed.

20. The display apparatus of claim 14, 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.

21. A method for addressing a plurality of display elements, the method comprising:

setting each segment electrode voltage in a line of display elements to one of first and second different voltage levels;

strobing a common electrode of the line of display elements with a voltage pulse;

wherein the common electrode voltage pulse has an amplitude and duration such that when applied to a display element with a segment voltage at the first level the display element does not actuate, and when applied to a display element with a segment voltage at the second level the display element does actuate, and further wherein the common electrode voltage pulse has an amplitude that would actuate both elements if applied for a sufficiently long duration.

22. The method of claim 21, comprising releasing all the display elements in the line prior to strobing the common electrode.