Display methods and apparatus

• US 8,519,923 B2
• Filed: 03/09/2012
• Issued: 08/27/2013
• Est. Priority Date: 02/23/2005
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Pixtronix, Incorporated (Qualcomm, Inc.)
• Inventors: Hagood, Nesbitt W. IV, McAllister, Abraham, Lewis, Stephen R., Barton, Roger W.
• Primary Examiner(s): Boddie, William
• Assistant Examiner(s): Said, Mansour M
• Application Number:
  US13/416,542
• Publication Number:
  US 20120169795A1
• Time in Patent Office: 536 Days
• Field of Search: 345 83- 84, 345 87- 88, 345/90, 345/92, 345 95- 96, 345/100, 345108-109, 345/48, 345/211, 345/214, 359/198, 359/230, 359/233, 359/290
• US Class Current: 345/84
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 2300/0885 Pixel comprising a non-linear two-terminal element alone in series with each display pixel element
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 2310/063 Waveforms for resetting the whole screen at once
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3433 using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices using liquid crystal devices G09G3/36; using electrochromic devices G09G3/38
• CPC Class Codes: H04N 5/7416 involving the use of a spatial light modulator, e.g. a light valve, controlled by a video signal

Abstract

The invention relates to methods and apparatus for forming images on a display utilizing a control matrix to control the movement of MEMs-based light modulators.

Claims

1. A display apparatus comprising:

an array of pixels arranged in rows and columns including;

a transparent substrate, and

a plurality of light modulators, and

a control matrix disposed on the transparent substrate including,

a common electrical connection among a set of pixels for providing a common voltage to each of the pixels in the set of pixels, the set of pixels including pixels in at least two of the columns and in at least two of the rows,

a data voltage interconnect corresponding to one of the columns, and

a switch incorporated into one of the pixels in the set of pixels for controlling actuation of a corresponding light modulator in response to a voltage applied by the data voltage interconnect.

2. The display apparatus of claim 1, wherein the common electrical connection is a global actuation interconnect.

3. The display apparatus of claim 1, comprising a global actuation voltage source for applying a global actuation voltage to the common electrical connection.

4. The display apparatus of claim 1, wherein the common electrical connection comprises a common current drain for accepting charge stored in the pixels in the array of pixels, thereby allowing for actuation of the plurality of corresponding light modulators.

5. The display apparatus of claim 1, wherein the light modulators comprise MEMS-based shutter assemblies.

6. The display apparatus of claim 5, wherein the shutter assemblies are electrically bi-stable.

7. The display apparatus of claim 5, wherein the shutter assemblies are mechanically bi-stable.

8. The display apparatus of claim 1, wherein application of a voltage to the data voltage interconnect substantially reduces a minimum additional voltage change needed to actuate one of the light modulators.

9. The display apparatus of claim 8, wherein the common electrical connection supplies the minimum additional voltage change.

10. The display apparatus of claim 1, wherein at least one pixel in the array of pixels includes a first actuator for driving the light modulator into a first state and a second actuator for driving the light modulator into a second state.

11. The display apparatus of claim 1, wherein the one pixel comprises a memory element, and wherein the switch corresponding to the pixel controls the storage of the data voltage by the memory element.

12. The display apparatus of claim 1, wherein the common electrical connection supplies a bias voltage to the set of pixels.

13. The display apparatus of claim 1, wherein the switch comprises a transistor.

14. The display apparatus of claim 1, wherein at least one pixel in the array of pixels includes a memory element for storing a light modulator movement instruction.

15. The display apparatus of claim 14, wherein the memory element comprises a capacitor.

16. A display apparatus comprising:

an array of pixels arranged in rows and columns including;

a transparent substrate, and

a means for modulating light, and

a control matrix disposed on the transparent substrate including;

a means for providing a common voltage to each of the pixels in a set of pixels, the set of pixels including pixels in at least two of the columns and in at least two of the rows,

a means for providing a data voltage to one of the columns, and

a means for controlling actuation of a corresponding means for modulating light in response to the data voltage.

17. The display apparatus of claim 16, wherein the means for providing a common voltage to each of the pixels in a set of pixels is a global actuation interconnect.

18. The display apparatus of claim 17, comprising a means for applying a global actuation voltage to the global actuation interconnect.

19. The display apparatus of claim 16, wherein the means for providing a common voltage comprises a means for accepting charge stored in the pixels in the array of pixels, thereby allowing for actuation of the means for modulating light.

20. The display apparatus of claim 16, wherein the means for modulating light comprises MEMS-based shutter assemblies.

21. The display apparatus of claim 20, wherein at least one pixel in the array of pixels includes a means for storing a shutter assembly movement instruction.

22. The display apparatus of claim 21, wherein the means for storing a shutter assembly movement instruction comprises a capacitor.

23. The display apparatus of claim 20, wherein the shutter assemblies are electrically bi-stable.

24. The display apparatus of claim 20, wherein the shutter assemblies are mechanically bi-stable.

25. The display apparatus of claim 16, wherein application of a data voltage substantially reduces a minimum additional voltage change needed to actuate the means for modulating light.

26. The display apparatus of claim 25, wherein the means for providing the common voltage supplies the minimum additional voltage change.

27. The display apparatus of claim 16, wherein at least one pixel in the array of pixels includes a means for driving the light modulator into a first state and a means for driving the light modulator into a second state.

28. The display apparatus of claim 16, wherein the one pixel comprises a means for controlling the storage of data in a memory element.

29. The display apparatus of claim 16, wherein the means for providing a common electrical connection supplies a bias voltage to the set of pixels.

30. The display apparatus of claim 16, wherein the means for controlling actuation of a corresponding means for modulating light comprises a transistor.