IP Library Granted Patent US 8,519,945
Granted Patent B2
US 8,519,945 · App. 11/978,829 · Granted Aug 27, 2013

Circuits for controlling display apparatus

Inventors: Nesbitt W. Hagood (Andover, MA); Stephen R. Lewis (Reading, MA); Abraham McAllister (Annandale, VA); Roger W. Barton (Grand Marais, MN)
Assignee: Pixtronix, Inc.
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Quick Facts
Patent No.
US 8,519,945
App. No.
11/978,829
Granted
Aug 27, 2013
Kind
B2
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 (42)

1. A direct view display apparatus comprising:

a transparent substrate;

an array of pixels formed on the substrate including, for each pixel, a MEMS-based light modulator including a first movable electrostatic actuator; and

a control matrix connected to the substrate including, for a pixel, a write-enabling interconnect for enabling the pixel to respond to a data voltage and a data voltage interconnect for applying the data voltage to a data switch, thereby controlling the state of the light modulator of the pixel; and

a voltage regulator that limits variation in a voltage across the first movable electrostatic actuator, wherein the variation in the voltage is caused by a movement of at least a portion of the first movable electrostatic actuator.

2. The direct-view display apparatus of claim 1 , wherein the voltage regulator comprises a display driver including a DC voltage source.

3. The direct-view display apparatus of claim 2 , comprising for a pixel, an actuation voltage interconnect, distinct from the data voltage interconnect, for connecting the first movable electrostatic actuator to the direct-view display driver.

4. The direct-view display apparatus of claim 3 , comprising, for a pixel, a switch, other than the data switch, for controlling the application of the voltage output by the direct-view display driver to the first movable electrostatic actuator.

5. The direct-view display apparatus of claim 1 , wherein each pixel includes a voltage regulator.

6. The direct-view display apparatus of claim 5 , wherein the voltage regulator comprises a capacitor in electrical communication with the first electrostatic actuator.

7. The direct-view display apparatus of claim 1 , wherein the voltage variation is limited if, during actuation, movement of portions of the first movable electrostatic actuator results in a voltage reduction of less than twenty percent of a voltage level required to initiate actuation.

8. The direct-view display apparatus of claim 1 , wherein the voltage variation is limited if, during actuation, movement of portions of the first movable electrostatic actuator results in a voltage reduction of less than ten percent of a voltage level required to initiate actuation.

9. The direct-view display apparatus of claim 1 , wherein the voltage variation is limited if, during actuation, movement of portions of the first movable electrostatic actuator results in a voltage reduction of less than five percent of a voltage level required to initiate actuation.

10. The direct-view display apparatus of claim 1 , comprising a voltage inverter.

11. The direct-view display apparatus of claim 10 , wherein the voltage inverter comprises a CMOS circuit.

12. The direct-view display apparatus of claim 1 , wherein each light modulator comprises a second electrostatic actuator for applying a force opposing a force applied by the first actuator.

13. The direct-view display apparatus of claim 12 , comprising, for a pixel, a flip-flop electrically coupling the first movable electrostatic actuator and the second electrostatic actuator.

14. The direct-view display apparatus of claim 12 , comprising, for a pixel, a cross-coupled inverter electrically coupling the first movable electrostatic actuator and the second electrostatic actuator.

15. The direct-view display apparatus of claim 1 , wherein the MEMS-based light modulators comprise shutter-based light modulators.

16. The direct-view display apparatus of claim 1 , comprising a second electrostatic actuator, opposing the first movable electrostatic actuator, for controlling the state of the MEMS-based light modulators.

17. The direct-view display apparatus of claim 16 , comprising, for a pixel, a first actuation voltage interconnect for providing a voltage to the first movable electrostatic actuator sufficient to actuate the first movable electrostatic actuator.

18. The direct-view display apparatus of claim 17 , wherein the first actuation voltage interconnect provides a substantially constant voltage throughout the setting of an image and through the setting of subsequent images.

19. The direct-view display apparatus of claim 17 , wherein, throughout operation of the direct-view display, the first actuation voltage interconnect provides a substantially constant voltage.

20. The direct-view display apparatus of claim 17 , wherein first actuation voltage interconnect for a pixel is shared by a plurality of pixels.

21. The direct-view display apparatus of claim 17 , comprising, for a pixel, a second voltage actuation interconnect, distinct from the data voltage interconnect and the first voltage actuation interconnect, for providing a voltage sufficient to actuate the second actuator.

22. The direct-view display apparatus of claim 21 , wherein the voltage provided by the second actuation voltage interconnect is insufficient to actuate the second actuator if a voltage greater than a maintenance voltage is applied to the first actuator.

23. The direct-view display apparatus of claim 21 , comprising, for a pixel, a switch, other than the data switch, for regulating the application of the voltage provided via the first actuation voltage interconnect.

24. The direct-view display apparatus of claim 21 , wherein the data voltage interconnect for the pixel controls the actuation of both the first and second actuators.

25. The direct-view display apparatus of claim 21 , comprising a common voltage interconnect coupled to the light modulators of a plurality of pixels for applying a common bias voltage to the light modulators.

26. The direct-view display apparatus of claim 21 , wherein the data switch comprises a discharge transistor for selectively discharging the voltage provided via the first voltage actuation interconnect.

27. The direct-view display apparatus of claim 26 , comprising a global actuation interconnect coupled to the discharge transistors of a plurality of pixels for selectively enabling the voltage provided to the respective pixels via the data voltage interconnects corresponding to the pixels to control the discharge transistor.

28. The direct-view display apparatus of claim 1 , comprising a voltage actuation interconnect electrically connected directly to the first movable electrostatic actuators of pixels in multiple rows and multiple columns of the array of pixels.

29. A display apparatus comprising:

a transparent substrate;

an array of pixels including for each pixel, a MEMS-based light modulator formed on the transparent substrate; and

a control matrix formed on the transparent substrate for addressing the MEMS-based light modulators of the array, wherein for each pixel, the control matrix includes a CMOS circuit comprising a level shifting inverter for controlling an actuation voltage with a data voltage, wherein the data voltage is less than the actuation voltage.

30. The display apparatus of claim 29 , wherein the CMOS circuit comprises a flip-flop.

31. The display apparatus of claim 30 , wherein the flip-flop controls the application of an actuation voltage to the light modulator.

32. The display apparatus of claim 30 , wherein the flip-flop electrically couples opposing actuators of the light modulator.

33. The display apparatus of claim 29 , wherein the MEMS-based light modulator comprises at least one of a shutter-based light modulator, a light tap-based light modulator, and an electrowetting-based light modulator.

34. The direct-view display apparatus of claim 29 , wherein the MEMS-based light modulator comprises a light tap-based light modulator.

35. The direct-view display apparatus of claim 29 , wherein the MEMS-based light modulator comprises an electrowetting-based light modulator.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 2, 2016
From: PIXTRONIX, INC.
To: SNAPTRACK, INC.
Reel/Frame 039905/0188 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 9, 2011
From: HAGOOD, NESBITT W.; LEWIS, STEPHEN R.; MCALLISTER, ABRAHAM; BARTON, ROGER W.
To: PIXTRONIX, INC.
Reel/Frame 026724/0042 →
Continuity (2)
Continuation In Part 11326962 · Jan 6, 2006
Related Publication 20080129681A1 · Jun 5, 2008