Display methods and apparatus

• US 20060187190A1
• Filed: 01/06/2006
• Published: 08/24/2006
• Est. Priority Date: 02/23/2005
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Pixtronix, Incorporated (Qualcomm, Inc.)
• Inventors: Barton, Roger, Lewis, Stephen, Hagood, Nesbitt W., McAllister, Abraham
• Granted Patent: US 7,742,016 B2
• Time in Patent Office: Days
• US Class Current: 345/109
• CPC Class Codes: G02B 26/04 by periodically varying the intensity of light, e.g. using choppers shutters, diaphragms for cameras G03B9/00; devices for eliminating or reducing the effect of flicker in projection systems G03B21/40
• 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 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/088 using a non-linear two-terminal element
• 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 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833

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:

a shutter assembly comprising a shutter and a drive electrode, configured such that in response to the generation of a potential difference between the shutter and the drive electrode, the shutter is electrostatically drawn towards the drive electrode; and

a control matrix including,

a first voltage interconnect for applying a first voltage to one of the shutter and the drive electrode, and

a second voltage interconnect for applying a second voltage to the other of the shutter and the drive electrode, thereby generating the potential difference between the shutter,

wherein the first voltage has a higher magnitude than the second voltage and the first voltage is applied to the one of the shutter and the drive electrode having a lower capacitance.

2. The display apparatus of claim 1, wherein the second voltage is at or near ground.

3. The display apparatus of claim 1, wherein the second voltage varies between ground and about one half the first voltage.

4. The display apparatus of claim 1, wherein the second voltage interconnect is a global actuation interconnect.

5. The display apparatus of claim 1, wherein the shutter assembly comprises a second drive electrode connected to a third voltage interconnect.

6. The display apparatus of claim 5, wherein application of the first voltage to the drive electrode results in the opening of the shutter and application of a third voltage to the second drive electrode closes the shutter.

7. The display apparatus of claim 1, wherein the application of the first voltage to the drive electrode opens the shutter.

8. The display apparatus of claim 1, wherein the application of the first voltage to the drive electrode absent the application of the second voltage opens the shutter.

9. The display apparatus of claim 1, wherein application of the second voltage to the shutter prevents movement of the shutter in response to the application of the first voltage.

10. The display apparatus of claim 1, wherein the shutter assembly comprises a mechanical support for limiting the range of motion of the shutter substantially to a movement plane parallel to at which a light source is directed.

11. The display apparatus of claim 10, wherein the shutter is electrostatically drawn substantially in the movement plane.

18. The display apparatus of claim 1, wherein the application of the first voltage to the drive electrode opens the shutter.

19. The display apparatus of claim 1, wherein the application of the first voltage to the drive electrode absent the application of the second voltage opens the shutter.

20. The display apparatus of claim 1, wherein application of the second voltage to the shutter prevents movement of the shutter in response to the application of the first voltage.

21. The display apparatus of claim 1, wherein the shutter assembly comprises a mechanical support for limiting the range of motion of the shutter substantially to a movement plane parallel to at which a light source is directed.

22. The display apparatus of claim 10, wherein the shutter is electrostatically drawn substantially in the movement plane.

12. A method of forming an image, comprising:

providing a shutter assembly comprising a shutter and a drive electrode, configured such that in response to the generation of a potential difference between the shutter and the drive electrode, the shutter is electrostatically drawn towards the drive electrode; and

applying a first voltage to one of the shutter and the drive electrode;

applying a second voltage to the other of the shutter and the drive electrode, thereby generating the potential difference between the shutter,

wherein the first voltage has a higher magnitude than the second voltage and the first voltage is applied to the one of the shutter and the drive electrode having a lower capacitance.

13. The method of claim 12, wherein the second voltage is at or near ground.

14. The method of claim 12, comprising varying the second voltage between ground and about one half the first voltage.

15. The method of claim 14, wherein the shutter assembly forms part of a pixel in an array of pixel, and varying the second voltage provides for global actuation of a plurality of pixels in the array of pixels.

16. The method of claim 12, wherein the shutter assembly comprises a second drive electrode connected to a third voltage interconnect.

17. The method of claim 16, applying the first voltage to the drive electrode opens the shutter and applying a third voltage to the second drive electrode closes the shutter.