Altering temporal response of microelectromechanical elements

• US 20050195467A1
• Filed: 03/03/2004
• Published: 09/08/2005
• Est. Priority Date: 03/03/2004
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Cummings, William J., Kothari, Manish
• Granted Patent: US 7,119,945 B2
• Time in Patent Office: Days
• US Class Current: 359/292
• 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: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 7/1821 for rotating or oscillating mirrors
• CPC Class Codes: Y10S 359/904 Micromirror

Abstract

An array of movable elements is arranged on a substrate. Each element has a cavity and a movable member to move through the cavity. The pressure resistance of the elements varies, allowing actuation signals to be manipulated to activate elements with different pressure resistance at different levels of the actuation signal.

Claims

1. An array of movable elements on a substrate, each element comprising:

a cavity; and

a movable member to move through the cavity;

wherein a pressure resistance of the elements varies.

2. The array of claim 1, the movable member further comprising holes in the member to allow gas to escape when the element moves.

3. The array of claim 2, wherein different elements in the array have different patterns of holes.

4. The array of claim 1, the movable member further comprising a flexible portion and a rigid portion such that when the movable member moves through the cavity, the flexible portion collapses to trap gas between the rigid portion and the substrate.

5. The array of claim 1, the movable member further comprising a movable mirror formed from a support layer.

6. The array of claim 1, the movable member further comprising a movable mirror suspended over the cavity by at least one support post.

7. The array of claim 6, the support post further comprising support rails.

8. The array of claim 7, the support rails having holes to allow gas to escape.

9. The array of claim 1, the support layer to block edges of the movable mirror thereby trapping gas between the mirror and the substrate.

10. The array of claim 1, the pressure resistance being varied by a mechanical stiffness of the movable member.

11. The array of claim 1, the array further comprising an x-y grid of modulator elements forming a pixel, wherein modulator elements at outer edges of the pixel are arranged so as to actuate first, increasing the pressure resistance of elements at the middle of the pixel.

12. The array of claim 11, wherein the elements at the outer edge of the pixel have lower mechanical stiffness, thereby causing gas to trap under the elements at the middle of the pixel.

13. The array of claim 1, wherein the array further comprises an array of one of the group comprised of:

display elements, switches, tunable capacitors, and interferometric modulator elements.

14. The array of claim 1, the array further comprising structures across the cavity from the movable element to facilitate gas flow.

15. The array of claim 1, the movable element having structures formed on it to facilitate gas flow.

16. A method of manufacturing an array of movable elements, the method comprising:

forming movable members displaced from a substrate over a cavity such that a pressure resistance of at least one of the movable members varies from a pressure resistance of others of the movable members.

17. The method of claim 16, wherein forming movable members further comprises forming movable members with holes patterned in a surface of the member.

18. The method of claim 17, wherein the holes form a first pattern on at least one of the movable members, and the holes form a second pattern on others of the movable members.

19. The method of claim 16, wherein the pressure resistance is varied by manufacturing some of the movable members to have a lower mechanical resistance, thereby causing them to actuate in such a manner as to force gas into the cavities of other movable members.

20. A method of operating an array of light modulator elements on a substrate arranged into subarrays as pixels, the method comprising:

providing an actuation signal at a first level, thereby causing a first set of elements in the pixel to actuate thereby trapping gas between other elements in the pixel and the substrate; and

providing an actuation signal at a second level, causing a second set of elements in the pixel to actuate according to a response time determined by the pressure resistance.

21. The method of claim 20, causing a first set of elements to actuate further comprises causing elements on a first edge of the pixel to actuate.

22. The method of claim 20, causing a first set of elements to actuate further comprises causing elements along a second edge to actuate simultaneously with the elements along a first edge.

23. The method of claim 20, causing a first set of element to actuate further comprises causing elements along a second edge to actuate after the elements along the first edge.

24. The method of claim 20, causing a second set of elements to actuate according to their response time further comprises causing a second set of element to actuate having holes patterned in their surfaces, the holes to alter the pressure resistance of the elements.