Micro mirrors with piezoelectric release mechanism

• US 7,453,621 B2
• Filed: 03/01/2006
• Issued: 11/18/2008
• Est. Priority Date: 03/01/2006
• Status: Active Grant

• Current Assignee: Spatial Photonics Incorporated (Himax Technologies Incorporated)
• Original Assignee: Spatial Photonics Incorporated (Himax Technologies Incorporated)
• Inventors: Novotny, Vlad
• Primary Examiner(s): Lester; Evelyn A.
• Application Number:
  US11/366,943
• Publication Number:
  US 20070206266A1
• Time in Patent Office: 993 Days
• Field of Search: 359/223, 359/224, 359290-295, 359/298, 359/323, 345/85, 345/108, 348/770, 348/771
• US Class Current: 359/290
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 26/0858 the reflecting means being moved or deformed by piezoelectric means

Abstract

A spatial light modulator includes a substrate; a hinge in connection with the substrate; a mirror plate that is connected with the hinge and is configured to tilt about the hinge; and a piezoelectric device coupled with the substrate. The piezoelectric device is configured to produce an acoustic wave to assist the separation between the mirror plate and the object.

Claims

1. A spatial light modulator, comprising:

a substrate that includes an object;

a hinge in connection with the substrate;

a mirror plate that is connected with the hinge and is configured to tilt about the hinge, the object being configured and situated to stop the mirror plate at a particular tilt angle; and

a piezoelectric device coupled with the substrate, the piezoelectric device being configured to produce an acoustic wave to assist the separation between the mirror plate and the object.

2. The spatial light modulator of claim 1, wherein the object in connection with the substrate is a landing tip, and wherein the piezoelectric device is configured to produce an acoustic wave to assist the separation between the mirror plate and the landing tip.

3. The spatial light modulator of claim 1, wherein the mirror plate comprises one or more landing tips configured to contact the upper surface of the substrate to limit the tilt movement of the mirror plate in one or more directions, and wherein the piezoelectric device is configured to produce an acoustic wave to assist the separation between the landing tips and the substrate.

4. The spatial light modulator of claim 1, wherein the substrate comprises an electrode over the upper surface of the substrate and the mirror plate comprises a conductive surface.

5. The spatial light modulator of claim 4, wherein the mirror plate is configured to tilt when an electric voltage is applied between the electrode over the substrate and the conductive surface of the mirror plate.

6. The spatial light modulator of claim 1, wherein the mirror plate comprising a reflective upper surface, a lower surface having a conductive surface portion, and a cavity having an opening on the lower surface.

7. The spatial light modulator of claim 6, wherein the hinge extends into the cavity.

8. The spatial light modulator of claim 1, wherein the piezoelectric device is configured to produce an acoustic wave that vibrates substantially perpendicular or parallel to the surface of the substrate.

9. The spatial light modulator of claim 1, wherein the piezoelectric device is configured to produce a first acoustic wave that vibrates substantially parallel to the surface of the substrate and a second acoustic wave that vibrates substantially perpendicular to the surface of the substrate.

10. The spatial light modulator of claim 1, wherein the piezoelectric device comprises a piezoelectric material, and a first actuation electrode and a second actuation electrode configured to produce an electric field across the piezoelectric material to produce the acoustic wave to assist the separation between the mirror plate and the substrate.

11. The spatial light modulator of claim 10, wherein the piezoelectric material comprises lead zirconium titanate or zinc oxide.

12. The spatial light modulator of claim 10, wherein the first actuation electrode and the second actuation electrode are disposed on the same surface of the piezoelectric material.

13. The spatial light modulator of claim 12, further comprising a plurality of first actuation electrodes and a plurality of second actuation electrodes disposed on the same surface of the piezoelectric material.

14. The spatial light modulator of claim 10, wherein the first actuation electrode and the second actuation electrode are disposed on the opposite surfaces of the piezoelectric material.

15. The spatial light modulator of claim 1, wherein the substrate comprises an upper portion that supports the hinge and a lower portion, and wherein the piezoelectric device is sandwiched between the upper portion of the substrate and the lower portion of the substrate.

16. The spatial light modulator of claim 15, wherein the piezoelectric device is monolithically connected to the upper portion of the substrate or the lower portion of the substrate.

17. The spatial light modulator of claim 15, wherein the piezoelectric device is bonded with the upper portion of the substrate or the lower portion of the substrate.

18. The spatial light modulator of claim 1, wherein the piezoelectric device is connected to the lower surface of the substrate.

19. The spatial light modulator of claim 18, wherein the piezoelectric device is monolithically connected to or bonded with the lower surface of the substrate.

20. The spatial light modulator of claim 1, further comprising:

a plurality of piezoelectric devices coupled with the substrate, each configured to produce an acoustic wave to assist the separation between the mirror plate and the substrate.

21. A spatial light modulator, comprising:

a substrate;

a hinge in connection with the substrate;

a mirror plate that is connected with the hinge and is configured to tilt about the hinge;

a landing tip in connection with the substrate, wherein the landing tip is configured to contact the lower surface of the mirror plate to limit the tilt movement of the mirror plate; and

a piezoelectric device coupled with the substrate and configured to produce an acoustic wave to assist the separation between the mirror plate and the landing tip.

22. The spatial light modulator of claim 21, wherein the piezoelectric device is configured to produce an acoustic wave that vibrates substantially perpendicular or parallel to the surface of the substrate.

23. The spatial light modulator of claim 21, wherein the piezoelectric device comprises a piezoelectric material, and a first actuation electrode and a second actuation electrode configured to produce an electric field across the piezoelectric material to produce the acoustic wave to assist the separation between the mirror plate and the substrate.

24. The spatial light modulator of claim 23, wherein the first actuation electrode and the second actuation electrode are disposed on the same surface of the piezoelectric material.

25. The spatial light modulator of claim 24, further comprising a plurality of first actuation electrodes and a plurality of second actuation electrodes disposed on the same surface of the piezoelectric material.

26. The spatial light modulator of claim 23, wherein the first actuation electrode and the second actuation electrode are disposed on the opposite surfaces of the piezoelectric material.

27. The spatial light modulator of claim 21, wherein the substrate comprises an upper portion that supports the hinge and a lower portion, and wherein the piezoelectric device is sandwiched between the upper portion of the substrate and the lower portion of the substrate.

28. The spatial light modulator of claim 21, wherein the piezoelectric device is connected to the lower surface of the substrate.

29. A method for fabricating a spatial light modulator, comprising:

fabricating a hinge over a substrate;

fabricating a mirror plate in connection with the hinge, wherein the mirror plate can tilt about the hinge and be stopped when the mirror plate comes into contact with an object over the substrate; and

coupling a piezoelectric device with the substrate such that piezoelectric devices can produce an acoustic wave to assist the separation between the mirror plate and the object in connection with substrate.

30. The method of claim 29, wherein the piezoelectric device comprises a piezoelectric material, and a first actuation electrode and a second actuation electrode configured to produce an electric field across the piezoelectric material to produce the acoustic wave to assist the separation between the mirror plate and the object.

31. The method of claim 30, wherein the first actuation electrode and the second actuation electrode are disposed on the same surface of the piezoelectric material.

32. The method of claim 31, further comprising a plurality of first actuation electrodes and a plurality of second actuation electrodes disposed on the same surface of the piezoelectric material.

33. The method of claim 31, wherein the first actuation electrode and the second actuation electrode are disposed on the opposite surfaces of the piezoelectric material.

34. The method of claim 29, wherein the substrate comprises an upper portion that supports the hinge and a lower portion, and wherein the piezoelectric device is sandwiched between the upper portion of the substrate and the lower portion of the substrate.

35. The method of claim 34, further comprising:

connecting the piezoelectric device monolithically to the upper portion of the substrate or the lower portion of the substrate.

36. The method of claim 34, further comprising:

bonding the piezoelectric device with the upper portion of the substrate or the lower portion of the substrate.

37. The method of claim 29, further comprising:

connecting the piezoelectric device monolithically to the lower surface of the substrate.

38. The method of claim 29, further comprising:

bonding the piezoelectric device with the lower surface of the substrate.