Micromirror device with a single address electrode

• US 7,839,561 B2
• Filed: 02/25/2008
• Issued: 11/23/2010
• Est. Priority Date: 02/26/2007
• Status: Active Grant

• Current Assignee: Ignite USA (Ignite)
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Nishino, Hirokazu, Maeda, Yoshihiro, Arai, Kazuma, Ishii, Fusao
• Primary Examiner(s): Spector; David N
• Application Number:
  US12/072,448
• Publication Number:
  US 20090174926A1
• Time in Patent Office: 1,002 Days
• Field of Search: 345/85, 359/290, 359/291, 359/292
• US Class Current: 359/292
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A micromirror device comprises a plurality of mirrors arranged on a substrate, an elastic hinge for supporting each mirror to be deflectable in a plurality of directions, an address electrode composed of first and second regions that are arranged across the deflection axis of each mirror, and a driving circuit for controlling the mirror to deflect in the directions of the first and the second regions.

Claims

1. A micromirror device, comprising:

a plurality of mirrors arranged on a substrate;

an elastic hinge constituting a hinge electrode for supporting each of said mirrors to deflect to a plurality of directions;

a single address electrode for each of said mirrors, wherein each of said mirrors has a first region and a second regions across a deflection axis of each of said mirrors; and

a driving circuit connected to said single address electrode

whereby said address electrode is applied a driving voltage and controls each of said mirrors to deflect in two opposite directions across a deflection axis of each of the mirrors.

2. The micromirror device according to claim 1, wherein:

each of said mirrors deflects to two opposite directions with an equal angle from the deflection axis.

3. The micromirror device according to claim 1, wherein

each of said mirrors deflects to two opposite directions with two unequal angles from the deflection axis.

4. The micromirror device according to claim 1, wherein

a coulomb force generated between the first region of said address electrode and each of said mirrors, and a coulomb force generated between the second region of said address electrode and each of said mirrors are different when each of said mirrors is in a horizontal state.

5. The micromirror device according to claim 1, wherein:

said single address electrode has an asymmetrical structural feature including asymmetrical shapes and/or different properties with respect to the deflection axis of each of said mirrors.

6. The micromirror device according to claim 1, wherein

the address electrode has different areas in said first region and the second region.

7. The micromirror device according to claim 1, wherein

the first region and the second region of said address electrode has two different distances from each of said mirrors.

8. The micromirror device according to claim 1, wherein:

the first region and the second region of said address electrode has two different distances from each of said mirrors; and

the address electrode has different areas in said first region and the second region.

9. The micromirror device according to claim 1, wherein

said address electrode has two different material compositions with different permittivities, or have different configurations in said first region and the second region.

10. The micromirror device according to claim 1, wherein

said driving circuit comprises a memory circuit including a transistor and a capacitor.

11. The micromirror device according to claim 1, wherein:

said driving circuit comprises a memory circuit including a transistor and a capacitor; and

the capacitor is disposed across the deflection axis of each of said mirrors.

12. The micromirror device according to claim 1, wherein

said elastic hinge further comprises a cantilever.

13. The micromirror device according to claim 1, wherein

said elastic hinge further comprises a restoring spring.

14. The micromirror device according to claim 1, wherein

each of said mirrors further comprises a first and a second mirror regions having different thickness and facing the first and the second regions of the address electrode respectively.

15. The micromirror device according to claim 1, wherein

each of said mirrors further comprises a first and a second mirror regions having different permittivities and facing the first and the second regions of the address electrode respectively.

16. The micromirror device according to claim 1, wherein

said elastic hinge supports each of said mirrors in a position offset from a gravity center of said mirror.

17. The micromirror device according to claim 1, wherein

each of said mirrors has an symmetrical shape with respect to the deflection axis of said mirror.

18. The micromirror device according to claim 1, wherein

each of said mirrors is nearly parallel to the substrate when said address electrode is controlled to operate in an initial state.

19. The micromirror device according to claim 1, wherein

said address electrode controls each of said mirrors to deflect from a horizontal state to two opposite directions across said deflection axis at two different deflection speeds or in two different deflection periods.

20. A micromirror device, comprising:

a plurality of mirrors disposed on a substrate;

an elastic hinge for supporting each of said mirrors;

an address electrode having first and second regions arranged across a deflection axis of each of said mirrors; and

a driving circuit for controlling each of said mirrors to deflect in directions of the first and the second regions, wherein

a coulomb force generated between the first region of said address electrode and each of said mirrors, and a coulomb force generated between the second region of said address electrode and each of said mirrors are different when said driving circuit applies a predetermined voltage to said address electrode or each of said mirrors in a state where each of said mirrors is nearly horizontal to the substrate.

21. The micromirror device according to claim 20, wherein

the first and the second regions of said address electrode are linked within the substrate.

22. The micromirror device according to claim 20, wherein

the first and the second regions of said address electrode are provided consecutively as one piece on a surface of the substrate.

23. The micromirror device according to claim 20, wherein

the first and the second regions of said address electrode are separated on a surface of the substrate.

24. The micromirror device according to claim 20, wherein

a distance between the first region of said address electrode and each of said mirrors, and a distance between the second region of said address electrode and each of said mirrors are different.

25. The micromirror device according to claim 20, wherein

area sizes of the first and the second regions of said address electrode are different.

26. The micromirror device according to claim 20, wherein

a distance between the first region of said address electrode and the deflection axis, and a distance between the second region of said address electrode and the deflection axis are different.

27. The micromirror device according to claim 20, wherein

the voltage applied to each of said mirrors or said address electrode ranges from 3V To 15V.

28. The micromirror device according to claim 20, wherein

the voltage applied to each of said mirrors or said address electrode is a voltage of multiple values.

29. The micromirror device according to claim 20, wherein:

said driving circuit is a memory circuit including a transistor and a capacitor; and

the capacitor is arranged across the deflection axis of each of said mirrors.

30. The micromirror device according to claim 20, wherein

said address electrode and said driving circuit are arranged below each of said mirrors, which is shaped nearly like a square and has a pitch of 4 to 10 μ

m between centers of said mirror and another mirror.

31. The micromirror device according to claim 20, wherein

said driving circuit is connected in a closer position of one of the first and the second regions of said address electrode.

32. The micromirror device according to claim 20, wherein

said driving circuit is connected so that potentials of the first and the second regions of said address electrode become nearly equal.

33. The micromirror device according to claim 20, wherein

said driving circuit is connected to each of said mirrors via said elastic hinge.

34. The micromirror device according to claim 20, wherein:

each of said mirrors has first and second mirror regions respectively facing the first and the second regions of said address electrode; and

the voltage is applied to at least one of the mirror regions via said elastic hinge.

35. The micromirror device according to claim 20, wherein

a deflection speed or a deflection time for deflecting each of said mirrors from the horizontal state to the direction of the first region of said address electrode, and a deflection speed or a deflection time for deflecting each of said mirrors from the horizontal state to the direction of the second region of said address electrode are different.

36. A micromirror device, comprising:

a mirror arranged on a substrate;

an elastic hinge for supporting said mirror to be deflectable;

an address electrode corresponding to said mirror; and

a driving circuit for controlling said mirror to deflect in at least two directions with a coulomb force, wherein

a deflection speed or a deflection time of said mirror controlled by said driving circuit varies depending on each deflection direction.

37. A micromirror device, comprising:

a mirror is supported by an elastic hinge to be deflectable on a substrate;

an electrode arranged on the substrate so that said electrode faces said mirror; and

a driving circuit for controlling said mirror to deflect with a coulomb force generated between said electrode and said mirror, wherein

said driving circuit has a memory including a capacitor, and the capacitor is arranged on both sides of a deflection axis of said mirror within the substrate facing said mirror.

38. The micromirror device according to claim 37, wherein

the capacitor is a single capacitor arranged on both sides of the deflection axis.

39. The micromirror device according to claim 37, wherein

the capacitor is a capacitor partitioned into a plurality of regions arranged on both sides of the deflection axis.

40. The micromirror device according to claim 37, wherein

a voltage applied to said electrode is a voltage of multiple values.

41. The micromirror device according to claim 37, wherein

the Coulomb force generated between said electrode and said mirror varies depending on a deflection direction.