Mirror device

• US 20080285112A1
• Filed: 07/28/2008
• Published: 11/20/2008
• Est. Priority Date: 08/30/2006
• Status: Active Grant

• Current Assignee: Ignite USA (Ignite), Olympus Corporation
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Maeda, Yoshihiro, Sugimoto, Naoya, Ichikawa, Hirotoshi, Ishii, Fusao
• Granted Patent: US 7,652,813 B2
• Time in Patent Office: Days
• US Class Current: 359/290
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A mirror device comprises: an electrode which is covered with a protective film made of a material containing a semiconductor material and is placed on a substrate; a mirror placed above the electrode; and an electrically conductive hinge placed between the mirror and the electrode, wherein an opening part is formed in a part of the protective film, and the hinge penetrates the protective film in the opening part thereof.

Claims

1. A mirror device, comprising:

an electrode which is covered with a protective film made of a material containing a semiconductor material and is placed on a substrate;

a mirror placed above the electrode; and

an electrically conductive hinge placed between the mirror and the electrode, wherein an opening part is formed in a part of the protective film, and the hinge penetrates the protective film in the opening part thereof.

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

the protective film is made of any of poly-silicon, amorphous silicon and silicon carbide (SiC).

3. The mirror device according to claim 1, wherein:

the protective film is constituted by a plurality of layers containing a silicon (Si) material.

4. The mirror device according to claim 1, wherein:

the thickness of the protective film is between 500 angstroms and 3000 angstroms.

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

the resistance value of the protective film is a higher than that of the hinge.

6. The mirror device according to claim 1, wherein:

the hinge is connected to the electrode beneath the protective film.

7. The mirror device according to claim 1, wherein:

the height of the electrode from the substrate is the same as, or larger than, the height of a part of the hinge projected from the cavity of the electrode.

8. A mirror device, comprising:

an electrode placed on a substrate;

a protective film formed on the electrode;

a mirror placed above the electrode; and

a hinge which is joined to the electrode and is made of a semiconductor material, wherein the electrical resistance of the hinge is lower than that of the protective film.

9. The mirror device according to claim 8, wherein:

the hinge is made of any of single crystal silicon (Si), poly-silicon and amorphous silicon, which contain an additive selecting from among the materials belonging to the III group or V group.

10. The mirror device according to claim 8, wherein:

the protective film is made of any of poly-silicon, amorphous silicon and silicon carbide (SiC).

11. The mirror device according to claim 8, wherein:

the hinge is made of a silicon material in which a metal is diffused.

12. The mirror device according to claim 8, wherein:

the hinge and the protective film mutually contain the same material.

13. The mirror device according to claim 8, wherein:

the hinge or protective film is connected to the ground (GND).

14. The mirror device according to claim 8, further comprising:

an insulation layer or an air gap positioned between the hinge and the protective film.

15. The mirror device according to claim 8, wherein:

the resistance of the hinge is no more than 1 GΩ

.

16. The mirror device according to claim 8, wherein:

the resistance of the hinge is no more than 500MΩ

.

17. The mirror device according to claim 8, wherein:

a light-shield or stiction-preventing coating is deposited on the protective film surface so as to not influence the resistance value of the hinge.

18. A mirror device, comprising:

an electrode placed on a substrate;

a plurality of mirrors arranged in array above the electrode;

a protective film formed on the substrate; and

a hinge which is placed between the mirror and the electrode and is made of a semiconductor material, wherein the hinge is made of any of single crystal silicon (Si), poly-silicon and amorphous silicon, which contain an additive of phosphorous, boron or arsenic, and the reflection region of the mirror occupies no less than 85% of a region in which the mirrors are arranged in array.

19. The mirror device according to claim 18, wherein:

the hinge is a vertical hinge, and the height of the hinge is no more than one half of the distance between the mirror and the substrate.

20. The mirror device according to claim 18, wherein:

the hinge and the protective film mutually contain the same material.

21. The mirror device according to claim 18, wherein:

the resistance of the hinge is approximately 1 GΩ

or lower.

22. The mirror device according to claim 18, wherein:

the resistance of the hinge is approximately 500MΩ

or lower.

23. The mirror device according to claim 18, wherein:

the mirror is connected to the ground (GND) by way of the hinge.

24. The mirror device according to claim 18, wherein:

the thickness of the hinge is no more than 500 angstroms.

25. The mirror device according to claim 18, wherein:

the hinge is a torsion hinge placed approximately in parallel to the substrate.

26. The mirror device according to claim 18, further comprising:

a mirror connection part between the mirror and the hinge, wherein the resistance of the mirror connection part is approximately the same as that of the hinge or mirror.

27. The mirror device according to claim 18, further comprising:

a mirror connection part between the mirror and the hinge, wherein the mirror connection part and the hinge contain the same material.

28. The mirror device according to claim 18, further comprising:

a mirror connection part between the mirror and the hinge, wherein the resistance value of the mirror connection part is smaller than that of the protective film.

29. A projection apparatus, comprising:

a mirror device noted in claim 18;

a light source for emitting an illumination light to the mirror in claim 18; and

a projection optical system for projecting light reflected by the mirror device.