Mirror device

• US 7,796,321 B2
• Filed: 05/31/2008
• Issued: 09/14/2010
• Est. Priority Date: 11/01/2003
• Status: Active Grant

• Current Assignee: Ignite USA (Ignite)
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Maeda, Yoshihiro, Ichikawa, Hirotoshi, Ishii, Fusao
• Primary Examiner(s): Mack; Ricky L
• Assistant Examiner(s): Thomas; Brandi N
• Application Number:
  US12/156,261
• Publication Number:
  US 20080239454A1
• Time in Patent Office: 836 Days
• Field of Search: 359/290, 359/291, 359/292, 359/295, 359/298
• US Class Current: 359/295
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G09G 3/2011 by amplitude modulation
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833

Abstract

A spatial light modulator supported on a device substrate includes a plurality of light modulation elements to modulate a light emitted from a light source. The spatial light modulator and the device substrate further comprises a cyclic structure on a surface of the spatial light modulator and/or the device substrate for preventing a reflection of the incident light from the cyclic structure. In an exemplary embodiment the cyclic structure includes cyclic structural elements having a distance between two cyclic elements shorter than the wavelength of an incident light for preventing a reflection of the incident light from the cyclic structure.

Claims

1. A mirror device, comprising:

a plurality of deflectable mirrors;

an elastic vertical hinge perpendicular to a mirror surface of each of said deflectable mirrors for supporting each of the mirrors for deflecting to different deflection angles wherein said vertical hinge further connected to a hinge bottom electrode for providing a hinge-and-mirror voltage to said hinge and said mirror;

a drive electrode for driving the mirror; and

a control circuit for applying a drive voltage to the-drive electrode according to an input signal to control the deflection angles of the mirrors, wherein

the drive electrode further physically contacts the mirror and mechanically stops the mirror at a maximum deflection angle of the mirror.

2. The mirror device according to claim 1, wherein

the drive electrode is further covered by an anti-reflection structure for reducing a reflection from the drive electrode.

3. The mirror device according to claim 1, wherein

the mirror is deflected to physically contact the drive electrode disposed at a farthest side from a deflection axis of the mirror.

4. The mirror device according to claim 1, wherein

the drive electrode further comprises a part coated with an insulation layer for contacting and mechanically stopping the mirror.

5. The mirror device according to claim 4, wherein

the control circuit applies the drive voltage to the drive electrode different from said hinge-and-mirror voltage of the mirror.

6. The mirror device according to claim 4, wherein

the insulation layer is composed of an oxide compound.

7. The mirror device according to claim 4, wherein

the insulation layer is composed of a nitride compound.

8. The mirror device according to claim 4, wherein

the insulation layer is composed of a silicon or silicon compound.

9. The mirror device according to claim 4, wherein

the insulation layer coated over said drive electrode further comprises an etchant stop layer for covering and protecting an understructure from an etchant covered under the etchant stop layer.

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

the mirror comprises substantially a square-shaped mirror surface and wherein said drive electrode further comprises a first electrode and a second electrode to control said mirror to deflect along a deflection axis extended along a diagonal line of said square-shaped mirror.

11. The mirror device according to claim 1, wherein

a pitch between adjacent mirrors is in a range substantially between 4 μ

m through 15 μ

m.

12. The mirror device according to claim 1, wherein

the deflection angle of the mirror is in a range between about 0˜

13 degrees relative to a horizontal direction of the mirror.

14. The mirror device according to claim 1, wherein

the control circuit further controls the mirror to deflect to a first deflection angle for reflecting incident light to a first direction, a second deflection angle for reflecting the incident light to a second direction and a third deflection control state for freely oscillating between the first and second deflection angles for reflecting a controllable portion of light through said projection lens for projecting an image light with an intermediate light intensity between a maximum and a minimum light intensity reflected by the mirror when deflected to said first direction and second direction respectfully for displaying images.

13. An image projection apparatus comprising:

a mirror device comprising plurality of deflectable mirrors each supported by an elastic vertical hinge perpendicular to a mirror surface of each of said deflectable mirrors for supporting each of the mirrors for deflecting to different deflection angles wherein said vertical hinge further connected to a hinge bottom electrode for providing a hinge-and-mirror voltage to said hinge and said mirror;

a drive electrode for driving the mirror;

a control circuit for applying a drive voltage to the electrode according to an input signal to control the deflection angles of the mirrors, wherein

the drive electrode further physically contacts the mirror and mechanically stops the mirror at a maximum deflection angle of the mirror; and

a projection lens for projecting a light reflected from the mirror for projecting and displaying an image wherein the deflection angles of the mirror is functionally related to an aperture ratio of the projection lens for satisfying a resolution requirement based on a pitch between adjacent mirrors.

15. A mirror device comprising:

a plurality of deflectable mirrors;

an elastic member for supporting each of the mirrors for deflecting to different deflection angles;

a drive electrode for controlling the deflection angle of the mirror wherein said drive electrode is further covered with an antireflection cyclic structure with length between said cyclic structure shorter than a wavelength applied for displaying image implementing said mirror device; and

a control circuit for applying a voltage to the electrode according to an input signal to control the deflection angles of the mirrors wherein the drive electrode further physically contacts and mechanically stops the mirror at a maximum deflection angle of the mirror.