Deformable mirror device with oscillating states

• US 20080192212A1
• Filed: 12/24/2007
• Published: 08/14/2008
• Est. Priority Date: 11/01/2003
• Status: Active Grant

• Current Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Maeda, Yoshihiro, Ichikawa, Hirotoshi, Arai, Kazuma, Ishii, Fusao
• Granted Patent: US 7,956,319 B2
• Time in Patent Office: Days
• US Class Current: 353/98
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2320/0266 Reduction of sub-frame artefacts
• CPC Class Codes: G09G 3/001 using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/2081 with combination of amplitude modulation and time modulation space and time error diffusion G09G3/2066
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833

Abstract

A mirror device including: a mirror arranged on a substrate, supported by a hinge, and arranged substantially parallel to the substrate; a plurality of address electrodes for deflecting the mirror to an ON state, an OFF state, or an oscillating state; and a drive circuit for applying a voltage to the plurality of address electrodes. The mirror device is controlled such that a voltage can be applied to a corresponding address electrode to deflect the mirror, and oscillation in the oscillating state can be started from a state of the deflected mirror.

Claims

1. A control method for a mirror device that deflects incident light and comprises:

a mirror arranged on a substrate, supported by a hinge, and arranged substantially parallel to the substrate;

a plurality of address electrodes for deflecting the mirror to an ON state, an OFF state, or an oscillating state; and

a drive circuit for applying a voltage to the plurality of address electrodes, wherein;

a voltage is applied to a corresponding address electrode to deflect the mirror; and

oscillation in the oscillating state is started from a state of the deflected mirror.

2. The method according to claim 1, wherein:

in the oscillating state, the mirror repeats a locus including a state parallel to the substrate.

3. The method according to claim 1, wherein:

when the mirror is deflected to the ON state or the OFF state, first electrostatic force is applied between one of the plurality of address electrodes and the mirror; and

when the mirror is deflected to the oscillating state, second electrostatic force is applied between the address electrode and the mirror.

4. The method according to claim 3, wherein:

the address electrode to which the second electrostatic force is applied is an address electrode corresponding to the ON state or the OFF state.

5. The method according to claim 3, wherein:

the second electrostatic force is smaller than the first electrostatic force.

6. The method according to claim 3, wherein:

the second electrostatic force is larger than the first electrostatic force.

7. The method according to claim 3, wherein:

the second electrostatic force is applied such that a deflecting speed can be accelerated.

8. The method according to claim 3, wherein:

the second electrostatic force is applied such that a deflecting speed can be decelerated.

9. The method according to claim 3, wherein:

the second electrostatic force is applied such that the oscillation of the mirror can be stopped.

10. A projection system, comprising:

illumination light;

a mirror device having a plurality of mirror elements for modulating the illumination light by controlling the mirror in any of the ON state, the OFF state, and the oscillating state;

a control circuit for driving the mirror device; and

a projection light path through which the projection light modulated by the mirror device is projected, wherein

the control circuit controls the oscillating state from a state to which the mirror is modulated, and projects a part of the optical flux of the projection light through the projection light path.

11. The system according to claim 10, wherein:

the projection light has 1000 or more grayscales.

12. The system according to claim 10, wherein:

the control circuit applies a voltage to an address electrode corresponding to the mirror such that the oscillating state of the mirror can be changed.

13. The system according to claim 10, wherein:

a state to which the mirror is deflected is any of the ON state, the OFF state, and the oscillating state.

14. A mirror device which deflects incident light, comprising:

a mirror element having a mirror and a hinge;

a plurality of address electrodes for controlling the mirror element to a first state or a second state;

a control circuit for controlling a voltage to be applied to the plurality of address electrodes, wherein

in the first state, first electrostatic force is applied between the mirror and an address electrode corresponding to the first state, and in the second state, a second electrostatic force is applied between the mirror and an address electrode corresponding to the second state.

15. The device according to claim 14, wherein:

the first and second electrostatic forces are electrostatic force that deflects the mirror in a same direction.

16. The device according to claim 14, wherein:

the first and second electrostatic forces are electrostatic force that deflects the mirror in different directions.

17. The device according to claim 14, wherein:

the first state is an ON state, and the second state is one of an intermediate state and an oscillating state.

18. The device according to claim 14, wherein:

the first state is an OFF state, and the second state is one of an intermediate state and an oscillating state.

19. The device according to claim 14, wherein:

the first state and the second state are different oscillating states.

20. The device according to claim 14, wherein:

the first state is an intermediate state, and the second state is an oscillating state.

21. The device according to claim 14, wherein:

the first state is an oscillating state, and the second state is a state in which an oscillating state is changed.

22. The device according to claim 14, wherein:

the control circuit controls a voltage to be applied to all of a plurality of address electrodes corresponding to the mirror such that the voltage can be set to 0.

23. The device according to claim 14, wherein:

the mirror is connected to a ground of the control circuit.