Deformable mirror device with oscillating states

• US 7,646,528 B2
• Filed: 12/24/2007
• Issued: 01/12/2010
• Est. Priority Date: 12/26/2006
• Status: Active Grant

• Current Assignee: Ignite USA (Ignite), Olympus Corporation
• Original Assignee: Olympus Corporation, Silicon Quest Kabushiki-Kaisha
• Inventors: Maeda, Yoshihiro, Ichikawa, Hirotoshi, Arai, Kazuma, Ishii, Fusao
• Primary Examiner(s): Sugarman; Scott J
• Assistant Examiner(s): PINKNEY, DAWAYNE
• Application Number:
  US12/004,607
• Publication Number:
  US 20080174855A1
• Time in Patent Office: 750 Days
• Field of Search: 359290-292, 359/198, 359223-225, 359/245, 359260-263, 359/298, 359/295, 359301-303, 359317-318
• 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 which deflects incident light includes: a mirror arranged on a substrate and supported by a hinge; an address electrode deflecting the mirror to an ON state, an OFF state, or an oscillating state; a drive circuit applying a voltage to the address electrode; and a first stopper unit determining an oscillation amplitude in the oscillating state.

Claims

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

a mirror arranged on a substrate and supported by a hinge;

a first address electrode and a second address electrode disposed on opposite sides across said hinge on said substrate for deflecting the mirror to an ON state, an OFF state, or an oscillating state;

a drive circuit applying a plurality of voltage pulses to the first address electrode and the second electrode for controlling said mirror to continuously oscillate at a specific oscillation frequency in a controlled time period within a display frame period between said first address electrode and second address electrode serving also as a first stopper and a second stopper respectively wherein said mirror further projects a reflection light having an intermediate light intensity in said controlled time period within said display frame period to an image projection lens wherein the intermediate light intensity is a partial portion of a full light intensity reflected from said mirror to said image projection lens when said mirror is operated in the ON state; and

said drive circuit controls the intermediate light intensity by adjusting said oscillation frequency in said controlled time period within said display frame period and said plurality of voltage pulses.

2. The device according to claim 1, wherein:

said drive circuit further applies a zero voltage to both said first address and second address electrodes, represented by a voltage of (0,0), during at least a portion of said oscillating state to allow said mirror to continuously oscillate freely in said controlled time period within said display frame period for modulating said intermediate light intensity reflected from the mirror.

3. The device according to claim 1, wherein:

the drive circuit further controls the mirror to continuously oscillate in said controlled time period within said display frame period in said intermediate state to control said intermediate light intensity between a range of ¼

to ¾

of said full light intensity as that reflected by said mirror in said ON state.

4. The device according to claim 1, wherein:

the drive circuit further controls said mirror to continuously oscillate in said time period within said display frame period by applying a zero voltage, represented by a (0,0) voltage to said first and second address electrodes beginning from a time when said mirror is at said ON state or OFF state to allow said mirror to continuously oscillate freely in said time period within said display frame period.

5. The device according to claim 1, wherein:

said first address and second address electrodes functioning as said first stopper and said second stopper having different height supported and supported on said substrate.

6. The device according to claim 1, wherein:

said first address and second address electrodes functioning as said first stopper and said second stopper are disposed at different distances on two opposite sides from said hinge on said top surface of said substrate.

7. The device according to claim 1, further comprising:

a third address electrode for receiving control signals from said control circuit to control said mirror to operate in an intermediate state for reflecting a light of said intermediate light intensity.

8. The device according to claim, 7 wherein:

said third address electrode is disposed away from said first and second address electrode on said substrate.

9. The device according to claim, 7 wherein:

said third address electrode is disposed near one of said first and second address electrode on said substrate.

10. The device according to claim 1, further comprising:

an elastic stopper for regulating and limiting a maximum deflection angle of the mirror in addition to said first and second electrodes to operate and control said mirror in an intermediate or oscillating state.

11. A mirror device that deflects incident light, comprising:

a mirror arranged on a substrate and supported by a hinge;

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

a drive circuit for applying a plurality of voltages to the address electrodes for generating different electrostatic forces between the address electrode and said mirror for deflecting said hinge for tilting and continuously oscillating the mirror in a controlled time period within a display frame period to reflect an intermediate amount of light for image display less than a fully-On image display light.

12. The device according to claim 11, wherein:

said drive circuit applying said voltage to the address electrodes disposed on two opposite sides across said hinge for deflecting said mirror to tilt to an ON and OFF angular positions along a first deflection axis and applying said voltage to an intermediate address electrode disposed away from an axis connected between of said ON and OFF electrodes for deflecting said mirror to tilt to an intermediate angle along a second deflection axis different from said axis connected between said ON and OFF electrodes.

13. The device according to claim 11, wherein:

a maximum deflection angle of said continuous oscillation of the mirror in the oscillating state is smaller than a deflection angle of the mirror in the ON state or the OFF state.

14. The device according to claim 11, wherein:

a maximum deflection angle of said continuous oscillation of the mirror in the oscillating state is larger than a deflection angle of the mirror in the ON state or the OFF state.

15. The device according to claim 11, further comprising:

a stopper unit for regulating and limiting a maximum deflection angle of said continuous oscillation of the mirror in said oscillating state.

16. The device according to claim 15, wherein:

the driver circuit applies a first set of voltages to the address electrodes to control the mirror to operate in the intermediate state and applies a second set of voltages to the address electrodes to control the mirror to operate in the ON state or the OFF state wherein the first set of voltages are different from the second set of voltages.

17. The device according to claim 11 wherein:

the driver circuit controls the mirror to continuously oscillate in said controlled time period within said display frame period substantially in a range between three to twelve degrees relative to the substrate.

18. The device according to claim 11, wherein:

the driver circuit controls the mirror to tilt to a deflection angle in the ON state or the OFF state substantially in a range between −

16 to +16 degrees or smaller relative to the substrate.

19. The device according to claim 11, wherein:

the driver circuit controls the mirror to continuously oscillate in said controlled time period within a display frame period between an angle that is about three-fourth to one-fourth of the deflection angles of the ON and OFF state.

20. The device according to claim 12, wherein:

the intermediate address electrode extends vertically from the substrate; and

the intermediate address electrode is disposed at a location to function as a stopper unit for limiting a maximum tilt angle of the mirror during an intermediate or oscillating state.

21. A mirror device that deflects incident light, comprising:

a mirror arranged on a substrate and supported by a hinge extended from and substantially perpendicular to the substrate;

a plurality of address electrodes for deflecting the mirror to an ON state, an OFF state, or an oscillating state or an intermediate state wherein said address electrodes are disposed along at least a first axis and a second axis interconnecting said electrodes; and

a drive circuit for applying a voltage to the address electrodes for deflecting said hinge for tilting and oscillating the mirror along at least two different deflection axes depending on angular orientations of said first axis and said second axis.