Optical deflecting device, optical deflecting device array, method for driving the optical deflecting device and image projection display apparatus using the device

• US 20070091416A1
• Filed: 10/19/2006
• Published: 04/26/2007
• Est. Priority Date: 10/20/2005
• Status: Active Grant

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Ohtaka, Koichi, Nanjyo, Takeshi, Katoh, Seiichi
• Granted Patent: US 7,480,090 B2
• Time in Patent Office: Days
• US Class Current: 359/291
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

An optical deflecting device includes a plate-like member having a light reflective area and a conductor layer. The plate-like member rotates with substantially the middle portion thereof made a fulcrum to change an inclination direction thereof and thereby a reflection direction of a light flux incident to the light reflective area is changed. A first electrode group and a second electrode group are arranged so as to oppose the conductor layer of the plate-like member, respectively, and to sandwich a position corresponding to a position of the fulcrum of the plate-like member. Each electrode group includes a control electrode controlling starting of the plate-like member and a drive electrode driving the plate-like member.

Claims

1. An optical deflecting device comprising:

a plate-like member having a light reflective area and a conductor layer, the plate-like member rotating with substantially the middle portion thereof made a fulcrum to change an inclination direction thereof and thereby a reflection direction of a light flux incident to the light reflective area being changed; and

a first electrode group and a second electrode group arranged so as to oppose the conductor layer of the plate-like member, respectively, and to sandwich a position corresponding to a position of the fulcrum of the plate-like member, each electrode group including a control electrode controlling starting of the plate-like member and a drive electrode driving the plate-like member.

2. The optical deflecting device according to claim 1, wherein the control electrodes of the first electrode group and the second electrode group are connected with complimentary outputs of a semiconductor memory, respectively.

3. The optical deflecting device according to claim 1, wherein at least each control electrode of the first electrode group and the second electrode group is slanted substantially parallel to an inclination of the plate-like member.

4. The optical deflecting device according to claim 1, wherein the control electrodes of the first electrode group and the second electrode group are arranged in symmetrical positions with respect to a center point on the position of the fulcrum of the plate-like member.

5. The optical deflecting device according to claim 1, wherein the control electrodes of the first electrode group and the second electrode group are respectively arranged in the most distant positions from the position of the fulcrum of the plate-like member.

6. The optical deflecting device according to claim 1, wherein the control electrodes of the first electrode group and the second electrode group are respectively arranged in positions opposing corners of the plate-like member.

7. The optical deflecting device according to claim 1, wherein the control electrodes of the first electrode group and the second electrode group are respectively formed in shapes that are broader toward the distant side of the plate-like member with respect to the position of the fulcrum of the plate-like member and narrower toward the near side of the plate-like member with respect to the position of the fulcrum of the plate-like member.

8. The optical deflecting device according to claim 1, wherein each of the first electrode group and the second electrode group is consisted of three electrodes, an electrode at the center being the control electrode and an electrode on each side of the control electrode being the drive electrode.

9. A method for driving an optical deflecting device, the optical deflecting device including a plate-like member having a light reflective area and a conductor layer, the plate-like member rotating with substantially the middle portion thereof made a fulcrum to change an inclination direction thereof and thereby a reflection direction of a light flux incident to the light reflective area being changed, and a first electrode group and a second electrode group arranged so as to oppose the conductor layer of the plate-like member, respectively, and to sandwich a position corresponding to a position of the fulcrum of the plate-like member, each electrode group including a control electrode controlling starting of the plate-like member and a drive electrode driving the plate-like member, the method comprising:

applying complimentary outputs of a semiconductor memory to the control electrodes of the first electrode group and the second electrode group, respectively; and

applying potentials to the drive electrodes of the first electrode group or the second electrode group to induce a potential in the plate-like member,

wherein the potential induced in the plate-like member by the drive electrodes of the first electrode group or the second electrode group is about a low or high potential of an operation voltage of the semiconductor memory.

10. The method according to claim 9, wherein a potential of each drive electrode of the first electrode group or the second electrode group on the inclined side of the plate-like member and a potential of the control electrode of the first electrode group or the second electrode group on the inclined side of the plate-like member is substantially the same.

11. An optical deflecting device array comprising:

a plurality of optical deflecting devices two-dimensionally arranged, each optical deflecting device including a plate-like member having a light reflective area and a conductor layer, the plate-like member rotating with substantially the middle portion thereof made a fulcrum to change an inclination direction thereof and thereby a reflection direction of a light flux incident to the light reflective area being changed, and a first electrode group and a second electrode group arranged so as to oppose the conductor layer of the plate-like member, respectively, and to sandwich a position corresponding to a position of the fulcrum of the plate-like member, each electrode group including a control electrode controlling starting of the plate-like member and a drive electrode driving the plate-like member; and

a plurality of semiconductor memories arranged to correspond to the plurality of optical deflecting devices,

wherein the drive electrodes of the first electrode group and the second electrode groups, other than the control electrodes, of respective optical deflecting devices, that are located in corresponding positions, respectively, are connected with each other, and the control electrodes of each optical deflecting device are connected with complimentary outputs of a corresponding semiconductor memory of the plurality of semiconductors memories.

12. An image projection display apparatus comprising:

an optical deflecting device including a plate-like member having a light reflective area and a conductor layer, the plate-like member rotating with substantially the middle portion thereof made a fulcrum to change an inclination direction thereof and thereby a reflection direction of a light flux incident to the light reflective area being changed, and a first electrode group and a second electrode group arranged so as to oppose the conductor layer of the plate-like member, respectively, and to sandwich a position corresponding to a position of the fulcrum of the plate-like member, each electrode group including a control electrode controlling starting of the plate-like member and a drive electrode driving the plate-like member;

a light source illuminating the optical deflecting device; and

a projecting optical system projecting a reflected light from the optical deflecting device.

13. An image projection display apparatus comprising:

an optical deflecting device array in which a plurality of optical deflecting devices are two-dimensionally arranged, each optical deflecting device including a plate-like member having a light reflective area and a conductor layer, the plate-like member rotating with substantially the middle portion thereof made a fulcrum to change an inclination direction thereof and thereby a reflection direction of a light flux incident to the light reflective area being changed, and a first electrode group and a second electrode group arranged so as to oppose the conductor layer of the plate-like member, respectively, and to sandwich a position corresponding to a position of the fulcrum of the plate-like member, each electrode group including a control electrode controlling starting of the plate-like member and a drive electrode driving the plate-like member;

a light source illuminating the optical deflecting device array; and

a projecting optical system projecting a reflected light from the optical deflecting device array.