Micro machined mirror

• US 6,315,423 B1
• Filed: 07/13/1999
• Issued: 11/13/2001
• Est. Priority Date: 07/13/1999
• Status: Expired due to Term

• Current Assignee: Input/Output Incorporated
• Original Assignee: Input/Output Incorporated
• Inventors: Yu, Duli, Yu, Lianzhong, Schmidt, Martin A., Goldberg, Howard D., Ried, Robert P.
• Primary Examiner(s): Spy, Cassandra
• Assistant Examiner(s): Robinson, Mark A.
• Application Number:
  US09/352,835
• Time in Patent Office: 854 Days
• Field of Search: 359/871, 359/872, 359/212, 359/214, 359/223, 359/224
• US Class Current: 359/872
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 7/1821 for rotating or oscillating mirrors

Abstract

A micro machined mirror assembly is provided that includes a micro machined top cap, mirror, and bottom cap mounted onto a ceramic substrate. The micro machined mirror is resiliently supported by a pair of T-shaped hinges and includes travel stops that limit motion of the mirror in the z-direction. The top and bottom micro machined caps also include travel stops that limit motion of the mirror in the z-direction.

Claims

1. A mirror assembly, comprising:

a mirror including;

a mirror support structure;

a pair of T-shaped hinges coupled to the mirror support structure; and

a mirrored plate coupled to the T-shaped hinges, the mirrored plate including;

one or more travel stops for limiting movement of the mirrored plate;

a top cap coupled to one side of the mirror, the top cap including;

a top cap support structure including;

an opening for permitting light to reflect off of the mirrored plate; and

one or more travel stops coupled to the top cap support structure for limiting movement of the mirrored plate; and

a bottom cap coupled to another side of the mirror, the bottom cap including;

a bottom cap support structure including an opening; and

one or more travel stops coupled to the bottom cap support structure for limiting movement of the mirrored plate.

2. The mirror assembly of claim 1, wherein one or more of the T-shaped hinges include:

a first member; and

a second member coupled to the first member;

wherein the second member is perpendicular to the first member.

3. The mirror assembly of claim 1 wherein one or more of the T-shaped hinges include:

a first member; and

a second member coupled to the first member;

wherein the second member is serpentine.

4. The mirror assembly of claim 1 wherein one or more of the T-shaped hinges include:

a first member; and

a second member coupled to the first member;

wherein the second member is offset from the center of the first member.

5. The mirror assembly of claim 1, wherein one or more of the T-shaped hinges include:

a first member; and

a second member coupled to the first member;

wherein the second member intersects the first member at an acute angle.

6. A mirror assembly, comprising;

(a) a mass having an exposed reflective surface;

(b) a pair of hinges attached to a support structure supporting said mass, said hinges enabling the mass torsional movement about a common axis of the hinges, vertical movement, movement along a first planar direction of the reflective surface and movement along a second planar direction of the reflective surface, wherein said vertical, first and second planar directions are orthogonal to each other.

7. The mirror assembly of claim 6, wherein said hinges are T-shaped with a first leg member attached to the mass and a T-member attached to the leg and to the support structure at opposite ends of the T-member, said T-member capable of moving in the second planar direction, thereby providing compliancy to the mass in the second planar direction.

8. The mirror assembly of claim 7 further comprising at least one x-travel stop limiting movement of the mass in the first planar direction.

9. The mirror assembly of claim 8 wherein the at least one x-travel stop includes a first member carried by the support structure and a second member carried by the mass.

10. The mirror assembly of claim 9 wherein the mass has a plurality of sides and wherein the at least one x-travel stop includes a separate travel stop corresponding to each said side of the mass.

11. The mirror assembly of claim 7 further comprising at least one y-travel stop limiting movement of the mass in the second planar direction.

12. The mirror assembly of claim 11 wherein at least one y-travel stop includes a member carried by the support structure that limits the movement of the mass in the second planar direction.

13. The mirror assembly of claim 11 wherein the mass has a plurality of sides and at least one y-travel stop includes a separate member carried by the support structure to limit movement of the mass along each said side of the mass.

14. The mirror assembly of claim 11, wherein the first planar stop includes a first member carried by the support structure and a second member carried by the mass which cooperate with each other to limit travel of the mass in the first planar direction and the second planar stop includes a member carried by the mass that limits travel of the mass in the second planar direction.

15. The mirror assembly of claim 7, wherein one or more of the T-shaped hinges include:

a first member; and

a second member coupled to the first member;

wherein the second member is perpendicular to the first member.

16. The mirror assembly of claim 7, wherein one or more of the T-shaped hinges include:

a first member; and

a second member coupled to the first member;

wherein the second member is serpentine.

17. The mirror assembly of claim 7, wherein one or more of the T-shaped hinges include:

a first member; and

a second member coupled to the first member;

wherein the second member is offset from the center of the first member.

18. The mirror assembly of claim 7, wherein one or more of the T-shaped hinges include:

a first member; and

a second member coupled to the first member;

wherein the second member intersects the first member at an acute angle.

19. The mirror assembly of claim 6 further comprising a first planar stop to limit movement of the mass in a first planar direction and a second planar stop to limit the movement of the mass in the second planar direction.

20. The mirror assembly of claim 6 further comprising a vertical travel stop that limits the movement of the mass in a vertical direction that is perpendicular to the exposed reflective surface.

21. The mirror assembly of claim 20 wherein the vertical travel stop includes a separate finger member placed a predetermined distance from each said hinge, each said finger member having length greater than a planar dimension of the hinges.

22. The mirror assembly of claim 6 wherein the hinges permit torsional movement of the mass about a common axis of the hinges, said common axis in the second planar direction.

23. The mirror assembly of claim 6 wherein each said hinge has a predetermined torsional spring constant and a translational spring constant wherein the torsional spring constant is decoupled from the translational spring constant.

24. A mirror assembly, comprising:

(a) an enclosure having a top opening exposed to the environment;

(b) a mirror having a reflective planar surface; and

(c) a pair of hinges attached to said mirror and said support structure to suspend said mirror in the support structure with the reflective planar surface of the mirror exposed to the environment, said hinges allowing the mirror torsional movement about a common axis of the hinges, vertical movement, movement in a first planar direction and movement in a second planar direction.

25. The mirror assembly of claim 24 wherein the enclosure includes at least one of (i) a tapered upper side or (ii) a cut out to prevent clipping of a light beam striking said mirror at an angle.

26. The mirror assembly according to claim 24 wherein the support structure further includes a tapered section that limits movement of the mirror in a particular direction comprising a combination of z and x or z and y directions.

27. The mirror assembly according to claim 26 wherein the particular direction is a combination of one of the (i) z and x axis;

and (ii) z and y axis.

28. The mirror assembly according to claim 24 wherein the enclosure includes substantially identical top and bottom caps, each said bottom and top cap including a travel stop that limits movement of the mirror in the vertical direction.

29. The mirror assembly according to claim 24 further comprising a bottom cap and top cap that includes a separate travel stop that limits movement of the mirror in a particular direction comprising a combination of x, y and z directions.