Micromirrors with novel mirror plates

• US 6,980,349 B1
• Filed: 08/25/2004
• Issued: 12/27/2005
• Est. Priority Date: 08/25/2004
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Reflectivity, Inc. (Texas Instruments, Inc.)
• Inventors: Huibers, Andrew, Patel, Satyadev
• Primary Examiner(s): Dong, Hung Xuan
• Assistant Examiner(s): TRA, TUYEN Q
• Application Number:
  US10/927,560
• Time in Patent Office: 489 Days
• Field of Search: 359/290, 359/291, 359/292, 359/295, 359/220, 359/222, 359/230, 359/320, 359/322, 359/298
• US Class Current: 359/291
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A spatial light modulator is disclosed, along with methods for making such a modulator. The spatial light modulator comprises an array of micromirrors each of which comprises a deflectable and reflective mirror plate. For enabling the deflection of the mirror plate, incisions are made within the area of the mirror plate with each incision being fully enclosed within the area of the mirror plate. The incisions collectively define a deformable hinge that is on the same plane as the mirror plate at the non-deflected state.

Claims

1. A projector, comprising:

a light source for providing illumination light for the projector;

a condensing lens for condensing the light from the light source onto a spatial light modulator, said spatial light modulator comprising an array of micromirrors, each of which further comprises;

a substrate;

a mirror plate having a deformable portion and a non-deformable portion,

wherein the deformable portion of the mirror plate is defined by an incision that is fully enclosed within an area of the mirror plate and/or the deformable portion of the mirror plate; and

a post disposed at the deformable portion of the mirror plate and connecting the mirror plate to the substrate; and

a display target.

2. The projector of claim 1, wherein the deformable portion is surrounded by the non-deformable portion.

3. The projector of claim 2, wherein the incision has a U shape.

4. The projector of claim 2, wherein the incision has an L shape.

5. The projector of claim 2, wherein mirror plate has parallel incisions.

6. The projector of claim 2, wherein incision is square shaped.

7. The projector of claim 1, wherein the deformable portion is positioned within the mirror plate.

8. The projector of claim 1, wherein the mirror plate is generally four sided.

9. The projector of claim 1, wherein the spatial light modulator further comprises a circuit substrate positioned below and spaced apart from the visible light transmissive substrate.

10. The projector of claim 9, wherein said circuit substrate comprises an electrode for creating attraction between the mirror plate and the circuit substrate.

11. The projector of claim 1, wherein the mirror plate is held on the bottom surface of the visible light transmissive substrate;

and wherein the mirror plate has first and second portions such that during deflection of the mirror plate, the second portion of the mirror plate moves towards the bottom surface as the first portion moves away from the bottom surface.

12. The projector of claim 1, wherein the mirror plate includes a conductive layer.

13. The projector of claim 1, wherein the mirror plate has a zigzagged edge.

14. The projector of claim 13, wherein the mirror plate has a shape that is substantially four sided.

15. The projection of claim 1, wherein the hinge is parallel to but offset from a diagonal of the mirror plate when the mirror plate is not deflected.

16. A method of making a projector, comprising:

providing a light source, a collection lens, a projection lens and a display target;

providing a spatial light modulator, wherein the spatial light modulator comprises;

a substrate that is transmissive to visible light;

a mirror plate having a deformable portion and a non-deformable portion; and

a post disposed at the deformable portion of the mirror plate and connecting the mirror plate to the substrate; and

arranging the spatial light modulator, the collection lens, the light source, the projection lens and the display target such that, a light beam from the light source is focused by the collection lens onto the mirror plate through the glass substrate, and reflected by the mirror plate, the reflected light being collected by the projection lens and projected onto the display target.

17. A micromirror device, comprising:

a light transmissive substrate; and

a mirror plate held on the substrate such that the mirror plate is operable to rotate relative to the substrate, wherein the mirror plate has a deformable portion and a non-deformable portion, the deformable portion being defined by an incision fully enclosed within the mirror plate.

18. The micromirror device of claim 17, further comprising:

a post disposed proximate to the deformable portion of the mirror plate and connecting the mirror plate to the substrate.

19. The device of claim 17, wherein the deformable portion is surrounded by the non-deformable portion.

20. The device of claim 17, wherein the deformable portion is positioned within the mirror plate.

21. The device of claim 17, wherein the mirror plate is generally four sided.

22. The device of claim 17, wherein the incision has a U shape.

23. The device of claim 17, wherein the incision has an L shape.

24. The device of claim 17, wherein mirror plate has parallel incisions.

25. The device of claim 17, wherein incision is square shaped.

26. The device of claim 17, wherein the substrate is a semiconductor wafer having thereon an electrode and circuitry for deflecting the mirror plate.

27. The device of claim 17, wherein the substrate is glass that is transmissive to visible light.

28. The device of claim 27, further comprising:

a semiconductor wafer having thereon an electrode and circuitry, the semiconductor wafer being positioned proximate to the glass substrate.

29. The projection of claim 17, wherein the hinge is parallel to but offset from a diagonal of the mirror plate when the mirror plate is not deflected.