Micromirror and post arrangements on substrates

• US 20060007522A1
• Filed: 08/30/2005
• Published: 01/12/2006
• Est. Priority Date: 10/30/2003
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Huibers, Andrew, Patel, Satyadev
• Granted Patent: US 7,075,702 B2
• Time in Patent Office: Days
• US Class Current: 359/290
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A micromirror of a micromirror array of a spatial light modulator used in display systems comprises a mirror plate attached to a hinge that is supported by two posts formed on a substrate. Also the mirror plate is operable to rotate along a rotation axis that is parallel to but offset from a diagonal of the mirror plate when viewed from the top. An imaginary line connecting the two posts is not parallel to either diagonal of the mirror plate.

Claims

1. A projector, comprising:

a rectangular array of reflective and deflectable mirror plates on a substrate;

a light source providing light onto the rectangular array of mirror plates;

wherein the light has a first angle from 50°

to 70°

degrees to the substrate;

wherein the light has a second angle to a side of the rectangular array when viewed from the top of the mirror plates, said second angle being from 50°

to 65°

degrees; and

projection optics for projecting the light reflected from the mirror plates onto a screen.

2. The projector of claim 1, wherein the substrate is a light transmissive substrate.

3. The projector of claim 1, wherein the substrate is a semiconductor substrate.

4. The projector of claim 1, wherein the substrate has four predominant sides that form a rectangular shape;

and wherein each side of the mirror plate is at an angle of from 5°

degrees to 25°

degrees to the two sides of the rectangular substrate.

5. The projector of claim 1, wherein each mirror plate is in a shape of a rectangle, square, trapezoid or rhombus.

6. The projector of claim 1, wherein the mirror plate is in a shape of square.

7. The projector of claim 1, wherein at least one of the mirror plates is supported by two posts formed on the substrate.

8. The projector of claim 1, wherein the substrate has four predominant sides that form a rectangular shape;

and wherein each side of the mirror plate is at an angle of from 10°

degrees to 20°

degrees to the two sides of the rectangular substrate.

9. The projector of claim 1, wherein the mirror plate is attached to the hinge such that the mirror plate is capable of rotating along a rotation axis that is parallel to but offset from a diagonal of the mirror plate when viewed from the top of the substrate.

10. The projector of claim 1, wherein the micromirror further comprises:

a first electrode placed proximate to the mirror plate such that a first electrical filed is established between the first electrode and the mirror plate, and the mirror plate rotates relative to the substrate in a first rotation direction in response to the first electrical field.

11. The projector of claim 10, wherein the micromirror further comprises:

a second electrode placed proximate to the mirror plate such that a second electrical filed is established between the second electrode and the mirror plate, and the mirror plate rotates relative to the substrate in a second rotation direction in response to the first electrical field, wherein the second rotation direction is opposite to the first rotation direction.

12. The projector of claim 11, wherein the first and the second electrode are on a substrate other than the substrate to which the hinge support is connected.

13. The projector of claim 11, wherein the first electrode is on a substrate other than the substrate to which the hinge support is connected;

and wherein the second electrode is on the substrate to which the hinge support is connected.

14. The projector of claim 11, wherein the second electrode is an electrode film on a surface of the substrate to which the hinge support is connected.

15. The projector of claim 1, wherein the micromirror further comprises:

an extension plate connected to the mirror plate.

16. The projector of claim 15, wherein the extension plate is connected to the mirror plate via an extension-plate post and the extension plate defines a first gap between the extension and the mirror plate.

17. The projector of claim 15, wherein the extension plate is extended beyond the mirror plate and connected to the mirror plate via an extension-plate post;

and wherein the extension plate defines a second gap between the extension plate and the substrate to which the hinge support is connected.

18. The projector of claim 15, wherein the extension plate is electrically conducting.

19. The projector of claim 15, wherein the extension plate is dielectric with a dielectric constant larger than 1.0.

20. The projector of claim 1, wherein the micromirror further comprises:

a first stop for stopping the rotation of the mirror plate when the mirror plate rotates to an ON state angle.

21. The projector of claim 20, wherein the first stop is disposed on the hinge support.

22. The projector of claim 20, wherein the micromirror further comprises:

a second stop for stopping the rotation of the mirror plate when the mirror plate rotates to an OFF state.

23. The projector of claim 1, further comprising:

collection optics for directing the light from the light source onto the mirror plates.