Micromirror and post arrangements on substrates

• US 7,268,934 B2
• Filed: 01/05/2006
• Issued: 09/11/2007
• Est. Priority Date: 10/30/2003
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Huibers, Andrew, Patel, Satyadev
• Primary Examiner(s): Mack; Ricky
• Assistant Examiner(s): Dinh; Jack
• Application Number:
  US11/327,697
• Publication Number:
  US 20060171014A1
• Time in Patent Office: 614 Days
• Field of Search: 359290-292, 359/295, 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 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 spatial light modulator comprising:

an array of micromirrors, each micromirror comprising a mirror plate held on a substrate by a plurality of posts, each mirror plate having four predominant sides;

wherein the substrate is in a rectangular shape; and

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

to 25°

degrees to the two predominant sides of the rectangular substrate.

2. The spatial light modulator of claim 1, wherein the mirror plates are rectangular or square.

3. The spatial light modulator of claim 1, wherein the substrate is in a rectangular shape;

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

degrees to 20°

degrees to the two sides of the rectangular substrate.

4. The spatial light modulator of claim 1, wherein each micromirror further comprises:

a hinge support held by the posts on the substrate and connected to the substrate via the posts;

a hinge affixed to the hinge support; and

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.

5. The spatial light modulator of claim 4, 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; and

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.

6. The spatial light modulator of claim 5, wherein the second electrode is an electrode film on a surface of the substrate to which the hinge support is connected.

7. The spatial light modulator of claim 4, wherein the micromirror further comprises:

an extension plate connected to the mirror plate.

8. The spatial light modulator of claim 7, 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.

9. The spatial light modulator of claim 7, 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.

10. The spatial light modulator 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.

11. The spatial light modulator of claim 1, 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.