Micromirror and post arrangements on substrates

• US 7,697,193 B2
• Filed: 09/11/2007
• Issued: 04/13/2010
• 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): Dinh; Jack
• Application Number:
  US11/853,812
• Publication Number:
  US 20080049290A1
• Time in Patent Office: 945 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, wherein imaginary lines connecting centers of each micromirror in the array form an imaginary grid of rows and columns orthogonal to each other, and wherein the edges of the micromirrors are not parallel to either the rows or columns in the imaginary grid;

a hinge support held apart from and connected to the substrate via posts;

a hinge affixed to the hinge support; and

a mirror plate attached to the hinge such that the mirror plate rotates 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.

2. The spatial light modulator 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; 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.

3. The spatial light modulator of claim 2, wherein the second electrode is an electrode film on a surface of the substrate to which the hinge support is connected.

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

an extension plate connected to the mirror plate.

5. The spatial light modulator of claim 4, 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.

6. The spatial light modulator of claim 4, 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.

7. A spatial light modulator comprising:

an array of micromirrors on a substrate, each micromirror held on the substrate by a hinge connected to the micromirror and to two posts on the substrate, each micromirror having an axis of rotation, wherein a line drawn between centers of the two posts at hinge level is not parallel with the axis of rotation.

8. The spatial light modulator of claim 7, wherein the micromirrors are rectangular or square.

9. The spatial light modulator of claim 7, wherein the substrate is in a rectangular shape;

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

degrees to 25°

degrees to the two sides of the rectangular substrate.

10. The spatial light modulator of claim 7, wherein the substrate is in a rectangular shape;

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

degrees to 20°

degrees to the two sides of the rectangular substrate.

11. The spatial light modulator of claim 7, 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.

12. The spatial light modulator of claim 7, 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.

13. A spatial light modulator comprising an array of micromirrors comprising:

a hinge spaced apart from and connected to the substrate via the posts; and

a mirror plate attached to the hinge such that the mirror plate rotates 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.

14. The spatial light modulator of claim 13, 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.

15. The spatial light modulator of claim 14, wherein the second electrode is an electrode film on a surface of the substrate to which the hinge support is connected.

16. The spatial light modulator of claim 13, wherein the micromirror further comprises:

an extension plate connected to the mirror plate.

17. The spatial light modulator of claim 16, 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.

18. The spatial light modulator of claim 16, 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.