Microelectromechanical device with reset electrode

• US 7,298,542 B2
• Filed: 06/07/2006
• Issued: 11/20/2007
• Est. Priority Date: 04/02/2004
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Regan, Michael J.
• Primary Examiner(s): Lester; Evelyn A.
• Application Number:
  US11/448,489
• Publication Number:
  US 20060227405A1
• Time in Patent Office: 531 Days
• Field of Search: 359290-292, 359/295, 359/298, 359/223, 359/224
• US Class Current: 359/290
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A microelectromechanical device having a reset electrode for use in various devices including display devices such as those employing spatial light modulators. The device includes an optically transmissive substrate, a semiconductor substrate, and a member deflectable between a rest position and an operative position supported by one of the substrates. The deflectable member returns to an undeflected position by operation of the reset electrode.

Claims

1. A micro-electromechanical device, comprising:

a substrate;

an optically transmissive layer disposed a spaced distance from the substrate, wherein the substrate and the optically transmissive layer define at least one cavity, the at least one cavity containing a dielectrophoretic fluid;

a support structure coupled to one of the substrate or the optically transmissive layer, the support structure contained within the at least one cavity;

a transparent conductive material positioned on the optically transmissive layer; and

a reflective element coupled to the support structure, the reflective element configured to;

deflect between a rest position and at least one operative position when electrostatically attracted to an address electrode located on the substrate; and

return to the rest position when subjected to an electrostatic force generated by the transparent conductive material.

2. The micro-electromechanical device of claim 1 wherein the reflective element comprises a substantially rigid reflective plate.

3. The micro-electromechanical device of claim 1 wherein the support structure further comprises a ground electrode attached to the reflective element, wherein the ground electrode is electrically coupled to the substrate and configured for selective actuation of electronic circuitry.

4. The micro-electromechanical device of claim 1 wherein the support structure comprises at least one hinge and at least one post, the at least one post connected to at least one of the optically transmissive layer or the substrate, and wherein the at least one hinge extends from the at least one post and into connection with the reflective element.

5. The micro-electromechanical device of claim 1, further comprising a voltage controller, the voltage controller operable on the address electrode and a power source connected to the transparent conductive material to actuate deflection and return to the rest position of the reflective element.

6. The micro-electromechanical device of claim 1 wherein the transparent conductive material has a voltage potential sufficient to overcome electrostatic attraction between the reflective element and the address electrode.

7. The micro-electromechanical device of claim 1 wherein the substrate includes circuitry to control the address electrode, and wherein the transparent conductive material is connected to a power source independent of the substrate circuitry.

8. The micro-electromechanical device of claim 1 wherein the transparent conductive material exhibits optical transmission greater than about 70% at a material thickness of about 200 angstroms.