Micro-mirror element with double binge

• US 7,199,917 B2
• Filed: 04/18/2005
• Issued: 04/03/2007
• Est. Priority Date: 04/18/2005
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Mezenner, Rabah, Gong, Cuiling
• Primary Examiner(s): Mack; Ricky
• Assistant Examiner(s): TRA, TUYEN Q
• Application Number:
  US11/108,259
• Publication Number:
  US 20060245031A1
• Time in Patent Office: 715 Days
• Field of Search: 359/290, 359/291, 359/292, 359/295, 359/298, 359/222, 359/223, 359/224, 359/320, 359/332
• US Class Current: 359/291
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

According to one embodiment of the present invention a micro-mirror element comprises a lower layer, a first middle layer, a second middle layer, and a micro-mirror. The lower layer includes an address portion for receiving an address voltage and a bias portion for receiving a bias voltage respectively. The first middle layer is electrically coupled to the bias portion of the lower layer. The second middle layer is electrically coupled to the first middle layer. The micro-mirror is coupled to the second middle layer and comprises a reflective surface operable to selectively tilt, in response to an application of a bias voltage and an address voltage to the lower layer, to reflect a beam of light.

Claims

1. A micro-mirror element comprising:

a lower layer including an address portion for receiving an address voltage and a bias portion for receiving a bias voltage respectively;

a first middle layer including a first rotating beam and a pair of bias beams, each bias beam electrically coupled to the bias portion of the lower layer by at least one via;

a second middle layer including a hinge electrically coupled to at least one of the bias beams of the first middle layer and also including a second rotating beam electrically coupled to the hinge, the second rotating beam also electrically coupled to the first rotating beam by at least one via;

a micro-mirror comprising a reflective surface operable to selectively tilt to reflect a beam of light, the micro-mirror electrically coupled to the second rotating beam by at least one via;

wherein application of the bias voltage to the bias portion and the address voltage to the address portion creates a first, second, and third electrostatic attractions that collectively result in a force operable to tilt the mirror, the first electrostatic attraction being between the address portion and the first rotating beam, the second electrostatic attraction being between the address portion and the second rotating beam, and the third electrostatic attraction being between the address portion and the micro-mirror;

wherein the first middle layer is disposed between the lower layer and the second middle layer; and

wherein the second middle layer is disposed between the first middle layer and the micro-mirror.

2. The micro-minor element of claim 1, wherein:

the second rotating beam is operable to receive a portion of a bias voltage received by the hinge, and

the first rotating beam is operable to receive a portion of the bias voltage received by the second rotating beam.

3. The micro-mirror element of claim 1, wherein the first rotating beam and the second rotating beam are operable to rotate with the hinge.

4. The micro-mirror element of claim 1, wherein the second middle layer includes a second bias beam electrically coupled to hinge, the second middle layer also electrically coupled to at least one of the bias beams of the first middle layer by at least one via.

5. The micro-mirror element of claim 1, wherein the second rotating beam extends laterally further from a center of the micro-mirror than the first rotating beam.

6. The micro-mirror element of claim 1, wherein the address voltage is only applied to the lower layer.

7. A micro-mirror element comprising:

a lower layer including an address portion for receiving an address voltage and a bias portion for receiving a bias voltage respectively;

a first middle layer electrically coupled to the bias portion of the lower layer;

a second middle layer electrically coupled to the first middle layer; and

a micro-mirror coupled to the second middle layer comprising a reflective surface operable to selectively tilt, in response to an application of a bias voltage and an address voltage to the lower layer, to reflect a beam of light.

8. The micro-mirror element of claim 7, wherein

the first middle layer includes a first rotating beam,

the second middle layer includes a hinge and a second rotating beam, and

the first rotating beam and the second rotating beam are operable to rotate with the hinge.

9. The micro-mirror element of claim 8, wherein

application of the bias voltage to the bias portion and the address voltage to the address portion creates first and second electrostatic attractions resulting in at least a portion of a force operable to tilt the micro-mirror, the first electrostatic attraction being between the address portion and the first rotating beam, the second electrostatic attraction being between the address portion and the second rotating beam.

10. The micro-mirror element of claim 9, wherein

the first middle layer is disposed between the lower layer and the second middle layer;

and

the second middle layer is disposed between the first middle layer and the micro-mirror.

11. The micro-mirror element of claim 9, wherein the address voltage is only applied to the lower layer.

12. The micro-mirror element of claim 8, wherein

the micro-mirror is electrically coupled to the second middle layer;

and

application of the bias voltage to the bias portion and the address voltage to the address portion creates a first, second, and third electrostatic attraction that collectively result in a force operable to tilt the mirror, the first electrostatic attraction being between the address portion and the first rotating beam, the second electrostatic attraction being between the address portion and the second rotating beam, and the third electrostatic attraction being between the address portion and the micro-mirror.

13. The micro-mirror element of claim 7, wherein the address voltage is only applied to the lower layer.

14. The micro-mirror element of claim 8, wherein

the second rotating beam is operable to receive a portion of a bias voltage received by the first middle layer, and

the first rotating beam is operable to receive a portion of the bias voltage received by the second rotating beam.

15. The micro-mirror element of claim 14, wherein the first rotating beam and the second rotating beam are operable to rotate with the hinge.

16. The micro-mirror element of claim 7, wherein the second middle layer includes a bias beam electrically coupled to a hinge, the second middle layer also electrically coupled to the first middle layer by at least one via.

17. The micro-mirror element of claim 7, wherein

the second middle layer includes a second rotating beam,

the first middle layer includes a first rotating beam, and the second rotating beam extends laterally further from a center of the micro-mirror than the first rotating beam.

18. The micro-mirror element of claim 17, wherein

the second rotating beam is operable to receive a portion of a bias voltage received by the first middle layer, and

the first rotating beam is operable to receive a portion of the bias voltage received by the second rotating beam.

19. A method of tilting a digital micro-mirror pixel element, the method comprising:

providing a micro-mirror element with a lower layer that includes an address portion, a first middle layer that includes a rotating beam, a second middle layer that includes a second rotating beam, and a micro-mirror;

applying an address voltage to the address portion;

applying a bias voltage to the first rotating beam and the second rotating beam; and

creating a first electrostatic attraction between the address portion and the first rotating beam and a second electrostatic attraction between the address portion and the second rotating beam by applying the address voltage to the address portion and the bias voltage to the first and second rotating beams respectively, wherein the first and second electrostatic attractions result in at least a portion of a force operable to tilt the micro-mirror.

20. The method of claim 19, further comprising:

applying a bias voltage to the micro-mirror;

creating a third electrostatic attraction between the address portion and the micro-mirror by applying the address voltage to the address portion and the bias voltage to the micro-mirror, wherein the third electrostatic attraction results in at least a portion of the force operable to tilt the micro-mirror.