Pixel structure having deformable material and method for forming a light valve

• US 6,445,433 B1
• Filed: 06/19/2000
• Issued: 09/03/2002
• Est. Priority Date: 11/19/1999
• Status: Expired due to Term

• Current Assignee: Hanger Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Nokia Corporation
• Inventors: Levola, Tapani
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): NGUYEN, DUNG T
• Application Number:
  US09/596,622
• Time in Patent Office: 806 Days
• Field of Search: 349/113, 349/149, 359/231, 359/292
• US Class Current: 349/113
• CPC Class Codes: G02B 26/0808 by means of one or more diffracting elements
• CPC Class Codes: G02B 5/1828 having means for producing variable diffraction controlling the direction of light by means of one or more diffracting elements G02B26/0808; acousto-optical elements G02F1/11, G02F1/33; electro- or magneto-optical diffraction G02F1/292, G02F1/2955

Abstract

A light valve capable of operating in an “off” state for reflecting light and in an “on” state for diffracting and reflecting light. The valve includes a semiconductor substrate having a plurality of electrodes formed therein for receiving voltages and for generating an electric field in response to the received voltages. A layer of transparent deformable dielectric material is disposed on the reflective electrodes which deforms in response to the generated electric field. When the valve is in its “on” state, the electric field causes deformities in the dielectric material which diffract incident light reflected off of the valve. In another embodiment, the dielectric material is placed on the reflective electrodes or on a transparent substrate having a transparent electrode formed thereon. The transparent substrate is then disposed in spaced relation from the semiconductor substrate containing the reflective electrodes.

Claims

1. A light valve device for diffracting and reflecting incident light, comprising:

a substrate formed of semiconductor material;

a reflective electrode formed on a surface of said substrate and capable of receiving voltages;

a transparent substrate;

a transparent electrode formed on said transparent substrate; and

a layer of transparent dielectric material disposed on one of said transparent electrode and said reflective electrode and distally positioned in opposing spaced relation from the other of said reflective electrode and transparent electrode so that a gap is formed between said reflective electrode and said transparent electrode, said transparent and reflective electrodes forming an electric field through said transparent material when a potential difference is applied between said reflective electrode and said transparent electrode, said transparent material being capable of being deformed in response to the electric field so that when incident light is received by said valve, the light will be diffracted by deformities in said layer and reflected by said reflecting electrode.

2. The valve of claims 1, wherein said semiconductor substrate comprises silicon and said transparent substrate comprises glass.

3. The valve of claim 1, wherein said transparent electrode comprises indium-tin-oxide.

4. The valve of claim 1, further comprising spacers for maintaining spaced relation between said transparent material and said reflecting electrode.

5. The valve of claim 1, wherein said layer of transparent dielectric material is disposed on said transparent electrode.

6. The valve of claim 1, wherein said layer of transparent dielectric material is disposed on said reflective electrode.

7. The valve of claim 1, wherein said reflecting electrode comprises a plurality of actuating electrodes and a plurality of grounding electrodes arranged to form an array of valves, and wherein said grounding electrodes are maintained at a common voltage with each other.

8. A method of forming a light valve device for diffracting and reflecting incident light, comprising the steps of:

positioning a substrate formed of semiconductor material;

forming a reflective electrode on a surface of said substrate, said reflective electrode being capable of receiving voltages;

positioning a transparent substrate;

forming a transparent electrode on said transparent substrate;

disposing a layer of transparent dielectric material on one of said transparent electrode and said reflective electrode; and

distally positioning said transparent electrode in opposing spaced relation from said reflective electrode so that a gap is formed between said transparent electrode and said reflective electrode for forming an electric field through said transparent material between said transparent and reflective electrodes when a potential difference is applied between said reflective electrode and said transparent electrode, said transparent material being capable of being deformed in response to the electric field so that when incident light is received by said valve, the light will be diffracted by deformities in said layer and reflected by said reflecting electrode.

9. The method of claim 8, wherein said step of disposing comprises disposing the dielectric material on said transparent electrode.

10. The method of claim 8, wherein said step of disposing comprises disposing the dielectric material on said reflective electrode.

11. The method of claim 8, wherein said semiconductor substrate comprises silicon and said transparent substrate comprises glass.

12. The method of claim 8, wherein said transparent electrode comprises indium-tin-oxide.

13. The method of claim 8, wherein said reflecting electrode comprises a plurality of actuating electrodes and a plurality of grounding electrodes arranged to form an array of valves, and wherein said grounding electrodes are maintained at a common voltage with each other.