Membrane light modulating systems

• US 5,471,341 A
• Filed: 12/16/1993
• Issued: 11/28/1995
• Est. Priority Date: 07/17/1991
• Status: Expired due to Term

• Current Assignee: Optron Systems Incorporated
• Original Assignee: Optron Systems Incorporated
• Inventors: Horsky, Thomas N., Warde, Cardinal, Genetti, George J., Schiller, Craig M.
• Primary Examiner(s): Epps, Georgia Y.
• Assistant Examiner(s): Robbins, Thomas
• Application Number:
  US08/168,760
• Time in Patent Office: 712 Days
• Field of Search: 359/291, 359/292, 359/293, 359/295, 359/298, 359/262
• US Class Current: 359/293
• CPC Class Codes: G02B 26/0825 the reflecting element being a flexible sheet or membrane, e.g. for varying the focus flexible mirrors for cosmetic use A45D42/24
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field
• CPC Class Codes: H04N 9/3102 using two-dimensional electronic spatial light modulators micromechanical modulators as such G02B26/0833; liquid crystal modulators as such G02F1/13

Abstract

A membrane light modulator comprising a charge transfer plate, and having a multiplicity of conductors extending from the rear surface to the front surface of the plate. The conductors are supported in an insulating matrix. The front side of the transfer plate has a plurality of potential wells defined by insulating walls, each potential well constituting a pixel. A plurality of conductors is provided for each pixel. A deformable reflecting membrane comprising a metal layer spans the potential wells. An electric potential is provided on the metal layer, and a source of electrons is provided for impacting the rear surface of the charge transfer plate.

Claims

1. A system for modulating incident light by impinging said light on a membrane mirror which can be deformed in accordance with an electric charge on individual pixel portions of the membrane mirror;

the improvement wherein the membrane is supported on a plurality of insulating walls which are formed on an electrode-containing surface to define potential wells, each said potential well constituting a pixel so that the bottom of each of said wells has said electrode surface thereon and a charge difference can be created between the electrode and the portion of the membrane overlying each pixel, and means for creating an image defining charge difference across said membrane by addressing said membrane by impinging upon one side of said membrane with an image modified electron stream, each of said plurality of insulating walls including two transparent insulators and a mirror surface interposed between said two insulators, said insulating walls being mounted on a transparent electrode, said incident light to be modulated impinging upon the side of said membrane opposite to said one side.

2. The system of claim 1 wherein a grid is adjacent that side of said membrane addressed by said electron stream.

3. The system of claim 1 wherein the mirror membrane comprises discrete mirror segments overlying each pixel, and said electron stream impinges on said mirror membrane and modifies the charge on each pixel by secondary electron emission from said mirror segments.

4. The system of claim 1 wherein said mirror membrane comprises a dielectric coating and said electron stream impacts said dielectric coating and modifies the charge on each pixel by accumulation or depletion of electrons thereof.

5. The system of claim 1 wherein said stream of electrons comes from a matrix addressed field emitter array.

6. The system of claim 1, and further comprising a photocathode and microchannel plate assembly for generating said electron stream.

7. The system of claim 1, and further comprising a cathode ray tube for generating said electron stream.

8. The system of claim 1, wherein the mirror membrane comprises discrete mirror segments overlying and spaced from said pixels, said spacing being selected to provide a predetermined contrast ratio of modulation of said incident light.

9. The system of claim 1, wherein said transparent electrode comprises a layer of indium tin oxide disposed upon a transparent window.