Actuated mirror optical intensity modulation

• US 5,126,836 A
• Filed: 12/11/1989
• Issued: 06/30/1992
• Est. Priority Date: 11/01/1989
• Status: Expired due to Term

• Current Assignee: Aura Systems Inc.
• Original Assignee: Aura Systems Inc.
• Inventors: Um, Gregory
• Primary Examiner(s): Kostak, Victor R.
• Assistant Examiner(s): Burgess, Glenton B.
• Application Number:
  US07/448,748
• Time in Patent Office: 932 Days
• Field of Search: 358/60, 358/61, 358/62, 358/231-234, 350/169, 350/17 A, 350/162.23, 350/601, 350/6.2, 359/618, 359/572, 359/573, 359/196, 359/197, 359/209
• US Class Current: 348/771
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161

Abstract

A television display apparatus wherein a white light source emits a beam onto a plurality of dichroic mirrors which split the beam into three beams of the primary colors, then reflects the three primary beams onto three deformable reflective surfaces, which again reflect the beams through slits in a non-reflective surface, thereby modulating the intensity of the beams. The amount of light passing through the slits is horizontally scanned by one surface of a rotating polygonal mirror, then passes through collimating and projection lenses and onto a screen.

Claims

1. A television display apparatus comprising:

a source for emitting white light;

means for splitting said white light into a plurality of primary light beams, each of said primary light beams being one of the primary colors;

means for spreading each of primary light beams into a bell-shaped beam wherein said spreading means is a mirror array and further wherein said mirror array is comprised of a plurality of reflective surfaces;

means for clipping the profile of each of said bell-shaped beams into a clipped beam;

means for horizontally scanning each of said clipped beam simultaneously;

means for collimating said scanned light into a collimated beam; and

means for projecting said collimated beam onto a screen.

2. A television display apparatus in accordance with claim 1 wherein said deforming means is a piezoelectric crystal which deforms horizontally when a voltage is applied.

3. A television display apparatus in accordance with claim 1 wherein said deforming means is a plurality of piezoelectric crystals which deform when voltage is applied to them.

4. A television display apparatus in accordance with claim 3 wherein the voltage applied to at least one of said plurality of piezoelectric crystals is 180 degrees out of phase with the voltage applied to at least one of another of said plurality of piezoelectric crystals.

5. A television display apparatus in accordance with claim 2 wherein each of said reflective surfaces of said mirror array is cantilevered on said piezoelectric crystal.

6. A television display apparatus in accordance with claim 1 wherein each of said plurality of reflective surfaces further comprise a plurality of notches along the periphery of said reflective surface.

7. A television display apparatus comprising:

a source for emitting a white light;

means for splitting said white light into a plurality of primary light beams, each of said primary light beams being one of the primary colors;

means for spreading each of said primary light beams into a bell-shaped beam wherein said spreading means is a mirror array, said spreading means further including means for deforming each reflective surface of said mirror array in response to signals received by electrical control circuitry, said reflective surface being only attached to said deforming means;

means for clipping the profile of each of said bell-shaped beam into a clipped beam;

means for horizontally scanning each of said clipped beams simultaneously;

means for collimating said scanned light into a collimated beam; and

means for projecting said collimated beam onto a screen.

8. A television apparatus comprising:

a source of light wherein said light is formed into a beam;

an array of reflective surfaces upon which said beam is incident, each of said reflective surfaces being arranged in a plurality of rows and in a plurality of columns and further being deformable with the degree of deformation of each of said surfaces being commensurate with a predetermined intensity of a corresponding one of a plurality of pixels to be displayed;

a non-reflective surface having a plurality of apertures therein, each of said reflective surfaces directing a corresponding one of a plurality of reflected beams generally to a respective one of said apertures such that the flux of each of said reflected beams passing through said respective one of said apertures decreases with an increasing degree of movement of a corresponding one of said reflective surfaces to control an intensity of each of said beams; and

a projection lens upon which each of said reflected beams is incident subsequent to passing through said apertures to project said reflected beams on a screen whereby said pixels are displayed.

9. A television apparatus as set forth in claim 8 wherein the deformation of each of said reflective surfaces is a tilting of each of said surfaces.

10. A television apparatus as set forth in claim 8 wherein the deformation of each of said reflective surfaces is a bending of each of said reflective surfaces.

11. A television apparatus as set forth in claim 8 wherein said deformation of each of said reflective surfaces is a vibration of each of said reflective surfaces.

12. A method of displaying a plurality of pixels on a screen comprising steps of:

forming a light beam;

illuminating a plurality of reflective surfaces arranged in a plurality of rows and a plurality of columns with said beam;

deforming each of said reflective surfaces wherein the degree of deformation of each of said reflective surfaces is commensurate with a predetermined intensity of one of said pixels;

directing the reflected beams from each of said reflective surfaces to one of a plurality of apertures, wherein each of said apertures corresponds to one of said reflective surfaces, such that the flux of each of said reflective beams passing through of said corresponding one of said reflective surfaces controls an intensity of reflected beams; and

projecting each of said reflective beams subsequent to passing through said corresponding one of said apertures on a screen whereby pixels are displayed.

13. A method as set forth in claim 12 wherein said deforming step includes the substeps of tilting each of said reflective surfaces.

14. A method as set forth in claim 12 wherein said deforming step includes the substeps of bending each of said reflective surfaces.

15. A method as set forth in claim 12 wherein said deforming step includes the substeps of vibrating each of said reflective surfaces.