Actuated mirror optical intensity modulation

• US 5,185,660 A
• Filed: 02/22/1990
• Issued: 02/09/1993
• 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): Brinich, Stephen
• Application Number:
  US07/483,932
• Time in Patent Office: 1,083 Days
• Field of Search: 358/60-61, 350/173, 350/331 R, 350/400-403, 350/408, 353/30-31, 353/34
• US Class Current: 348/755
• 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 9a 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 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;

means for clipping the profile of each of said bell-shaped beams 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.

2. A television display apparatus in accordance with claim 1 wherein said white light is passed through a first collimation lens in order to collimate it.

3. A television display apparatus in accordance with claim 1 wherein said splitting means is a plurality of dichroic mirrors.

4. A television display apparatus in accordance with claim 1 wherein said splitting means is a diffraction grating.

5. A television display apparatus in accordance with claim 1 wherein said splitting means is a prism.

6. A television display apparatus in accordance with claim 1 wherein said splitting means is a rotating translucent wheel, said translucent wheel being divided into red, green and blue segments.

7. A television display apparatus in accordance with claim 6 wherein said rotating translucent wheel rotates at a rate of 60 cycles per second.

8. A television display apparatus in accordance with claim 6 wherein said rotating translucent wheel splits said white light into a plurality of primary light beams, each of said primary light beams being sequentially emitted from said rotating translucent wheel.

9. A television display apparatus in accordance with claim 1 wherein said spreading means is a mirror array.

10. A television display apparatus in accordance with claim 1 wherein said spreading means further comprises a means for altering the direction which the bell-shaped beams are reflected.

11. A television display apparatus in accordance with claim 9 wherein said mirror array is comprised of a plurality of reflective surfaces.

12. A television display apparatus in accordance with claim 9 wherein said spreading means further comprises a means for deforming each reflective surface of said mirror array in response to signals received by the electrical control circuitry.

13. A television display apparatus in accordance with claim 11 wherein each reflective surface of said mirror array is layered on both a base member and said deforming means.

14. A television display apparatus in accordance with claim 12 wherein each reflective surface of said mirror array is attached at one end to said base member and at the opposite end to said deforming means.

15. A television display apparatus in accordance with claim 12 wherein said reflective surface is only attached to said deforming means.

16. A television display apparatus in accordance with claim 11 wherein each reflective surface is attached at both ends to said deforming means.

17. A television display apparatus in accordance with claim 11 wherein said deforming means is a piezoelectric crystal which deforms horizontally when a voltage is applied.

18. A television display apparatus in accordance with claim 11 wherein said deforming means is a piezoelectric crystal which deforms vertically when a voltage is applied.

19. A television display apparatus in accordance with claim 11 wherein said deforming means is a plurality of piezoelectric crystals which deform when voltage is applied to them.

20. A television display apparatus in accordance with claim 19 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.

21. A television display apparatus in accordance with claim 17 wherein each of said reflective surfaces of said mirror array is mounted on a top surface of a bimorphic piezoelectric crystal layer, said bimorphic crystal layer having one layer which expands horizontally when a voltage is applied and one layer which contracts horizontally when a voltage is applied, thereby bending said mirror when a voltage is applied.

22. A television display apparatus in accordance with claim 17 wherein each of said reflective surfaces of said mirror array is cantilevered on said piezoelectric crystal.

23. A television display apparatus in accordance with claim 1 wherein said clipping means is a non-reflective surface with a plurality of apertures therein.

24. A television display apparatus in accordance with claim 17 wherein said plurality of apertures is a plurality of pinholes.

25. A television display apparatus in accordance with claim 17 wherein said plurality of apertures is a plurality of knife-edged apertures.

26. A television display apparatus in accordance with claim 17 wherein said clipping means further comprises a pair of sets of bar strips before and after the mirror arrays which allow the system to operate in a Schlieren mode.

27. A television display apparatus in accordance with claim 1 wherein said horizontal scanning means is a rotating polygonal mirror of which said plurality of clipped beams simultaneously reflect off of one side of said polygon.

28. A television display apparatus in accordance with claim 1 wherein said horizontal scanning means is a galvanometer mirror.

29. A television display apparatus in accordance with claim 1 wherein said horizontal scanning means is a rotating holographic plate.

30. A television display apparatus in accordance with claim 1 wherein said means for collimating said beams is a second collimation lens.

31. A television display apparatus in accordance with claim 1 wherein said means for projecting said beams is a projection lens.

32. 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 said primary light beams into a bell-shaped beam;

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

means for collimating said clipped beam into a collimated beam; and

means for projecting said collimated beam onto a screen.

33. A television display apparatus in accordance with claim 32 wherein said spreading means is a two-dimensional mirror array.

34. A television display apparatus in accordance with claim 33 wherein said means for clipping is an array of apertures in a non-reflective surface.

35. A method for projecting an image onto a screen comprising the steps of:

splitting a white light beam into three primary beams, one of each primary beams being one of the primary colors;

spreading each of the primary beams into a bell-shaped beam;

passing said bell-shaped beams through apertures in a non-reflective surface, thereby modulating the intensity of said bell-shaped beams;

horizontally scanning said beams simultaneously;

collimating said scanned beams into a collimated beam; and

projecting said collimated beam onto a screen.

36. A television display apparatus comprising:

a source of optical energy to emit a light beam;

a plurality of mirrors arranged in an MxN mirror array, said array positioned to be illuminated by said light beam and to reflect said light beam as a plurality of reflected beams, each of said reflected light beams emanating from a respective one of said mirrors;

a non-reflective surface having a plurality of elongated slits therein, said slits being arranged so that each row of said reflected beams normally passes through a respective one of said slits, each of said mirrors being movable to direct a portion of said optical energy of said respective one of said reflected beams to an obfuscation adjacent said respective one of said slits thereby controlling intensity of each said reflected beams;

a screen illuminated by said reflected beams subsequent to passing through said slits to display an image.

37. An apparatus in accordance with claim 36 further comprising a projection lens operatively disposed intermediate said surface and said screen.

38. An apparatus in accordance with claim 36 further comprising a color wheel operatively disposed intermediate said source and said array, said color wheel sequentially passing each one of three primary colors during each frame of said image, said mirrors being adjusted for each of said primary colors.

39. A television display apparatus comprising:

a source of optical energy to emit a light beam;

a first non-reflective surface having a plurality of elongated first slits therein and first obfuscations adjacent each of said first slits, said first surface being positioned to be illuminated by said light beam;

a second non-reflective surface having a plurality of elongated seconds slits therein and second obfuscations adjacent each of said second slits;

a plurality of mirrors arranged in an MxN array, said array being positioned to reflect optical energy passing through said first slits so that said optical energy is directed toward said second array;

a first lens positioned to image each of said first slits to a respective one of said second obfuscations, each of said mirrors being movable to direct selectively a portion of said optical energy reflected therefrom through a respective one of said second slits thereby controlling intensity of optical energy reflected from each of said mirrors;

a screen disposed to be illuminated by optical energy passing through said second slits; and

a second lens to project said optical energy passing through said second slits to said screen.

40. An apparatus as set forth in claim 39 further comprising a color wheel sequentially passing each one of three primary colors during each frame of said image, said mirrors being adjusted for each of said primary colors.