Digitized color video display system

• US 5,192,946 A
• Filed: 05/30/1991
• Issued: 03/09/1993
• Est. Priority Date: 02/27/1989
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Thompson, E. Earle, DeMond, Thomas W.
• Primary Examiner(s): Brier, Jeffery A.
• Application Number:
  US07/711,495
• Time in Patent Office: 649 Days
• Field of Search: 340/701, 340/702, 340/705, 340/763, 340/764, 340/783, 340/794, 340/795, 359/48, 358/62, 358/63, 350/174, 353/30, 353/31
• US Class Current: 348/764
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: G09F 19/16 involving the use of mirrors
• CPC Class Codes: G09F 19/18 involving the use of optical projection means, e.g. projection of images on clouds projection apparatus per se G03B
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0847 being a dynamic memory without any storage capacitor, i.e. with use of parasitic capacitances as storage elements
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/0262 The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
• CPC Class Codes: G09G 2310/066 Waveforms comprising a gently increasing or decreasing portion, e.g. ramp
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 3/2007 Display of intermediate tones
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/2025 the sub-frames having all the same time duration
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/346 based on modulation of the reflection angle, e.g. micromirrors micromirrors devices per se G02B26/0833
• CPC Class Codes: H04N 5/7458 the modulator being an array of deformable mirrors, e.g. digital micromirror device [DMD]
• CPC Class Codes: H04N 9/3161 : using laser light sources using laser beams scanning the display screen H04N9/3129

Abstract

A digitized display system providing multiplexed color beams at one frequency less than the critical flicker frequency for the human eye with each color beam being provided at a higher frequency. The beams are directed at a spatial light modulator. The individual light beams from the spatial light modulator is directed toward a display surface.

Claims

1. A color visual display system comprising:

(a) a plurality of light beams, with at least some of said beams being centered about different frequencies, time ordered in a sequence during a first time period less than the critical flicker frequency for the human eye with each light beam within said sequence being generally directed along an optical path for a second time period less than said first time period; and

(b) a plurality of individually controllable elements, each located along said optical path to have impinged thereon a predetermined portion of each said light beam, each said element switchable between a first state and a second state in a time period less than or equal to said second time period and allowing substantially all of said predetermined portion of said light beams to impinge at a predetermined location on a surface during said first state and not allowing said predetermined portion to impinge on said surface during said second state.

2. System as in claim 1 includes a light source producing said light beams.

3. System as in claim 2 wherein said light source includes at least one laser.

4. System as in claim 2 wherein said light source includes a plurality of lasers.

5. System as in claim 2 wherein at least one of said light beams is in the non-visible spectrum.

6. System as in claim 2 wherein said light source comprises a plurality of light generators, each light generator operative to generate one of said light beams, each light generator being associated with a light shutter, each said light shutter operative in synchrony for generating said light beams in said sequence.

7. System as in claim 2 wherein said light source comprises a light generator for generating white light and a color wheel;

said color wheel including a plurality of filters; and

said color wheel rotatable affixed wherein said white light is caused to be filtered into said light beams due to rotation of said color wheel.

8. System as in claim 2 wherein said light source includes at least one tunable laser.

9. System as in claim 2 wherein said light source includes a white light source and a tunable filter.

10. System as in claim 1 includes mirror device array.

11. System as in claim 10 wherein said mirror device array includes:

(a) an array of individual display cells;

(b) each said display cell having at least two memory cells associated therewith, each said display cell selectively directly connected with one of said memory cells for control of said display cell;

(c) a first decoder for addressing said memory cells for storing information therein; and

(d) a second decoder for addressing said memory cells for selecting which of said memory cells is directly connected for control.

12. System as in claim 11 wherein each memory cell includes at least two components.

13. System as in claim 12 wherein one component is a transistor.

14. System as in claim 12 wherein one component stores capacitively.

15. System as in claim 12 wherein both components are transistors.

16. System as in claim 11 wherein said memory cells is implemented in CMOS.

17. System as in claim 11 wherein said memory cell is implemented in NMOS.

18. System as in claim 11 wherein said memory cell is implemented in PMOS.

19. System as in claim 11 wherein said second decoder simultaneously addresses one memory cell associated with substantially all of said display cells to display an image.

20. System as in claim 11 wherein said second decoder simultaneously addresses one memory cell associated with all of said display cells to display an image.

21. System as in claim 11 wherein said first decoder addresses a row of said array at a time.

22. System as in claim 1 wherein said individually controllable elements includes light valves.

23. A method of producing an image utilizing a color visual display system comprising the steps of:

(a) directing a plurality of light beams centered about different frequencies and time ordered in a sequence during a first time period less than the critical flicker frequency for the human eye with each said light beam within said sequence being generally directed along an optical path for a second time period less than said first time period;

(b) impinging said light beams upon a plurality of individual elements wherein each said element has impinged thereon a predetermined portion of each said light beam; and

(c) switching said elements between a first state and a second state in a time period less than or equal to said time period to allow substantially all of said predetermined portions of said light beams to impinge at a predetermined location on a surface during said first state and not allow said predetermined portions to impinge on said surface during said second state.

24. Method as in claim 23 includes the step of producing at least one light beam utilizing a laser.

25. Method as in claim 23 includes the step of producing said light beams utilizing a plurality of lasers.

26. Method as in claim 23 includes the step of producing at least one of said light beams in the non-visible spectrum.

27. Method as in claim 23 includes the step of producing said light beams utilizing a light shutter.

28. Method as in claim 23 includes the steps of generating white light and filtering said white light utilizing a color wheel to form said light beams.

29. Method as in claim 28 includes the step of rotating said color wheel.

30. Method as in claim 23 includes the step of producing said light beams utilizing at least one tunable laser.

31. Method as in claim 23 includes the step of producing said light beams utilizing a white light source and a tunable filter.

32. A color visual display system comprising:

(a) a light source for generating a plurality of light beams, each said light beam being centered around a different frequency, in a time ordered sequence during a first time period, said first time period being less than the critical flicker frequency for the human eye, each of said light beam being generated for a second time period substantially less than said first time period;

(b) a spatial light modulator having a plurality of individually controllable elements located in the optical path of said light beams wherein each said element is impinged thereon by a predetermined portion of each said beam;

(c) each said element having a first state for allowing substantially all of said predetermined portion of each of said light beam to impinge at a predetermined location on a remote surface and a second state for not allowing each said predetermined portion to impinge on said remote surface; and

(d) wherein said controllable elements are operative to selectively switch from said first state to said second state in a time period less than or equal to said second time period.

33. System as in claim 32 wherein said light source includes at least one laser.

34. System as in claim 32 wherein said light source includes a plurality of lasers.

35. System as in claim 32 wherein at least one of said light beams is in the non-visible spectrum.

36. System as in claim 32 wherein said light source comprises a plurality of light generators, each light generator operative to generate one of said light beams, each light generator being associated with a light shutter, each said light shutter operates in synchrony for generating said light beams in said sequence.

37. System as in claim 32 wherein said light source comprises a light generator for generating white light and a color wheel;

said color wheel including a plurality of filters; and

said color wheel rotatable affixed where said white light is caused to be filtered into said light beams due to rotation of said color wheel.

38. System as in claim 32 wherein said light source includes a tunable laser.

39. System as in claim 32 wherein said light source includes a white light source and a tunable filter.

40. System as in claim 39 wherein said tunable filter is an acoustooptic spectral filter.

41. A method of generating perceived color comprising:

(a) generating a plurality of light beams in a time ordered sequence, at least some of said beams being centered about different frequencies;

(b) selecting and deselecting a pixel location at a rate faster than said time ordered sequence;

(c) imaging a predetermined portion of each of said beams from substantially all of said selected pixel location; and

(d) time integrating said different frequencies of predetermined portions of each said beam imaged from said selected pixel location.

42. A method according to claim 41 wherein said pixel is located on the surface of a spatial light modulator.

43. A method according to claim 42 wherein said spatial light modulator includes a mirror device array.

44. A method according to claim 41 wherein said pixel location is on a display surface.

45. A method according to claim 41 wherein at least some of said light beams are generated for different periods of time.

46. A method according to claim 41 wherein the intensity of at least one of said light beams varies from another of said light beams.

47. A method according to claim 41 wherein the intensity of at least one of said light beams varies over time.

48. A method according to claim 41 wherein said generating step occurs during a time period not exceeding the integration time of the human eye.

49. A method comprising:

(a) generating a plurality of light beams in a time ordered sequence, at least some of said beams being centered about different frequencies;

(b) impinging a predetermined portion of each of said beams upon a controllable element;

(c) controlling said element to select and deselect a plurality of said predetermined portions at a rate faster than said time ordered sequence; and

(d) impinging substantially all of a pixel location with each of said selected plurality.

50. A method according to claim 49 including the step of time integrating said different frequencies of said selected plurality impinging said pixel location.

51. A method according to claim 49 wherein said controlled element is a component of a spatial light modulator.

52. A method according to claim 49 wherein said spatial light modulator includes a mirror device array.

53. A method according to claim 52 wherein said controlled element comprises a mirror device.

54. A method according to claim 49 wherein said pixel location is on a display surface.

55. A method according to claim 49 wherein at least some of said light beams are generated for different periods of time.

56. A method according to claim 49 wherein at least some of said predetermined portions are selected for different periods of time.

57. A method according to claim 49 wherein the intensity of at least one of said light beams varies from another of said light beams.

58. A method according to claim 49 wherein the intensity of at least one of said light beams varies over time.

59. A method according to claim 49 wherein said impinging step occurs within a time period not exceeding the integration time of the human eye.

60. A method according to claim 49 wherein the human eye integrates said selected plurality of beams.