Flat screen color video display

• US 4,978,952 A
• Filed: 02/24/1989
• Issued: 12/18/1990
• Est. Priority Date: 02/24/1989
• Status: Expired due to Fees

• Current Assignee: Elizabeth Irwin, James Friedlander, Richard Pekelney
• Original Assignee: Collimated Displays Incorporated
• Inventors: Irwin, Dean S.
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): Powell, Mark R.
• Application Number:
  US07/315,734
• Time in Patent Office: 662 Days
• Field of Search: 340/716, 340/794, 340/795, 340/783, 340/784, 358/56, 358/60, 358/62, 358/236, 358/230, 358/241, 358/55, 358/59, 350/345, 350/96.1, 350/96.15, 350/96.17, 350/96.2
• US Class Current: 345/102
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G09G 3/02 by tracing or scanning a light beam on a screen
• CPC Class Codes: H04N 9/12 Picture reproducers H04N9/11 takes precedence
• CPC Class Codes: H04N 9/31 Projection devices for colour picture display , e.g. using electronic spatial light modulators [ESLM]

Abstract

A video display having a shutter assembly with apertures, optical guides extending behind the assembly and a group of different light sources channeling their light into each of the optical guides, respectively. The guides may be collimators which allow light to escape perpendicular to their front surfaces, which surfaces are located in back of the shutter assembly. The collimators have parabolic and hyperbolic mirrored surfaces facing each other within the collimator. Electronic control circuitry is provided to control the light outputs with a video input signal in relation to a horizontal sweep signal and to selectively make the shutter apertures transparent so as to expose a portion of the illuminated collimators in response to a vertical sweep signal. The intensity of the light source is varied to produce a high resolution, high speed video display.

Claims

1. A video display having a display area of a width W and a height H, comprising:

light producing means for producing a column of light which substantially spans the height of the display area and is substantially narrower than the width thereof, said light producing means including light source means for emitting the light and including means for directing and reflecting the light to form said column;

shutter means arranged so that the light produced is incident thereon for selectively controlling transmission of at least a portion of the incident light, said shutter means having a plurality of vertically aligned, elongated horizontal strip apertures selectively controllable to transmit and block said light; and

sweeping means for sweeping the light produced substantially across the width of the display area.

50. A display as claimed in claim 1, wherein said sweeping means sweeps the light across the width of said display at a horizontal scan rate, said shutter means opening and closing said strip apertures in sequence over the height of said display at a vertical scan rate, said horizontal scan rate being faster then said vertical scan rate.

51. A display as claimed in claim 1, further comprising:

separating means for separating composite video signals into vertical and horizontal sync pulses and video intensity and color signals;

converting means for converting the video intensity signals into amplitudes corresponding to a plurality of color intensities;

clock means for dividing up the period between horizontal sync pulses into clocked horizontal pulses and for dividing up the period between vertical sync pulses into clocked vertical pulses;

counter means responsive to said clock means for counting a number of clocked horizontal pulses; and

actuating means for actuating said light source means to form said column of light in response to said counter means counting the clocked horizontal pulses and for actuating the apertures in response to said counter means counting the clocked vertical pulses.

52. A display as claimed in claim 1, wherein said light producing means including a plurality of light sources each producing a light of a different color, said light sources being arranged for mixing the light together prior to producing said column of light.

2. A video display having a display area of a width w and a height H, comprising:

light producing means for producing a column of light which substantially spans the height of the display area and is substantially narrower than the width thereof;

shutter means arranged so that the light produced is incident thereon for selectively controlling transmission of at least a portion of the incident light, said shutter means having a plurality of vertically aligned, elongated horizontal strip apertures selectively controllable to transmit and block said light; and

sweeping means for sweeping the light produced substantially across the width of the display area, said light producing means including;

light source means for emitting the light; and

a plurality of elongated optical light guide means arranged side by side across at least a portion of the width of the display area for guiding light from said light source means, each guide means having an entrance surface and a front face, each front face extending over at least a portion of the height of said display, each entrance surface being positioned to receive emitted light from said light source means, said optical light guide means directing the light from said entrance surface to said front surface, said shutter means being located in front to said front faces so as to receive at least a portion of the light escaping from said front faces.

3. The display as claimed in claim 2, wherein said plurality of optical light guide means are collimators having first and second mirrored surfaces facing each other and being positioned and constructed such that the light entering said collimators through said entrance surface diverges and comes into contact with said first mirrored surface and is reflected therefrom so as to come into contact with said second mirrored surface, from which the light is reflected through the front face of said collimators as light rays substantially parallel to each other.

4. The display as claimed in claim 3, wherein said first mirrored surface is convex parabolic in shape and said second mirrored surface is concave hyperbolic in shape.

5. The display as claimed in claim 3, wherein at least one of said collimators has cladding members along side surfaces that are adjacent to other collimators, said cladding members having a reflective surface facing into said collimators for reflecting the light, said cladding members preventing light interference between said collimators.

6. The display as claimed in claim 2, wherein said shutter means is a liquid crystal display.

7. The display as claimed in claim 2, wherein said light sources are light emitting diodes.

8. The display as claimed in claim 2, wherein said shutter means is placed against said optical light guide means so as to minimize light loss.

9. The display as claimed in claim 2, wherein said apertures extend across the width of said display area and are located one above the other, said sweeping means comprising:

horizontal sweep means for activating said light sources so as to illuminate, in a predetermined sequence, each of said optical light guide means with light from said light source means; and

vertical sweep means for selectively opening said apertures to allow light to pass therethrough in a predetermined sequence, said apertures being normally closed.

10. The display as claimed in claim 9, further comprising:

means for interlacing an image scan to give the appearance of a continuous moving image, said vertical sweep means being responsive to said interlacing means to selectively allow light to pass through a first field of said apertures extending at least partly over the width and height of said display, and said vertical sweep means allowing light to pass through a second field of said apertures of similar size to, but offset from, the first field so as to cause said fields to interlace each other.

11. The display as claimed in claim 2, further comprising:

a synchronization separator for separating composite video signals into vertical sync pulses, horizontal sync pulses and video intensity and color signals;

video amplifiers for converting the video intensity signals into amplitudes corresponding to a plurality of color intensities;

clock circuit means for dividing up the period between horizontal sync pulses by the number of optical light guide means so as to form clocked horizontal pulses and for dividing up the period between vertical sync pulses so as to form clocked vertical pulses;

counter circuit means responsive to said clock circuit means for counting the number of clocked horizontal pulses and the number of clocked vertical pulses; and

means for actuating the light sources to illuminate the optical light guide means with light in response to the counter circuit means counting the clocked horizontal pulses and for actuating the apertures in response to said counter circuit means counting the clocked vertical pulses.

12. The display as claimed in claim 11, further comprising:

persistence means located across the light source means for keeping the light source means activated for a predetermined period of time in response to said actuating means.

13. The display as claimed in claim 2, wherein said light source means includes a vacuum tube having excitable phosphor and means for exciting said phosphor to produce the light.

14. The display as claimed in claim 13, wherein said phosphor exciting means includes means for varying the flow of electrons, means for focussing said electrons into beams directed toward said phosphor and means for selectively blocking said beams from reaching said phosphor.

15. The display as claimed in claim 14, wherein said phosphor exciting means includes means for suppressing the flow of electrons toward said phosphor.

16. The display as claimed in claim 14, wherein said means for varying includes a cathode and an anode, said phosphor being coated on said anode, said cathode generating said electrons.

17. The display as claimed in claim 14, wherein said light source means includes a plurality of strips of phosphor each strip being excitable for giving off different colors of light, said varying means including a plurality of cathodes generating the electrons, said focussing means being arranged so that varying the intensity of the electrons from a respective one of said cathodes by said varying means causes a change in an amount of light given off from a respective one of said phosphor strips.

18. The display as claimed in claim 14, wherein said means for selectively blocking includes a plurality of blocking elements, said blocking elements being aligned with said plurality of optical guide means, respectively.

19. The display as claimed in claim 2, wherein said light source means includes:

light emitting elements;

a rotatable mirror positioned to intercept light emitted from said light emitting elements;

means for rotating said rotatable mirror, said light emitting elements emitting light to strike said rotatable mirror, said mirror reflecting the light, said rotating means rotating said rotatable mirror so as to direct the light reflecting off said rotatable mirror to the entrance surface of each of said optical light guide means.

20. The display as claimed in claim 19, wherein said entrance surface of each of said optical guide means is angled relative to said rotatable mirror so that the light reaching the entrance surface refracts into said optical guide means as light rays that travel parallel to each other in each of said plurality of optical guide means.

21. The display as claimed in claim 19, wherein said light emitting element is a laser.

22. The display as claimed in claim 2, wherein said light source means includes a light emitting element and a piezoelectric flapper mirror, which responds piezoelectrically to reflect light emitted from said light emitting surface to the entrance surface of each of said plurality of optical light guide means individually.

23. The display as claimed in claim 22, wherein said entrance surface of each of said optical guide means is angled relative to said flapper mirror so that the light reaching the entrance surface refracts into said optical light guide means as light rays which travel parallel to each other in each of said optical light guide means.

24. The display as claimed in claim 22, wherein said flapper mirror is composed of polyvinylfluoride.

25. The display as claimed in claim 2, wherein all of said light source means, optical light guide means and shutter means are a single piece construction.

26. The display as claimed in claim 2, wherein said light source means includes groups of different colored light emitting elements, said elements of said groups all respectively directing their emitted light into the entrance surfaces of corresponding optical light guide means.

30. The display according to claim 4, wherein said collimator also has a lens arranged at said entrance surface to focus light from outside said collimator so as to strike against said first mirrored surface.

27. A video display having a display area of a width W and a height H, comprising:

light producing means for producing a column of light which substantially spans the height of the display area and is substantially narrower than the width thereof;

shutter means arranged so that the light produced is incident thereon for selectively controlling transmission of at least a portion of the incident light, said shutter means having a plurality of vertically aligned, elongated horizontal strip apertures selectively controllable to transmit and block said light; and

sweeping means for sweeping the light produced substantially across the width of the display area said light producing means including a mirror reflecting the light to said shutter means, said sweeping means including means for moving said mirror so that the light reflecting off the mirror sweeps across the display.

28. The display according to claim 27, wherein said mirror is a rotatable mirror.

29. The display according to claim 27, wherein said mirror is a piezoelectric flapper mirror.

31. A color video flat screen display system having a display area of width W and height H, comprising:

a plurality of groups of three light emitting diodes, each of said diodes in each group emitting light which differs in color from each other;

a plurality of light guide means each for collimating the light emitted by the diodes of a corresponding group to a respective front face of said light guide means which has a height at least equivalent to a portion of the height of said display area, said plurality of light guide means being located side by side across at least a portion of the width of the display area; and

a liquid crystal display having a plurality of horizontal apertures extending across the width of the display and being located one above the other.

32. The color flat screen display as claimed in claim 31, wherein the front face of each light guide means is the width of a picture element.

33. The color flat screen display as claimed in claim 32, wherein the height of the apertures corresponds to a picture element.

34. The color flat screen display as claimed in claim 33, wherein each light guide means is a collimator.

35. The color flat screen display as claimed in claim 31 further comprising:

horizontal sweep means for activating said light sources and illuminating, in a predetermined sequence, each of said light guide means with light from said light sources; and

vertical sweep means for selectively allowing light to pass through said apertures in a predetermined sequence.

36. The color flat screen display as claimed in claim 35, further comprising:

means for interlacing to give the appearance of a continuous moving image, said vertical sweep means being responsive to said interlacing means to selectively allow light to pass through a first field of said apertures extending substantially over at least a portion of the width and height of said display, and then to allow light to pass through a second field of said apertures of similar size to, but offset from, the first field so as to cause said fields to interlace each other.

37. The color flat screen display as claimed in claim 31, further comprising:

a synchronization separator for separating composite video signals into vertical sync pulses, horizontal sync pulses and video intensity and color signals;

video amplifiers for converting the video intensity signals into amplitudes corresponding to a plurality of color intensities;

clock circuit means for dividing up the period between horizontal sync pulses by the number of light guide means so as to form clocked horizontal pulses and for dividing up the period between vertical sync pulses by the number of apertures so as to form clocked vertical pulses;

counter circuit means responsive to said clock circuit means for counting the number of clocked horizontal pulses and the number of clocked vertical pulses; and

means for actuating the light sources to illuminate the light guide means in response to the counter circuit means counting the clocked horizontal pulses and for actuating the apertures in response to said counter circuit means counting the clocked vertical pulses.

38. A method of creating video display having a display area of a width W and a height H, comprising:

producing a column of light which substantially spans the height of the display area and is substantially narrower than the width thereof, the step of producing including directing and reflecting the light to form the column;

selectively controlling transmission of at least a portion of said light to said display area through a plurality of vertically aligned, elongated horizontal strip apertures; and

sweeping the produced light substantially across the width of the display area.

40. The method as claimed in claim 38, wherein the step of selectively controlling transmission includes rearranging molecules of a liquid crystal display so that the liquid crystal display serves as a shutter.

41. The method as claimed in claim 38, wherein the step of sweeping includes selectively illuminating portions of the display area by directing the produced light through optical guides in sequence, and the step of selectively controlling transmission includes activating apertures in sequence to allow the light to pass.

42. The method as claimed in claim 41, wherein the step of sweeping includes activating every other aperture in sequence to interlace a plurality of fields of the display which are offset from one another.

39. A method of creating video display having a display are of a width W and a height H, comprising:

producing a column of light which substantially spans the height of the display area and is substantially narrower than the width thereof;

selectively controlling transmission of at least a portion of said light to said display area through a plurality of vertically aligned, elongated horizontal strip apertures; and

sweeping the produced light substantially across the width of the display area the step of producing including diverging light from groups of different colored light sources and directing the diverged light to the display area.

43. The method as claimed in claim 39, wherein the step of producing includes collimating the light through optical guides.

44. The method as claimed in claim 43, wherein the step of sweeping includes reflecting the produced light substantially across the width of the display to each entrance surface of optical light guides.

45. The method as claimed in claim 44, wherein the step of producing includes exciting phosphor to produce the light by bombarding the phosphor with electrons at selected areas of the phosphor.

46. A collimator, comprising:

first and second mirrored surfaces in spaced facing relationship; and

a front face of substantially greater height than width, said first mirrored surface being shaped and arranged so that light incident on said first mirrored surface is diverged and reflected to said second mirrored surface, said second mirrored surface being shaped and arranged so that the diverged and reflected light incident thereon is collimated and reflected through said front face.

47. The collimator as claimed in claim 46, wherein said first mirrored surface is parabolic and said second mirrored surface is hyperbolic.

48. The collimator as claimed in claim 46, wherein said mirrored surfaces are elliptical.

49. The collimator as claimed in claim 46, wherein said mirrored surfaces are circular.

53. A video display having a display area of a width W and a height H, comprising:

light producing means for producing a column of light which substantially spans the height of the display area and is substantially narrower than the width thereof;

shutter means arranged so that the light produced is incident thereon for selectively controlling transmission of at least a portion of the incident light, said shutter means having a plurality of vertically aligned, elongated horizontal strip apertures selectively controllable to transmit and block said light;

sweeping means for sweeping the light produced substantially across the width of the display area;

separating means for separating composite video signals into vertical and horizontal sync pulses and video intensity and color signals;

converting means for converting the video intensity signals into amplitudes corresponding to a plurality of color intensities;

clock means for dividing up the period between horizontal sync pulses into clocked horizontal pulses and for dividing up the period between vertical sync pulses into clocked vertical pulses;

counter means responsive to said clock means for counting a number of clocked horizontal pulses; and

actuating means for actuating said light source means to form said column of light in response to said counter means counting the clocked horizontal pulses and for actuating the apertures in response to said counter means counting the clocked vertical pulses.