Optimized color display device which uses a matrix to control the hue and uses a matrix to control color saturation

• US 5,479,279 A
• Filed: 08/25/1994
• Issued: 12/26/1995
• Est. Priority Date: 09/07/1993
• Status: Expired due to Fees

• Current Assignee: Sextant Avionique
• Original Assignee: Sextant Avionique
• Inventors: Migozzi, Jean-Blaise, Barbier, Bruno, Ebert, Jean-Claude, Lach, Patrick
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Dudek, James A.
• Application Number:
  US08/296,101
• Time in Patent Office: 488 Days
• Field of Search: 359/53, 359/48, 359/50
• US Class Current: 349/74
• CPC Class Codes: G02F 1/13473 for wavelength filtering or for colour display without the use of colour mosaic filters
• CPC Class Codes: G09G 2300/023 Display panel composed of stacked panels
• CPC Class Codes: G09G 2320/06 Adjustment of display parameters
• CPC Class Codes: G09G 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 3/36 using liquid crystals
• CPC Class Codes: H01J 29/89 Optical or photographic arrangements structurally combined or co-operating with the vessel H01J29/866 and H01J29/868 take precedence

Abstract

The device includes a source of white images, a liquid crystal matrix to control the hue and a liquid crystal matrix to control the saturation of the images displayed.

Claims

1. Color image display device whose image parameters can be optimized, in particular with respect to human visual acuity, which includes in cascade to a light beam, a device to control a luminance of displayed images, a liquid crystal device to control a hue of the displayed images depending on an electrical signal applied thereto which changes an orientation of the liquid crystal therein, and a device to control a saturation of the dismayed images.

2. Device according to claim 1, wherein said device to control the luminance of the displayed images is a cathode ray tube.

3. Device according to claim 2, wherein said cathode ray tube has white phosphors.

4. Device according to claim 1, wherein said device to control the luminance of the displayed images includes a matricial optical valve.

5. Device according to claim 4, wherein said optical valve is spectrally neutral.

6. Device according to claim 4, wherein said optical valve is a helical nematic liquid crystal optical valve.

7. Device according to claim 6, wherein said optical valve is associated with a neutral polarizer.

8. Device according to claim 4, wherein said optical valve is back-lit by a collimated light source.

9. Device according to claim 8, wherein said light source is a white light source.

10. Device according to claim 1, wherein said devices to control the hue of the images and to control the saturation of the images each include a liquid crystal matrix controlled by a variable electrical voltage.

11. Device according to claim 10, which also includes a spectrally neutral polarizer.

12. Device according to claim 10, which also includes a third liquid crystal matrix of variable polarization.

13. Device according to any of the previous claims, which includes at least one connecting optic associated with the said devices to control the hue of the images and to control the saturation of the images.

14. Device according to claim 1, which includes a translucent screen.

15. Device according to claim 14, in which said translucent screen is associated with a connecting optic.

16. A color display device, comprising, arranged along a light path:

a variable intensity light source;

a first variable polarizer, which splits light input thereto into light having two perpendicular polarization axes and two complementary colors; and

a second variable polarizer, which suppresses light along one of said two polarization axes.

17. A color display device according to claim 16, wherein said variable intensity light source is a white light source.

18. A color display device according to claim 17, wherein said variable light source includes a cathode ray tube.

19. A color display device according to claim 17, wherein said variable intensity light source includes a liquid crystal light valve back-lit by a light source.

20. A color display device according to claim 16, wherein said variable intensity light source includes a polarizer, different from said first and second variable polarizers.

21. A color display according to claim 20, wherein:

said polarizer of the variable intensity light source is a spectrally neutral polarizer.

22. A color display according to claim 21, wherein:

said polarizer of the variable intensity light source is a fixed polarizer.

23. A color display according to claim 21, wherein:

said polarizer of the variable intensity light source is a variable polarization matrix.

24. A color display according to claim 20, wherein:

said polarizer which is different from the first and second variable polarizers polarizes light along a first direction;

said first polarizer polarizes light along the first direction and a second direction which is perpendicular to the first direction; and

said second polarizer filters light which is polarized along the first direction.

25. A color display according to claim 16, further comprising:

connecting optics between each of the variable intensity light source, the first variable polarizer, and the second variable polarizer.

26. A color display according to claim 16, wherein:

said first variable polarizer is different from said second variable polarizer;

said first variable polarizer is a first variable polarization means for primarily controlling hue; and

said second variable polarizer is a second variable polarization means for primarily controlling saturation.

27. A method of generating a color display, comprising the steps of:

generating light along a path;

variably polarizing the light along the path into light having two perpendicular polarization axes and two complementary colors; and

variably polarizing the light along the path in order to suppresses light along one of said two polarization axes.

28. A method according to claim 27, wherein:

the step of variably polarizing the light along the path into light having two perpendicular polarization axes is primarily for controlling hue; and

the step of variably polarizing the light along the path to suppress light is primarily for controlling saturation.

29. A method according to claim 28, wherein said step of generating light generates white light which is controllable for individual pixels of said color display.