Light emitting diode backlighting systems and methods that use more colors than display picture elements

• US 20060221272A1
• Filed: 04/04/2005
• Published: 10/05/2006
• Est. Priority Date: 04/04/2005
• Status: Abandoned Application

• Current Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: van de Ven, Antony P., Negley, Gerald H.
• Application Number:
  US11/098,126
• Publication Number:
  US 20060221272A1
• Time in Patent Office: Days
• US Class Current: 349/64
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence
• CPC Class Codes: G02F 2201/52 RGB geometrical arrangements

Abstract

Backlight systems for display screens include multiple arrays of multiple different color picture elements and multiple arrays of LED devices that are configured to radiate light of multiple colors in a light path that impinges on the display screen, to provide backlighting on the display screen. More arrays of different color LED devices than arrays of different color picture elements are provided. For example, red, green and blue color picture elements may be provided, whereas red, green, blue and cyanine and/or amber backlighting LED devices may be provided.

Claims

1. A backlight system for a display screen that includes a plurality of arrays of a respective plurality of different color picture elements, the backlight system comprising:

a plurality of arrays of different color Light Emitting Diode (LED) devices that are configured to radiate light of a respective plurality of different colors in a light path that impinges on the display screen to provide backlighting on the display screen that includes a plurality of arrays of a respective plurality of different color picture elements, wherein more arrays of different color LED devices than arrays of different color picture elements are provided.

2. A backlight system according to claim 1 wherein the plurality of arrays of a respective plurality of different color picture elements comprise three arrays of a respective three different color picture elements and wherein the plurality of arrays of different color LED devices comprise four arrays of four different color LED devices.

3. A backlight system according to claim 1 wherein the plurality of arrays of different color LED devices are configured to radiate light of a respective plurality of different colors so as to create a perception of white light.

4. A backlight system according to claim 2 wherein the four arrays of different color LED devices are configured to radiate light of a respective four different colors so as to create a perception of white light.

5. A backlight system according to claim 1 wherein the display screen that includes a plurality of arrays of a respective plurality of different color picture elements comprises a two-dimensional array of Liquid Crystal Display (LCD) devices including the respective plurality of different color filters thereon.

6. A backlight system according to claim 5 wherein the two-dimensional array of LCD devices includes red, blue and green color filters thereon and does not include a cyanine color filter thereon, and wherein the plurality of arrays of different color LED devices include arrays of red, green, blue and cyanine LED devices.

7. A backlight system according to claim 5 wherein the two-dimensional array of LCD devices includes red, blue and green color filters thereon and does not include a cyanine color filter or an amber color filter thereon, and wherein the plurality of arrays of different color LED devices include arrays of red, green, blue, cyanine and amber LED devices.

8. A display screen comprising a plurality of arrays of a respective plurality of different color picture elements and a backlight system according to claim 1.

9. A display screen comprising a two-dimensional array of LCD devices including the red, blue and green color filters thereon and a backlight system according to claim 5.

10. A method of operating a display panel that includes a display screen comprising a two-dimensional array of Liquid Crystal Display (LCD) devices and three different color filters thereon, and three arrays of Light Emitting Diode (LED) devices that are configured to radiate light of a respective three different colors in a light path that impinges on the display screen to provide backlighting that is perceived as white light on the display screen, the method comprising:

adding at least a fourth array of Light Emitting Diode (LED) devices that is configured to radiate light in a fourth color that is different from the three different colors, to continue to provide backlighting that is perceived as white light on the display screen.

11. A method according to claim 10 wherein the two-dimensional array of LCD devices includes red, blue and green color filters thereon, wherein the three arrays of LED devices include arrays of red, green and blue LED devices and wherein the at least a fourth array of LED devices includes a fourth array of cyanine LED devices.

12. A method according to claim 10 wherein the two-dimensional array of LCD devices includes red, blue and green color filters thereon, wherein the three arrays of LED devices include three arrays of red, green and blue LED devices and wherein the at least a fourth array of LED devices includes a fourth array of cyanine LED devices and a fifth array of amber LED devices.

13. A backlighting method for a display screen that includes picture elements of different colors, the backlighting method comprising:

backlighting the display screen with more different colors than the picture elements.

14. A method according to claim 13 wherein the display screen includes red, green and blue picture elements but does not include cyanine picture elements and wherein backlighting comprises backlighting the display screen with red, green, blue and cyanine colors.

15. A method according to claim 13 wherein the display screen includes red, green and blue picture elements but does not include cyanine or amber picture elements and wherein backlighting comprises backlighting the display screen with red, green, blue, cyanine and amber colors.

16. A method according to claim 13 wherein the picture elements include a two dimensional array of Liquid Crystal Display (LCD) devices and three different color filters thereon, and wherein the more different colors are generated by Light Emitting Diode (LED) devices of the more different colors than the picture elements.

17. A method according to claim 13 wherein the more different colors are generated by a plurality of light sources of the more different colors than the picture elements.

18. A method according to claim 13 wherein backlighting comprises backlighting the display screen with the more different colors than the picture elements to provide backlighting that is perceived as white light on the display screen.

19. A backlight system for a display screen that includes picture elements of different colors, the backlight system comprising:

at least one light source that is configured to radiate light of more different colors than the picture elements, in a light path that impinges on the display screen, to provide backlighting on the display screen.

20. A backlight system according to claim 19 wherein the picture elements of different colors comprise three different color picture elements and wherein the at least one light source radiates light of four different colors.

21. A backlight system according to claim 19 wherein the at least one light source is configured to radiate light of more different colors than the picture elements so as to create a perception of white light.

22. A backlight system according to claim 19 wherein the picture elements of different colors include red, blue and green picture elements but do not include cyanine picture elements, and wherein the more different colors than the picture elements include red, green, blue and cyanine colors.

23. A backlight system according to claim 19 wherein the picture elements of different colors include red, blue and green picture elements but do not include cyanine or amber picture elements, and wherein the more different colors than the picture elements include arrays of red, green, blue, cyanine and amber colors.

24. A display screen comprising picture elements of different colors and a backlight system according to claim 19.

25. A backlighting method for a display screen that includes picture elements of different colors, the backlighting method comprising:

backlighting the display screen with at least one different color than the picture elements.

26. A method according to claim 25 wherein the display screen includes red, green and blue picture elements but does not include cyanine picture elements and wherein backlighting comprises backlighting the display screen with cyanine color.

27. A method according to claim 25 wherein the display screen includes red, green and blue picture elements but does not include cyanine or amber picture elements and wherein backlighting comprises backlighting the display screen with cyanine and amber colors.

28. A backlight system for a display screen that includes picture elements of different colors, the backlight system comprising:

at least one light source that is configured to radiate light of at least one different color than the picture elements, in a light path that impinges on the display screen, to provide backlighting on the display screen.

29. A backlight system according to claim 28 wherein the picture elements of different colors include red, blue and green picture elements but do not include cyanine picture elements, and wherein the at least one different color than the picture elements includes cyanine color.

30. A backlight system according to claim 28 wherein the picture elements of different colors include red, blue and green picture elements but do not include cyanine or amber picture elements, and wherein the at least one different color than the picture elements include cyanine and amber colors.