Liquid crystal display with colored backlight

• US 20050248524A1
• Filed: 10/15/2004
• Published: 11/10/2005
• Est. Priority Date: 05/04/2004
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Daly, Scott J., Feng, Xiao-fan, Messing, Dean
• Granted Patent: US 7,602,369 B2
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix

Abstract

A backlit display with improved dynamic range.

Claims

1. A method of illuminating a backlit display, said method comprising the step of varying the luminance of a light source illuminating a plurality of displayed pixels and varying the transmittance of a light valve of said display in a non-binary manner, wherein said light source is spatially displaced at a location at least partially directly beneath said plurality of pixels, and wherein said light source includes a plurality of different colored light emitting elements.

2. The method of claim 1 wherein said light emitting elements are light emitting diodes.

3. The method of claim 2 wherein said light emitting elements are red, green, and blue.

4. The method of claim 1 wherein some of said light emitting elements include a plurality of different colors and others of said light emitting elements include a substantially white light emitting element.

5. A method of illuminating a backlit display, said method comprising the step of varying the luminance of a light source illuminating a plurality of displayed pixels and varying the transmittance of a light valve of said display in a non-binary manner, wherein said light source is spatially displaced at a location at least partially directly beneath said plurality of pixels, and wherein said light source includes a plurality of different colored light emitting elements, and wherein said display includes regions thereof where light is emitted from said display that are free from color filters.

6. A method of illuminating a backlit display, said method comprising the step of varying the luminance of a light source illuminating a plurality of displayed pixels and varying the transmittance of a light valve of said display in a non-binary manner, wherein said light source is spatially displaced at a location at least partially directly beneath said plurality of pixels, and wherein said light source includes a plurality of different colored light emitting elements, and wherein the user may modify the color temperature of said display by changing the illumination of said light emitting elements.

7. A method of illuminating a backlit display, said method comprising the step of varying the luminance of a light source illuminating a plurality of displayed pixels and varying the transmittance of a light valve of said display in a non-binary manner, wherein said light source is spatially displaced at a location at least partially directly beneath said plurality of pixels, and wherein said light source includes a plurality of different colored light emitting elements, and wherein based upon a defect in said display modifying the luminance of a plurality of said light emitting elements.

8. The method of claim 7 wherein said modifying results in said reduces the ability of a user to observe said defect.

9. A method of illuminating a backlit display, said method comprising the step of varying the luminance of a light source illuminating a plurality of displayed pixels and varying the transmittance of a light valve of said display in a non-binary manner, wherein said light source is spatially displaced at a location at least partially directly beneath said plurality of pixels, and wherein said light source includes a plurality of different colored light emitting elements, and wherein the signal to said light emitting diodes is sub-sampled in a manner to maintain high luminance resolution while attenuating high frequency chromatic information of and image.

10. A method of illuminating a backlit display, said method comprising the step of varying the luminance of a light source illuminating a plurality of displayed pixels and varying the transmittance of a light valve of said display in a non-binary manner, wherein said light source is spatially displaced at a location at least partially directly beneath said plurality of pixels, and wherein said light source includes a plurality of different colored light emitting elements, and wherein the luminance information to said light emitting elements is based upon at least one of (a) the total luminance of the signal, and (b) separate luminance each said different colored light emitting elements.