Liquid crystal display device and apparatus and method for driving the same

• US 20070152953A1
• Filed: 12/29/2006
• Published: 07/05/2007
• Est. Priority Date: 12/29/2005
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Hong, Hee Jung, Kwon, Kyung
• Granted Patent: US 8,026,893 B2
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• 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 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127

Abstract

A liquid crystal display device includes a liquid crystal display panel with four colors of sub-pixels, and a backlight unit having light emitting diodes of at least five colors to apply multi-primary light to the liquid crystal display panel.

Claims

1. A liquid crystal display device comprising:

a liquid crystal display panel with four colors of sub-pixels; and

a backlight unit having light emitting diodes of at least five colors to apply multi-primary light to the liquid crystal display panel.

2. The liquid crystal display device of claim 1, wherein the backlight unit includes a light emitting diode array with a plurality of light emitting diode groups that each group has red, green and blue light emitting diodes, and at least two of cyan, yellow and magenta light emitting diodes.

3. The liquid crystal display device of claim 2, wherein the four colors of sub-pixels are arranged in a quad-type arrangement.

4. The liquid crystal display device of claim 3, further comprising:

a plurality of optical sheets positioned between the light emitting diode array and the liquid crystal display panel.

5. The liquid crystal display device of claim 3, further comprising:

a light emitting diode array driver that drives the red, green and blue light emitting diodes in accordance with the input data of three colors, and also drives the at least two of the cyan, yellow and magenta light emitting diodes in accordance with at least two color ratio signals.

6. A liquid crystal display device comprising:

a liquid crystal display panel with red, green, blue and white sub-pixels; and

a backlight unit having red, green, and blue, and at least two other colors of light emitting diodes for applying multi-primary light to the liquid crystal display panel.

7. The liquid crystal display device of claim 6, wherein the backlight unit includes:

a light emitting diode array with a plurality of light emitting diode groups that each group has red, green and blue light emitting diodes, and at least two of cyan, yellow and magenta light emitting diodes; and

a plurality of optical sheets positioned between the light emitting diode array and the liquid crystal display panel.

8. The liquid crystal display device of claim 6, wherein the red, green, blue and white sub-pixels are arranged in a quad-type arrangement.

9. The liquid crystal display device of claim 6, further comprising:

a light emitting diode array driver that drives the red, green and blue light emitting diodes in accordance with the input data of three colors, and also drives the two other colors of light emitting diodes in accordance with two color ratio signals.

10. An apparatus for driving a liquid crystal display device having four colors of sub-pixels comprising:

a data converter that converts input data of three colors inputted externally into four-color data;

a data driver that converts the four-color data into video signals and then supplies the video signals to the sub-pixels;

a gate driver that supplies a scan pulse to each sub-pixel;

a timing controller that arranges the four-color data supplied from the data converter, and then supplies the arranged four-color data to the data driver while controlling the data driver and the gate driver;

a backlight unit that provides light to the liquid crystal display panel using at least five colors of light emitting diodes; and

a light emitting diode controller that controls the backlight unit in accordance with the three-color input data.

11. The apparatus of claim 10, wherein the data converter includes:

a data amplifying unit that generates three-color amplified data by multiplying the three-color input data and a gain value inputted externally;

a common-component extracting unit that extracts common components as white data from the three-color amplified data; and

a subtracting unit that subtracts the white data from the three-color amplified data, to thereby generate first to third color data,

wherein the four-color data corresponds to the first to third color data and the white data.

12. The apparatus of claim 10, wherein the light emitting diode controller includes:

a color-ratio discriminating unit that generates at least two of cyan, yellow and magenta color ratio signals in accordance with the ratio of at least two colors of cyan, yellow and magenta colors from the three-color input data; and

a dimming signal generating unit that generates at least two light emission signals corresponding to the at least two ratio signals.

13. The apparatus of claim 12, wherein the cyan-color ratio signal is generated by the ratio of green/red to blue/red, the yellow-color ratio signal is generated by the ratio of green/blue to red/blue, and the magenta-color ratio signal is generated by the ratio of red/green to blue/green.

14. The apparatus of claim 12, wherein the backlight unit includes:

a light emitting diode array with a plurality of light emitting diode groups that each group has red, green and blue light emitting diodes, and at least two of cyan, yellow and magenta light emitting diodes; and

a light emitting diode array driver that drives the red, green and blue light emitting diodes in accordance with the input data of three colors, and also drives at least two of the cyan, yellow and magenta light emitting diodes in accordance with the at least two color ratio signals.

15. A method for driving a liquid crystal display device having a light emitting diode panel provided with four colors of sub-pixels comprising:

converting input data of three colors inputted externally into four-color data;

supplying a scan pulse to each sub-pixel;

converting the four-color data into video signals, and then supplying the video signals to the sub-pixels in synchronization with the scan pulse; and

driving a backlight unit having light emitting diodes of at least five colors to provide light to a liquid crystal display panel.

16. The method of claim 15, wherein the converting input data of three colors inputted externally into four-color data includes:

generating three-color amplified data by multiplying the three-color input data and a gain value inputted externally;

extracting common components as white data from the three-color amplified data; and

subtracting the white data from the three-color amplified data, to thereby generate first to third color data,

wherein the four-color data corresponds to the first to third color data, and the white data.

17. The method of claim 15, further comprising:

controlling the backlight unit in accordance with the first to third color data.

18. The method of claim 17, wherein the controlling the backlight unit includes:

generating at least two of cyan, yellow and magenta color ratio signals in accordance with the ratio of at least two colors of cyan, yellow and magenta colors from the three-color input data;

generating at least two light emission signals corresponding to the at least two ratio signals; and

driving the red, green and blue light emitting diodes in accordance with the set three-color light emission signal, and driving at least two of the cyan, yellow and magenta light emitting diodes in accordance with the ratio signal of at least two colors.

19. The method of claim 18, wherein the cyan-color ratio signal is generated by the ratio of green/red to blue/red, the yellow-color ratio signal is generated by the ratio of green/blue to red/blue, and the magenta-color ratio signal is generated by the ratio of red/green to blue/green.