LIQUID CRYSTAL DISPLAY APPARATUS

• US 20120026211A1
• Filed: 07/13/2011
• Published: 02/02/2012
• Est. Priority Date: 07/27/2010
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kikuchi, Ken, Yano, Tomoya
• Granted Patent: US 9,270,958 B2
• Time in Patent Office: Days
• US Class Current: 345/690
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• 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
• CPC Class Codes: H04N 9/67 for matrixing camera processing pipelines for matrixing of colour signals H04N23/85

Abstract

A LCD display includes a light source section, a LCD panel including a plurality of pixels each having sub-pixels of R, G, B, and Z, and a display control section including an output signal generation section. The display control section performs a display drive on the sub-pixels with use of the respective output video signals, and performs a lighting drive on the light source section with use of the lighting signal. The output signal generation section generates output video signals corresponding to the respective four colors, based on the input video signals, and generates a lighting signal of the light source section, based on the input video signals, to perform a predetermined dimming processing, based on both the input video signals and the generated lighting signal, and finally generates the output video signals through performing a predetermined color conversion processing, based on a resultant video signal from the dimming processing.

Claims

1. A liquid crystal display apparatus comprising:

a light source section;

a liquid crystal display panel including a plurality of pixels each of which having sub-pixels of three colors of red (R), green (G), and blue (B), and a sub-pixel of a color (Z) showing luminance higher than those of the three colors, the liquid crystal display panel being configured to modulate light emitted from the light source section, based on input video signals corresponding to the respective three colors of R, G, and B to perform a video display; and

a display control section including an output signal generation section adapted to generate, based on the input video signals, output video signals corresponding to the respective four colors of R, G, B, and Z, and to generate a lighting signal of the light source section, the display control section being configured to perform a display drive on the sub-pixels of R, G, B, and Z in the liquid crystal display panel with use of the respective output video signals, and perform a lighting drive on the light source section with use of the lighting signal, wherein

the output signal generation section generates the lighting signal, based on the input video signals, to carry out a predetermined dimming processing, based on both the input video signals and the generated lighting signal, and

the output signal generation section generates the output video signals through carrying out, based on a resultant video signal from the dimming processing, a predetermined color conversion processing.

2. The liquid crystal display apparatus according to claim 1, wherein

the output signal generation section uses a first look-up table (LUT) when performing the color conversion processing, the LUT being provided in advance according to nonlinearity in a relationship between a signal level of a Z-sub-pixel video signal of the output video signals and a signal level of each of R-, G-, and B-sub-pixel intermediate video signals which are specified if an assumption is made that the signal level of the Z-sub-pixel video signal is replaced by a set of the R-, G-, and B-sub-pixel intermediate video signals.

3. The liquid crystal display apparatus according to claim 2, wherein

the output signal generation section carries out a predetermined chromaticity point adjustment on the resultant video signal from the dimming processing, to allow a chromaticity point of the display light emitted from the liquid crystal display panel to come to a white color chromaticity point when the input video signals are for white (W) color;

and then

the output signal generation section generates the output video signal through carrying out the color conversion processing on a resultant video signal from the chromaticity point adjustment.

4. The liquid crystal display apparatus according to claim 1, wherein

the output signal generation section carries out the color conversion processing to allow the signal levels of the sub-pixel video signals configuring the output video signals to be substantially equal to one another.

5. The liquid crystal display apparatus according to claim 1, wherein

the output signal generation section limits, in the color conversion processing, each of the signal levels of the sub-pixel video signals configuring the output video signals to be equal to or less than a predetermined upper limit.

6. The liquid crystal display apparatus according to claim 1, wherein

the output signal generation section generates the lighting signal with use of a second look-up table (LUT) which specifies, in advance, a relationship between a chromaticity represented by the input video signals and the highest signal level expressible for the corresponding chromaticity or the inverse of the highest signal level.

7. The liquid crystal display apparatus according to claim 6, wherein

the second look-up table is configured to limits signal level variation in the lighting signal which is specified by a chromaticity variation in the input video signal to be equal to or lower than a predetermined threshold level.

8. The liquid crystal display apparatus according to claim 1, wherein

each of the pixels includes a sub-pixel of white (W) as the sub-pixel of Z.

9. The liquid crystal display apparatus according to claim 8, wherein

the sub-pixels of three colors are provided with color filters corresponding to respective colors of R, G, and B, whereas the sub-pixel of W is provided with no color filter.