LIQUID CRYSTAL DISPLAY DEVICE AND METHOD FOR CONTROLLING DISPLAY OF LIQUID CRYSTAL DISPLAY DEVICE

• US 20120112991A1
• Filed: 03/09/2010
• Published: 05/10/2012
• Est. Priority Date: 07/07/2009
• Status: Abandoned Application

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Hashimoto, Katsuteru, Otoi, Katsuya, Ichioka, Hideki, Fujiwara, Kohji
• Application Number:
  US13/382,009
• Publication Number:
  US 20120112991A1
• Time in Patent Office: Days
• US Class Current: 345/89
• CPC Class Codes: G09G 2320/0209 Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
• 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
• 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

An embodiment of a liquid crystal display device includes: a liquid crystal panel including pixels arranged in a pixel; and a backlight that irradiates it with light. In at least one example embodiment, the pixels included in the liquid crystal panel each include picture elements different in color. The picture elements are each provided with a color filter corresponding to the color of the picture element. The liquid crystal display device includes: an aperture ratio converting section that, to reduce optical cross talk, decreases an aperture ratio for inputted image data and outputs data of the aperture ratio; and a backlight data converting section that, to supplement the aperture ratio for the image data which is decreased by the aperture ratio converting section, converts data to increase a backlight luminance. This backlight luminance control prevents or reduces optical or electrical cross talk.

Claims

1. A liquid crystal display device, comprising:

a liquid crystal panel including pixels arranged in a matrix; and

a backlight that irradiates the liquid crystal panel with light,

the pixels each including a plurality of picture elements that are different from one another in color,

the picture elements each being provided with a color filter corresponding to a color of the picture element,

the liquid crystal display device further comprising;

an aperture ratio converting section that, in order to reduce light which has a wavelength of a color different from the color of the picture element and which is transmitted through the color filter with which the picture element is provided, decreases an aperture ratio of a picture element, the aperture ratio being included in inputted image data, and outputs data of the decreased aperture ratio; and

a backlight luminance control section that, in order to supplement the aperture ratio decreased by the aperture ratio converting section, increases a backlight luminance as compared to a case in which the aperture ratio is not decreased,

the liquid crystal display device carrying out an intended gray scale display on a basis of (i) backlight luminances determined by the backlight luminance control section and (ii) aperture ratios of the respective picture elements in the liquid crystal panel, said aperture ratios having been obtained through an aperture ratio conversion process by the aperture ratio converting section.

2. The liquid crystal display device according to claim 1,

wherein:

the backlight includes light sources having respective colors that correspond to picture elements having a plurality of colors;

the aperture ratio converting section decreases an aperture ratio, included in image data, of a picture element among said picture elements having the plurality of colors and constituting a pixel, which picture element is provided with a first color filter that transmits an amount of light having a color other than a color of the picture element provided with the first color filter, the amount being greater than for any other color filter; and

the backlight luminance control section increases, over a luminance of a light source of any other color, a luminance of a light source having a color corresponding to the color of the picture element provided with a first color filter of which picture element the aperture ratio is decreased by the aperture ratio converting section.

3. The liquid crystal display device according to claim 2,

wherein:

the pixels are each made up of a red picture element, a green picture element, and a blue picture element;

the backlight includes a red light source, a green light source, and a blue light source;

the aperture ratio converting section decreases an aperture ratio included in image data for the green picture element; and

the backlight luminance control section increases a luminance of the green light source over respective luminances of the red light source and the blue light source.

4. The liquid crystal display device according to claim 1,

wherein:

the backlight has a light-emitting surface that is divided into a plurality of light-emitting regions; and

the backlight luminance control section carries out luminance controls different from one another for the respective divisional light-emitting regions.

5. The liquid crystal display device according to claim 1,

wherein:

the backlight includes light sources having respective colors that correspond to picture elements having a plurality of colors;

the liquid crystal display device further comprises;

a second aperture ratio converting section that, in order to reduce a gray scale difference between the picture elements in a pixel, converts aperture ratios, included in the inputted image data, of said picture elements in the pixel and outputs data of the converted aperture ratios; and

a second backlight luminance control section that, in order to correct the gray scale difference between said picture elements in the pixel which gray scale difference has been reduced by the second aperture ratio converting section, (i) increases, over a luminance of a light source having a color identical to a color of a picture element of which an aperture ratio is not changed by the second aperture ratio converting section, a luminance of a light source having a color identical to a color of a picture element of which an aperture ratio is decreased by the second aperture ratio converting section and (ii) decreases, against the luminance of the light source having the color identical to the color of the picture element of which the aperture ratio is not changed by the second aperture ratio converting section, a luminance of a light source having a color identical to a color of a picture element of which an aperture ratio is increased by the second aperture ratio converting section; and

the liquid crystal display device causes the aperture ratio converting section, the backlight luminance control section, and at least one of the second aperture ratio converting section and the second backlight luminance control section to convert the aperture ratios of the respective picture elements in the liquid crystal panel and control the backlight luminances.

6. A liquid crystal display device, comprising:

a liquid crystal panel including pixels arranged in a matrix; and

a backlight that irradiates the liquid crystal panel with light,

the pixels each including a plurality of picture elements that are different from one another in color,

the picture elements each being provided with a color filter corresponding to a color of the picture element,

the backlight including light sources having respective colors that correspond to picture elements having a plurality of colors,

the liquid crystal display device further comprising;

an aperture ratio converting section that, in order to reduce a gray scale difference between the picture elements in a pixel, converts aperture ratios, included in inputted image data, of said picture elements in the pixel and outputs data of the converted aperture ratios; and

a backlight luminance control section that, in order to correct the gray scale difference between said picture elements in the pixel which gray scale difference has been reduced by the aperture ratio converting section, (i) increases, over a luminance of a light source having a color identical to a color of a picture element of which an aperture ratio is not changed by the aperture ratio converting section, a luminance of a light source having a color identical to a color of a picture element of which an aperture ratio is decreased by the aperture ratio converting section and (ii) decreases, against the luminance of the light source having the color identical to the color of the picture element of which the aperture ratio is not changed by the aperture ratio converting section, a luminance of a light source having a color identical to a color of a picture element of which an aperture ratio is increased by the aperture ratio converting section,

the liquid crystal display device carrying out an intended gray scale display on a basis of (i) backlight luminances determined by the backlight luminance control section and (ii) aperture ratios of the respective picture elements in the liquid crystal panel, said aperture ratios having been obtained through an aperture ratio conversion process by the aperture ratio converting section.

7. The liquid crystal display device according to claim 6,

wherein:

the backlight has a light-emitting surface that is divided into a plurality of light-emitting regions; and

the backlight luminance control section carries out luminance controls different from one another for the respective divisional light-emitting regions.

8. A method for controlling display of a liquid crystal display device including:

a liquid crystal panel including pixels arranged in a matrix; and

a backlight that irradiates the liquid crystal panel with light, the pixels each including a plurality of picture elements that are different from one another in color, the picture elements each being provided with a color filter corresponding to a color of the picture element,

the method comprising;

an aperture ratio converting step for, in order to reduce light which has a wavelength of a color different from the color of the picture element and which is transmitted through the color filter with which the picture element is provided, decreasing an aperture ratio, included in inputted image data, of a picture element and outputting data of the decreased aperture ratio; and

a backlight luminance control step for, in order to supplement the aperture ratio decreased in the aperture ratio converting step, increasing a backlight luminance as compared to a case in which the aperture ratio is not decreased,

the liquid crystal display device carrying out an intended gray scale display on a basis of (i) backlight luminances determined in the backlight luminance control step and (ii) aperture ratios of the respective picture elements in the liquid crystal panel, said aperture ratios having been obtained through an aperture ratio conversion process in the aperture ratio converting step.

9. A method for controlling display of a liquid crystal display device including:

a liquid crystal panel including pixels arranged in a matrix; and

a backlight that irradiates the liquid crystal panel with light, the pixels each including a plurality of picture elements that are different from one another in color, the picture elements each being provided with a color filter corresponding to a color of the picture element, the backlight including light sources having respective colors that correspond to picture elements having a plurality of colors,

the method comprising;

an aperture ratio converting step for, in order to reduce a gray scale difference between the picture elements in a pixel, converting aperture ratios of said picture elements in the pixel for inputted image data and outputting data of the converted aperture ratios; and

a backlight luminance control step for, in order to correct the gray scale difference between said picture elements in the pixel which gray scale difference has been reduced in the aperture ratio converting step, (i) increasing, over a luminance of a light source having a color identical to a color of a picture element of which an aperture ratio is not changed in the aperture ratio converting step, a luminance of a light source having a color identical to a color of a picture element of which an aperture ratio is decreased in the aperture ratio converting step and (ii) decreasing, against the luminance of the light source having the color identical to the color of the picture element of which the aperture ratio is not changed in the aperture ratio converting step, a luminance of a light source having a color identical to a color of a picture element of which an aperture ratio is increased in the aperture ratio converting step,

the method causing the liquid crystal display device to carry out an intended gray scale display on a basis of (i) backlight luminances determined in the backlight luminance control step and (ii) aperture ratios of the respective picture elements in the liquid crystal panel, said aperture ratios having been obtained through an aperture ratio conversion process in the aperture ratio converting step.