Control device for liquid crystal display device, liquid crystal display device, method for controlling liquid crystal display device, program, and storage medium

• US 8,917,293 B2
• Filed: 03/13/2009
• Issued: 12/23/2014
• Est. Priority Date: 06/27/2008
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Shiomi, Makoto
• Primary Examiner(s): FRY, MATTHEW A
• Application Number:
  US12/736,660
• Publication Number:
  US 20110037785A1
• Time in Patent Office: 2,111 Days
• Field of Search: 345/87, 345/102, 345/296, 345/619, 345/690, 345698-699, 348/556
• US Class Current: 345/690
• CPC Class Codes: G09G 2310/0232 Special driving of display border areas
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0238 Improving the black level
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• 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 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

Image data obtained by adding a dummy image to a periphery of inputted image data is divided into blocks which correspond to positions of LEDs. A light-emitting luminance of an LED in an image display area is determined in accordance with a maximum value among gradation values of pixels included in a block corresponding to the LED. A light-emitting luminance of an LED in an image non-display area is determined in accordance with an average luminance level of some of small blocks which are adjacent to the block corresponding to the LED in the image non-display area, the small blocks being obtained by further dividing a block of the image display area adjacent to the block corresponding to the LED.

Claims

1. A control device for controlling operations of a liquid crystal display device which includes a liquid crystal display panel and a backlight unit having a plurality of light sources arranged in a matrix manner in a backside of the liquid crystal display panel, said control device comprising:

a liquid crystal control section configured to control pixels of the liquid crystal display panel in accordance with inputted image data;

a backlight control section configured to control light-emitting states of respective ones of the plurality of light sources in accordance with the inputted image data; and

an image size adjusting section configured to generate size-adjusted image data in a case where an aspect ratio of the inputted image data is different from an aspect ratio of the liquid crystal display panel, the image size adjusting section adding dummy image data to a periphery of (i) image data which is obtained by subjecting the inputted image data to a predetermined process or (ii) the inputted image data so as to generate the size-adjusted image data, so that an aspect ratio of the size-adjusted image data corresponds to the aspect ratio of the liquid crystal display panel,

the backlight control section is configured to

divide the size-adjusted image data into a plurality of blocks which correspond to respective positions in which the plurality of light sources are provided, each block being non-overlapping and at least two of the plurality of blocks being in a same row and at least two of the plurality of blocks being in a same column,

determine a light-emitting luminance of each light source in an image display area among the plurality of light sources in accordance with a maximum value among gradation values of pixels included in that one of the plurality of blocks corresponding to the light source, the image display area being an area for displaying an image corresponding to the inputted image data, and

determine a light-emitting luminance of each light source in an image non-display area among the plurality of light sources based on (i) an average luminance level of at most pixels included in a block of an image display area adjacent to a block corresponding to the light source in the non-display area, a number of the at most pixels included in the block of the image display area adjacent to the block corresponding to the light source in the non-display area being greater than zero, the image display area adjacent to the block corresponding to the light source in the non-display area being at most a portion of the image display area, the image non-display area being an area in which an image corresponding to the dummy image data is displayed, or (ii) an average luminance level of some of a plurality of small blocks which are adjacent to the block corresponding to the light source in the image non-display area, the plurality of small blocks being obtained by further dividing the block of the image display area adjacent to the block corresponding to the light source, a number of the some of the plurality of small blocks which are adjacent to the block corresponding to the light source in the image non-display area being less than all of the plurality of small blocks, each small block being non-overlapping and corresponding to an area of at least two pixels in a same column and two pixels in a same row.

2. The control device as set forth in claim 1, wherein:

for each light source among the plurality of light sources which is in a block of the image non-display area which block is not adjacent to a block of the image display area, the backlight control section is configured to determine a light-emitting luminance of the light source in accordance with (i) an average luminance level of pixels included in a block of the image display area which is nearest to the block corresponding to the light source or (ii) an average luminance level of some of a plurality of small blocks which are positioned near the image non-display area corresponding to the light source, the plurality of small blocks being obtained by further dividing the block of the image display area which is nearest to the block corresponding to the light source.

3. The control device as set forth in claim 2, wherein:

in a case where plural blocks of the image non-display area are aligned in a direction off from the image display area, the backlight control section is configured to determine light-emitting luminances of some of the plurality of light sources corresponding to the plural blocks of the image non-display area so that the light-emitting luminances becomes darker as a distance from the image display area increases.

4. The control device as set forth in claim 1, further comprising:

a luminance distribution data generating section configured to generate luminance distribution data indicative of luminance distribution caused in the liquid crystal display panel due to light emitted by the plurality of light sources, the plurality of light sources emitting the light according to the respective light-emitting luminances determined by the backlight control section, and

the liquid crystal control section (i) including a compensating section configured to compensate the inputted image data in accordance with the luminance distribution data, and (ii) configured to control the pixels of the liquid crystal display panel in accordance with image data which has been compensated by the compensating section.

5. The control device as set forth in claim 1, wherein:

the image size adjusting section is configured to carry out the addition of the dummy image data so that an image corresponding to the inputted image data is displayed in substantially center of the liquid crystal display panel.

6. A liquid crystal display device, comprising:

a liquid crystal display panel;

a backlight unit having a plurality of light sources arranged in a matrix manner in a backside of the liquid crystal display panel; and

the control device as set forth in claim 1.

8. A non-transitory computer-readable storage medium, when executed on a computer, configured to operate the control device of claim 1.

7. A method for controlling operations of a liquid crystal display device which includes a liquid crystal display panel and a backlight unit having a plurality of light sources arranged in a matrix manner in a backside of the liquid crystal display panel,

said method comprising the steps of:

(a) controlling pixels of the liquid crystal display panel in accordance with inputted image data;

(b) controlling light-emitting states of respective ones of the plurality of light sources in accordance with the inputted image data; and

(c) generating size-adjusted image data in a case where an aspect ratio of the inputted image data is different from an aspect ratio of the liquid crystal display panel, the size-adjusted image data being generated by adding dummy image data to a periphery of (i) image data which is obtained by subjecting the inputted image data to a predetermined process or (ii) the inputted image data so that the size-adjusted image data has an aspect ratio which corresponds to the aspect ratio of the liquid crystal display panel, the step (b) including;

(d) dividing the size-adjusted image data into a plurality of blocks which correspond to respective positions in which the plurality of light sources are provided, each block being non-overlapping and at least two of the plurality of blocks being in a same row and at least two of the plurality of blocks being in a same column;

(e) determining a light-emitting luminance of each light source in an image display area among the plurality of light sources in accordance with a maximum value among gradation values of pixels included in that one of the plurality of blocks corresponding to the light source, the image display area being an area for displaying an image corresponding to the inputted image data; and

(f) determining a light-emitting luminance of each light source in an image non-display area among the plurality of light sources based on (i) an average luminance level of at most pixels included in a block of an image display area adjacent to a block corresponding to the light source in the non-display area, a number of the at most pixels included in the block of the image display area adjacent to the block corresponding to the light source in the non-display area being greater than zero, the image display area adjacent to the block corresponding to the light source in the non-display area being at most a portion of the image display area, the image non-display area being an area in which an image corresponding to the dummy image data is displayed, or (ii) an average luminance level of some of a plurality of small blocks which are adjacent to the block corresponding to the light source in the image non-display area, the plurality of small blocks being obtained by further dividing the block of the image display area adjacent to the block corresponding to the light source, a number of the some of the plurality of small blocks which are adjacent to the block corresponding to the light source in the image non-display area being less than all of the plurality of small blocks, each small block being non-overlapping and corresponding to an area of at least two pixels in a same column and two pixels in a same row.