Image display device and image display method
AssigneeSharp Kabushiki Kaisha
InventorYuhji Tanaka
Life of this patent
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Abstract
When first and second region-processing sections (510, 520) calculate in parallel backlight luminances required for an input image halved by a regional image division section (505) included in an area-active drive processing section (5) of a liquid crystal display device, LED data (Db1, Db2) are exchanged for each other, allowing reference to backlight luminances not calculated for one region but calculated for the other region. As a result, when an area is illuminated by surrounding backlight sources, the actual display luminance can be calculated correctly. Thus, pixel display can be provided with correct display tones across the entire screen, thereby preventing a reduction in display quality.
Claims10
An image display device with a function of controlling a backlight luminance, comprising:
- a display panel including a plurality of display elements for controlling light transmittances;
- a backlight including a plurality of light sources;
- an image division section for generating a plurality of input images by subjecting a plurality of images included in a plurality of frames of an externally provided video signal to either regional division within each frame or temporal division in units of a frame, or both;
- a plurality of luminance calculation sections for setting a plurality of areas in accordance with the light sources for the plurality of input images, processing the plurality of input images in parallel on the basis of the input image for the set areas, to calculate emission luminance data specifying luminance upon emission of the light source corresponding to the areas, and processing the plurality of input images in parallel on the basis of the emission luminance data calculated for the areas and its predetermined surrounding areas, to calculate display luminance, which is luminance for display provided in the areas;
- a display data calculation section for obtaining display data to control the light transmittances of the display elements, on the basis of the input images and the display luminances obtained by the luminance calculation sections;
- a panel driver circuit for outputting signals to the display panel on the basis of the display data, said signals controlling the light transmittances of the display element;
- and
- a backlight driver circuit for outputting signals to the backlight on the basis of the emission luminance data, said signals controlling the luminances of the light sources, wherein,
- each of the luminance calculation sections receives other emission luminance data calculated by the other luminance calculation sections or values for calculating said other emission luminance data, and calculates the display luminance on the basis of the received other emission luminance data or values.
A method for controlling an image display device having a function of controlling a backlight luminance and being provided with a backlight including light sources and a display panel including a plurality of display elements for displaying a plurality of pixels by transmitting light from the light sources therethrough, the method comprising:
- an image division step of generating a plurality of input images by subjecting a plurality of images included in a plurality of frames of an externally provided video signal to either regional division within each frame or temporal division in units of a frame, or both;
- a plurality of luminance calculation steps of setting a plurality of areas in accordance with the light sources for the plurality of input images, processing the plurality of input images in parallel on the basis of the input image for the set areas, to calculate emission luminance data specifying luminance upon emission of the light source corresponding to each of the areas, and processing the plurality of input images in parallel on the basis of the emission luminance data calculated for the areas and its predetermined surrounding areas, to calculate display luminance, which is luminance for display provided in the areas;
- a display data calculation step of obtaining display data to control the light transmittances of the display elements, on the basis of the input images and the display luminances obtained by the luminance calculation steps;
- a panel drive step of outputting signals to the display panel on the basis of the display data, said signals controlling the light transmittances of the display element;
- and
- a backlight drive step of outputting signals to the backlight on the basis of the emission luminance data, said signals controlling the luminances of the light sources, wherein,
- in each of the luminance calculation steps, other emission luminance data calculated in other luminance calculation steps or values for calculating said other emission luminance data are received, and the display luminance is calculated on the basis of the received other emission luminance data or values.
Dependencies are inferred from the claim text.