Victor Company of Japan, Limited

Jvc Kenwood Corporation

Yoshinori Ohshima

Naoto Hirohata

Shigehiro Masuji

A display has light emitting elements, a first driver, a power source, and a second driver. Each light emitting element includes 'n' emission layers formed one over another to form a color dot in each pixel. The first driver drives the emission layers to emit light or no light. The power source passes a current through the first driver to the light emitting element. The second driver individually weights the n emission layers and makes the emission layers emit light so that each dot may express a gradation level.

Display with multiple emission layers

A backlight device is divided into multiple regions, and has a configuration in which light emitted from a light source of each of the regions is allowed to leak to other regions. A maximum gradation detector detects a maximum gradation of a regional image signal displayed on each of the regions of the liquid crystal panel. An image gain calculator obtains a gain to be multiplied to each regional image signal. An emission luminance calculator obtains an emission luminance of light to be emitted by each light source, by using an operation expression according to the emission luminance of light to be emitted by the backlight device. At this time, if the emission luminance takes a negative value as a result of calculation, the emission luminance calculator makes a correction so that the emission luminance can take a value equal to or greater than 0.

Liquid crystal display device and image display method thereof

High quality images on liquid crystal panel can be obtained alleviating variations of the brightness and color among regions, in which backlight is divided when emission luminance of the backlight is controlled in each region based on image signal. A backlight device is divided into multiple regions, and has a configuration in which light emitted from a light source of each of the regions is allowed to leak to other regions. A maximum gradation detector detects a maximum gradation of a regional image signal displayed on each of the regions of the liquid crystal panel. An image gain calculator obtains a gain to be multiplied to each regional image signal by using luminance bitmap held by luminance bitmap memory. An emission luminance calculator obtains an emission luminance of light to be emitted by each light source.

A display apparatus divides each frame period of an input image signal into a plurality of subframes and selects the subframes according to a gray-scale level of the input signal, to display a gray-scale image. The display apparatus alternately employs two sets of tables having different gray-scale-level input/output characteristics, to move locations to cause false contours frame by frame, thereby minimizing false contours.

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Yamato, Japan

Yoshinori Ohshima