Fujitsu Hitachi Plasma Display Limited

Shunji Ohta

Akira Yamamoto

Masaya Tajima

Masanori Takeuchi

Yutaka Chiaki

Yuichiro Kimura

Yoshinori Miyazaki

In a conventional image display apparatus, since display load ratios for respective lines are different, voltage drop amounts are also different and a difference in brightness occurs in spite of giving the same inputted luminance signal, so that image quality of display image is degraded. In the case where signals at the same luminance level are inputted and displayed, for a pixel on a display panel, an ON pattern of a subfield in one field is changed when a line load ratio of a line including the pixel is changed. That is, an image display apparatus using a display panel having a plurality of pixels is configured so as to include, for each of the plurality of pixels connected to one driving electrode, a load calculating means that calculates the load ratio and a luminance correcting means that calculates a drop amount in luminance level of an inputted video signal for correction.

Image display apparatus and driving method thereof

A display apparatus displaying gray scale by using a subfield method has a gain control circuit, a sub gain control circuit, and an error diffusion circuit. The gain control circuit has the number of gray scale levels of an input signal and outputting a first intermediate image signal with a first number of gray scale levels, and the sub gain control circuit receives the first intermediate image signal, compresses the number of gray scale levels of the first intermediate image signal, and outputs a second intermediate image signal with a second number of gray scale levels. The error diffusion circuit receives the second intermediate image signal and increase the number of gray scale levels by simulating additional gray scale levels through error diffusion.

Display apparatus and display driving method for effectively eliminating the occurrence of a moving image false contour

A display apparatus displaying gray scale by using a subfield method has a main path, a sub path, a switch circuit, a motion region detection circuit, a first judging circuit, a level detection circuit, a motion detection correction circuit, and a second judging circuit. The switch circuit outputs a first image signal generated by the main path or a second image signal generated by the sub path by switching therebetween, and the first judging circuit outputs a first motion signal in accordance with an output of the motion region detection circuit. The motion detection correction circuit receives the first motion signal and a level signal, and outputs a second motion signal in accordance with the level signal, and the second judging circuit receives the second motion signal and the level signal, and outputs a switching control signal to the switch circuit.

A signal processor for multiple gradations for carrying out coding by replacing an input image signal with a plurality of subfields, comprising a main path for generating a primary color signal having a first number of gradations, a sub-path for generating a primary color signal having a second number of gradations, which is smaller than the first number of gradations, a switch, a movement detection circuit, a level detection circuit, a path switching control circuit for switching the switch based on the amount of movement and the level, plural subfield coding circuits for carrying out subfield coding different from each another, a superposing circuit for selecting one of the outputs of the plural subfield coding circuits, and a superposing control circuit, and thus preventing a moving false contour.

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Kawasaki, Japan

Shunji Ohta