Panasonic Liquid Crystal Display Co., Ltd.

Hitachi Displays, Ltd.

Japan Display Inc.

Other

Kenichi Akiyama

Yoshihiro Kotani

Mitsuru Goto

Hiroko Sehata

Kouichi Kotera

Yoshinori Aoki

Shinji Yasukawa

Shuuichirou Matsumoto

Hironobu Isami

Koichi Kotera

Yuji Yamashita

A drive circuit of a display device includes decoder circuit which outputs a voltage based on a 8-bit digital value. The decoder circuit includes a first decoder circuit and a second decoder circuit which output one voltage respectively using upper-order 6 bits of the 8-bit digital value; a selection circuit which receives voltages outputted from the first decoder circuit and the second decoder circuit, and distributes the two voltages to three terminals; and an intermediate voltage output circuit which outputs an intermediate voltage which is a one of five kinds of values based on the three voltages. The first decoder circuit and the second decoder circuit respectively include a select-switch-type decoder circuit and a tournament-type decoder circuit.

Display device

An object of the invention is to reduce the size of a decoder circuit of a display device. A decoder circuit which outputs voltages corresponding to 8-bit digital values includes a predecoder section, which includes an A decoder, B decoder, and C decoder, each of which is configured of a matrix type decoder circuit which carries out a three bits' worth of decoding, and a tournament type decoder circuit which carries out a three bits' worth of decoding, a selection circuit which, having input thereinto three voltages output respectively from the A decoder, B decoder, and C decoder, and applied to three output signal lines, selects two voltages of the three input voltages using a bit with one of the digital values and applies them to two output signal lines, and an intermediate voltage output circuit which, having input thereinto the two voltages selected by the selection circuit, outputs a voltage which is the average of the two voltages.

A liquid crystal display device used in miniaturized portable equipment includes a distribution circuit to cope with a high-definition multi-grayscale display. A distribution circuit distributes an output of a drive circuit to a plurality of video signal lines within one scanning period, the distribution circuit being divided into a plurality of distribution circuits, and control signals being supplied to each distribution circuit from both end portions of each distribution circuit. When an output part of the drive circuit is configured such that a high withstand-voltage output amplifier and a low withstand-voltage output amplifier are alternately connected with the distribution circuit, a master function and a slave function are imparted to the drive circuit so as to allow the drive circuit to cope with odd-numbered outputs.

Liquid crystal display device having drive circuits with master/slave control

A decoder circuit which outputs a voltage based on a 8-bit digital value includes: a first decoder circuit and a second decoder circuit which output one voltage respectively using upper-order 6 bits of the 8-bit digital value; a selection circuit which receives voltages outputted from the first decoder circuit and the second decoder circuit, and distributes the two voltages to three terminals; and an intermediate voltage output circuit which outputs an intermediate voltage which is a one of five kinds of values based on the three voltages. The first decoder circuit and the second decoder circuit respectively include a select-switch-type decoder circuit and a tournament-type decoder circuit. Due to such a constitution, it is possible to reduce a circuit scale of the decoder circuit which outputs the voltage corresponding to the 8-bit digital value.

An optimum driving method is realized in a miniaturized liquid crystal display device having two liquid crystal display panels so as to low power consumption. The liquid crystal display device includes a first liquid crystal display panel, a second liquid crystal display panel, a drive circuit which is mounted on the first liquid crystal display panel, output terminals which are formed on the first liquid crystal display panel and to which signals outputted from the drive circuit are supplied, and connection lines which connect the output terminals and the second liquid crystal display panel, wherein the drive circuit can change the AC driving method employed during a display period of the first liquid crystal display panel and the AC driving method employed during a display period of the second liquid crystal display panel which are present within the same frame.

Liquid crystal display device

A liquid crystal display device includes a liquid crystal panel having plural pixels and a video signal line driver circuit for supplying a video signal voltage to each of the pixels via a corresponding one of plural video lines in accordance with a P-bit display data. The video signal line driver circuit includes a power supply circuit for supplying Q different gray-scale voltages, plural selector circuits corresponding to the video lines, each of the selector circuits for outputting one of first and second pairs of voltages in accordance with the display data, the first pair being two voltages equal to a same one selected from among the Q different gray-scale voltages, the second pair being two different voltages selected from among the Q different gray-scale voltages, and plural amplifiers corresponding to the video lines, each of the amplifiers for outputting the video signal voltage to a corresponding one of the video lines based upon one of the first and second pairs of voltages or a voltage intermediate between the second pair of voltages and produced from the second pair of voltages in the amplifiers.

Growing community of inventors

Mobara, Japan

Kenichi Akiyama