Sanyo Electric Co., Ltd.

Tottori Sanyo Electric Co., Ltd.

Norimitsu Kobayashi

Toshihiko Tanaka

Shoji Iwasaki

Kouji Maeta

Jouji Yamada

Akinori Matsushita

Makoto Kasami

A simple matrix drive type liquid crystal display device with enhanced display quality is provided. In line-at-a-time scanning, a scanning electrode group is supplied with two selecting voltages alternately; a signal electrode group is supplied with two voltages close to the intermediate value between the two selecting voltages. Which voltage is applied to the signal electrode is determined in accordance with the selecting voltage applied to the scanning electrode at that moment and a video signal in such a way that selected picture elements receive a large voltage and non-selected picture elements receive a small voltage. The output voltage of the power source circuit, which supplies power to the scanning circuit and the signal circuit that apply voltages to the scanning and signal electrode groups, is monitored so that, if the voltage is below a predetermined value, the liquid display device will not start display even when it receives a signal requesting starting of display from the outside.

Liquid crystal display device

A liquid crystal display apparatus includes an LCD having a plurality (N) of row electrodes and a plurality (M) of column electrodes which intersect to each other orthogonally. A plurality (n) of row electrodes of the plurality (N) of row electrodes are individually and simultaneously driven by a plurality (n) of row drivers with voltages which are determined according to Walsh functions. A VGA controller which receives a video signal outputs display data of one frame. A plurality (n) of storages individually store the display data of each of n rows which are simultaneously driven. The display data from respective storages are applied to a plurality (m) of calculation circuits. Respective calculation circuits calculate driving voltage values for respective column electrodes in accordance with the Walsh function and the display data so as to apply the same to a plurality (m) of column drivers, respectively. Respective column drivers drive the column electrodes included in each of a plurality (m) column electrode groups with the driving voltage values.

Liquid crystal display apparatus

A liquid crystal display apparatus is driven by a voltage averaging method. The display apparatus is provided with voltages via a scanning circuit and a driver circuit from a power supplying circuit. The power supplying circuit has a voltage compensating circuit which is provided with an operational amplifier whose first input terminal is provided with a predetermined voltage and whose second input terminal is connected to an output terminal thereof through a resistor, an impedance circuit connected between the output terminal of the operational amplifier and an output terminal of the power supplying circuit, and feedback circuit for feeding back both of an alternating current component and a direct current component of an output of the impedance circuit to the second input terminal of the operational amplifier.

Dot matrix type liquid crystal display apparatus

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Tottori, Japan

Norimitsu Kobayashi