Sanyo Electric Co., Ltd.

Tottori Sanyo Electric Co., Ltd.

Shoji Iwasaki

Toshihiko Tanaka

Norimitsu Kobayashi

Kouji Maeta

Jouji Yamada

Masahiro Nakamura

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 driving power supply and a driving circuit are provided which are suitable for use in a high resolution matrix liquid crystal display. A power source circuit generates two selecting potentials and an intermediate potential between the selecting potentials to be supplied to scanning electrodes through a scanning circuit, two potentials close to the intermediate potential to be supplied to signal electrodes through a signal circuit, and potentials for driving the scanning circuit and the signal circuit. A receiving circuit controls the scanning circuit and the signal circuit based on control signals and an image signal and monitors the potential of the power supplied to the liquid crystal display to start the potential generation by the power source circuit when the potential has sufficiently increased.

Liquid crystal display

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

In a picture display device in accordance with the present invention, a selector (18) selects alternately the address output of a write address counter (15) and the address output of read address counters (16 and 17), and a selector (19) selects alternately the address output of a first read address counter (16) and the address output of a second address read counter (17). Then, picture element data based on a video signal from a picture processing circuit (1) is written in frame memories (4 and 5) corresponding to the two display areas (11) and (12) divided as the upper half and the lower half of the screen of a liquid crystal display (10) and after that, the picture element data is read out from the frame memory (4) and displayed on the upper display area (11) and written in the frame memory (5). Subsequently, the picture element data is read out from the frame memory (5) corresponding to the lower display area (12) so as to be displayed on the display area (12). Writing and reading of the frame memories (4 and 5), reading of the frame memory (4) and reading of the frame memory (5) are performed alternately. Then, writing and reading of the frame memory (5) and reading of the frame memory are performed alternately, whereby the picture element data is displayed with good quality on the liquid crystal display (10) by using the frame memories (4 and 5) corresponding to one frame.

Picture display device

Character information to be displayed is stored in a temporary memory. Character data (ASCII code) is provided from the temporary memory to a character generator. The character generator is responsive to the character data to convert them into a dot display signal displaying each character in m columns and n rows. Then the display signal of each common row of the respective characters is transferred to a shift register in a bit serial fashion. Each time the display signal for one character is transferred a display blank signal is loaded in the shift register. A dot matrix display comprises rows of the same number as the cells of the shift register for producing a blank of one column between the adjacent characters, while displaying each character in m columns and n rows. After display is made on the display for all the rows, a leftward shift is made in succession one column by one column from the lowest row. When the shift amount comes to correspond to one character, new character information is loaded in the temporary memory.

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Tottori, Japan

Shoji Iwasaki