Sharp Kabushiki Kaisha Corporation

Hirofumi Fukuoka

Yoshiharu Kanatani

Toshihiro Yanagi

Hisao Okada

Takeshi Takarada

Shigeyuki Uehira

Kuniaki Tanaka

Makoto Yoshimura

Yoshihiko Orii

Haruyoshi Hanada

Tadatsugu Nisitani

A method of driving a display apparatus includes the steps of receiving output requests at a interval and outputting an oscillating voltage to a source line connected to display section, the oscillating voltage including a component which oscillates during one output period of time defined by the output requests.

Method of driving a display apparatus

A drive device for driving a matrix-type LCD apparatus comprises a voltage signal supply means for outputting a plurality of voltage signals with different levels. The voltage signals have alternately positive and negative levels with respect to an AC reference voltage applied to a counter-electrode of the LCD apparatus. The AC reference voltage is approximately 180.degree. out-of-phase with the voltage signals. The drive device also comprises a signal electrode drive means which selects one of the voltage signals depending upon an input digital video signal, and which supplies the selected voltage signal to a signal electrode of the LCD apparatus.

Drive device for driving a matrix-type LCD apparatus

A driving circuit for a matrix type liquid crystal display device is disclosed. The driving circuit comprises: a gate driver for, during a writing period, selectively driving a scanning line included in a group of scanning lines which correspond to the field to be scanned, and for, during an erasing period, selectively driving a scanning line included in another group of scanning lines which do not correspond to the field to be scanned; a source driver for, during said writing period of an even field, applying a signal voltage the level of which corresponds to a video signal, to the signal lines, and for, during the erasing period, applying a voltage to the signal lines to set the voltage applied to the picture elements to a level below the threshold level of the picture elements; and another source driver for, during said writing period of an odd field, applying a signal voltage the level of which corresponds to a video signal, to the signal lines, and for, during the erasing period, applying a voltage to the signal lines to set the voltage applied to the picture elements to a level below the threshold level of the picture elements. The writing period and the erasing period shares one horizontal scanning period.

Driving circuit for a matrix type display device

A driving circuit for a matrix type display device in which a plurality of picture elements are arranged in a matrix is disclosed. The driving circuit comprises a video signal output circuit for supplying video signals through output portions to the display device at each horizontal scan. The video signal output circuit comprises for each of the output portions: a comparison circuit for comparing the level of a video signal to be output, with the level of the output portion which is caused by the video signal output at the previous horizontal scan; and an output level control circuit for, when the level of said video signal to be output is higher than the level of the output portion, raising the level of said output portion to the level substantially identical with the level of the video signal to be output, and, when the level of said video signal to be otuput is lower than the level of the output portion, lowering the level of said output portion to the level substantially identical with the level of the video signal to be output.

A display device of a type for displaying in two levels is so controlled as to display images of different colors by hatching according to different patterns such that images of different colors can be distinguished. In order to prevent distortion of image caused by hatching, hatching corresponding to any particular color can be selectively prevented. With a binary conversion circuit with adjustable reference voltages, an image with various combinations of analog color signals can also be displayed.

Two-level display device with hatching control means

A liquid crystal display device for an overhead projector has a light-transmissive liquid crystal display cell sandwiched between protective plates both from above and below. At least one of these protective plates is separated from the cell surface to form an air passage provided with a fan such that air can be caused to flow therethrough and come into direct contact with the cell. The cell can thus be cooled efficiently and the light of the projector can be increased for projecting a clearer image.

Growing community of inventors

Osaka, Japan

Hirofumi Fukuoka