Casio Computer Co., Ltd.

Minoru Usui

Hideki Mori

Ken Yoshino

Kouji Yamagishi

Masao Kawamura

Saburo Kobayashi

Tomohiro Mogi

Ryota Odake

Tsuyoshi Aoki

An image display circuit supplies gray scale data according to a video signal to a liquid crystal panel to present a gray-scaled display and scans the liquid crystal panel N times during one field period of a video signal. The image display circuit includes a table ROM comparing a current video signal with a previous video signal of one frame before, and generates gray scale data for N times in accordance with the comparison result. Gray scale data greater than the gray scale of the current video signal is generated when the comparison result indicates that the gray scale of the current video signal is greater than that of the previous video signal, and gray scale data smaller than the gray scale of the current video signal is generated when the gray scale of the current video signal is found to be smaller than that of the previous video signal. Based on the generated gray scale data, the liquid crystal panel is driven with the proper gray scales.

Gray scale liquid crystal display

An image display circuit supplies gray scale data according to a video signal to a liquid crystal panel to present a gray-scaled display, and scans the liquid crystal panel N times during one field period of a video signal. The image display circuit includes a table ROM comparing a current video signal with a previous video signal of one frame before, and generates gray scale data for N times in accordance with the comparison result. Gray scale data greater than the gray scale of the current video signal is generated when the comparison result indicates that the gray scale of the current video signal is greater than that of the previous video signal, and gray scale data smaller than the gray scale of the current video signal is generated when the gray scale of the current video signal is found to be smaller than that of the previous video signal. Based on the generated gray scale data, the liquid crystal panel is driven with the proper gray scales.

Image display apparatus

In a liquid crystal display device, to improve the contrast, the frame frequency is raised by scanning the scanning electrodes of the liquid crystal display panel a plurality of times during one field interval of the video signal. The scanning electrodes are divided into two groups, which are scanned alternately. An image memory is provided to store video signals. In scanning the liquid crystal display panel, the video signal from the video signal supplying source and the video signal read from the image memory are alternately supplied to the liquid crystal display panel. The image memory stores only part of the video signal such as the video signal for every other horizontal scanning period or the signal consisting of the most significant bit only, not the entire video signal.

Liquid crystal display device with scanning electrode selection means

A liquid-crystal display apparatus having scanning electrodes and signal electrodes, both being disposed in a matrix arrangement, which divides a selection period for a scanning electrode by m and performs a display based on same data for m times, and which makes different a wave level of a scanning-electrode driving signal during each divided selection period. A liquid-crystal panel driving circuit for driving a liquid crystal panel having scanning-electrodes and signal electrodes, both being disposed in a matrix arrangement, which divides a selection period for a scanning electrode by m and performs a display based on same data for m times, and which makes different a wave level of a signal-electrode driving signal during each divided selection period. A liquid-crystal panel driving circuit for driving a liquid crystal panel having scanning electrodes and signal electrodes, both being disposed in a matrix arrangement, which divides a selection period for a scanning electrode by m and performs a display based on same data for m times, and which makes different respective wave levels of a signal-electrode driving signal and a scanning-electrode driving signal during each divided selection period.

Liquid-crystal display apparatus

In a signal electrode drive circuit of an image display apparatus, the latch pulses are sequentially shifted for a plurality of latch circuits so as to sequentially latch the digital image data, and the signal electrode of the dot-matrix type display panel is driven by the signal having a plurality of gradation, based upon the digital image data latched in the latch circuits. The image input data are alternately read out via the buffer circuits by two-phase clock pulses, the input data are transferred to the latch circuits in response to the two-phase clock pulses, and, as a consequence, image data of higher transfer frequency can be satisfactorily processed.

Signal electrode drive circuit for image display apparatus operable

A liquid-crystal display apparatus has liquid-crystal display panels, in which scanning and signal electrodes are arranged in a matrix, and the number of scanning electrodes in divided into 1/N. A RAM has a video data storage capacity corresponding to an (N-1)/N field of the 1/N-divided liquid-crystal display panel. An electrode drive signal for driving the scanning electrodes selects an identical scanning electrode for each 1/N field, so that video data corresponding to a 1/N image from the RAM is distributed to be displayed on divided display regions.

An image display apparatus having an A/D converter which samples a television signal a plurality of times in each horizontal effective display period and converts the sampled signal into digital data, and a gradation signal generator combines gradation signals produced in a plurality of horizontal effective display periods according to the digital data to produce a new gradation signal. An image display panel is driven for display according to the new gradation signal.

Image display using liquid crystal display panel

A liquid crystal drive circuit includes a first buffer circuit for outputting a selection high level segment voltage V0' using a nonselection high level common voltage V1 from a common voltage generator as a reference, and a first operational amplifier for outputting a nonselection high level segment voltage V2' having an inverted voltage level of the selection high level segment voltage. The liquid crystal drive circuit also includes a second buffer circuit for outputting a selection low level segment voltage V5' using a nonselection low level common voltage V4 as a reference, and an operational amplifier for outputting a nonselection low level segment voltage V3' having an inverted voltage level of the nonselection low level segment voltage.

Liquid crystal drive circuit for driving a liquid crystal display

A plurality of music number data records of several hundreds of music numbers are sequentially recorded on a magnetic tape, such as a compact cassette tape with a blank space therebetween. The recorded music number data records are continuously and randomly reproduced and stored in digital form in a RAM so as to continuously auto-play a plurality of music numbers by means of a tone generator.

Recording apparatus with random music selection

Tone data produced by operating a keyboard is stored in a RAM to be saved into a tape recorder through an interface. Of a plurality of music numbers saved in the tape recorder a selected one is loaded into the RAM through the interface. A tone generator converts the tone data from the RAM into a tone signal which is sounded from a loudspeaker. The save and load operations are all controlled by a CPU.

Electronic apparatus with magnetic recording and reproducing device

Electronic equipment has a memory which stores input data to be displayed. The data read out from the memory is formed as a corresponding character pattern signal and is output from a character pattern generator. The character pattern signal generated by the character pattern generator is displayed in n characters at a display section in response to a first mode signal which is supplied by a mode switching section. The mode switching section supplies different display mode signals determined by the contents of the data to be displayed. The character pattern signal from the character pattern generator is displayed in m characters (n&lt;m) at the display section in response to a second mode signal supplied by the mode switching section.

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Akishima, Japan

Minoru Usui