Sharp Kabushiki Kaisha Corporation

Sharp Kabushiki Kaishi

Katsuya Mizukata

Makoto Takeda

Takafumi Kawaguchi

Toshihiro Yanagi

Kouji Kumada

Noboru Noguchi

Hisashi Nagata

Hiroshi Take

Yasukuni Yamane

Hidetaka Mizumaki

Takashige Ohta

Manabu Tanaka

Takaaki Iemoto

Kazuhiko Tsuda

Masaru Tanaka

Kenichi Katoh

Masanobu Okano

Satoru Kishimoto

Shiro Takeda

The display system of the present invention includes: a body unit () for transmitting image data that has been generated; and a display device () for displaying an image in accordance with the image data that has been transmitted from the body unit (), and said display system is characterized in that the body unit () and the display device () perform communications via radio communication means, and the body unit () and the display device () are separately providable. Thus, the radio transmission is used as communication means, and there is no cable, connecting the display device () and the body unit (), that transfers the data signal, so that the device user can operate the system freely while watching the display device (). As a result, it is possible to improve the workability of the user of the present display system. Further, since there is no wire connection section, using a connection clip, that is provided in a conventional display device, it is possible to simplify a mechanism for securing the strength of the wire connection section.

Display device and display system

Each signal line enters a preliminary polarity inversion period prior to a normal polarity inversion period so as to be inverted to the opposite polarity. By the preliminary polarity inversion a signal line on a border of blocks experiences a potential hike and the potential oscillates, which, however, is restored later by the application of a correct potential in the normal polarity inversion period. When transferring data per block, the problem of different potential states between the border of the blocks and an area surrounding it, which is caused by the potential oscillation of the signal line on the border of the blocks, is relieved.

Data transfer method, image display device and signal line driving circuit, active-matrix substrate

The display system of the present invention includes: a body unit for transmitting display data that has been generated; and a display device for displaying an image in accordance with the display data that has been transmitted from the body unit. The display system is characterized in that the body unit and the display device perform communications via radio communication means, and the body unit and the display device are separately provided. Thus, the radio transmission is used as communication means, and there is no cable connecting the display device and the body unit that transfers the display data, so that the user can operate the system freely while watching the display device.

Disclosed is a portable information apparatus, which is provided with a display section capable of displaying a color display and a dynamic display in a high image quality, and which consumes less electricity. When the portable information apparatus of a folder type is in a folded state, a display screenis composed of an image display region and a non-image region, so that at least a part of the image display region can be seen via a transparent section

Portable information apparatus for displaying information in a folded state

In an active matrix type display device, a signal voltage is applied from a signal line driving circuit via an active element such as a TFT to display electrodes on a matrix substrate, and a common voltage is applied to a counter electrode on a facing substrate so that the common voltage is shared by respective display cells. A level of the common voltage is switched in every refresh period of a different length. Thus, it is possible to appropriately set a value of the common voltage which is a reference for specifying an effective voltage of positive polarity and an effective voltage of negative polarity according to the refresh periods. As a result, even when the refresh periods of a different length exist in a mixed manner, it is possible to equalize the effective voltage of positive polarity and the effective voltage of negative polarity so as to suppress an occurrence of a flicker.

Active matrix type display and a driving method thereof

An active matrix liquid crystal display drives liquid crystal by writing through TFTs, etc. a source signal from a signal line drive circuit to display electrodes in display cells on a matrix substrate and applying a common signal supplied from a common signal generator to common electrodes on an opposite substrate, the common signal changing in polarity in each frame. After scanning is completed for scan lines corresponding to one frame, a controller controls the interval between scan periods and the cycle of change in polarity of the common signal so as to provide a non-scan period that is longer than the scan period. The provision of the non-scan period extends the duration in which a specified voltage is retained by the display cell. This reduces the effects of variations in retained voltages caused by parasitic capacitance which develops in reflective electrode structures in which the display electrodes partly overlook scan lines and signal lines. Thus, in frame inversion drive, differences in brightness between the top and bottom of the display screen are reduced, and display quality is improved.

Active matrix liquid crystal display and method of driving the same

According to a driving method of a matrix-type display device of the present invention, a reference clock signal supplied by a reference clock oscillator is divided by a plurality of frequency dividing circuits, so that division clock signals are obtained. One among the division clock signals is selected by a switching operation by a switching circuit, and the selected division clock signal is outputted as a sampling clock signal to a row electrode driving circuit. Timings for the switching operation of the switching circuit are controlled by a switching control circuit in accordance with a horizontal synchronization signal and the reference clock signal. One or more of the frequency dividing circuits outputs a division clock signal having unequal clocks, when necessary. By thus arranging the division clock signals so that they have unequal clocks, it is allowed to set N of the division ratio 1/N to a value other than an integral number. Therefore, it is possible to set the division ratios close to each other, and hence, it is ensured that the reference clock signal has a lower frequency.

Matrix-type display device and method for driving the same

A driving circuit for an image display device includes a signal generating circuit for generating an initiation control signal for controlling the initiation of sampling of a video signal to be input, and a sampling pulse timing signal for determining timing of sampling. When a set of discrete signals is input as the video signal, the signal generating circuit generates two sampling pulse timing signals whose phases differ from each other, selects one of the sampling pulse timing signals alternately in each horizontal scanning period, and outputs the selected sampling pulse timing signal to a shift register in a source driver. The signal generating circuit also switches the output signal between the two sampling pulse timing signals in a set of four fields.

Driving circuit for image display device including signal generator

On a matrix form display panel which realizes a display device with a high image quality, the return circuits of condensers, connected to picture elements in the last row among picture elements arranged in a matrix form, are connected to a common line independently of the return circuits of the condensers in the other rows, a common electrode driving circuit is provided, and a common electrode driving voltage is applied, whereby the effective values of driving voltages applied to the picture elements in the last row are equalized to the effective values of driving voltages applied to the picture elements in the other rows. Thereby, all the picture elements forming the panel are equal in optical transmissivity, and as a result the displayed image quality is improved. Additionally, since the last scanning line can be used for displaying, the utility factor of display panel is enhanced.

Display device

A driving method of the invention is suitable for an active matrix type liquid crystal display apparatus having row and column electrodes. The driving method includes the steps of applying a gate-one pulse for writing data for one line to the column electrodes to each of the row electrodes. The gate-on pulse has a pulse waveform which includes at least one concave portion during a horizontal period.

Driving apparatus and method for an active matrix type liquid crystal

A matrix-type display device capable of effecting color-displaying is constructed such that the mode of sampling neighboring RGB data can be optionally selected from two modes, e.g., three-point successive sampling mode and three-point simultaneous sampling mode. In the case of the three-point successive sampling mode, since pulses are generated successively so that each pulse is shifted by one-dot term .tau. from one another, the pulse terms of sampling pulses are shifted by one-dot term .tau. from one another. Accordingly, pixel signals supplied to respective three neighboring RGB pixels are shifted by one-pixel equivalent. On the other hand, in the case of the three-point simultaneous sampling, generated pulses all stay at high level at any time. Therefore, the pulse terms of sampling pulses are made coincident, so that pixel signals supplied to respective three neighboring RGB pixels are of data on an identical point.

Driving circuit for display devices

When a specific signal (such as copy guard signal) is added between horizontal synchronizing signals in a composite synchronizing signal, and the addition period of the specific signal is defined in a specific period on the basis of the vertical synchronizing signal, the composite synchronizing signal is masked to remove the specific signal, thereby obtaining a masked composite synchronizing signal. Afterwards, from the masked composite synchronizing signal, the horizontal synchronizing signal and vertical synchronizing signal are obtained. In the case of composite synchronizing signal containing noise, without masking, the horizontal synchronizing signal and vertical synchronizing signal are directly obtained from the composite synchronizing signal. Therefore, when noise is not present, the horizontal synchronizing signal and vertical synchronizing signal may be obtained without disturbing the video image.

Synchronizing circuit

An improved flat display apparatus such as a liquid crystal display apparatus is disclosed. The apparatus is constructed so that when video signals from a VTR is reproduced to be displayed, the switching noise portion included in the video signals is changed to black level before being displayed, the section within the picture image area in which the switching noise originally appeared is masked by black level, making it possible to conceal the disorder in the picture image. In the case where television video signals are to be displayed, the picture can be enjoyed on a wide picture image area because the mask of black level is not generated.

Display driving method and apparatus with noise signal processing

A phase looped oscillating circuit includes a signal comparing device which can compare a plurality of different input signals with each other and emit a signal based on this comparison. The signal comparing device emits a control signal to a level converting device, a signal converting device is operatively connected to the level converting device. A signal from the converting device is received by an oscillating device and an oscillating signal is fed back to the signal comparing device via a divider. To compensate for fluctuation of an invertor in the signal converting device, the signal comparing device provides a fixed level signal stabilized at a 50% duty cycle. This stabilization also stabilizes electrical noises that may be present.

Growing community of inventors

Shijonawate, Japan

Katsuya Mizukata