Sharp Kabushiki Kaisha Corporation

Hiroshi Yoneda

Yasushi Kubota

Kenichi Katoh

Shigeto Yoshida

Ichiro Shiraki

Yutaka Ishii

Hajime Washio

Nobuhiro Kuwabara

Tamotsu Sakai

Makoto Kanbe

Yasuhisa Itoh

Osamu Sasaki

Manabu Matsuura

Kazuhiro Maeda

Yoshitaka Yamamoto

Akihito Jinda

Shinji Shimada

Takao Tagawa

Yasukuni Yamane

Minehiro Konya

Masahiro Fujiwara

Hiroshi Tsujioka

Yuji Asoh

An erasing device for a liquid crystal display image of the present invention is furnished with an auxiliary power source for continuously supplying power source to a liquid crystal display panel for a certain period after the main power source of the main body of the liquid crystal display device is turned OFF. Upon input of a power source OFF signal directing to turn OFF the main power source, a driving signal generating circuit and a driver controller light up the liquid crystal display panel entirely on a saturation voltage of the liquid crystal and subsequently shut off the same entirely using the power supply from the auxiliary power source. Consequently, it has become possible to erase an afterimage quickly on an active matrix liquid crystal display panel with a memory maintaining function of a liquid crystal display device, thereby not only upgrading the display quality, but also preventing deterioration of the liquid crystal caused by an application of an abnormal voltage associated with the occurrence of an afterimage.

Erasing device for liquid crystal display image and liquid crystal display device including the same

A shift register circuit includes a plurality of latch circuits connected in series to sequentially transfer a pulse signal ST from one to another, a clock signal line transmitting a clock signal CLK, and a plurality of switching circuits performing electrical connection and disconnection between the clock signal line and the plurality of latch circuits. Upon turning on the shift register, at least one of the switching circuits electrically disconnects at least one of the latch circuits from the clock signal line. During an initialization period immediately after power has been turned on, the frequency of the clock signal CLK is lower than in a normal operation period and gradually increases toward the frequency used in the normal operation period.

Shift register circuit, image display apparatus having the circuit, and driving method for LCD devices

In a vertical retrace interval, a pre-charge potential or a signal potential is applied to each polarity for AC driving liquid crystal at least once each, so as to maintain fluctuations in pixel potential between the positive polarity side and the negative polarity side uniform, and minimum required potentials are supplied to the data signal line, thereby suppressing decrease in image quality without significantly increasing power consumption.

Image display device and driving method of the same

An image display device of this invention includes a pre-charging voltage stabilizing section having current controlling means and charge holding means which respectively include a resistor and a capacitor to stabilize a pre-charging voltage. The charge holding means holds a voltage to be supplied to data signal lines, and the current controlling means suppresses a current flow from a control signal generating circuit, thereby suppressing power fluctuation at the control signal generating circuit. This suppresses fluctuation in the pre-charging voltage and enables data signal lines to be charged to a predetermined voltage, thereby suppressing deterioration of image quality and an increase in power consumption of the image display device. Further, when using the pre-charging voltage stabilizing section and setting a portion of a display as a video data non-display area avoiding display of video data in a non-match image display mode to display at fixed brightness in the video data non-display area by a pre-charging voltage from a pre-charging circuit, a control signal is suspended in a fixed period, thus realizing a non-match image display mode to display a video image of an aspect ratio different from that of a screen of a display without impairing an image quality, and saving power.

Image display device and driving method thereof

A driving method for an active-matrix-type image display in which: in the case when the number of divisions of a video signal decreases in accordance with the scanning frequency of an original video signal, eight video signal lines through are divided into groups the number of which corresponds the reduced number of divisions so that the same video signal is inputted to the video signal lines belonging to the same group; and four systems of shift registers SRA through SRD are also divided into groups, SRA, SRB, SRC and SRD so that the same shift clock signal is inputted to the same group. With this method, even upon application of the device to a usage having a different scanning frequency, the construction of the external circuits are optimized so as to fit the different scanning frequency, and the shared use of the substrate is available so that cost reduction is achieved.

Active-matrix-type image display and a driving method thereof

A delay detecting section detects the phase difference between a first detection signal as a reference and a second detection signal produced by delaying the first detection signal with part of a data signal line driving circuit itself or part of a circuit formed by the same process as the data signal line driving circuit. A phase adjusting section presumes an internal delay of the data signal line driving circuit, and adjusts the phase difference between a clock signal and start signal, and a video signal so that the data signal line driving circuit samples the video signal at an appropriate timing. These structures prevent a lowering of the image quality due to a difference in the timings of the video signal and sampling signal, and provide an image display device capable of displaying a good-quality image with a simple circuit structure.

Image display device

The image display apparatus of the present invention including a display device having a plurality of pixels arranged in a matrix and driven by a field sequential scanning system, includes: a display driving circuit for supplying a display signal to each of the pixels; a scanning circuit for supplying a scanning signal to each of the pixels, the scanning circuit allowing the pixel to receive a charge corresponding to the display signal during a predetermined write time; and a write time modulation circuit for modulating the write time of the pixel according to the progress of the scanning by the scanning circuit.

Image display apparatus and a method for driving the same

Erasing device for liquid crystal display image and liquid crystal

A voltage output circuit has decoders, a selecting circuit, a logical circuit and an output circuit in order to select one of plural gradation power source lines for a prescribed period based upon k bits and m bits of an n-bit digital signal. The k bits of the digital signal are converting into 2.sup.k decoded signals by one decoder, and another m bits are converted into 2.sup.m decoded signals by the other decoder. The selecting circuit generates a signal for selecting one of periods which were obtained by dividing one horizontal scanning period into 2.sup.k based upon k-numbered timing signals by using the 2.sup.k decoded signals. The logical circuit generates 2.sup.n signals composed of combinations of the signals from the selecting circuit and the 2.sup.m decoded signals. Moreover, one of the 2.sup.m gradation power source lines is selected by an output switch by using the signal from the logical circuit. As a result, in an image display device using a digital signal as an input video signal, a number of gradation power source lines is reduced and the arrangement of driving circuits is simplified without deteriorating display quality. As a result, a cost of the image display device can be lowered.

Voltage output circuit and image display device

An active-matrix image display device which includes n shift registers, analog switches for sampling video input signals and a data-signal-line driving circuit to which n series of clock signals and n.times.m series of video input signals are input, and controls the analog switches according to the result of a logic operation of output pulses from successive l stages in the shift registers. A scanning circuit without using shift registers. Here, n is an integer not smaller than one, m and l are integers not smaller than two. With the image display device, sampling of video signals is surely executed without increasing the number of shift registers. It is thus possible to reduce the size and weight of the image display device and to decrease the defect rate thereof. Moreover, the scanning circuit achieves a higher yield compared with a conventional scanning circuit using a shift register.

Image display scanning circuit with outputs from sequentially switched

An image display device includes an operational amplifier, a signal amplifier provided with a condenser for setting a gain of the operational amplifier, a signal amplifier circuit having such signal amplifier or a buffer amplifier, the signal amplifier circuit being provided with an offset adjusting function, and a data signal line drive circuit having a signal amplifier or a signal line drive circuit. The described arrangement enables the gain of the signal amplifier to be set by a capacitance of the condenser, thereby providing a signal amplifier circuit which permits the gain to be set much more precisely as compared to the conventional signal amplifier circuits even when adopting a signal amplifier formed on a semiconductor thin film such as a polycrystalline silicone thin film. The arrangement also provides a signal amplifier circuit which permits a voltage in the same level as a voltage of the input signal to be outputted. Furthermore, the arrangement provides high quality data signal line drive circuit and the image display device.

Signal amplifier, signal amplifier circuit, signal line drive circuit

An image-displaying apparatus that is provided with a display section which is constituted of a plurality of pixels disposed in the form of a matrix and which is capable of displaying images that are different depending on viewing angles from which they are viewed. This arrangement makes it possible to select desired images by changing the viewing angles from which the display section is viewed. This eliminates the necessity of having to wear conventional glasses with a shutter and their inherent inconveniences. Further, this apparatus is suitable for public use as well as for private use, even when only one apparatus is used.

Two-dimensional image display device and driving circuit

An active matrix type image display apparatus which includes: a plurality of data signal lines; a plurality of scanning signal lines crossing the plurality of data signal lines; and a plurality of pixel portions disposed in a matrix in areas enclosed by the plurality of data signal lines and the plurality of scanning signal lines, wherein each of the plurality of pixel portions includes: a pixel capacitor for storing electric charge supplied from at least one of the plurality of data signal lines, to display an image; storage unit connected to the pixel capacitor; and switching unit which alternately selects one of an operation for electrically connecting the pixel capacitor to the storage unit and an operation for electrically disconnecting the pixel capacitor from the storage unit.

Growing community of inventors

Ikoma, Japan

Hiroshi Yoneda