Sharp Kabushiki Kaisha Corporation

Norio Yasunishi

Koki Taniguchi

Kiyohisa Matsui

Futoshi Satoh

Yutaka Ishii

Hajime Washio

Kunihiko Yamamoto

Toshihiro Nakamura

Satoshi Ueno

Hiroyuki Furukawa

Toshihiro Ohba

Hiromasa Asada

A digital video signal transmission apparatus is provided with (a) a digital video signal conversion circuit for converting each chrominance signal of an input digital video signal in such a manner that every plural frames (1) in one frame of the plural frames each chrominance signal is converted into a signal having plural bits, (2) in the other frames of the plural frames, each chrominance signal is converted into a signal having 1 bit, so that an average of gradation levels of the respective chrominance signals in plural frames after the conversion is substantially equal to gradation levels of the respective chrominance signals in a single frame before conversion, (b) a flag signal generation circuit for generating a flag signal for setting the respective chrominance signals in each pixel signal, so that one of the chrominance signal has plural bits, while the other chrominance signal has one bit, (c) a converted data combination circuit for assigning each signal to each of the chrominance signal in accordance with the flag signal, and (d) a bit expansion circuit for carrying out bit expansion of the digital video signal in accordance with the flag signal, so that each chrominance signal has an identical number of bits in each pixel signal. This provides an image display apparatus that can reduce a data amount of the digital video signal which is transmitted via a data transmission path.

Digital video signal transmission apparatus and image display apparatus

A method for driving a liquid crystal display device including a plurality of row electrodes intersecting a plurality of column electrodes, a scanning voltage applied to each of the row electrodes, and a signal voltage applied to each of the column electrodes, the method comprising the steps of: a) determining, for each of the column electrodes, correction data for correcting the signal voltage based on an increment or a decrement of an effective voltage value between each of row electrodes and each of the column electrodes; and b) applying a correction voltage for correcting the signal voltage to each of the column electrodes in accordance with the correction data. An increment or decrement of the effective voltage value may be due to i) at least either a blunt waveform or induced distortion of the signal voltage or ii) at least either a blunt waveform or induced distortion of the scanning voltage, or iii) both.

Liquid crystal display device and method for driving the same

A control circuit for use in a display device capable of displaying gray scale including a plurality of column electrodes and a plurality of row electrodes intersecting each other and pixels provided around the intersections thereof, includes a display data converting section for receiving input display data, dividing the input display data into binary display data and gray scale display data in such a manner as to enable pulse width modulation one frame in a plurality of frames, and outputting the binary display data and the gray scale display data: a pulse controlling section for determining the timing of applying a voltage to each of the plurality of column electrodes for the gray scale display data; and a column electrode driving section for applying a voltage corresponding to the gray scale display data to at least one said column electrode based on the timing of applying a voltage determined by the pulse controlling section.

Control circuit and control method for display device

A method for driving a liquid crystal display device is provided. The device includes a plurality of row electrodes to which a scanning signal is applied: a plurality of column electrodes disposed so as to cross the plurality of row electrodes, to which a display data signal is applied; and a liquid crystal layer interposed between one of the plurality of row electrodes and one of the plurality of column electrodes, for performing a display at a crossing portion of one of the plurality of row electrodes and one of the plurality of column electrodes in response to an effective value of a voltage applied across one of the plurality of row electrodes and one of the plurality of column electrodes, wherein gray-scale display data consisting of a plurality of bits is received, and a voltage of a display data signal selected per bit by a scanning signal is applied during a period in which weights are assigned to bits during one horizontal scanning period and a voltage applying timing is made different at at least one column electrode, whereby a gray-scale display is realized.

A liquid crystal display device having a plurality of row electrodes to which a scanning voltage is applied; a plurality of column electrodes provided so as to cross the plurality of row electrodes, to which a display data voltage is applied; and a liquid crystal layer interposed between the plurality of row electrodes and the plurality of column electrodes, which provides a display function at intersections between the plurality of row electrodes and the plurality of column electrodes in response to a RMS value of a voltage applied between the plurality of row electrodes and the plurality of column electrodes, includes: a section for outputting a display data signal representing the display data voltage having three or more voltage levels; a compensation circuit for outputting a compensation data signal based on a RMS value difference between the display data voltage and a respective resultant display data voltage applied to the plurality of column electrodes; and a driving circuit for applying a compensation voltage to at least one of the plurality of column electrodes based on the compensation data signal.

Liquid crystal display device

A liquid crystal display device including a liquid crystal panel is disclosed. The liquid crystal display device includes: a display data transformer for receiving input image data for one frame, for dividing a selection period for each row electrode in the frame into subframes of a number equal to or greater than a number of gray-scale bits representing a gray-scale level of the input image data, the scanning signal being applied to the row electrode during the corresponding selection period, and for generating binary display data in which respective binary data is associated with each subframe according to the gray-scale bits. The Liquid crystal display device further includes a pulse width controller for controlling the division of the selection period in the display data transformer and for setting a respective subframe period independently for each subframe; and a pulse amplitude controller for transforming the binary display data by setting a respective voltage amplitude independently for each subframe according to the binary display data so as to generate a display signal having a respective voltage value set independently for each subframe.

A driving method for a liquid crystal display is provided with the steps of (a) applying a row select voltage to each of the row electrodes simultaneously, the row select voltage corresponding to an element of an orthogonal matrix and being either +1 or -1 ; (b) conducting an exclusive-or operation with respect to each element of a row select vector and a display vector, the row select vector indicating the row select voltages by vector notation and the display vector indicating a display data by the vector notation, and conducting a summation of each exclusive-or operation; (c) applying to the column electrode a voltage of a level which varies depending on the summation so as to simultaneously drive the plurality of rows; and (d) in a case where all the display data correspond to ON display or OFF display in the step (c), assigning the row select voltage, applied to either the selected row electrode having the lowest select voltage among driving voltages within one frame period for the ON display or the selected row electrode having the highest select voltage among the driving voltages within one frame period for the OFF display, to a virtual row electrode outside a display area, and applying a virtual display data to the virtual row electrode.

Driving method for a liquid crystal display

A driving device for a display apparatus having excellent contrast and a high display quality without crosstalk and display irregularities, and a driving method for the same are provided. In the driving device, scanning signals and data signals having a plurality of periodical inactive portions in one frame are applied to respective display dots. In the inactive term, a fixed voltage is applied to each of the display dots. The signal applied to the display dot is divided into small terms by the inactive portions, resulting in more high frequency components in a voltage signal applied to the display dot. As a result, the frequency components of a driving signal applied to the display dot are averaged. Further, a complete orthogonal function having 2.sup.r base function series is used, and a desired display data is completely reproduced on the display apparatus by an arithmetic process assuming auxiliary data in accordance with the number of the scanning electrodes.

Growing community of inventors

Kitakatsuragi-gun, Japan

Norio Yasunishi