Fujitsu Corporation

Masafumi Itokazu

Hiroshi Murakami

Keizo Morita

Munehiro Haraguchi

Koji Yoshioka

Ken-ichi Nakabayashi

Akira Yamamoto

Kazuhiro Takahara

Masami Oda

Takayuki Hoshiya

Mitsuharu Nakazawa

Michiya Oura

Kenichi Nakabayashi

A capacitor electrode is formed simultaneously with drain bus lines. This capacitor electrode is electrically connected to the contact of two TFT's through the medium of a contact hole. Then, an interlayer insulating film is formed on the entire face and a black matrix of such light blocking metal film as Ti is formed on the interlayer insulating film so as to overlie the channel parts and the contacts of the TFT's and the capacitor electrode. The capacitor electrode, the interlayer insulating film formed thereon, and the black matrix jointly form a capacitor.

Liquid crystal display device and process for production thereof

A liquid-crystal display device includes a substrate with a pixel area including a plurality of scanning buses, a plurality of data buses intersecting therewith and pixel transistors and pixel electrodes formed at the intersections therebetween; a scanning driver for energizing these scanning buses; and a data driver for presenting these data buses with data signals. A checkout circuit equipped with a plurality of checkout transistors connected to the corresponding data buses or scanning buses; an input bus for applying prescribed checkout signals to the plurality of checkout transistors; and an output bus for picking up the signals from the plurality of checkout transistors.

Liquid-crystal display device having checkout circuit

An active-matrix LCD causes no cross-talk even if the capacitance between a given cell and adjacent data lines is large. The LCD has a liquid crystal panel which has data lines arranged in parallel with one another, scan lines arranged orthogonally to the data lines, and liquid crystal cells arranged at the intersections of the data and scan lines, respectively. Each of the cells has a cell electrode and a switching device that is arranged between and connected to the cell electrode and a corresponding one of the data lines. The conduction of the switching device is controlled in response to a scan pulse applied to a corresponding one of the scan lines. The LCD also has a data driver for applying data signals to the data lines, respectively, so that the data signals are written to corresponding ones of the cells, and a scan driver for applying the scan pulse sequentially to the scan lines. The data driver applies positive and negative signals that are opposite to each other with respect to a reference level, to each of the data lines within the period of the scan pulse, to zero an effective voltage applied to each data line. As a result, a voltage sustained by any cell to which data has been written is not affected by voltages successively applied to a data line to which the cell is connected and a data line to which the cell is capacitively connected.

Active-matrix liquid crystal display and method of driving same

Disclosed is a liquid-crystal display having the capability of a tablet which offers high image quality and a high response speed. An active matrix type liquid-crystal display having the capability of a tablet comprises: an active matrix type liquid-crystal display composed of a device substrate having a plurality of scan electrodes, a plurality of data electrodes, a plurality of pixel electrodes, and a plurality of switching devices, and an opposed substrate holding a liquid crystal in cooperation with the device substrate; a voltage detector that when brought into contact with a display surface of the liquid-crystal display, detects pulses, which are applied consecutively to the scan electrodes and data electrodes, through electrostatic coupling between the detector and the scan electrodes or between the detector and the data electrodes and that outputs a detected signal; and a position detector for detecting a contact position of the detector on the basis of the detected signal. Herein, the device substrate is situated on the side of the observer of the display. The positions of data electrodes lying in the vicinity of a stylus are detected during a data electrode position detection period defined as a period during which no pulses are applied to scan electrodes. Positions of scan electrodes lying in the vicinity of the stylus are identified by detecting display scanning pulses that are applied consecutively to a plurality of scan electrodes in order to cause the switching devices to conduct consecutively during a display data writing period.

Liquid-crystal display having the capability of a tablet

A driving circuit for a liquid-crystal display device, the driving circuit including a shift register for outputting n control signals driving n signal lines coupled to display elements of the liquid-crystal display device where n is an integer, the shift register having a plurality of stages cascaded. Each of the plurality of stages includes delay elements connected in parallel, each of the delay elements having a unit delay time, and a selector for selecting, in response to a select signal commonly supplied to the plurality of stages, at least one of output signals of the delay elements and for outputting the above at least one of the output signals as a corresponding one of the n control signals.

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Kawasaki, Japan

Masafumi Itokazu