Hitachi, Ltd.

Masaaki Kitazima

Hideaki Kawakami

Yoshiharu Nagae

Jun-ichi Ohwada

Katsumi Kondo

Kenkichi Suzuki

Masayoshi Suzuki

Sakae Someya

Masahiro Eto

Hiroshi Jitsukata

Yutaka Yoneda

Naoyuki Izaki

A testing method is provided for a semiconductor device which includes a control terminal and a pair of main terminals wherein one of the main terminals is isolated from the outside by a dielectric. First, a voltage which changes with time is applied to the isolated main terminal through the dielectric. A control signal which controls conduction and non-conduction of the semiconductor device is the applied to the control terminal. Following this, the test is made by detecting a displacement current flowing through at least one of the two main terminals and the control terminal.

Method for testing an on-off function of semiconductor devices which

A display device suitable for a high speed operation liquid crystal display device includes a matrix circuit having a plurality of signal lines, scanning lines disposed so as to intersect the signal lines and pixels provided at the positions corresponding to the intersections of the signal lines and the scanning lines; and a switching circuit for incorporating picture signals provided in correspondance to the signal lines, wherein the adjacent switching circuits are both turned on simultaneously.

Display device and its displaying method

A liquid crystal matrix driving method capable of shortening the re-write time of a picture surfaces is disclosed. In accordance with this method, pixels are brought to the light ON state or OFF state by changing in advance the light transmission state by utilizing the bistability of the display of the ferroelectric liquid crystal, a voltage keeping the light ON state or an OFF voltage is then applied to the pixels when they are already in the ON state in accordance with a time-division driving method such as line sequence scanning driving or dot sequence scanning driving, and a voltage keeping the OFF state or an ON voltage is applied when the pixels are already in the OFF state.

Ferroelectric liquid crystal matrix driving apparatus and method

A display device consisting of a plurality of scanning electrodes, a plurality of signal electrodes, a driving circuit feeding these electrodes with a scanning voltage and a signal voltage applied thereto, display elements having a pair of electrodes opposite to each other, which are disposed on the intersecting portion of the signal electrodes with the scanning electrodes, and switching elements controlling the feeding of one of the electrodes with the signal voltage, depending on the scanning voltage, comprises further a delaying circuit, which retards the timing of applying the signal voltage applied to a part of the signal electrodes, which are distant from the input terminal of the scanning voltage, with respect to the timing of applying the scanning voltage applied to the scanning electrodes.

Display device comprising a delaying circuit to retard signal voltage

An information holding device comprises a pair of substrates having a first electrode and a second electrode oppositely formed on opposing surfaces thereof, and a dielectric material held between the pair of substrates. A capacitance of the dielectric material between the first and second electrodes is changed and a voltage varying with time is applied to the dielectric. A displacement current flowing through the dielectric is then detected.

Information holding device

A matrix display comprises: a plurality of picture cells generally arranged in a matrix, the picture cells being defined by a plurality of first electrodes arranged on a first substrate and at least one common electrode arranged on a second substrate and a display medium held therebetween; a plurality of first signal lines and a plurality of second signal lines crossing to the first signal lines, arranged on at least one of the first and second substrates; a plurality of first semiconductor switches each having a control terminal, a first main terminal and a second main terminal, a plurality of second semiconductor switches each having a control terminal, a first main terminal and a second main terminal, and a plurality of storage means, arranged at respective crosspoints of the first signal lines and the second signal lines; each of the first signal lines being connected to the control terminal of the associated one of the first semiconductor switches and the first main terminal of the associated one of the second semiconductor switches; each of the second signal lines being connected to the first main terminal of the associated one of the first semiconductor switches; each of the second main terminals of the first semiconductor switches being connected to the associated one of the storage means and the control terminal of the associated one of the second semiconductor switches; and each of the second main terminals of the second semiconductor switches being connected to the associated one of the first electrodes.

Matrix display and driving method therefor

Disclosed is a method of driving a matrix type display panel which includes a phase transition liquid crystal layer sandwiched between a pair of electrode groups arranged in the form of a matrix and including at least one transparent electrode group, and employs intersecting portions of said electrode groups as display segments for displaying information by driving one electrode group with the one-line-at-a-time scanning system; wherein a write-in voltage signal having a sufficient root mean square value for the phase transition of the liquid crystal layer and an erasing voltage substantially equal to OV are employed to drive the panel, and segments just subjected to scanning are applied with the write-in voltage signal when information is written in the segments and are applied with the erasing voltage when information written in the segments is erased.

Method of driving a matrix type phase transition liquid crystal display

A liquid crystal display device in which an electronic switch having a double threshold characteristic is combined with each of a plurality of liquid crystal cells, and an ac signal voltage and an ac bias voltage are applied to one and the other terminals respectively of the combined circuit of the liquid crystal cells and electronic switches. In the device, the electronic switches are turned on or off depending on the relation between the phase of the signal voltage and that of the bias voltage so that the liquid crystal cells can be excited for display by the voltage applied thereacross in response to the turn-on of the electronic switches.

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Hitachiohta, Japan

Masaaki Kitazima