Abstract: A semiconductor electronic circuit, which can generate high voltage pulses, includes a current source coupled to form a series circuit with a pair of impedances between first and second voltage source terminals. A driving source is connected with a control terminal of the current source. Output voltage-current characteristics of the driving source are such that its output current is almost 0, when the output voltage is in the proximity of 0 V and that it is not 0 for other voltages. Thus, the voltage at the control terminal of the current source is clamped at a predetermined voltage level determined by the circuit structure of the driving source, when the voltage at the output terminal is lower than the predetermined voltage.

Abstract: 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.

Abstract: A driving device for a matrix-type display panel using a guest-host type liquid crystal made by adding a pleochroic dye to a nematic-cholesteric phase transition liquid crystal or a chiralnematic phase transition liquid crystal is disclosed in which the display plane of a display panel is divided into a plurality of blocks in such a manner that each block includes a plurality of scanning lines, that is, a plurality of regions are formed, only one of the regions is selected to be used a scanning region, the one-line-at-a-time scanning operation is repeated many times in the scanning region in order to write and display information to perfection, and the regions are selected successively and cyclically to be used as the scanning region.