Hitachi, Ltd.

Hitachi Vlsi Engineering Corp.

Kunio Ono

Kazumasa Yanagisawa

Katsuyuki Sato

Yasuyuki Kojima

Masanobu Hanazono

Kiyohiko Tanno

Osamu Asai

Tetsuo Doi

Yoichi Shiraishi

Junya Sakemi

Ichiro Naka

A dynamic RAM, in which the difference between a data signal level from one of a pair of complementary data lines coupled to a memory cell and a reference potential level of the other of the complementary data lines is differentially amplified by a sense amplifier. The data line taking the reference potential level is coupled to the other data line through a switch element so that its data line capacitance is increased. As a result, the reference potential level is held at a relatively stable level irrespective of a leakage current such as that caused by .alpha. particles. This construction makes it possible to use a full-size dummy cell because the capacitance of the data lines which takes the reference potential level is increased. The reference potential level achieved by the use of the full-size dummy cell is made relatively accurate because of the relative accuracy between the capacitances of the memory cells and the capacitance of the full-size dummy cell.

Dynamic RAM having a full size dummy cell

Interconnections interconnecting terminals to be connected by routings are dissolved into two-terminal interconnections and it is determined to which kind of terminals the terminals of each two-terminal interconnection belong, among connected diffusion layer, separated diffusion layer and gate. The interconnections are classified into groups by the combination of the kind of two terminals for each interconnection. The respective groups of interconnections are routed in the channel on the field effect transistor row according to a predetermined order of groups.

Routing among field effect transistors

A thermal recording apparatus for recording an information signal on the heat-sensitive recording medium in a form of visible information comprises a plurality of heat-generating resistance elements, a drive circuit for supplying selectively drive current to said heat-generating resistance elements in response to the information signal, a recording medium disposed in contact with the plurality of heat-generating resistance elements and adapted to change color upon sensing heat, means for driving the plurality of heat-generating resistance elements and the recording medium relative to each other, and a switching circuit means for inverting the direction of the drive current applied to the heat-generating resistance elements in a predetermined manner.

Thermal recording apparatus

A narrow track width magnetic head can be formed using an integrated circuit formation techniques such as evaporation plating, chemical etching, etc. But, there has been such a problem that it is difficult to provide a center tap in a conventional thin film magnetic head structure including coils of four or more turns. A magnetic head according to the present invention comprising a coil divided into two sections by the center tap, the electrostatic capacitance of each section being substantially the same. The coil may be formed into a precise pattern with ease by photoetching technique. A plurality of sets of conductive films insulated from one another are provided crossing a magnetic core, each set consisting of two conductive films of the same pattern. The alternating layers of the conductive films are connected on the backward of a magnetic gap to provide the two sections of the coil. A center tap is derived from a connection portion of the two sections of the coil and a coil terminal is provided at each of the opposite free ends of the coil. Thus, the thin film magnetic head having a multi-turn coil with a center tap is provided.

Thin film magnetic head with a center tap

Growing community of inventors

Ome, Japan

Kunio Ono