Patents by Inventor Jun Etoh

Jun Etoh has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4992985
    Abstract: An address multiplexed dynamic RAM device is provided which is capable of initiating (setting) and terminating (resetting) the test mode in response to the signal level combinations of the row address and column address strobe signals with the write enable signal, which signal level combinations correspond to those which are otherwise left unused in the normal operating mode thereby obviating the requirement of an additional external control signal terminal. Such initiating of the test mode can be effected by setting the RAS signal of the DRAM at a logic "low" level when the CAS signal and the WE signal are at a logic "low" level. Clearing or resetting thereof is effected by the same combination sequence, except that the WE signal is at a logic "high" level. The setting or initiating of a test mode is also implemented by the additional combination of one of the row address signal bits, e.g. the most significant bit.
    Type: Grant
    Filed: March 7, 1989
    Date of Patent: February 12, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Kazuyuki Miyazawa, Katsuhiro Shimohigashi, Jun Etoh, Katsutaka Kimura
  • Patent number: 4965769
    Abstract: A semiconductor memory having a plurality of word lines, and a plurality of data lines arranged to intersect the word lines. Memory cells are arranged at nodes of the word lines and the data lines. Each of the memory cells has a field effect transistor and a capacitor. A word line multiple selection circuit is provided for selecting a plurality of the word lines. The multiple selection circuit simultaneously accesses all of the memory cells by selecting all the word lines of a memory array when a semiconductor memory is in a clear mode. In the clear mode a detector selects data lines of the memory array. A plate voltage control circuit controls a voltage at one plate of each of the capacitors in the memory cells. The plate control circuit changes a voltage at the plate to a preselected clear mode voltage when a semiconductor memory is in a clear mode. It is a feature of the invention that preselected data is written in the memory cells by data communication through the data lines during the clear mode.
    Type: Grant
    Filed: November 30, 1988
    Date of Patent: October 23, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Jun Etoh, Kiyoo Itoh, Masakazu Aoki, Ryoichi Hori
  • Patent number: 4873672
    Abstract: This invention relates to a semiconductor memory having a high speed operation and a high integration density. When a high integration semiconductor memory is applied to a large scale computer system, storage data must be erased at a high speed for data security. The present invention erases the storage data by a method which is different from the write method of conventional prior art. In the invention, the erasing operation is made by continuously selecting word lines while sense amplifiers are kept in this on-state. The present invention includes a control circuit for attaining such an operation, and can be used for a semiconductor memory implemented in a computer system accessed by a plurality of users.
    Type: Grant
    Filed: May 20, 1987
    Date of Patent: October 10, 1989
    Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.
    Inventors: Jun Etoh, Katsuhiro Shimohigashi, Kazuyuki Miyazawa, Katsutaka Kimura, Takesada Akiba
  • Patent number: 4811299
    Abstract: Disclosed is a dynamic RAM device capable of initiating and cancelling the test mode in response to the combinations of the row address and column address strobe signals with the write enable signal, which combinations are left unused in the normal operating mode, instead of increasing the number of external control signals.
    Type: Grant
    Filed: April 22, 1987
    Date of Patent: March 7, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Kazuyuki Miyazawa, Katsuhiro Shimohigashi, Jun Etoh, Katsutaka Kimura
  • Patent number: 4796234
    Abstract: It is contemplated to realize a semiconductor memory with a large memory capacity, high in integration and low in power dissipation. A semiconductor memory is disclosed, comprising a plurality of blocks each having a memory cell array and sense amplifier(s) to differentially amplify signals read out from the array, wherein a common driving line of amplifiers composed of N-channel MOS transistors among said sense amplifiers and a common driving line of amplifiers composed of P-channel MOS transistors among the sense amplifers are connected between different blocks.
    Type: Grant
    Filed: November 5, 1986
    Date of Patent: January 3, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Kiyoo Itoh, Yoshiki Kawajiri, Katsutaka Kimura, Ryoichi Hori, Jun Etoh
  • Patent number: 4716313
    Abstract: In order to drive a capacitance load at a high speed without an undesirably large increase in the circuit size, a driving arrangement is provided to charge the capacitance load in accordance with a limited voltage. A voltage limiter is coupled to a supply voltage providing a predetermined limited voltage. A pulse generator is coupled to receive the limited voltage and to provide output pulses which are, in turn, limited in accordance with the output voltage of the voltage limiter. A driver is coupled between the supply voltage and the capacitance load, and is controlled by the output pulses of the pulse generator. In this way, the capacitance load is charged through the driver in accordance with the limited voltage. Since the voltage limiter is not arranged along a series connection between the driver and the capacitance load, the internal equivalent resistance of the voltage limiter does not detrimentally influence the resistance along the series connection.
    Type: Grant
    Filed: June 3, 1987
    Date of Patent: December 29, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Ryoichi Hori, Kiyoo Itoh, Jun Etoh
  • Patent number: 4635146
    Abstract: An automatic tape loading type recording and/or reproducing apparatus comprises a mechanism for loading a tape in a predetermined path in which the tape makes contact with a guide drum by intercepting and drawing the tape out of the tape cassette, a mechanism for moving the tape in the predetermined path in forward and reverse directions depending on a mode of the apparatus, a tension control mechanism for controlling a tension in the tape and comprising a tension arm and a braking member which acts on a supply reel disc, a cam mechanism for operating a braking system which is provided with respect to supply and take-up reel discs and comprising a cam body which rotates in response to the mode of the apparatus, a cam controlling mechanism responsive to a reverse reproduction mode of the apparatus, for rotating the cam body to a predetermined rotational position which is different from a rotational position of the cam body during a normal recording or reproducing mode of the apparatus, and a mechanism operated
    Type: Grant
    Filed: March 20, 1984
    Date of Patent: January 6, 1987
    Assignee: Victor Company of Japan, Ltd.
    Inventors: Kazuo Koda, Jun Etoh
  • Patent number: 4503522
    Abstract: A dynamic type semiconductor memory using MOS transistors, in which first and second booster circuits utilizing capacitances, respectively, are provided at each of stages preceding and succeeding to a word driver, respectively. Data lines of the memory are each provided with a voltage compensating circuit for increasing a voltage for charging a memory cell to a level higher than a source voltage for being rewritten in the memory cell. A first boosting circuit is operated after a word line driving pulse signal is produced. Subsequently, word driver selecting transistors are turned off, which is followed by operation of the second booster circuit. Thus, the word line voltage is boosted twice.
    Type: Grant
    Filed: March 16, 1982
    Date of Patent: March 5, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Jun Etoh, Yoshiki Kawajiri, Ryoichi Hori, Kiyoo Itoh
  • Patent number: 4475181
    Abstract: A semiconductor memory of multiplexed address inputs is made operative to receive column addresses and row addresses through common external address lines and to decode them consecutively in response to first and second strobe signals thereby to select one of memory cells. The semiconductor memory is equipped with address buffers exclusively for column and row addressing operations, respectively, the outputs of which are consecutively transmitted to column decoders and row decoders through common internal address lines.
    Type: Grant
    Filed: January 5, 1982
    Date of Patent: October 2, 1984
    Assignee: Hitachi, Ltd.
    Inventors: Jun Etoh, Ryoichi Hori, Yoshiki Kawajiri, Kiyoo Itoh
  • Patent number: 4086642
    Abstract: A protective circuit comprises a metal-oxide-semiconductor field effect transistor (MOSFET) to be protected, and a depletion-type MOSFET the gate and source of which are connected to each other and the souce of which is connected to the gate of the MOSFET to be protected, whereby the protective circuit which is suitable for a high-speed operation is completed.
    Type: Grant
    Filed: January 13, 1976
    Date of Patent: April 25, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Isao Yoshida, Ryoichi Hori, Hiroo Masuda, Osamu Minato, Jun Etoh, Masaaki Nakai
  • Patent number: 4021835
    Abstract: A MOS-FET (Metal-Oxide-Semiconductor Field Effect Transistor) comprises a semiconductor body, source and drain regions disposed in the body at portions separated from each other, a second semiconductor region having a higher impurity concentration than that of the body, formed by ion implantation in the body between the source and drain regions, a first semiconductor region having a lower impurity concentration than that of the second semiconductor region but a higher impurity concentration than that of the body, and having an opposite conductivity type to that of the second semiconductor region, formed by ion implantation, so that the second semiconductor region is very thin, and which has a very small amount of a minute current, that is a tailing current.
    Type: Grant
    Filed: January 27, 1975
    Date of Patent: May 3, 1977
    Assignee: Hitachi, Ltd.
    Inventors: Jun Etoh, Toshiaki Masuhara