Patents by Inventor Seiji Sawada
Seiji Sawada 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).
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Patent number: 5903514Abstract: In a multi-bank semiconductor memory device, if only one bank is in the active state, a bank drive signal generating circuit supplies, operation mode designation signals corresponding to an operation mode instruction signal supplied from a command decoder according to array activation signals from bank driving circuits provided corresponding to banks respectively, to the bank driving circuit provided for the bank in the active state. The state of the bank address signal is arbitrary. Accordingly, control of bank designation in the multi-bank semiconductor memory device is simplified.Type: GrantFiled: March 12, 1998Date of Patent: May 11, 1999Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Seiji Sawada
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Patent number: 5893925Abstract: A read control flip-flop circuit is activated upon activation of an internal readout instruction signal from a command decoder to generate a signal for activating an internal data reading circuit. A write control flip-flop circuit activates an internal data writing circuit in response to an internal write operation instruction signal from the command decoder. When one of the internal write instruction signal and the internal readout instruction signal from this command decoder is activated, a burst length counter counts a predetermined number of clock cycles, and when the counted value reaches a predetermined value, a reset signal is activated to reset the read control flip-flop circuit and the write control flip-flop circuit. Thus, the layout area of the control portion for internal data read operation and internal data write operation in a synchronous semiconductor memory device is reduced.Type: GrantFiled: December 17, 1996Date of Patent: April 13, 1999Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Seiji Sawada
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Patent number: 5818768Abstract: A correspondence defining circuit changes a correspondence between an external signal and an internal signal and supplies it to a mode designating signal generating circuit according to a logic state of an operation mode switching signal. The mode designating signal generating circuit activates a mode designating signal which designates a specific operation mode in a semiconductor device when the internal signal satisfies a prescribed condition. An operation mode setting circuit, applicable to applications in which states of external signals are different without a change of its internal structure, is thus provided.Type: GrantFiled: December 16, 1996Date of Patent: October 6, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Seiji Sawada, Yasuhiro Konishi
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Patent number: 5815462Abstract: A first clock signal for controlling the inputting of an external signal and for controlling internal operation and a second clock signal for controlling data output are applied to separate clock input nodes, respectively. Data output timing with respect to the first clock signal can be adjusted and thus clock access time and data hold time can be adjusted. Internal data read path is pipelined to include a first transfer gate responsive to the first clock signal for transferring internal read data and a second transfer gate responsive to the second clock signal for transferring the internal read data from the first transfer gate for external outputting through an output buffer. A synchronous semiconductor memory device is provided capable of setting clock access time and data hold time at the optimal values depending on the application and of reducing the clock access time.Type: GrantFiled: February 12, 1997Date of Patent: September 29, 1998Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric Engineering Co., Ltd.Inventors: Yasuhiro Konishi, Hisashi Iwamoto, Takashi Araki, Yasumitsu Murai, Seiji Sawada
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Patent number: 5814685Abstract: The present invention relates to an aqueous ink jet recording liquid of a pigment type, which liquid has excellent stability and printing characteristics; and also to a process for the preparation of said liquid. The ink jet recording liquid of the present invention is obtained by dispersing a pigment and a resin in an aqueous medium. Said resin is an aqueous dispersion-type resin comprising a shell composed of a polymer having a glass transition point in the range of 50.degree. C. to 150.degree. C. and a core composed of a polymer having a glass transition point in the range of -100.degree. C. to 40.degree. C.Type: GrantFiled: March 17, 1997Date of Patent: September 29, 1998Assignee: Toyo Ink Manufacturing Co., Ltd.Inventors: Sunao Satake, Seiji Sawada, Yasuharu Iida, Tsutomu Fujigamori
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Patent number: 5808961Abstract: An internal clock signal generation circuit includes a portion to generate an internal clock signal (intCLK) generated in synchronization with an external clock signal, a pulse width setting circuit which sets the pulse width of the internal clock signal depending the operation condition. By adjusting the pulse width of the internal clock signal to generate depending upon the operation condition, an internal clock signal having an optimum pulse may be readily generated. An internal clock signal having an optimum pulse width depending upon the operation condition may be generated accordingly, and internal data may be accurately transferred as a result.Type: GrantFiled: July 25, 1997Date of Patent: September 15, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Seiji Sawada
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Patent number: 5772746Abstract: The present invention relates to an ink jet recording liquid obtained by dispersing a pigment in an aqueous medium, said aqueous medium comprising glycerol and 1,3-propanediol. The ink jet recording liquid of the present invention is capable of sustaining prolonged stable discharge onto the recording surface without clogging the nozzle of an ink jet printer and exhibits excellent storage stability.Type: GrantFiled: March 31, 1997Date of Patent: June 30, 1998Assignee: Toyo Ink Manufacturing Co., Ltd.Inventors: Seiji Sawada, Sunao Satake, Yasuharu Iida, Seiji Aida, Yoshimitsu Ueno
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Patent number: 5748560Abstract: An internal read/write termination detect circuit generates a one shot pulse signal when a read operation activation signal and a write operation activation signal are both set to an inactive state. An internal operation activation signal generation circuit holds an auto precharge enable signal by a flipflop according to an auto precharge command to generate a precharge operation trigger signal according to the auto precharge enable signal and the one shot pulse signal. An internal operation activation signal is reset to an inactive state. The auto precharge command is made valid to carry out an internal precharge operation only when internal write/read operation is completed. A synchronous semiconductor memory device with easy control of an auto precharge command and reduced in layout area is provided.Type: GrantFiled: October 28, 1996Date of Patent: May 5, 1998Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Seiji Sawada
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Patent number: 5716435Abstract: A water-dispersed inkjet recording liquid excellent in water resistance and transparency and also excellent in the property of ejection from a nozzle, containing, as a colorant, a water-based dispersion of an organic pigment (A) having an average particle diameter of 10 to 150 nm (measured by laser scattering), the water-based dispersion of the organic pigment (A) being obtained by mechanically kneading a mixture containing at least three components, said components being, the organic pigment (A), a water-soluble inorganic salt (B) in an amount by weight at least three times as large as the amount of the organic pigment (A) and a water-soluble solvent (C) to finely mill the organic pigment (A), and then removing the water-soluble inorganic salt (B) and the water-soluble solvent (C) by washing the kneaded mixture with water, and a process for the production thereof.Type: GrantFiled: September 17, 1996Date of Patent: February 10, 1998Assignee: Toyo Ink Manufacturing Co., Ltd.Inventors: Seiji Aida, Tsutomu Fujigamori, Hisashi Uraki, Ichiro Toyoda, Sunao Satake, Seiji Sawada, Yasuharu Iida
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Patent number: 5703831Abstract: In a synchronous semiconductor memory device in which contents of an internal operation is designated by commands applied in synchronization with a clock signal, operations of decoding read, write and precharge commands different from an active command for activating the internal operation are enabled only when the active command is active. Even if a command such as read command other than the active command is applied during an inactive state of internal circuits, other command decoder cannot perform the decoding, so that unnecessary circuit operation can be prevented.Type: GrantFiled: December 16, 1996Date of Patent: December 30, 1997Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Seiji Sawada
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Patent number: 5691661Abstract: A pulse signal generating circuit includes a ring oscillator and an internal voltage generating circuit. The internal voltage generating circuit generates an internal voltage depending on an operation temperature. The internal voltage is low at a normal temperature, and is high at a high temperature. Each inverter in the ring oscillator is driven by the internal voltage supplied from the internal voltage generating circuit. Thereby, a period of a pulse signal increases at a normal temperature, and decreases at a high temperature.Type: GrantFiled: June 2, 1995Date of Patent: November 25, 1997Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Tatsuya Fukuda, Shigeru Mori, Masanori Hayashikoshi, Seiji Sawada
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Patent number: 5587950Abstract: In order to reduce a test time for a synchronous type memory device, a compression circuit compresses a plurality of memory cell data which are inputted in a plurality of read registers provided for a data output terminal to 1-bit data. A bank selection circuit selects an output of the compression circuit of either a bank #A or a bank #B. A tristate inverter buffer passes the 1-bit compression data selected by the bank selection circuit in accordance with a test mode command signal. The data output terminal outputs compressed data of a plurality of bits of memory cells. Thus, it is possible to simultaneously determine pass/fail of a plurality of memory cells, thereby reducing the test time.Type: GrantFiled: June 5, 1995Date of Patent: December 24, 1996Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Seiji Sawada, Yasuhiro Konishi
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Patent number: 5517462Abstract: In a synchronous semiconductor memory device, memory arrays (MA) forming activation units each are divided into a plurality of small memory arrays (MK). There are provided local I/O line pairs (LIO) each for two small memory arrays. The global I/O line pairs (GIO) crossing word lines are arranged in word line shunt regions (WS). The connection switches (BS) are arranged in the crossing between the local I/O line pairs and global I/O line pairs. Each small memory array in the activated memory array is connected to the corresponding global I/O line pair through the local I/O line pair. Thereby, a plurality of bits can be simultaneously read without increasing an area occupied by interconnections. The control of connection switch is made using a sense amplifier activation signal. Global I/O lines are precharged/equalized after data are transferred to read data registers provided for data output terminal for sequential data output or into selected memory cells.Type: GrantFiled: January 31, 1995Date of Patent: May 14, 1996Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric Engineering Co., Ltd.Inventors: Hisashi Iwamoto, Yasumitsu Murai, Yasuhiro Konishi, Naoya Watanabe, Seiji Sawada
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Patent number: 5511029Abstract: In order to reduce a test time for a synchronous type memory device, a compression circuit compresses a plurality of memory cell data which are inputted in a plurality of read registers provided for a data output terminal to 1-bit data. A bank selection circuit selects an output of the compression circuit of either a bank #A or a bank #B. A tristate inverter buffer passes the 1-bit compression data selected by the bank selection circuit in accordance with a test mode command signal. The data output terminal outputs compressed data of a plurality of bits of memory cells. Thus, it is possible to simultaneously determine pass/fail of a plurality of memory cells, thereby reducing the test time.Type: GrantFiled: May 19, 1994Date of Patent: April 23, 1996Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Seiji Sawada, Yasuhiro Konishi
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Patent number: 5471430Abstract: A synchronous semiconductor memory device includes an automatic refresh detection circuit for detecting that an automatic refresh mode is specified in accordance with an automatic refresh command, an address counter for generating a refresh address, a refresh execution unit for refreshing a memory array in accordance with an automatic refresh detection signal and the refresh address, an inactivation circuit for inactivating the refresh execution unit after a lapse of a prescribed time in accordance with the automatic refresh detection signal, a counter check mode detection circuit for bringing the inactivation circuit into an inoperable state in accordance with a counter check mode command, and a second inactivation circuit for inactivating the refresh execution unit in accordance with a precharge detection signal generated in response to a precharge command. Thus synchronous semiconductor memory device with an operation mode which can test the function of an internal refresh address counter is provided.Type: GrantFiled: May 19, 1994Date of Patent: November 28, 1995Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Seiji Sawada, Yasuhiro Konishi
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Patent number: 5465063Abstract: A pulse signal generating circuit includes a ring oscillator and an internal voltage generating circuit. The internal voltage generating circuit generates an internal voltage depending on an operation temperature. The internal voltage is low at a normal temperature, and is high at a high temperature. Each inverter in the ring oscillator is driven by the internal voltage supplied from the internal voltage generating circuit. Thereby, a period of a pulse signal increases at a normal temperature, and decreases at a high temperature.Type: GrantFiled: April 21, 1993Date of Patent: November 7, 1995Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Tatsuya Fukuda, Shigeru Mori, Masanori Hayashikoshi, Seiji Sawada
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Patent number: 5404338Abstract: In a synchronous semiconductor memory device, memory arrays (MA) forming activation units each are divided into a plurality of small memory arrays (MK). There are provided local I/O line pairs (LIO) each for two small memory arrays. The global I/O line pairs (GIO) crossing word lines are arranged in word line shunt regions (WS). The connection switches (BS) are arranged in the crossing between the local I/O line pairs and global I/O line pairs. Each small memory array in the activated memory array is connected to the corresponding global I/O line pair through the local I/O line pair. Thereby, a plurality of bits can be simultaneously read without increasing an area occupied by interconnections. The control of connection switch is made using a sense amplifier activation signal. Global I/O lines are precharged/equalized after data are transferred to read data registers provided for data output terminal for sequential data output or into selected memory cells.Type: GrantFiled: January 31, 1994Date of Patent: April 4, 1995Assignees: Mitsubishi Denki Kabushiki Kaisha, Mitsubishi Electric Engineering Co., Ltd.Inventors: Yasumitsu Murai, Hisashi Iwamoto, Yasuhiro Konishi, Naoya Watanabe, Seiji Sawada
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Patent number: 5365481Abstract: A semiconductor memory device according to the present invention includes a memory cell array, internal circuits for reading and writing of data of the memory cell array, a test mode controller, and power-on-reset circuits. The test mode controller sets a test mode of the memory cell array in response to a predetermined pattern of change of logic levels of at least several control signals out of a plurality of control signals for controlling the internal circuits. The power-on-reset circuits set the test mode controller in an initial state over a variable period which is defined based on a timing of change of a logic level of a control signal determining a timing of setting of the test mode out of the at least several control signals, in response to power-on. As a result, it is possible to prevent the semiconductor memory device from erroneously entering the test mode caused by a noise or the like after power-on.Type: GrantFiled: July 9, 1993Date of Patent: November 15, 1994Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Seiji Sawada