Patents by Inventor Takayuki Kawahara
Takayuki Kawahara 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: 6026014Abstract: In a nonvolatile semiconductor memory in which multiple-value information is stored in one memory cell by setting a plurality of threshold values, data is successively read from word lines while continuously changing the word-line read level from a lowest level to a highest level, and the next bit line is selectively precharged in accordance with the data stored in latch means for storing read data.Type: GrantFiled: December 19, 1997Date of Patent: February 15, 2000Assignees: Hitachi, Ltd., Hitachi ULSI Engineering Corp., Hitachi Device Engineering Co., Ltd.Inventors: Hiroshi Sato, Shoji Kubono, Toshinori Harada, Takayuki Kawahara, Naoki Miyamoto
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Patent number: 5982667Abstract: To enable one non-volatile memory cell to store four-value information, three different kinds of threshold voltages are serially applied to a word line in a verify operation to execute a write operation, the threshold voltages of the memory cell are controlled, and two-value (one-bit) information corresponding to the four-value (two-bit) information to be written are synthesized by a write data conversion circuit for each of the write operations carried out three times. In this way, the four-value (two-bit) information are written into one memory cell, and the memory capacity of the memory cell can be increased. In the information read operation, three different kinds of voltages are applied to a word line, three kinds of two-value (one-bit) information so read out are synthesized by a read conversion circuit and the memory information of the memory cell are converted to the two-bit information.Type: GrantFiled: June 11, 1998Date of Patent: November 9, 1999Assignee: Hitachi, Ltd.Inventors: Yusuke Jyouno, Takayuki Kawahara, Katsutaka Kimura
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Patent number: 5910911Abstract: Disclosed is a semiconductor memory having memory cells, each containing a selection transistor and a capacitor using a ferroelectric film, which memory can be operated in both volatile and nonvolatile modes (e.g., a shadow RAM). A common plate electrode is used for the capacitors of the plurality of memory cells, and this common plate electrode is held at a fixed (constant) voltage. The memory has two data lines for each memory cell, and a sense amplifier connected between the two data lines. Volatile or nonvolatile operation is established depending on the voltage applied to the amplifier. The voltage applied to the amplifier is increased and the ferroelectric capacitor is completely polarized to write nonvolatile information; to write volatile information, this voltage is decreased and polarization reversal is minimized.Type: GrantFiled: December 27, 1996Date of Patent: June 8, 1999Assignee: Hitachi, Ltd.Inventors: Tomonori Sekiguchi, Hiroki Fujisawa, Takeshi Sakata, Takayuki Kawahara, Katsutaka Kimura
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Patent number: 5892713Abstract: The memory mat is divided in two banks, which share the sense & latch circuit. As an example of the circuit operation, the information contained in the memory cells in a block of four bit lines BL11a-BL14a connected to a word line WL1a in the memory array MAa of the bank A is temporarily stored in the sense & latch circuits SL11-SL14. The information of bit lines is latched to the sense & latch circuit SLa through the sub-input/output signal lines IO1a and IO2a by the switches YS1a and YS2a that alternately operates at a cycle two times that of the external clock. The latched information is then output onto the input/output signal line IOa by the switch SWa in synchronism with the clock. After the four bit lines BL11a-SB14a have been read out, the sense & latch circuits SL11-S114 in that block are reset and the bit lines on the bank B are precharged while the information on the bank A is being output.Type: GrantFiled: February 23, 1996Date of Patent: April 6, 1999Assignee: Hitachi, Ltd.Inventors: Yusuke Jyouno, Takayuki Kawahara, Katsutaka Kimura
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Patent number: 5880604Abstract: A semiconductor integrated circuit device is composed of logic gates each provided with at least two MOS transistors. The logic gates are connected to a first potential point and a second potential point. The semiconductor integrated circuit device includes a current control device connected between the logic gate and the first potential point and/or between the logic gate and the second potential point for controlling a value of a current flowing in the logic gate depending on an operating state of the logic gate. The circuit can be used in devices that cycle in operation between high and low power consumption modes, such as microprocessors that have both an operation mode and a low power back-up or sleep mode used for power reduction.Type: GrantFiled: September 17, 1996Date of Patent: March 9, 1999Assignee: Hitachi, Ltd.Inventors: Takayuki Kawahara, Ryoichi Hori, Masashi Horiguchi, Ryoichi Kurihara, Kiyoo Itoh, Masakazu Aoki, Takeshi Sakata, Kunio Uchiyama
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Patent number: 5870218Abstract: To enable one non-volatile memory cell to store four-value information, three different kinds of threshold voltages are serially applied to a word line in a verify operation to execute a write operation, the threshold voltages of the memory cell are controlled, and two-value (one-bit) information corresponding to the four-value (two-bit) information to be written are synthesized by a write data conversion circuit for each of the write operations carried out three times. In this way, the four-value (two-bit) information are written into one memory cell, and the memory capacity of the memory cell can be increased. In the information read operation, three different kinds of voltages are applied to a word line, three kinds of two-value (one-bit) information so read out are synthesized by a read conversion circuit and the memory information of the memory cell are converted to the two-bit information.Type: GrantFiled: April 30, 1997Date of Patent: February 9, 1999Assignee: Hitaachi, Ltd.Inventors: Yusuke Jyouno, Takayuki Kawahara, Katsutaka Kimura
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Patent number: 5828235Abstract: A semiconductor integrated circuit device is composed of logic gates each provided with at least two MOS transistors. The logic gates are connected to a first potential point and a second potential point. The semiconductor integrated circuit device includes a current control device connected between the logic gate and the first potential point and/or between the logic gate and the second potential point for controlling a value of a current flowing in the logic gate depending on an operating state of the logic gate. The circuit can be used in devices that cycle in operation between high and low power consumption modes, such as microprocessors that have both an operation mode and a low power back-up or sleep mode used for power reduction.Type: GrantFiled: May 24, 1996Date of Patent: October 27, 1998Assignee: Hitachi, Ltd.Inventors: Masashi Horiguchi, Kunio Uchiyama, Kiyoo Itoh, Takeshi Sakata, Masakazu Aoki, Takayuki Kawahara
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Patent number: 5822267Abstract: A semiconductor integrated circuit comprises a semiconductor chip, a power supply terminal provided on the semiconductor chip for receiving a voltage from an external power supply source, an internal circuit provided on the semiconductor chip, a power supply circuit provided on the semiconductor chip for transforming an external power supply voltage received from the power supply terminal for supplying a source voltage resulting from the voltage transformation to the internal circuit, and a control circuit provided on the semiconductor chip for controlling the power supply circuit, wherein the control circuit includes external power supply voltage detecting means and/or temperature detecting means and responds to the signal from the external power supply voltage detecting means and/or the temperature detecting means by changing the power supply voltage to the internal circuit to thereby maintain the operating speed of the internal circuit to be constant.Type: GrantFiled: September 13, 1994Date of Patent: October 13, 1998Assignee: Hitachi, Ltd.Inventors: Takao Watanabe, Ryoichi Hori, Goro Kitsukawa, Yoshiki Kawajiri, Takayuki Kawahara, Kiyoo Itoh
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Patent number: 5694358Abstract: This invention provides a nonvolatile semiconductor memory device having a word line, a plurality of bit lines crossing the word line, and a plurality of memory cells including MOS transistors. Each of control gates of the MOS transistors are coupled to the word line and each of drains thereof are coupled to the bit lines, respectively. Each of the MOS transistors also has a floating gate. Further, the non-volatile semiconductor memory device comprises latch circuits, first switches, a sense amplifier coupled to the plurality of bit lines in common, and second switches. The latch circuits are coupled to the plurality of bit lines through the first switches which are coupled between the plurality of bit lines and the latch circuits, respectively. The second switches are respectively coupled between the plurality of bit lines and the sense amplifier, thereby coupling the sense amplifier to the bit lines.Type: GrantFiled: September 24, 1996Date of Patent: December 2, 1997Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.Inventors: Takayuki Kawahara, Yusuke Jyouno, Syunichi Saeki, Naoki Miyamoto, Katsutaka Kimura
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Patent number: 5614847Abstract: A semiconductor integrated circuit device is composed of logic gates each provided with at least two MOS transistors. The logic gates are connected to a first potential point and a second potential point. The semiconductor integrated circuit device includes a current control device connected between the logic gate and the first potential point and/or between the logic gate and the second potential point for controlling a value of a current flowing in the logic gate depending on an operating state of the logic gate. The circuit can be used in devices that cycle in operation between high and low power consumption modes, such as microprocessors that have both an operation mode and a low power back-up or sleep mode used for power reduction.Type: GrantFiled: August 24, 1994Date of Patent: March 25, 1997Assignee: Hitachi, Ltd.Inventors: Takayuki Kawahara, Ryoichi Hori, Masashi Horiguchi, Ryoichi Kurihara, Kiyoo Itoh, Masakazu Aoki, Takeshi Sakata, Kunio Uchiyama
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Patent number: 5583457Abstract: A semiconductor integrated circuit device is composed of logic gates each provided with at least two MOS transistors. The logic gates are connected to a first potential point and a second potential point. The semiconductor integrated circuit device includes a current control device connected between the logic gate and the first potential point and/or between the logic gate and the second potential point for controlling a value of a current flowing in the logic gate depending on an operating state of the logic gate. The circuit can be used in devices that cycle in operation between high and low power consumption modes, such as microprocessors that have both an operation mode and a low power back-up or sleep mode used for power reduction.Type: GrantFiled: February 8, 1994Date of Patent: December 10, 1996Assignee: Hitachi, Ltd.Inventors: Masashi Horiguchi, Kunio Uchiyama, Kiyoo Itoh, Takeshi Sakata, Masakazu Aoki, Takayuki Kawahara
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Patent number: 5543522Abstract: There are disclosed a process for preparing an ambient temperature molten salt, which comprises treating an ambient temperature molten salt consisting essentially of 20 to 50 mole % of an aluminum halide and 80 to 50 mole % of an onium halide, containing oxygen-containing impurities originating from water with thionyl chloride anda process for preparing an ambient temperature molten salt for effecting aluminum electroplating, which comprises treating mixed ambient temperature molten salts consisting essentially of 30 to 50 mole % of an aluminum halide and 70 to 50 mole % of an onium halide, containing oxygen-containing impurities originating from water with thionyl chloride, and then adding aluminum halide to the molten salt to prepare an ambient temperature molten salt composition consisting essentially of 50 to 80 mole % of an aluminum halide and 50 to 20 mole % of an onium halide.Type: GrantFiled: August 25, 1994Date of Patent: August 6, 1996Assignees: Mitsubishi Chemical Corporation, Nisshin Steel Co., Ltd.Inventors: Takayuki Kawahara, Hitoshi Suzuki, Asao Kominato
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Patent number: 5474862Abstract: A nonaqueous electrolyte secondary battery having excellent cycle life characteristic, stability in storage at high temperatures and low-temperature characteristic, which is provided with an anode including a carbon material capable of doping and undoping lithium ion, a nonaqueous electrolyte and a cathode including a lithium-containing oxide, the solvent for the nonaqueous electrolyte being a mixed solvent including an aliphatic carboxylate, a cyclic carbonate and a chain carbonate, with the aliphatic carboxylate being represented by the formula RCOOR' where R represents an ethyl group and R' represents an alkyl group of 1-3 carbon atoms and the cyclic carbonate being one of ethylene carbonate and propylene carbonate.Type: GrantFiled: October 29, 1993Date of Patent: December 12, 1995Assignees: Matsushita Electric Industrial Co., Ltd., Mitsubishi Petrochemical Company LimitedInventors: Hiromi Okuno, Hizuru Koshina, Takayuki Kawahara, Katsuaki Hasegawa
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Patent number: 5448526Abstract: An intermediate voltage generating circuit for generating a voltage lying between an external power supply voltage and a ground voltage, and two voltage limiter circuits for generating internal power supply voltages and stabilized with this intermediate voltage as a reference are provided in a semiconductor integrated circuit. Even if the external power supply voltage or the ground voltage fluctuates, no disagreement is produced between a logical threshold of a circuit operating on the external power supply voltage and a logical threshold of a circuit operating on the internal power supply voltage.Type: GrantFiled: July 29, 1994Date of Patent: September 5, 1995Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.Inventors: Masashi Horiguchi, Kiyoo Itoh, Yoshiki Kawajiri, Goro Kitsukawa, Takayuki Kawahara, Takesada Akiba
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Patent number: 5426603Abstract: A dynamic RAM is provided using a sense amplifier compensating for the disparities of characteristics for paired MOSFET's. With this arrangement parasitic capacitance of the bit lines can be increased to be at least 20 times the capacitance of the memory cells. Each bit line is bisected by a switch MOSFET and is disconnected thereby as needed. A plurality of sets of memory arrays are furnished, each including a switch MOSFET for interconnecting common source lines to which the sense amplifier is connected. This permits recycling of the charges of the common source lines.Type: GrantFiled: January 25, 1994Date of Patent: June 20, 1995Assignee: Hitachi, Ltd.Inventors: Masayuki Nakamura, Takayuki Kawahara, Kazuhiko Kajigaya, Kazuyoshi Oshima, Tsugio Takahashi, Hiroshi Otori, Tetsuro Matsumoto
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Patent number: 5396116Abstract: A semiconductor integrated circuit comprises a semiconductor chip, a power supply terminal provided on the semiconductor chip for receiving a voltage from an external power supply source, an internal circuit provided on the semiconductor chip, a power supply circuit provided on the semiconductor chip for transforming an external power supply voltage received from the power supply terminal for supplying a source voltage resulting from the voltage transformation to the internal circuit, and a control circuit provided on the semiconductor chip for controlling the power supply circuit, wherein the control circuit includes external power supply voltage detecting means and/or temperature detecting means and responds to the signal from the external power supply voltage detecting means and/or the temperature detecting means by changing the power supply voltage to the internal circuit to thereby maintain the operating speed of the internal circuit to be constant.Type: GrantFiled: December 3, 1992Date of Patent: March 7, 1995Assignee: Hitachi, Ltd.Inventors: Takao Watanabe, Ryoichi Hori, Goro Kitsukawa, Yoshiki Kawajiri, Takayuki Kawahara, Kiyoo Itoh
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Patent number: 5393204Abstract: A wobble plate type compressor includes a cylinder housing having a cylinder block and a front end plate. The interior of the housing defines a crank chamber between the cylinder block and the front end plate. Pistons are respectively slidably fitted within each of a plurality of cylinders within the cylinder block and are reciprocated by a drive mechanism. The drive mechanism includes a drive shaft, a rotor fixed to the drive shaft and a wobble plate disposed on an inclined surface of the rotor. The drive shaft is supported in the center of the front end plate through a radial needle bearing. The radial needle bearing comprises a plurality of cylindrical rollers annularly arranged around the drive shaft and a cylindrical outer race covering the rollers. At least one hole is formed on the circumference of the outer race. An oil passageway is formed within the front end plate and extends between the interior of the crank chamber outside of the rotor and the hole in the race.Type: GrantFiled: January 29, 1993Date of Patent: February 28, 1995Assignee: Sanden CorporationInventor: Takayuki Kawahara
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Patent number: 5386394Abstract: The semiconductor device has more-significant global data lines and less-significant data lines hierarchically formed, and switches for controlling the more-significant global data lines and the less-significant data lines to be connected each other. In addition, the semiconductor device has the unit for precharging the global data lines independently of the data lines.Type: GrantFiled: September 2, 1993Date of Patent: January 31, 1995Assignee: Hitachi, Ltd.Inventors: Takayuki Kawahara, Masakazu Aoki, Yoshinobu Nakagome, Makoto Hanawa, Kunio Uchiyama, Masayuki Nakamura, Goro Kitsukawa, Kanji Oishi
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Patent number: 5377156Abstract: A semiconductor integrated circuit comprises a semiconductor chip, a power supply terminal provided on the semiconductor chip for receiving a voltage from an external power supply source, an internal circuit provided on the semiconductor chip, a power supply circuit provided on the semiconductor chip for transforming an external power supply voltage received from the power supply terminal for supplying a source voltage resulting from the voltage transformation to the internal circuit, and a control circuit provided on the semiconductor chip for controlling the power supply circuit, wherein the control circuit includes external power supply voltage detecting means and/or temperature detecting means and responds to the signal from the external power supply voltage detecting means and/or the temperature detecting means by changing the power supply voltage to the internal circuit to thereby maintain the operating speed of the internal circuit to be constant.Type: GrantFiled: December 3, 1992Date of Patent: December 27, 1994Assignee: Hitachi, Ltd.Inventors: Takao Watanabe, Ryoichi Hori, Goro Kitsukawa, Yoshiki Kawajiri, Takayuki Kawahara, Kiyoo Itoh
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Patent number: 5347492Abstract: An intermediate voltage generating circuit for generating a voltage lying between an external power supply voltage and a ground voltage, and two voltage limiter circuits for generating internal power supply voltages and stabilized with this intermediate voltage as a reference are provided in a semiconductor integrated circuit. Even if the external power supply voltage or the ground voltage fluctuates, no disagreement is produced between a logical threshold of a circuit operating on the external power supply voltage and a logical threshold of a circuit operating on the internal power supply voltage.Type: GrantFiled: November 16, 1993Date of Patent: September 13, 1994Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.Inventors: Masashi Horiguchi, Kiyoo Itoh, Yoshiki Kawajiri, Goro Kitsukawa, Takayuki Kawahara, Takesada Akiba