Patents by Inventor Masaaki Namekawa
Masaaki Namekawa 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: 9612579Abstract: Provided is an electronic clock which is capable of finely controlling a driving force of a normal driving pulse and suppresses variation in current consumption without an increase in circuit size. The electronic clock is configured so that while a chopped driving pulse is output and in an interval in which coil terminals have heretofore been short-circuited, a pulse is output (hereinafter referred to as adjustment pulse) for control from a terminal that is different from a terminal of a motor driver from which the normal driving pulse has been output. The output pattern of the adjustment pulse is changed with reference to a driving rank selecting circuit to increase or decrease a motor driving current and hence change the driving force.Type: GrantFiled: July 23, 2013Date of Patent: April 4, 2017Assignee: CITIZEN WATCH CO., LTD.Inventors: Yu Takyo, Masaaki Namekawa
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Publication number: 20150160619Abstract: Provided is an electronic clock which is capable of finely controlling a driving force of a normal driving pulse and suppresses variation in current consumption without an increase in circuit size. The electronic clock is configured so that while a chopped driving pulse is output and in an interval in which coil terminals have heretofore been short-circuited, a pulse is output (hereinafter referred to as adjustment pulse) for control from a terminal that is different from a terminal of a motor driver from which the normal driving pulse has been output. The output pattern of the adjustment pulse is changed with reference to a driving rank selecting circuit to increase or decrease a motor driving current and hence change the driving force.Type: ApplicationFiled: July 23, 2013Publication date: June 11, 2015Inventors: Yu Takyo, Masaaki Namekawa
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Patent number: 8848492Abstract: When recovering power from a motor driver, a forward voltage across a parasitic diode can reduce the recovery efficiency, and control of a power recovery operation can take an unnecessarily long time. In order to address this problem, the power recovery operation is performed as follows without being affected by a parasitic diode: near a peak position of a waveform of an induced current resulting from free oscillation of a rotor after a drive pulse is output, a recovery pulse having such a level that the rotor does not rotate is output from a terminal different from a motor driver terminal to which the drive pulse was output. Also, by adjusting the width and output timing of the recovery pulse based on a power supply voltage, the power recovery can be optimized for the power supply voltage.Type: GrantFiled: February 9, 2011Date of Patent: September 30, 2014Assignees: Citizen Holdings Co., Ltd., Citizen Watch Co., LtdInventors: Masaaki Namekawa, Yu Takyo
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Patent number: 8692518Abstract: The invention provides a compact and highly reliable electronic apparatus that can be driven by a small-capacity battery, and that can achieve high-speed continuous driving of a load by quickly judging the recovery state of the battery after driving the load. More particularly, the invention provides an electronic apparatus includes a power supply, a load, a load driver for driving the load by the power supply, a power supply state detecter for outputting power supply recovery information by measuring physical quantity of the power supply at predetermined intervals of time after the driving of the load is stopped, and a controller for instructing the load driver to drive the load, based on the power supply recovery information supplied from the power supply state detecter.Type: GrantFiled: July 24, 2007Date of Patent: April 8, 2014Assignee: Citizen Holdings Co., Ltd.Inventors: Takayuki Uchida, Kohichi Satoh, Masaaki Namekawa
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Publication number: 20120307602Abstract: When recovering power from a motor driver, a forward voltage across a parasitic diode can reduce the recovery efficiency, and control of a power recovery operation can take an unnecessarily long time. In order to address this problem, the power recovery operation is performed as follows without being affected by a parasitic diode: near a peak position of a waveform of an induced current resulting from free oscillation of a rotor after a drive pulse is output, a recovery pulse having such a level that the rotor does not rotate is output from a terminal different from a motor driver terminal to which the drive pulse was output. Also, by adjusting the width and output timing of the recovery pulse based on a power supply voltage, the power recovery can be optimized for the power supply voltage.Type: ApplicationFiled: February 9, 2011Publication date: December 6, 2012Applicants: CITIZEN WATCH CO., LTD, CITIZEN HOLDINGS CO., LTD.Inventors: Masaaki Namekawa, Yu Takyo
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Patent number: 7961557Abstract: An analog electronic watch of the present invention includes: a display unit (2) for displaying time with a position of a hand; a stepper motor (3) for driving the hand; a motor drive unit (4) for controlling driving of the stepper motor at a predetermined hand drive cycle at normal time; hand position detection means (5) for detecting a position of the hand; a hand position detection means control unit (6) for intermittently controlling driving of the hand position detection means (5) at a first detection cycle which is longer than the hand drive cycle; and a detection cycle changing unit (7) for instructing the hand position detection means (5) to change the detection cycle.Type: GrantFiled: March 2, 2007Date of Patent: June 14, 2011Assignee: Citizen Holdings Co., Ltd.Inventors: Teruhiko Fujii, Isao Kitazawa, Masaaki Namekawa, Takayuki Uchida, Takayuki Hasumi, Takuji Ike
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Publication number: 20100072974Abstract: The invention provides a compact and highly reliable electronic apparatus that can be driven by a small-capacity battery, and that can achieve high-speed continuous driving of a load by quickly judging the recovery state of the battery after driving the load. More particularly, the invention provides an electronic apparatus includes a power supply, a load, a load driver for driving the load by the power supply, a power supply state detecter for outputting power supply recovery information by measuring physical quantity of the power supply at predetermined intervals of time after the driving of the load is stopped, and a controller for instructing the load driver to drive the load, based on the power supply recovery information supplied from the power supply state detecter.Type: ApplicationFiled: July 24, 2007Publication date: March 25, 2010Inventors: Takayuki Uchida, Kohichi Satoh, Masaaki Namekawa
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Publication number: 20090016172Abstract: An analog electronic watch of the present invention includes: a display unit (2) for displaying time with a position of a hand; a stepper motor (3) for driving the hand; a motor drive unit (4) for controlling driving of the stepper motor at a predetermined hand drive cycle at normal time; hand position detection means (5) for detecting a position of the hand; a hand position detection means control unit (6) for intermittently controlling driving of the hand position detection means (5) at a first detection cycle which is longer than the hand drive cycle; and a detection cycle changing unit (7) for instructing the hand position detection means (5) to change the detection cycle.Type: ApplicationFiled: March 2, 2007Publication date: January 15, 2009Inventors: Teruhiko Fujii, Isao Kitazawa, Masaaki Namekawa, Takayuki Uchida, Takayuki Hasumi, Takuji Ike
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Patent number: 7408845Abstract: A radio correcting timepiece that can reduce the influence of a radio wave situation of the standard radio wave having time information according to an area, and can make a correction to the exact time in a shorter time is provided. The radio correcting timepiece comprises a signal receiving means (1) for receiving a standard radio wave and a timepiece means (2) for correcting and displaying time on the basis of the time information outputted from the signal receiving means. The signal receiving means (1) can receive plural standard radio waves and includes memory means (1I) which is able to store signal receiving order of the plural standard radio waves. Since the plural standard radio waves can be received, the influence of a radio wave situation according to an area can be reduced and a correction to the exact time can be made in a shorter time by using the standard radio wave transmitted every minute.Type: GrantFiled: September 10, 2002Date of Patent: August 5, 2008Assignee: Citizen Holdings Co., Ltd.Inventors: Takashi Ihara, Masao Sakuyama, Akinari Takada, Masaaki Namekawa
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Patent number: 7385876Abstract: A radio-controlled timepiece includes a regional-information storage unit that stores information on a target time region, a receiving circuit that receives a standard frequency that contains UTC time information, and that outputs a received signal, a regional-time calculating unit that calculates a current time of the target time region based on the information on the target time region and the received signal, a display unit that displays the current time calculated, a display-time correcting unit that corrects the current time to be displayed in DST or in standard time in timing determined based on the current time when information on a DST switching day is included in the received signal.Type: GrantFiled: June 7, 2004Date of Patent: June 10, 2008Assignee: Citizen Holdings Co., Ltd.Inventors: Takashi Ihara, Akinari Takada, Masaaki Namekawa, Masami Fukuda, Minoru Kobayashi
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Patent number: 7372779Abstract: The invention is directed to obtaining a radio controlled timepiece that, in a case when the user who uses it moves from one country or one region to another where the time difference is different, has simplified an operation of correcting the time difference between the countries or regions and an operation of correcting the time difference due to daylight saving time's being executed.Type: GrantFiled: September 5, 2003Date of Patent: May 13, 2008Assignee: Citizen Holdings Co., Ltd.Inventors: Akinari Takada, Takashi Ihara, Masaaki Namekawa, Masami Fukuda, Minoru Kobayashi
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Patent number: 7190745Abstract: The receiver receives the standard frequency signal that includes a time code. A sampling unit samples one bit of the received signal at 32 positions. A smoothing unit smoothens the result of sampling by dividing the 32 positions in two to four intervals and determines a value of the received signal in each interval. A waveform determining unit determines waveform of each bit of the received signal based on the value obtained in the smoothing unit. The decoding unit extracts the time code based on the determined waveform. A time unit correct the time based on the extracted time code.Type: GrantFiled: November 19, 2002Date of Patent: March 13, 2007Assignee: Citizen Watch Co., Ltd.Inventors: Akinari Takada, Takashi Ihara, Masaaki Namekawa
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Publication number: 20050185514Abstract: A radio-controlled timepiece includes a regional-information storage unit that stores information on a target time region, a receiving circuit that receives a standard frequency that contains UTC time information, and that outputs a received signal, a regional-time calculating unit that calculates a current time of the target time region based on the information on the target time region and the received signal, a display unit that displays the current time calculated, a display-time correcting unit that corrects the current time to be displayed in DST or in standard time in timing determined based on the current time when information on a DST switching day is included in the received signal.Type: ApplicationFiled: June 7, 2004Publication date: August 25, 2005Inventors: Takashi Ihara, Akinari Takada, Masaaki Namekawa, Masami Fukuda, Minoru Kobayashi
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Publication number: 20050094495Abstract: The invention is directed to obtaining a radio controlled timepiece that, in a case when the user who uses it moves from one country or one region to another where the time difference is different, has simplified an operation of correcting the time difference between the countries or regions and an operation of correcting the time difference due to daylight saving time's being executed.Type: ApplicationFiled: September 5, 2003Publication date: May 5, 2005Inventors: Akinari Takada, Takashi Ihara, Masaaki Namekawa, Masami Fukuda, Minoru Kobayashi
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Publication number: 20040202051Abstract: A radio correcting timepiece that can reduce the influence of a radio wave situation of the standard radio wave having time information according to an area, and can make a correction to the exact time in a shorter time is provided. The radio correcting timepiece comprises a signal receiving means (1) for receiving a standard radio wave and a timepiece means (2) for correcting and displaying time on the basis of the time information outputted from the signal receiving means. The signal receiving means (1) can receive plural standard radio waves and includes memory means (1I) which is able to store signal receiving order of the plural standard radio waves. Since the plural standard radio waves can be received, the influence of a radio wave situation according to an area can be reduced and a correction to the exact time can be made in a shorter time by using the standard radio wave transmitted every minute.Type: ApplicationFiled: February 27, 2004Publication date: October 14, 2004Inventors: Takashi Ihara, Masao Sakuyama, Akinari Takada, Masaaki Namekawa
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Publication number: 20030117901Abstract: The receiver receives the standard frequency signal that includes a time code. A sampling unit samples one bit of the received signal at 32 positions. A smoothing unit smoothens the result of sampling by dividing the 32 positions in two to four intervals and determines a value of the received signal in each interval. A waveform determining unit determines waveform of each bit of the received signal based on the value obtained in the smoothing unit. The decoding unit extracts the time code based on the determined waveform. A time unit correct the time based on the extracted time code.Type: ApplicationFiled: November 19, 2002Publication date: June 26, 2003Applicant: CITIZEN WATCH CO., LTD.Inventors: Akinari Takada, Takashi Ihara, Masaaki Namekawa
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Patent number: 5811028Abstract: A 2H-5,6-optically active dihydropyran derivative represented by the general formula (I) or (I'): ##STR1## wherein Rf represents a fluoroalkyl group having 1 or 2 carbon atoms; a liquid crystal composition and a liquid crystal device comprising the derivative; and a racemic mixture comprising at least one type of the derivative. The derivative is a novel compound which exhibits the liquid crystal property by itself or can be used as an excellent dopant providing a high speed response to a composition comprising it even when the compound does not exhibit the liquid crystal property by itself. The derivative also exhibits a large spontaneous polarization.Type: GrantFiled: August 13, 1997Date of Patent: September 22, 1998Assignee: Kashima Oil CompanyInventors: Tatsushi Ishizuka, Mitsunori Takeda, Masaaki Namekawa, Keizou Itoh
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Patent number: 5698137Abstract: A 2H-5,6-optically active dihydropyran derivative represented by the general formula (I) or (I'): ##STR1## wherein Rf represents a fluoroalkyl group having 1 or 2 carbon atoms; a liquid crystal composition and a liquid crystal device comprising the derivative; and a racemic mixture comprising at least one type of the derivative. The derivative is a novel compound which exhibits the liquid crystal property by itself or can be used as an excellent dopant providing a high speed response to a composition comprising it even when the compound does not exhibit the liquid crystal property by itself. The derivative also exhibits a large spontaneous polarization.Type: GrantFiled: April 15, 1996Date of Patent: December 16, 1997Assignee: Kashima Oil CompanyInventors: Tatsushi Ishizuka, Mitsunori Takeda, Masaaki Namekawa, Keizou Itoh
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Patent number: 5595684Abstract: An optically active tetrahydropyran derivative represented by one of the following general formulae, a liquid crystal composition containing the derivative, and a liquid crystal device containing the composition are disclosed. The optically active tetrahydropyran derivative is a novel compound which is chemically stable, causes no coloring, has excellent optical stability, and shows a large spontaneous polarization and a quick response. The optically active tetrahydropyran derivative can show a more excellent quick response when it is used in a composition, and is useful as a component in a ferroelectric liquid crystal which induces a large spontaneous polarization.Type: GrantFiled: April 3, 1995Date of Patent: January 21, 1997Assignee: Kashima Oil CompanyInventors: Masaaki Namekawa, Keizou Itoh, Shinichi Nayuki, Mitsunori Takeda, Yoshinobu Murayama
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Patent number: 5443755Abstract: There are disclosed a novel optically active tetrahydropyrane derivatives (for example, (2R,5R,6R)-tetrahydro-6-trifluoromethyl-2-hexyloxy-5-(4"-hexyloxybiphenyl) -4'-carbonyloxy)pyrane; (2S,5R,6R)-tetrahydro-6-trifluoromethyl-2-hexyloxy-5-(4"-hexyloxybiphenyl) -4'-carbonyloxy)pyrane, etc. may be mentioned.) represented by the formula (I): ##STR1## or (I'): ##STR2## wherein symbols in the formula are as described in the specification, which is available as a liquid crystal material used for a display device or an electro-optic device, a liquid crystal composition and a liquid crystal device containing the same.The optically active tetrahydropyrane derivative of the present invention can improve high speed response particularly when it is made a composition, and is available as a compositional component for a ferroelectric liquid crystal which induces a large spontaneous polarization.Type: GrantFiled: June 8, 1994Date of Patent: August 22, 1995Assignee: Kashima Oil CompanyInventors: Masaaki Namekawa, Shinichi Nayuki, Keizou Itoh, Mitsunori Takeda, Yoshinobu Murayama