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).

  • Patent number: 9612579
    Abstract: 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: Grant
    Filed: July 23, 2013
    Date of Patent: April 4, 2017
    Assignee: CITIZEN WATCH CO., LTD.
    Inventors: Yu Takyo, Masaaki Namekawa
  • Publication number: 20150160619
    Abstract: 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: Application
    Filed: July 23, 2013
    Publication date: June 11, 2015
    Inventors: Yu Takyo, Masaaki Namekawa
  • Patent number: 8848492
    Abstract: 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: Grant
    Filed: February 9, 2011
    Date of Patent: September 30, 2014
    Assignees: Citizen Holdings Co., Ltd., Citizen Watch Co., Ltd
    Inventors: Masaaki Namekawa, Yu Takyo
  • Patent number: 8692518
    Abstract: 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: Grant
    Filed: July 24, 2007
    Date of Patent: April 8, 2014
    Assignee: Citizen Holdings Co., Ltd.
    Inventors: Takayuki Uchida, Kohichi Satoh, Masaaki Namekawa
  • Publication number: 20120307602
    Abstract: 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: Application
    Filed: February 9, 2011
    Publication date: December 6, 2012
    Applicants: CITIZEN WATCH CO., LTD, CITIZEN HOLDINGS CO., LTD.
    Inventors: Masaaki Namekawa, Yu Takyo
  • Patent number: 7961557
    Abstract: 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: Grant
    Filed: March 2, 2007
    Date of Patent: June 14, 2011
    Assignee: Citizen Holdings Co., Ltd.
    Inventors: Teruhiko Fujii, Isao Kitazawa, Masaaki Namekawa, Takayuki Uchida, Takayuki Hasumi, Takuji Ike
  • Publication number: 20100072974
    Abstract: 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: Application
    Filed: July 24, 2007
    Publication date: March 25, 2010
    Inventors: Takayuki Uchida, Kohichi Satoh, Masaaki Namekawa
  • Publication number: 20090016172
    Abstract: 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: Application
    Filed: March 2, 2007
    Publication date: January 15, 2009
    Inventors: Teruhiko Fujii, Isao Kitazawa, Masaaki Namekawa, Takayuki Uchida, Takayuki Hasumi, Takuji Ike
  • Patent number: 7408845
    Abstract: 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: Grant
    Filed: September 10, 2002
    Date of Patent: August 5, 2008
    Assignee: Citizen Holdings Co., Ltd.
    Inventors: Takashi Ihara, Masao Sakuyama, Akinari Takada, Masaaki Namekawa
  • Patent number: 7385876
    Abstract: 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: Grant
    Filed: June 7, 2004
    Date of Patent: June 10, 2008
    Assignee: Citizen Holdings Co., Ltd.
    Inventors: Takashi Ihara, Akinari Takada, Masaaki Namekawa, Masami Fukuda, Minoru Kobayashi
  • Patent number: 7372779
    Abstract: 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: Grant
    Filed: September 5, 2003
    Date of Patent: May 13, 2008
    Assignee: Citizen Holdings Co., Ltd.
    Inventors: Akinari Takada, Takashi Ihara, Masaaki Namekawa, Masami Fukuda, Minoru Kobayashi
  • Patent number: 7190745
    Abstract: 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: Grant
    Filed: November 19, 2002
    Date of Patent: March 13, 2007
    Assignee: Citizen Watch Co., Ltd.
    Inventors: Akinari Takada, Takashi Ihara, Masaaki Namekawa
  • Publication number: 20050185514
    Abstract: 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: Application
    Filed: June 7, 2004
    Publication date: August 25, 2005
    Inventors: Takashi Ihara, Akinari Takada, Masaaki Namekawa, Masami Fukuda, Minoru Kobayashi
  • Publication number: 20050094495
    Abstract: 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: Application
    Filed: September 5, 2003
    Publication date: May 5, 2005
    Inventors: Akinari Takada, Takashi Ihara, Masaaki Namekawa, Masami Fukuda, Minoru Kobayashi
  • Publication number: 20040202051
    Abstract: 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: Application
    Filed: February 27, 2004
    Publication date: October 14, 2004
    Inventors: Takashi Ihara, Masao Sakuyama, Akinari Takada, Masaaki Namekawa
  • Publication number: 20030117901
    Abstract: 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: Application
    Filed: November 19, 2002
    Publication date: June 26, 2003
    Applicant: CITIZEN WATCH CO., LTD.
    Inventors: Akinari Takada, Takashi Ihara, Masaaki Namekawa
  • Patent number: 5811028
    Abstract: 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: Grant
    Filed: August 13, 1997
    Date of Patent: September 22, 1998
    Assignee: Kashima Oil Company
    Inventors: Tatsushi Ishizuka, Mitsunori Takeda, Masaaki Namekawa, Keizou Itoh
  • Patent number: 5698137
    Abstract: 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: Grant
    Filed: April 15, 1996
    Date of Patent: December 16, 1997
    Assignee: Kashima Oil Company
    Inventors: Tatsushi Ishizuka, Mitsunori Takeda, Masaaki Namekawa, Keizou Itoh
  • Patent number: 5595684
    Abstract: 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: Grant
    Filed: April 3, 1995
    Date of Patent: January 21, 1997
    Assignee: Kashima Oil Company
    Inventors: Masaaki Namekawa, Keizou Itoh, Shinichi Nayuki, Mitsunori Takeda, Yoshinobu Murayama
  • Patent number: 5443755
    Abstract: 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: Grant
    Filed: June 8, 1994
    Date of Patent: August 22, 1995
    Assignee: Kashima Oil Company
    Inventors: Masaaki Namekawa, Shinichi Nayuki, Keizou Itoh, Mitsunori Takeda, Yoshinobu Murayama