Patents by Inventor Akira Torisawa
Akira Torisawa 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: 4952859Abstract: A stepping motor characterized by the provision of an anisotropic resin magnet rotor which is the rotor of the motor and comprises an anisotropic resin magnet and which has recesses formed at the centers of the magnetic poles thereof and in which the wave form of the magnetic force is one of a two-head wave form and a trapezoidal wave form in the range of 0.1-0.2 of the air gap between the rotor and stator teeth during the use of the motor.Type: GrantFiled: November 30, 1988Date of Patent: August 28, 1990Assignees: Canon Kabushiki Kaisha, Canon Denshi Kabushiki KaishaInventors: Akira Torisawa, Katsumi Yoshida, Hiroshi Koizumi, Hiroyuki Yoshikawa
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Patent number: 4928050Abstract: A data recorder in which a recording is moved by stepping motor whose rotor rotation angle is detected, the stepping motor having a current switching circuit which controls the application of excitation current to the drive coils of the motor in accordance with the detected rotation angle. A control circuit counts the detected result of the rotor rotation angle, detects the position of the head and generates start and stop control signals of the head, thereby starting and stopping switch-over control of the current switching circuit being effected.Type: GrantFiled: January 27, 1989Date of Patent: May 22, 1990Assignee: Canon Kabushiki KaishaInventors: Akira Torisawa, Masaaki Kakizaki, Noriaki Ito, Shigeru Yoshimura
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Patent number: 4794292Abstract: A stepping motor with a rotor having magnetic poles arranged at a constant pitch along the periphery, first and second stator sets each having stator poles at a constant pitch and arranged at a mutual offset of 1/4 pitch with respect to the rotor, and coils for magnetizing the first and second stator sets, wherein each stator pole is provided with a magnetic polarity and is practically divided, at least on a face directed to the rotor, into plural areas, so as to form an area of a high magnetic reluctance at the center.Type: GrantFiled: July 15, 1987Date of Patent: December 27, 1988Assignee: Canon Kabushiki KaishaInventor: Akira Torisawa
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Patent number: 4445784Abstract: A driver circuit for a stepping motor having a coil, a stator and a rotor receives pulse signals from a pulse signal generator to rotationally drive the rotor. A rotation detection circuit comprises switching circuitry switchable between a high impedance loop formed of the coil and a high impedance element and a low impedance loop formed of the coil and a low impedance element, and means for detecting the voltage induced in the coil. After a pulse signal is applied to the stepping motor, the switching circuitry forms the high impedance loop and the detecting means compares the voltage developed across the high impedance element with a predetermined voltage to thereby detect the rotation and non-rotation states of the rotor.Type: GrantFiled: March 12, 1982Date of Patent: May 1, 1984Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Masaharu Shida, Makoto Ueda, Akira Torisawa, Shuji Owada, Masaaki Mandai
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Patent number: 4382691Abstract: In an analog electronic watch having a calendar display the power required during change of the calendar display, about 6 hours out of 24, is greater than at other times. In order to effect economy in power consumption, the pulse for driving the watch motor during the time other than the period in which the calendar display is being changed is only sufficient to drive the time indicating means. In case the motor fails to step when such pulse is applied, this is detected by a detecting circuit and a corrective drive pulse is applied to the motor so as to drive it.Type: GrantFiled: July 16, 1980Date of Patent: May 10, 1983Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Masaharu Shida, Akira Torisawa, Jun Ueda, Masaaki Mandai, Katsuhiko Sato
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Patent number: 4368990Abstract: An analog electronic timepiece has a stepping motor for rotationally driving the timepiece hands. The motor is driven by normal driving pulses during normal load conditions and in the event the normal driving pulses are unable to effect rotation of the motor, correction driving pulses of longer pulse width than the normal driving pulses are used. A detection circuit detects whether or not the motor has rotated by switching a resistance element in series with the motor drive coil after the application of each normal driving pulse. Rotation and non-rotation of the motor is determined by measuring the voltage across the resistance element and comparing the measured voltage with a reference voltage.Type: GrantFiled: March 10, 1980Date of Patent: January 18, 1983Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Makoto Ueda, Masaharu Shida, Akira Torisawa
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Patent number: 4352172Abstract: An electronic timepiece has a stepping motor comprised of a stator, rotor and coil, and circuitry for producing and applying driving pulses to the coil to effect stepwise rotation of the rotor. The presence of an external alternating magnetic field is detected by switching the coil from an open-circuit condition to a low impedance loop comprised of the coil and a low impedance element. The rotation of the rotor is detected by alternately switching the coil between the low impedance loop and a high impedance loop comprised of the coil and a high impedance element. Control circuitry controls the switching operations to ensure that the magnetic field detection and the rotor rotation detection are carried out at different times.Type: GrantFiled: April 28, 1980Date of Patent: September 28, 1982Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Makoto Ueda, Akira Torisawa, Shuji Otawa, Masaaki Mandai, Masaharu Shida, Katsuhiko Sato
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Patent number: 4326278Abstract: An electronic timepiece having a stepping motor including a stator, rotor and coil, a driving circuit for applying driving pulses to the coil, an oscillating circuit for generating a time standard signal and a dividing circuit for dividing the time standard signal, is provided with a pulse combining circuit receptive of the output of the dividing circuit for producing a correction driving pulse having sufficient effective power to drive the motor under worst case conditions, a detector for detecting the rotation or non-rotation condition of the rotor after the application to the coil by the driving circuit of a normal driving pulse having less effective power than the correction driving pulse, and a controller for the driving circuit to apply normal driving pulses to the coil and responsive to the output of the detector to apply a correction driving pulse when a non-rotation condition is detected.Type: GrantFiled: December 4, 1978Date of Patent: April 20, 1982Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Masaharu Shida, Makoto Ueda, Akira Torisawa, Shuji Owada, Masaaki Mandai
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Patent number: 4321520Abstract: An electronic timepiece includes a stepping motor having a stator, a drive coil and a rotor which is driven in one of at least two different states. The state of the driving motor is changed in response to a change in the load of the motor or in response to the locating of the motor in an external magnetic field.Type: GrantFiled: June 19, 1979Date of Patent: March 23, 1982Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Makoto Ueda, Akira Torisawa, Shuji Otawa, Masaaki Mandai, Masaharu Shida, Katsuhiko Sato
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Patent number: 4321521Abstract: An electronic timepiece has a stepping motor comprised of a stator, rotor and driving coil. A wave shaping circuit produces normal driving pulses and correction driving pulses having a longer pulse width than the normal driving pulses. A rotor rotation detection device detects rotation and non-rotation of the rotor after normal driving pulses are applied to the driving coil and in response to detection of a non-rotation condition, a correction driving pulse is applied to the driving coil. A magnetic field detection device detects the presence and absence of an external alternating magnetic field and in response to detection of a magnetic field, a driving pulse of longer pulse width than the correction driving pulses is applied to the driving coil to effect rotor rotation.Type: GrantFiled: December 4, 1979Date of Patent: March 23, 1982Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Makoto Ueda, Akira Torisawa, Shuji Otawa, Masaaki Mandai, Masaharu Shida, Katsuhiko Sato
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Patent number: 4321519Abstract: An electronic timepiece of the type having a frequency dividing circuit, and a drive circuit for driving a motor having a rotor, a stator and a driving coil, is provided with a magnetic field detection device comprised of a low impedance closed loop including a low resistance element and the driving coil and a high impedance closed loop including a high resistance element and the driving coil. The driving coil develops an induced voltage when placed in an external alternating magnetic field and also functions to drive the rotor. The strength of the alternating magnetic field is measured by the voltage level developed across the high resistance element and the measuring sensitivity is improved by alternately switching between the low impedance closed loop and the high impedance closed loop.Type: GrantFiled: April 25, 1979Date of Patent: March 23, 1982Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Makoto Ueda, Akira Torisawa, Shuji Otawa, Masaaki Mandai, Masaharu Shida, Katsuhiko Sato
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Patent number: 4315329Abstract: A load measuring device for a stepping motor of an analogue electronic timepiece having a stator, a rotor and a coil includes a pulse generator for producing a range of different pulse width normal driving pulses and a driving circuit for successively applying the driving pulses to the motor. A detector detects the rotation and non-rotation state of the rotor in response to the application of each driving pulse and a control circuit is responsive to the detection by the detector for controlling the application by the driving circuit of the minimum pulse width normal driving pulse capable of driving the motor. Each minimum pulse width driving pulse corresponds to the load on the motor at that time and an analyzer analyzes the pulse width of the driving pulses to thereby indicate the load on the motor.Type: GrantFiled: May 24, 1979Date of Patent: February 9, 1982Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Akira Torisawa, Makoto Ueda, Masaharu Shida
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Patent number: 4312059Abstract: In an electronic timepiece, a motor is driven by a pulse having a shorter pulse width than the conventional driving pulse and afterwards, a detection pulse is applied to the motor coil so as to determine rotation of the rotor. If the rotor fails to rotate a correction is effected by driving the motor by a pulse having a pulse width greater than the normal driving pulse.Type: GrantFiled: April 20, 1978Date of Patent: January 19, 1982Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Masaaki Mandai, Akira Torisawa, Makoto Ueda, Kazuhiro Asano, Masaharu Shida, Katsuhiko Satoh
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Patent number: 4312058Abstract: In an electronic watch having a stepping motor, a battery voltage detecting circuit, a rotation detecting circuit for indicating rotation or non-rotation of the stepping motor and a motor driving power control circuit for applying a higher power drive pulse to the motor than a normal drive pulse upon detection of non-rotation, the operation of the rotation detecting circuit is inhibited upon indication of a low battery voltage condition and the motor is driven continuously with the higher power drive pulses for the extent of the battery low voltage condition. In this way, the electronic watch can be operated stably when the battery is at the end of its life and operated with lower power consumption during the time when the battery is operated at full voltage.Type: GrantFiled: April 20, 1978Date of Patent: January 19, 1982Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Masaharu Shida, Akira Torisawa, Makoto Ueda
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Patent number: 4276626Abstract: In an electronic watch having an oscillator for producing a time base signal and stepping motor, drive pulses are produced for normally driving the motor under normal load conditions. The rotation and non-rotation of the motor in response to the last drive pulse is detected in response to a detecting pulse, and if non-rotation has been detected, a predetermined plurality of correction pulses are applied to the motor for driving same, the correction pulses being sufficient to drive the motor under a high torque loading. In this way, power consumption is decreased since a high power driving is saved only for high torque loading conditions.Type: GrantFiled: April 20, 1978Date of Patent: June 30, 1981Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Katsuhiko Satoh, Kazuhiro Asano, Masaaki Mandai, Makoto Ueda, Akira Torisawa, Masaharu Shida
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Patent number: 4272837Abstract: An electronic timepiece including a dividing circuit for developing different output pulse signals having different respective pulse repetition rates, a stepping motor and a drive circuit responsive to control signals for driving the stepping motor at a normal rate and for applying a correction pulse to the stepping motor according to the control signals. A pulse combining circuit combines the different output pulse signals from the dividing circuit for generating control signals and for applying the control signals to the drive circuit. The pulse combining circuit normally generates a control signal effective to drive the stepping motor at a normal rate, and the pulse combining circuit is responsive to a correction signal to control the drive circuit to apply a corrective pulse to the stepping motor. A detection circuit detects rotation and non-rotation of the stepping motor rotor and generates a detection voltage signal indicative of the state of rotation of the rotor.Type: GrantFiled: April 20, 1978Date of Patent: June 9, 1981Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Makoto Ueda, Akira Torisawa, Katsuhiko Satoh, Masaharu Shida, Masaaki Mandai, Kazuhiro Asano
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Patent number: 4271496Abstract: An electronic timepiece including a stepping motor and a time-indicating hand moved in a stepwise manner by the stepping motor for indicating time. During normal operation the time-indicating hand moves at a normal periodic rate. When operating conditions such as a low battery cause the stepping motor to not rotate, correcting pulses are applied to the stepping motor to supply additional energy to it to cause it to rotate. Additionally, the correcting pulses cause the rotor, and the time-indicating hand to rotate at a rate different from the normal periodic rate to alert the timepiece user that some condition exists tending to cause non-rotation of the stepping motor.Type: GrantFiled: April 20, 1978Date of Patent: June 2, 1981Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Masaharu Shida, Akira Torisawa, Makoto Ueda, Masaaki Mandai, Katsuhiko Sato, Kazuhiro Asano
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Patent number: 4241434Abstract: An electronic timepiece includes a stepping motor having a coil and a rotor. Circuitry is provided for generating and applying alternating pulses to the motor coil to effect forward stepwise rotation of the motor rotor in a forward direction and for generating and applying alternating pulses to the motor coil to effect reverse stepwise rotation of the motor rotor in a reverse direction. The reverse rotation is achieved by sets of three alternating pulses with the first pulse of each set effecting incremental angular movement of the motor rotor in the forward direction followed by the second and third pulses which effect greater icremental angular movement of the motor rotor in the reverse direction to thereby obtain for each pulse set a net angular movement of the motor rotor in the reverse direction.Type: GrantFiled: June 14, 1978Date of Patent: December 23, 1980Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Masaharu Shida, Akira Torisawa, Makoto Ueda
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Patent number: 4217751Abstract: In an electronic timepiece having a stepping motor, a drive pulse is produced for normally driving the motor, a detecting pulse is generated for detecting whether the motor has rotated in response to the last drive pulse and a correction pulse is produced for driving the motor when non-rotation has been detected. A current limiting resistor is disposed in series with the motor for limiting the current thereto and a switching transistor is connected across the current limiting resistor to short circuit same to effect an increase in the current to the motor. During the detecting pulse, the voltage across the current limiting resistor is compared to a predetermined value.Type: GrantFiled: April 20, 1978Date of Patent: August 19, 1980Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Akira Torisawa, Makoto Ueda, Kazuhiro Asano, Katsuhiko Satoh, Masaaki Mandai, Masaharu Shida
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Patent number: 4209971Abstract: An electronic timepiece comprises a detection circuit provided with a resistance element which discriminates rotation and non-rotation of a stepping motor by variation of an oscillating circuit, a dividing circuit, a pulse composing circuit, a stepping motor driving circuit, a two phase driving system stepping motor and an inductance, wherein said resistance element is directly connected across a coil output of the stepping motor within an integrated circuit.Type: GrantFiled: April 20, 1978Date of Patent: July 1, 1980Assignee: Kabushiki Kaisha Daini SeikoshaInventors: Makoto Ueda, Masaharu Shida, Akira Torisawa