Seiko Instruments Inc

Seiko Watch Kabushiki Kaisha

Tetsuya Nobe

Kazumi Sakumoto

Kosuke Yamamoto

Satoshi Sakai

Akihito Okumura

Akihiro Iino

Keisuke Tsubata

Takayuki Satodate

Tamotsu Maesawa

Ayako Inoue

A stepping motor control device includes a driving unit that drives a stepping motor including a rotor that rotates a hand and a coil that generates a magnetic flux for rotating the rotor, a control unit that outputs, to the driving unit, a driving pulse for rotating the rotor and a swinging pulse for swinging the rotor, a voltage detecting unit that detects an induced voltage generated in the coil when the rotor vibrates, and a determining unit that determines, based on a result of the detection of the voltage detecting unit, a mechanical load received by the rotor.

Stepping motor control device, movement, timepiece, and stepping motor control method

A motor driving apparatus including a driving circuit for supplying a first pulse with which a first coil included in a two-phase stepping motor generates a first magnetic flux, a second pulse with which a second coil included in the stepping motor generates a second magnetic flux opposite to the first magnetic flux, a third pulse with which the first coil generates the second magnetic flux, and a fourth pulse with which the second coil generates the first magnetic flux, to the stepping motor. The driving circuit supplies the second pulse, the third pulse, and the fourth pulse in this order to the stepping motor in a state of being stopped to start the stepping motor, and supplies the first pulse, the second pulse, the third pulse, and the fourth pulse in this order to the stepping motor after starting to continuously drive the stepping motor.

Motor driving apparatus, motor driving method, and timepiece

A timepiece includes a stepping motor having a rotor and a coil, and a drive circuit that applies a first drive pulse having a stable stationary position at a rotor rotation angle of 90 degrees or less from a reference position and a second drive pulse having the stable stationary position at a rotor rotation angle of 90 degrees or more from the reference position, as a pulse for driving the rotor, to the coil. When a period during which the pulse is not applied to the coil is assumed as a waiting period, the drive circuit generates the waiting period after a first application of the second drive pulse after an application of the pulse to the coil is started and rotates the rotor by one or more turns without passing through the waiting period at at least one predetermined timing after the waiting period.

Timepiece and motor control method

A motor driving apparatus is a pulse generation circuit applying a drive pulse for rotating a rotor to a two stepping motor including the rotor magnetized in two poles and a stator in which a two-phase coil is wound around a yoke. The drive pulse is constituted of a drive pulse Pand a drive pulse P. The pulse generation circuit applies the drive pulse Phaving a stable stationary position at which a rotor rotation angle from a reference position is 90 degrees or less and applies the drive pulse Phaving a stable stationary position at which the rotor rotation angle from the reference position is 90 degrees or more continuously to the application of the drive pulse P

Motor driving apparatus, motor control method, and timepiece

A proposed electronic apparatus is capable of charging a secondary battery and performing data communication using a solar cell while suppressing effects of ambient light even when the intensity of light radiated to the solar cell is low. The electronic apparatus includes a control circuitand a resistance. The control circuitreceives data based on an output voltage of a solar cell. The resistanceis connected between electrodes of the solar cell. The control circuitcontrols a resistance value of the resistancebased on whether during an operation of receiving data or not.

Electronic apparatus and control method

An electronic apparatus includes an outer case, and a piezoelectric element mounted to an inner surface of the outer case and configured to impart vibration to the outer case due to deformation in correspondence with an applied voltage and to generate a voltage corresponding to deformation due to a shock imparted to the outer case. An induction element applies an increased voltage to the piezoelectric element, a first switch performs control as to whether or not to supply an electric current from a power source to the induction element, a second switch effects connection or disconnection between the induction element and the piezoelectric element, and a shock detection unit to detects a shock imparted to the outer case based on the voltage generated in the piezoelectric element.

Electronic apparatus and shock detection method

An electric motor has a rotor having an end portion and a recessed portion formed at the end portion. A rotational shaft is mounted to the rotor. A stator covers an outer peripheral portion of the rotor and forms a magnetic field that generates a torque around the rotational shaft to thereby rotate the rotational shaft and the rotor. A bearing rotatably supports the rotational shaft and is entirely spaced-apart from the end portion of the rotor in an axial direction of the rotational shaft. A slider is slidably mounted around the rotational shaft and supports rotation of the rotational shaft about a rotational axis thereof. The slider is interposed between the bearing and the rotor so that a portion of the slider is entirely contained in the recessed portion of the rotor and the remaining portion of the slider is disposed in the space between the bearing and the rotor and in contact with the bearing.

Growing community of inventors

Chiba, Japan

Tetsuya Nobe