Seiko Epson Corporation

Takashi Kawaguchi

Reiko Nagahama

Teruhiko Fujisawa

Makoto Okeya

Jun Matsuzaki

Hiroshi Yabe

Akihiko Maruyama

Yutaka Yamazaki

Fumiaki Miyahara

Masaru Kubota

Joji Kitahara

Shinji Nakamiya

Akihiro Sawada

Kenji Sakamoto

Tatsuo Moriya

Masato Yoshino

Keiichiro Oguchi

Yoshitaka Iijima

Hidenori Nakamura

Kunio Koike

Hidehiro Akahane

Shuichi Tamura

Katsuaki Karasawa

Hidenori Makiba

Hideyuki Arai

Hiroyuki Kubo

Youichi Hayashi

Mikiko Ito

An electronic watch includes a driver controlled to be in an ON state in which a drive current is supplied to a coil of a watch motor, and an OFF state in which the drive current is not supplied, a current detector that detects a current value flowing through the coil, a driver controller that controls the driver, a polarity switching controller that alternately switches a polarity of the drive current to a first polarity and a second polarity, a sampling controller that, at a sampling cycle, intermittently causes the current detector and the driver controller to operate, and a sampling cycle setting controller that detects a sampling cycle setting condition and changes the sampling cycle in at least two stages of a first cycle and a second cycle longer than the first cycle.

Watch motor control circuit, electronic watch, and watch motor control method

Provided is an electronic timepiece capable of suppressing variation in the drive speed of a rotor, and driving a motor at a constant speed. The electronic timepiece has a driver; a controller that controls the driver to the on state or the off state according to a current flowing through a coil of a motor; a detection signal output device configured to output a detection signal when the on time or the off time, which are the continuous time of the on state and off state of the driver, meets a specific condition; a reference signal output device that outputs a reference signal used as a reference of a drive speed of the motor; and a drive cycle adjuster that compares the output timing of the detection signal and the reference signal, shortens the drive cycle when the detection signal is output after the reference signal, and when the detection signal is output before the reference signal, lengthens the drive cycle of the motor.

Electronic timepiece, movement, and motor control circuit

An electronic timepiece enables driving by appropriate drive conditions even when the load on a motor changes. The electronic timepiece includes a motor having a coil; a driver that is controlled to an on state supplying drive current to the coil, and an off state not supplying the drive current; a driver controller configured to control the driver to the on state or the off state based on a control parameter and current value through the coil; and a control parameter setter configured to maintain or change the control parameter based on the on state or the off state control state of the driver controller.

An electronic watch includes a motor including a coil, a driver controlled to an ON state for supplying a driving current to the coil and an OFF state for not supplying the driving current, a driver controller configured to control the driver to the ON state or the OFF state depending on a value of a current flowing through the coil, and a polarity switcher configured to switch a polarity of the driving current when a prescribed condition is satisfied after detecting that an ON time, which is a duration of the ON state of the driver controller, reaches a maximum.

Electronic watch and method for controlling electronic watch

A motor control circuit includes a driver having ON and OFF states, and outputs a drive signal to a coil of a motor, a lower limit detector detecting whether current flowing through the coil is less than a lower limit, an upper limit detector detecting whether current flowing through the coil is more than an upper limit, a drive controller placing the driver into the ON state based on a detection result in the lower limit detector after the driver is brought into the OFF state, and placing the driver into the OFF state when the upper limit detector detects that the current is more than the upper limit after a predetermined time elapses from the driver being placed in the ON state, and a polarity switcher switching a polarity of the drive signal when an OFF time of the driver satisfies a polarity switching condition.

Motor control circuit, movement, and electronic timepiece

An electronic timepiece detects an external magnetic field without using a magnetic sensor. The electronic timepiece has a driver that drives a motor; a current detector that detects a current value flowing through a coil of the motor; a controller that controls the driver to the on state or the off state according to the detected current value; a polarity changer that alternately changes the polarity of the drive current to a first polarity and a second polarity when an on time, which is a continuous time of the on state, meets a specific condition; a counter that counts the number of on states in the first polarity and the number of on states in the second polarity; and an external magnetic field detector that detects an external magnetic field based on a result of comparing the counted number of on states in the first polarity and the second polarity.

Electronic timepiece and motor controller

A movement includes a driver having ON and OFF states, and outputting a drive signal to a coil of a motor, a lower limit detector detecting that a current flowing through the coil is less than a lower limit, a drive controller bringing the driver into the ON state based on a result of the lower limit detector, and bringing the driver into the OFF state based on an elapsed time from the ON state, a polarity switcher switching a polarity of the drive signal when an elapsed time from the OFF state of the driver satisfies a switching condition, and a drive stopper stopping driving of the driver when the OFF time satisfies a stopping condition.

Movement and electronic timepiece

An electronic timepiece can prevent overrunning when driving a motor at a high speed. The electronic timepiece has a controller that controls a driver to an on state or an off state according to the current value detected by the current detector; a polarity changer that determines driving one step of the motor ended and changes the polarity of the drive current when the on time or off time is detected to meet a specific condition; and a drive period adjuster that sets the terminal supplying the drive current to the coil to a first state if the remaining drive step count is greater than the remaining count evaluation number, and if the remaining drive step count is less than or equal to the remaining count evaluation number, sets the terminal to a second state in which the brake force applied to the rotor is greater than in the first state.

Electronic timepiece and motor control circuit

Provided is a motor drive circuit capable of driving a stepper motor even if the load on the stepper motor varies. A motor drive circuit has a first drive circuit that outputs a first drive signal to the driver; a second drive circuit that outputs a second drive signal to the driver; a controller that controls the first drive circuit and second drive circuit. The first drive circuit is configured to output a first drive signal based on the current value of current flow of a coil of a stepper motor. The second drive circuit is configured to output multiple types of second drive signals that differ by the supply time of drive current supplied to the coil. Based on a result of driving by the first drive circuit, the controller selects the type of second drive signal the second drive circuit outputs.

Movement, electronic timepiece, and motor drive control method

An electronic device that has a secondary battery and a controller which receives power supply from the secondary battery so as to perform a drive control on one or other multiple circuits driven by receiving the power supply from the secondary battery includes an initializing unit that starts processing for outputting an initializing signal to instruct the controller to perform initializing at predetermined timing, in response to a starting point in which a voltage of the secondary battery becomes equal to or lower than a first threshold voltage which is set to be higher than an operation-guaranteed voltage of the controller and a lower state thereof continues for a predetermined period of time.

Electronic device and method of initializing controller of electronic device

A time measurement device includes: a higher-digit indication hand that is configured to indicate a higher digit of a measured time; a lower-digit indication hand that is configured to reciprocate and indicate a lower digit of the measured time on a forward route and on a return route; a first drive unit that is configured to drive the higher-digit indication hand; a second drive unit that is configured to drive the lower-digit indication hand; a time counter that is configured to measure a time; a first drive controller that is configured to control the first drive unit to drive the higher-digit indication hand based on the measured time measured by the time counter; and a second drive controller that is configured to control the second drive unit to drive the lower-digit indication hand based on the measured time measured by the time counter, the second drive controller reciprocating the lower-digit indication hand at a predetermined period, and the first drive controller moving the higher-digit indication hand at a time interval equal to or less than a half of the predetermined period.

Time measurement device

An electronic timepiece with a generator function, including a generating means, a storage means that stores electrical energy produced by the generating means, a timekeeping control means that is driven by the electrical energy stored in the storage means, a time display means that is controlled by the timekeeping control means and displays time, a power generation detection means that detects the power generation state of the generating means, and a power generation display means that displays the power generation state based on a detection result signal output from the power generation detection means. The power generation detection means includes a hand and an actuator that drives the hand in both forward and reverse directions.

Electronic timepiece with generator function

An electronic timepiece with a generator function, including a generator, a battery or the like that stores electrical energy produced by the generator, a timekeeping controller that is driven by the stored electrical energy, a time display that is controlled by the timekeeping controller and displays time, a generator output detector that detects peaks of an electrical characteristic of the power generated by the generator, a remaining operating time calculator that integrates the average values corresponding to detected peaks and calculates a remaining operating time, and a remaining operating time display that displays the remaining operating time calculated by the remaining operating time calculator.

An electronic device comprising a power source, a piezoelectric actuator A, and a drive control apparatusfor controlling the driving of the piezoelectric actuator, wherein the drive control apparatusis provided with a drive circuitfor supplying a drive signal SDR to the piezoelectric element of the vibrating body, a phase difference detection meansfor detecting the phase difference indicating the vibration state of the vibrating body, a comparison voltage setting circuitfor correcting the target phase difference to be the target for the vibration state, and a drive frequency setting meansfor comparing the phase difference with the target phase difference; and the piezoelectric actuator A can be driven with high efficiency independent of the drive voltage by modifying the drive frequency of the drive signal SDR so that the phase difference approaches the target phase difference based on the results of the above comparison.

Drive apparatus of piezoelectric actuator, electronic apparatus, drive method of electronic apparatus, drive control program of electronic apparatus, and medium

In an electronic devicecomprising a batteryand a piezoelectric actuator A, a power source voltage before drive control is started is maintained by a sample holding circuita reference voltage is set by a reference voltage generating circuiton the basis of the power source voltage, and a control circuitstops driving when the power source voltage falls below a drive stop voltage as compared by a second comparison circuitand begins driving the piezoelectric actuator A again when the power source voltage exceeds the reference voltage as compared by a first comparison circuitTherefore, the device can be more easily reduced in size by using a small power source, and the driving time can be markedly reduced using an intermittent driving procedure that corresponds to the conditions of the battery voltage.

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Shiojiri, Japan

Takashi Kawaguchi