Patent ID: 8848492
Filing Date: 2014-09-30
Classification: G04C,G04G,H02P

Abstract:
1. An electronic watch, comprising: a power source; a stepper motor for driving an indicator; a motor driver for driving the stepper motor; a motor control circuit for outputting a control signal for controlling the stepper motor to the motor driver; a drive pulse output circuit for outputting a drive pulse for driving the stepper motor to the motor driver; and a recovery pulse output circuit for outputting, in a vicinity of a peak position of a waveform of an induced current resulting from free oscillation of a rotor of the stepper motor after the output of the drive pulse, a recovery pulse having such a level that the rotor does not rotate, wherein the motor control circuit outputs the drive pulse and the recovery pulse in a switching manner so that electric power of the induced current is regenerated into the power source when the recovery pulse is output, further comprising: a rotation detection pulse output circuit for outputting a rotation detection pulse used for detecting the waveform of the induced current to the stepper motor control circuit; a rotation detection circuit for determining presence or absence of rotation of the stepper motor based on the waveform of the induced current detected by the rotation detection pulse; and an adjustment circuit for controlling operations of the rotation detection pulse output circuit and the recovery pulse output circuit in order to prevent an erroneous determination on the presence or absence of the rotation performed by the rotation detection circuit.