Abstract: A mechanical timepiece includes: a hairspring; a permanent magnet; a soft magnetic core; a control circuit for performing rate adjustment based on a counter-electromotive voltage caused in a coil by a motion of the permanent magnet accompanying a forward direction motion and a reverse direction motion of the balance wheel. The permanent magnet is arranged so that, under a state in which the hairspring is brought to an equilibrium length, a direction of magnetization is directed to the first end portion side or the second end portion side.

Abstract: A step motor drive device includes a step motor including a rotor, stators, and a coil, a drive circuit that outputs a drive signal including a plurality of partial signals that are output intermittently, a detecting circuit that detects an electromagnetic induced current that is generated in the coil after the partial signals are output, and a control unit that controls the drive circuit. The drive circuit outputs one of the partial signals included in the drive signal to the coil, and, in response to a change in an electromagnetic induced current generated in the coil after the partial signal is output, outputs a next partial signal to the coil. The control unit determines a control method of the step motor based on an interval of the plurality of partial signals, and controls the drive circuit based on the determined control method.

Abstract: A step motor drive device includes a step motor including a rotor, stators, and a coil, a drive circuit that outputs a drive signal including a plurality of partial signals that are output intermittently, a detecting circuit that detects an electromagnetic induced current that is generated in the coil after the partial signals are output, and a control unit that controls the drive circuit. The drive circuit outputs one of the partial signals included in the drive signal to the coil, and, in response to a change in an electromagnetic induced current generated in the coil after the partial signal is output, outputs a next partial signal to the coil. The control unit determines a control method of the step motor based on an interval of the plurality of partial signals, and controls the drive circuit based on the determined control method.

Abstract: Provided is an electronic watch which achieves a highest-speed fast-forward operation of a step motor based on various environments under which the watch is placed, and enables low-power driving.

Abstract: Provided is an electronic watch which achieves a highest-speed fast-forward operation of a step motor based on various environments under which the watch is placed, and enables low-power driving.

Abstract: Provided is an electronic timepiece, including: a step motor; a motor driver; a normal drive pulse generation circuit configured to output a normal drive pulse at a designated drive rank; a rotation detection pulse generation circuit configured to output a detection pulse; a rotation detection circuit which comprises at least a first detection mode determination circuit configured to conduct determination in a first detection mode and which is configured to detect rotation or non-rotation of a rotor; a rotation determination counter circuit configured to count a number of times that the rotation has been successively detected by the rotation detection circuit; a first detection mode determination counter circuit configured to count a number of times that a detection signal generated by the detection pulse becomes a predetermined detection pattern in the first detection mode; and a drive rank selection circuit configured to designate a drive rank of the normal drive pulse based on results of the counting condu

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.

Abstract: Provided is an electronic timepiece, including: a step motor; a motor driver; a normal drive pulse generation circuit configured to output a normal drive pulse at a designated drive rank; a rotation detection pulse generation circuit configured to output a detection pulse; a rotation detection circuit which comprises at least a first detection mode determination circuit configured to conduct determination in a first detection mode and which is configured to detect rotation or non-rotation of a rotor; a rotation determination counter circuit configured to count a number of times that the rotation has been successively detected by the rotation detection circuit; a first detection mode determination counter circuit configured to count a number of times that a detection signal generated by the detection pulse becomes a predetermined detection pattern in the first detection mode; and a drive rank selection circuit configured to designate a drive rank of the normal drive pulse based on results of the counting condu

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.

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.

Abstract: Provided is an electronic watch capable of, even if an indicating hand having a large moment of inertia is used, accurately determining success and failure of rotation. The electronic watch detects rotation by using a first detection mode determination circuit (12) and a second detection mode determination circuit (13). In the electronic watch, a timing counter (14) for measuring a time after an output of a normal drive pulse is followed by a detection pulse selection circuit (151) provided as changing means for changing a width or a frequency of a detection pulse in accordance with an output time of the detection pulse. The detection pulse detects the rotation and simultaneously serves as an electromagnetic brake for a rotor (10). The electromagnetic brake for the rotor (10) is controlled by changing the width or the frequency of the detection pulse in a predetermined period, thereby achieving an accurate rotation detection.

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.

Abstract: Provided is an electronic watch capable of, even if an indicating hand having a large moment of inertia is used, accurately determining success and failure of rotation. The electronic watch detects rotation by using a first detection mode determination circuit (12) and a second detection mode determination circuit (13). In the electronic watch, a timing counter (14) for measuring a time after an output of a normal drive pulse is followed by a detection pulse selection circuit (151) provided as changing means for changing a width or a frequency of a detection pulse in accordance with an output time of the detection pulse. The detection pulse detects the rotation and simultaneously serves as an electromagnetic brake for a rotor (10). The electromagnetic brake for the rotor (10) is controlled by changing the width or the frequency of the detection pulse in a predetermined period, thereby achieving an accurate rotation detection.