An electric pulse tool is configured to deliver torque in pulses on an output shaft thereof and includes an electric motor to drive the output shaft. The electric pulse tool is configured to, for each period, provide a current pulse to the electric motor during a current-on time interval, pause a current feed to the electric motor after the current-on time interval until an end of a torque pulse, determine a width of the torque pulse, and continue pausing the current feed to the electric motor during a pause interval from the end of the torque pulse. The pause interval is determined based on the width of the torque pulse such that a wider torque pulse results in a wider pause interval and a narrower torque pulse results in a shorter pause interval.

An electric pulse tool is configured to deliver torque in pulses on an output shaft thereof and includes an electric motor to drive the output shaft. The electric pulse tool is configured to, for each period, provide a current pulse to the electric motor during a current-on time interval, pause a current feed to the electric motor after the current-on time interval until an end of a torque pulse, determine a width of the torque pulse, and continue pausing the current feed to the electric motor during a pause interval from the end of the torque pulse. The pause interval is determined based on the width of the torque pulse such that a wider torque pulse results in a wider pause interval and a narrower torque pulse results in a shorter pause interval.

A motor drive control device includes a control unit generating a control signal Sd such that one-phase excitation of exciting, of coils and of two phases of a two-phase stepping motor, a coil for one phase and two-phase excitation of exciting the coils for two phases are alternately repeated, and a drive unit driving the coils of two phases based on the control signal Sd. An energization angle θ representing a magnitude of an electric angle for continuously energizing the coil of one phase in one direction is capable of being set in the control unit. Specifically, the control unit determines a period T1n for performing the one-phase excitation based on a back electromotive voltage generated in the coil non-excited in the one-phase excitation, and determines a period T2n for performing the two-phase excitation based on an elapsed time per unit angle while the two-phase stepping motor is being excited and the energization angle θ.

A motor drive control device includes a control unit monitoring a rotational state of a rotor of a two-phase stepping motor, setting an energization angle θ representing a magnitude of an electric angle for continuously energizing, of coils of two phases of the two-phase stepping motor, a coil of one phase in one direction based on the rotational state of the rotor, and generating a control signal Sd for controlling driving of the two-phase stepping motor based on the set energization angle θ, and a drive unit driving the coils of two phases based on the control signal Sd.

A motor control unit having a motor structure that rotates a rotor by voltage excitation includes a photo interrupter, a slit rotation plate, a comparator, and an encoder circuit in order to obtain a position detection signal corresponding to a rotational phase of an output shaft. During a period of time from the motor stopping to the change of the output of an encoder circuit after the supply of a drive voltage waveform, a CPU supplies a drive voltage waveform that is advanced by an advance angle amount that has been set in advance to the motor, and after the change of the output of the encoder circuit, a drive signal by which the advance angle amount is controlled based on the output of the encoder circuit is supplied to the motor.

A motor control unit having a motor structure that rotates a rotor by voltage excitation includes a photo interrupter, a slit rotation plate, a comparator, and an encoder circuit in order to obtain a position detection signal corresponding to a rotational phase of an output shaft. During a period of time from the motor stopping to the change of the output of an encoder circuit after the supply of a drive voltage waveform, a CPU supplies a drive voltage waveform that is advanced by an advance angle amount that has been set in advance to the motor, and after the change of the output of the encoder circuit, a drive signal by which the advance angle amount is controlled based on the output of the encoder circuit is supplied to the motor.

The present invention relates to a driving circuit and a driving method for a stepping motor, and an electronic machine using the same. A current value setting circuit generates a current setting value. A constant current chopper circuit generates a pulse modulation signal, which pulse-width modulates by having a detection value of a coil current flowing through a coil approach close to the current setting value. A logic circuit controls a bridge circuit connected to the coil of the stepping motor according to the pulse modulation signal. The current value setting circuit sets the current setting value to a predetermined full-torque setting value in a first period after rotation starts, reduces the current setting value to a predetermined second setting value less than the first setting value in the following second period, and switches to a high-efficiency mode and adjusts the current setting value by means of feedback control.

A linear drive for pigmentation devices, comprising a stator, an air gap which is provided in the stator and is formed so as to be offset in a defined manner, an electric coil within the stator, said coil being designed to produce a concentration of the magnetic flux in the air gap as a result of the coil being energized, an armature which is designed to carry out sliding axial movements in the stator, and a permanent magnet which is captively connected to the armature.

A motor drive control device includes a control unit generating a control signal Sd such that one-phase excitation of exciting, of coils and of two phases of a two-phase stepping motor, a coil for one phase and two-phase excitation of exciting the coils for two phases are alternately repeated, and a drive unit driving the coils of two phases based on the control signal Sd. An energization angle θ representing a magnitude of an electric angle for continuously energizing the coil of one phase in one direction is capable of being set in the control unit. Specifically, the control unit determines a period T1n for performing the one-phase excitation based on a back electromotive voltage generated in the coil non-excited in the one-phase excitation, and determines a period T2n for performing the two-phase excitation based on an elapsed time per unit angle while the two-phase stepping motor is being excited and the energization angle θ.

The present invention optimizes a current setting value within a short time. The present invention relates to a driving circuit and a driving method for a stepping motor, and an electronic machine using the same. A current value setting circuit generates a current setting value. A constant current chopper circuit generates a pulse modulation signal, which pulse-width modulates by way of having a detection value of a coil current flowing through a coil approach close to the current setting value. A logic circuit controls a bridge circuit connected to a coil of a stepping motor according to the Pulse modulation signal. The current value setting circuit sets the current setting value to a predetermined full-torque setting value in a first period after rotation starts, reduces the current setting value by a predetermined method to a predetermined second setting value less than the first setting value in the following second period, and switches to a high-efficiency mode and adjusts the current setting value by means of feedback control.