A driving device for a stepping motor includes a motor driving circuit configured to generate a current waveform representing an electrical angle in synchronization with a mechanical angle of the stepping motor, and excite the stepping motor using the current waveform; a memory configured to store a value of the electrical angle; and a controller configured to: when a power supply to the stepping motor and the motor driving circuit is stopped, store a first value of the electrical angle held by the motor driving circuit in the memory; and when the power supply is resumed, replace a value of the electrical angle of the motor driving circuit with the first value while suppressing a rotational operation of the stepping motor.

A rotational stop position of a motor is accurately controlled. A motor driving control device (100) includes a BEMF detection unit (118) for detecting zero-cross of back electromotive force of a motor coil provided in a motor, and a CPU (101) for controlling driving of the motor by a 1-phase energization method and, without a position sensor, performing commutation based on the zero-cross of the back electromotive force detected by the BEMF detection unit (118), controlling driving of the motor based on a rotational speed corresponding to a drive voltage and a load, and performing extension control of a commutation time for each step from a calculated deceleration start step until the rotational speed of the motor decreases to a predetermined rotational speed or less for enabling the motor to stop at a desired stop position when the driving of the motor is stopped.

A rotational stop position of a motor is accurately controlled. A motor driving control device (100) includes a BEMF detection unit (118) for detecting zero-cross of back electromotive force of a motor coil provided in a motor, and a CPU (101) for controlling driving of the motor by a 1-phase energization method and, without a position sensor, performing commutation based on the zero-cross of the back electromotive force detected by the BEMF detection unit (118), controlling driving of the motor based on a rotational speed corresponding to a drive voltage and a load, and performing extension control of a commutation time for each step from a calculated deceleration start step until the rotational speed of the motor decreases to a predetermined rotational speed or less for enabling the motor to stop at a desired stop position when the driving of the motor is stopped.

A driving device for a stepping motor includes a motor driving circuit configured to generate a current waveform representing an electrical angle in synchronization with a mechanical angle of the stepping motor, and excite the stepping motor using the current waveform; a memory configured to store a value of the electrical angle; and a controller configured to: when a power supply to the stepping motor and the motor driving circuit is stopped, store a first value of the electrical angle held by the motor driving circuit in the memory; and when the power supply is resumed, replace a value of the electrical angle of the motor driving circuit with the first value while suppressing a rotational operation of the stepping motor.

A driving device for a stepping motor includes a motor driving circuit configured to generate a current waveform representing an electrical angle in synchronization with a mechanical angle of the stepping motor, and excite the stepping motor using the current waveform; a memory configured to store a value of the electrical angle; and a controller configured to: when a power supply to the stepping motor and the motor driving circuit is stopped, store a first value of the electrical angle held by the motor driving circuit in the memory; and when the power supply is resumed, replace a value of the electrical angle of the motor driving circuit with the first value while suppressing a rotational operation of the stepping motor.

A stepping motor control device is provided with a stopping position determination section and a drive control section. The stopping position determination section determines whether a mover stopping position during the holding state is a stabilized phase or a semistable phase. When it is determined that the mover stopping position is a semistable phase during the holding state by the stopping position determination section, and the control state of the stepping motor transitions from the holding state to the standby state in which the holding of the mover is released due to a trigger signal from a device or the holding state persisting for a fixed time, the drive control section changes the mover stopping position to one of the stabilized phases adjacent to the mover stopping position during the holding state.

A stepping motor control device is provided with a stopping position determination section and a drive control section. The stopping position determination section determines whether a mover stopping position during the holding state is a stabilized phase or a semistable phase. When it is determined that the mover stopping position is a semistable phase during the holding state by the stopping position determination section, and the control state of the stepping motor transitions from the holding state to the standby state in which the holding of the mover is released due to a trigger signal from a device or the holding state persisting for a fixed time, the drive control section changes the mover stopping position to one of the stabilized phases adjacent to the mover stopping position during the holding state.

A display device includes: a stepping motor; a concave mirror that moves in accordance with the operation of the stepping motor, the concave mirror reflecting display light emitted from a display unit toward the windshield; a lever part that moves together with the concave mirror; a drive unit for driving the stepping motor by a microstep drive system; a control unit for controlling the movement of the concave mirror by controlling the drive unit; and a stopper unit provided within the range of movement of the lever part. The drive unit is configured to detect the counter-electromotive force generated by the stepping motor when the lever part comes into contact with the stopper unit. The control unit determines the reference position when the movement of the concave mirror is controlled in accordance with the counter-electromotive force detected by the drive unit.

A display device includes: a stepping motor; a concave mirror that moves in accordance with the operation of the stepping motor, the concave mirror reflecting display light emitted from a display unit toward the windshield; a lever part that moves together with the concave mirror; a drive unit for driving the stepping motor by a microstep drive system; a control unit for controlling the movement of the concave mirror by controlling the drive unit; and a stopper unit provided within the range of movement of the lever part. The drive unit is configured to detect the counter-electromotive force generated by the stepping motor when the lever part comes into contact with the stopper unit. The control unit determines the reference position when the movement of the concave mirror is controlled in accordance with the counter-electromotive force detected by the drive unit.

A control device is a control device (1) configured to be switched between open control and servo control and control a stepping motor (3), and includes a control unit (11) configured to reduce a switching frequency to the servo control, to be switched to open control after being switched to servo control to stop a mover at a target position and determine a current supplied to the stepping motor (3) in the open control based on a current command value when the mover is stopped at the target position in the servo control when a deviation between a position of the mover and the target position is a predetermined threshold or more when control of stopping the mover of the stepping motor (3) at the target position through the open control is performed.