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.

A motor control apparatus includes a high-resolution encoder for position control and a low-resolution encoder for velocity control, position control means for generating a velocity command in accordance with a difference between a given position command and the output of the high-resolution encoder, and velocity control means for generating a current command in accordance with a difference between the velocity command and a detected velocity that is based upon the output of the low-resolution encoder. A velocity control cycle based upon the velocity control means is made faster than a position control cycle based upon the position control means.

A motor control apparatus includes a high-resolution encoder for position control and a low-resolution encoder for velocity control, position control means for generating a velocity command in accordance with a difference between a given position command and the output of the high-resolution encoder, and velocity control means for generating a current command in accordance with a difference between the velocity command and a detected velocity that is based upon the output of the low-resolution encoder. A velocity control cycle based upon the velocity control means is made faster than a position control cycle based upon the position control means.

Controlling a stepper motor. A stepper motor is driven towards an index position. An attempt is made to stop the stepper motor on the index position in a fashion that would ordinarily cause the stepper motor to ring at the index position. Characteristics of one or more subsequent pulses that would counteract the ringing are determined. The one or more determined subsequent pulses are issued to the stepper motor.

Controlling a stepper motor. A stepper motor is driven towards an index position. An attempt is made to stop the stepper motor on the index position in a fashion that would ordinarily cause the stepper motor to ring at the index position. Characteristics of one or more subsequent pulses that would counteract the ringing are determined. The one or more determined subsequent pulses are issued to the stepper motor.

A stepping motor driving device includes a table, a driving pulse control part, an interpolation number indicating part and a driving part. The table stores thinned data which is thinned from original data and designates a pulse width of a driving pulse relating to a slow-up control or a slow-down control of a stepping motor. The driving pulse control part sequentially reads the thinned data from the table at predetermined intervals, to interpolate the thinned data in accordance with a given interpolation number so as to generate interpolated data and to output the driving pulse with the pulse width designated by the thinned data or the interpolated data by sequentially using the thinned data and the interpolated date at predetermined intervals. The interpolation number indicating part indicates the interpolation number to the driving pulse control part. The driving part drives the stepping motor in accordance with the driving pulse.

A stepping motor driving device includes a table, a driving pulse control part, an interpolation number indicating part and a driving part. The table stores thinned data which is thinned from original data and designates a pulse width of a driving pulse relating to a slow-up control or a slow-down control of a stepping motor. The driving pulse control part sequentially reads the thinned data from the table at predetermined intervals, to interpolate the thinned data in accordance with a given interpolation number so as to generate interpolated data and to output the driving pulse with the pulse width designated by the thinned data or the interpolated data by sequentially using the thinned data and the interpolated date at predetermined intervals. The interpolation number indicating part indicates the interpolation number to the driving pulse control part. The driving part drives the stepping motor in accordance with the driving pulse.

A motor drive control device includes: a deceleration start position calculating unit that calculates a deceleration start position indicating an address at which a pulse period is stored, the pulse period being equal to or larger than a pulse period at the time of forced stopping and closest to the pulse period at the time of forced stopping among the pulse periods included in a driving information; a stop pulse number calculating unit that calculates the number of pulses required for stopping the motor at an exciting position; and a driving control unit that outputs a total number of pulses of a counted number of pulses and the number of pulses from the deceleration start position until the motor is stopped in forcibly stopping the motor, and outputs a shortage of the number of pulses required for stopping the motor calculated by the stop pulse number calculating unit.

A motor drive control device includes: a deceleration start position calculating unit that calculates a deceleration start position indicating an address at which a pulse period is stored, the pulse period being equal to or larger than a pulse period at the time of forced stopping and closest to the pulse period at the time of forced stopping among the pulse periods included in a driving information; a stop pulse number calculating unit that calculates the number of pulses required for stopping the motor at an exciting position; and a driving control unit that outputs a total number of pulses of a counted number of pulses and the number of pulses from the deceleration start position until the motor is stopped in forcibly stopping the motor, and outputs a shortage of the number of pulses required for stopping the motor calculated by the stop pulse number calculating 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.