Motor Control Device and Image Forming Apparatus

A motor control device comprising:

• a motor control unit configured to control a motor;
• and
• a signal output unit configured to output a signal according to rotation of the motor, wherein the motor control unit controls the motor based on an output signal of the signal output unit so that a driven object, which is driven by the motor, is displaced to a target stop position,
• wherein the motor control unit is configured to function as:
• an earlier-stage control unit that operates in an earlier stage of the process of displacing the driven object up to a target stop position,
• a later-stage control unit that operates in a later stage of the process of displacing the driven object up to the target stop position, and
• a switching unit that sequentially switches the earlier-stage control unit and the later-stage control unit,
• wherein the earlier-stage control unit performs a earlier motor control, in which a current upper limit, which is an upper limit of current applicable to the motor and which is adjusted by current degradation caused by a counter-electromotive force, is estimated based on a rotation speed of the motor specified from an output signal of the signal output unit, and in which a earlier driving current corresponding to the estimated current upper limit is input to the motor,
• wherein the later-stage control unit performs a later motor control, in which a later driving current to be input to the motor is determined, based on both of at least one of a speed and a displacement amount, as an operation amount of one of the motor and the driven object, specified from the output signal of the signal output unit and a target trajectory of the operation amount, and in which the later driving current is input so that the driven object is displaced up to a target stop position along the target trajectory, and
• wherein, after a predetermined condition is satisfied after the motor control of the earlier-stage control unit finishes, the switching unit operates the later-stage control unit so that driving current is not input to the motor until the predetermined condition is satisfied after the motor control of the earlier-stage control unit finishes.