A drive apparatus according to the present invention includes a stepping motor that transmits power to a rotating shaft of a conveyance roller, a brushless motor that transmits power to the rotating shaft of the conveyance roller, a first controller that controls an operation of the stepping motor so that the stepping motor rotates at a constant speed, and a second controller that controls an operation of the brushless motor. The second controller switches control of the brushless motor between, in accordance with a conveyance state of the sheet, assist control in which power of the brushless motor assists a rotation of the stepping motor, brake control in which power of the brushless motor prevents the rotation of the stepping motor, and neutral control in which power of the brushless motor does not affect the rotation of the stepping motor.

A motor control device include a detector that detects a drive current flowing through a winding of a motor, a first determiner that determines a rotation phase of a rotor of the motor, using preset control values, a controller that controls the drive current to reduce a deflection between the rotation phase determined by the first determiner and an instructed phase representing a target phase of the rotor, a first discriminator that determines whether rotation of the motor is abnormal, and a second discriminator that identifies a type of a motor attached to the motor control device.

If the first discriminator determines that the rotation of the motor attached to the motor control device is abnormal, the controller sets a control value corresponding to the type of the motor identified by the second discriminator, as the control value that the first determiner uses when determining the rotation phase.

A sheet conveying device has a supporting frame that supports a pick-up roller and that moves downward when a sheet is fed, a stepping motor that rotates the pick-up roller and moves the supporting frame downward, and a control portion that starts driving the stepping motor when a job is started and then increases a frequency of the pulse signal to a target frequency. The control portion keeps the frequency of the pulse signal not more than of the target frequency at least until the pick-up roller touches the sheet first.

A sheet conveying apparatus includes: a plurality of conveyors provided along a sheet conveying direction; a plurality of main driving parts that is respectively provided to the plurality of conveyors and independently drives the conveyors; an auxiliary driving part that drives the plurality of conveyors; and a transmitter that transmits driving force between the plurality of conveyors and transmits driving force of the auxiliary driving part to the plurality of conveyors.

A sheet processing apparatus includes a conveying portion, a first stack portion on which sheets conveyed are stacked, a first regulating portion which regulates a position of a sheet bundle in a crossing direction crossing to the sheet transport direction, a second regulating portion which regulates a position of a sheet bundle in the conveying direction, a first binding portion binding a corner portion of the sheet bundle by a staple, a second binding portion which binds a corner portion of a sheet bundle without a staple, a second stack portion which stacks a sheet bundle discharged from the first stack portion, and a lifting-lowering motor which lifts and lowers the second stack portion. The lifting-lowering motor is located at a downstream, in the conveying direction, of a first binding position where the first binding portion binds a sheet bundle.

Provided is a paper-discharge apparatus that suppresses operating sound of the paper-discharge apparatus. A contact member changes the posture of the introduction guide by coming in contact with the introduction lever and rotating the introduction lever. A control unit sets a state in which paper is introduced to the paper-discharge-conveying unit to a non-contact state of the introduction lever and contact member, and sets a state when conveyed paper is guided to another discharge destination to a contact state of the introduction lever and the contact member. The control unit rotates the motor at a first speed and moves the contact member, and brings the contact member in contact with the introduction lever after setting the rotating speed of the motor to a second speed that is slower than the first speed.

A PWM signal generation unit generates a PWM signal based on a driving voltage so that a midpoint of the longer period out of an H level period and an L level period in each PWM period matches a midpoint of the PWM period. FETs of a full bridge circuit (a driving circuit) are driven according to a PWM signal, and a driving current that corresponds to an A-phase is supplied to a stepping motor. A current detector detects a driving current flowing through an A-phase winding of the motor based on a voltage that is generated across a shunt resistor, at a fixed time point that is in each PWM period and in the H level or L level period that is at the center of the PWM period.

A sheet conveying device has a supporting frame that supports a pick-up roller and that moves downward when a sheet is fed, a stepping motor that rotates the pick-up roller and moves the supporting frame downward, and a control portion that starts driving the stepping motor when a job is started and then increases a frequency of the pulse signal to a target frequency. The control portion keeps the frequency of the pulse signal not more than of the target frequency at least until the pick-up roller touches the sheet first.

A drive apparatus according to the present invention includes a stepping motor that transmits power to a rotating shaft of a conveyance roller, a brushless motor that transmits power to the rotating shaft of the conveyance roller, a first controller that controls an operation of the stepping motor so that the stepping motor rotates at a constant speed, and a second controller that controls an operation of the brushless motor. The second controller switches control of the brushless motor between, in accordance with a conveyance state of the sheet, assist control in which power of the brushless motor assists a rotation of the stepping motor, brake control in which power of the brushless motor prevents the rotation of the stepping motor, and neutral control in which power of the brushless motor does not affect the rotation of the stepping motor.

A sheet conveying apparatus includes: a plurality of conveyors provided along a sheet conveying direction; a plurality of main driving parts that is respectively provided to the plurality of conveyors and independently drives the conveyors; an auxiliary driving part that drives the plurality of conveyors; and a transmitter that transmits driving force between the plurality of conveyors and transmits driving force of the auxiliary driving part to the plurality of conveyors.