Motor control device, sheet conveying device, document feeding device, document reading device, and image forming apparatus

A motor control device comprising:

• a detector configured to detect a drive current flowing in a winding of a motor;
• a phase determiner configured to determine a rotation phase of a rotator of the motor based on the drive current detected by the detector;
• a speed determiner configured to determine a rotating speed of the rotator of the motor based on the drive current detected by the detector;
• a controller configured to perform control in a first mode for controlling the drive current flowing in the winding based on a torque current component so that deviation between an instructed speed indicating a target speed of the rotator and the rotating speed determined by the speed determiner becomes small, and in a second mode for controlling the drive current flowing in the winding based on a current having a predetermined magnitude, the torque current component being a current component represented in a rotating coordinate system based on the rotation phase determined by the phase determiner and being a current component that generates a torque in the rotator;
• and
• an outputter configured to output a signal, which indicates that a value of an excitation current component of the drive current is equal to or smaller than a threshold value, when the value of the excitation current component of the drive current detected by the detector is equal to or smaller than the threshold value in a condition that the second mode is executed and a value corresponding to the rotating speed of the rotator is larger than a predetermined value, the excitation current component being a current component represented in the rotating coordinate system and being a current component that affects an intensity of a magnetic flux passing through the winding.

A motor control device comprising:

• a detector configured to detect a drive current flowing in a winding of a motor;
• a phase determiner configured to determine a rotation phase of a rotator of the motor based on the drive current detected by the detector;
• a controller configured to perform control in a first mode for controlling the drive current flowing in the winding based on a torque current component so that deviation between an instructed phase indicating a target phase of the rotator and the rotation phase determined by the phase determiner becomes small, and in a second mode for controlling the drive current flowing in the winding based on a current having a predetermined magnitude, the torque current component being a current component represented in a rotating coordinate system based on the rotation phase of the rotator and being a current component that generates a torque in the rotator;
• and
• an outputter configured to output a signal, which indicates that a value of a torque current component of the drive current is larger than a threshold value when the value of the torque current component of the drive current detected by the detector is larger than the threshold value in a condition that the second mode is executed and a value corresponding to the rotating speed of the rotator is larger than a predetermined value.

A motor control device comprising:

• a detector configured to detect a drive current flowing in a winding of a motor;
• a phase determiner configured to determine a rotation phase of a rotator of the motor based on the drive current detected by the detector;
• a speed determiner configured to determine a rotating speed of the rotator of the motor based on the drive current detected by the detector;
• a controller configured to perform control in a first mode for controlling the drive current flowing in the winding based on a torque current component so that deviation between an instructed speed that expresses a target speed of the rotator and the rotating speed determined by the speed determiner becomes small, and in a second mode for controlling the drive current flowing in the winding based on a current having a predetermined magnitude, the torque current component being a current component represented in a rotating coordinate system based on the rotation phase determined by the phase determiner and being a current component that generates a torque in the rotator;
• and
• an outputter configured to output a signal, which indicates that a value of a torque current component of the drive current is larger than a threshold value when the value of the torque current component of the drive current detected by the detector is larger than the threshold value in a condition that the second mode is executed and a value corresponding to the rotating speed of the rotator is larger than a predetermined value.

A motor control device comprising:

• a detector configured to detect a drive current flowing in a winding of a motor;
• a phase determiner configured to determine a rotation phase of a rotator of the motor based on the drive current detected by the detector;
• and
• a controller configured to perform control in a first mode for controlling the drive current flowing in the winding based on a torque current component so that deviation between an instructed phase indicating a target phase of the rotator and the rotation phase determined by the phase determiner becomes small, and in a second mode for controlling the drive current flowing in the winding based on a current having a predetermined magnitude, the torque current component being a current component represented in a rotating coordinate system based on the rotation phase of the rotator and being a current component that generates a torque in the rotator;
• wherein
• the controller stops driving of the motor when the value of the excitation current component of the drive current detected by the detector is equal to or smaller than a threshold value in a condition that the second mode is executed and a value corresponding to the rotating speed of the rotator is larger than a predetermined value, the excitation current component being a current component represented in the rotating coordinate system and being a current component that affects an intensity of a magnetic flux passing through the winding, and
• the threshold value is set to a value equal to or larger than zero.

A motor control device comprising:

• a detector configured to detect a drive current flowing in a winding of a motor;
• a phase determiner configured to determine a rotation phase of a rotator of the motor based on the drive current detected by the detector;
• a speed determiner configured to determine a rotating speed of the rotator of the motor based on the drive current detected by the detector;
• and
• a controller configured to perform control in a first mode for controlling the drive current flowing in the winding based on a torque current component so that deviation between an instructed speed indicating a target speed of the rotator and the rotating speed determined by the speed determiner becomes small, and in a second mode for controlling the drive current flowing in the winding based on a current having a predetermined magnitude, the torque current component being a current component represented in a rotating coordinate system based on the rotation phase determined by the phase determiner and being a current component that generates a torque in the rotator,
• wherein
• the controller stops driving of the motor when the value of an excitation current component of the drive current detected by the detector is equal to or smaller than a threshold value in a condition that the second mode is executed and a value corresponding to the rotating speed of the rotator is larger than a predetermined value, the excitation current component being a current component represented in the rotating coordinate system and being a current component that affects an intensity of a magnetic flux passing through the winding, and
• the threshold value is set to a value equal to or larger than zero.

A motor control device comprising:

• a detector configured to detect a drive current flowing in a winding of a motor;
• a phase determiner configured to determine a rotation phase of a rotator of the motor based on the drive current detected by the detector;
• a controller configured to control the motor based on a current having a predetermined magnitude;
• and
• an outputter configured to output a signal, which indicates that a value of an excitation current component of the drive current is equal to or smaller than a threshold value when a value of the excitation current component of the drive current detected by the detector is equal to or smaller than the threshold value in a condition that a value corresponding to a rotating speed of the rotor of the motor controlled by the controller is larger than a predetermined value, the excitation current component being a current component represented in a rotating coordinate system based on the rotation phase determined by the phase determiner and being a current component that affects an intensity of a magnetic flux passing though the winding.

A motor control device comprising:

• a detector configured to detect a drive current flowing in a winding of a motor;
• a phase determiner configured to determine a rotation phase of a rotator of the motor based on the drive current detected by the detector;
• a controller configured to control the motor based on a current having a predetermined magnitude;
• and
• an outputter configured to output a signal, which indicates a value of a torque current component of the drive current is equal to or larger than a threshold value when a value of the torque current component of the drive current detected by the detector is equal to or larger than the threshold value in a condition that a value corresponding to the rotating speed of the rotator of the motor controlled by the controller is larger than a predetermined value, the torque current component being a current component represented in a rotating coordinate system based on the rotation phase determined by the phase determiner and being a current component which generates a torque in the rotator.

A sheet conveyance device comprising:

• a conveyance roller configured to convey a sheet;
• a motor configured to drive the conveyance roller;
• a detector configured to detect a drive current flowing in a winding of the motor;
• a phase determiner configured to determine a rotation phase of a rotator of the motor based on the drive current detected by the detector;
• a controller configured to perform control in a first mode for controlling the drive current flowing in the winding based on a torque current component so that deviation between an instructed phase indicating a target phase of the rotator and the rotation phase determined by the phase determiner becomes small, and in a second mode for controlling the drive current flowing in the winding based on a current having a predetermined magnitude, the torque current component being a current component represented in a rotating coordinate system based on the rotation phase of the rotator and being a current component, which generates a torque in the rotator;
• and
• an outputter configured to output a signal, which indicates that a value of an excitation current component of the drive current is equal to or smaller than a threshold value, when the value of the excitation current component of the drive current detected by the detector is equal to or smaller than the threshold value in a condition that the second mode is executed and a value corresponding to the rotating speed of the rotator is larger than a predetermined value, the excitation current component being a current component represented in the rotating coordinate system and being a current component that affects an intensity of a magnetic flux passing through the winding.

A document feed device comprising:

• a document stacking unit configured to stack document;
• a conveyance roller configured to convey the document;
• a motor configured to drive the conveyance roller;
• a detector configured to detect a drive current flowing in a winding of the motor;
• a phase determiner configured to determine a rotation phase of a rotator of the motor based on the drive current detected by the detector;
• a controller configured to perform control in a first mode for controlling the drive current flowing in the winding based on a torque current component so that deviation between an instructed phase indicating a target phase of the rotator and the rotation phase determined by the phase determiner becomes small, and in a second mode for controlling the drive current flowing in the winding based on a current having a predetermined magnitude, the torque current component being a current component represented in a rotating coordinate system based on the rotation phase of the rotator and being a current component becomes small, which generates a torque in the rotator;
• and
• an outputter configured to output a signal, which indicates that a value of an excitation current component of the drive current is equal to or smaller than a threshold value, when the value of the excitation current component of the drive current detected by the detector is equal to or smaller than the threshold value in a condition that the second mode is executed and a value corresponding to the rotating speed of the rotator is larger than a predetermined value, the excitation current component being a current component represented in the rotating coordinate system and being a current component that affects an intensity of a magnetic flux passing through the winding.

A document reading device comprising:

• a document stacking unit configured to stack document;
• a conveyance roller configured to convey the document;
• a reading unit configured to read the document conveyed by the conveyance roller;
• a motor configured to drive the conveyance roller;
• a detector configured to detect a drive current flowing in a winding of the motor;
• a phase determiner configured to determine a rotation phase of a rotator of the motor based on the drive current detected by the detector;
• a controller configured to perform control in a first mode for controlling the drive current flowing in the winding based on a torque current component so that deviation between an instructed phase indicating a target phase of the rotator and the rotation phase determined by the phase determiner becomes small, and in a second mode for controlling the drive current flowing in the winding based on a current having a predetermined magnitude, the torque current component being a current component represented in a rotating coordinate system based on the rotation phase of the rotator and being a current component becomes small, which generates a torque in the rotator;
• and
• an outputter configured to output a signal, which indicates that a value of an excitation current component of the drive current is equal to or smaller than a threshold value, when the value of the excitation current component of the drive current detected by the detector is equal to or smaller than the threshold value in a condition that the second mode is executed and a value corresponding to the rotating speed of the rotator is larger than a predetermined value, the excitation current component being a current component represented in the rotating coordinate system and being a current component that affects an intensity of a magnetic flux passing through the winding.

An image forming apparatus comprising:

• an image forming unit configured to form an image on a sheet;
• a motor configured to drive a load;
• a detector configured to detect a drive current flowing in a winding of the motor;
• a phase determiner configured to determine a rotation phase of a rotator of the motor based on the drive current detected by the detector;
• a controller configured to perform control in a first mode for controlling the drive current flowing in the winding based on a torque current component so that deviation between an instructed phase indicating a target phase of the rotator and the rotation phase determined by the phase determiner becomes small, and in a second mode for controlling the drive current flowing in the winding based on a current having a predetermined magnitude, the torque current component being a current component represented in a rotating coordinate system based on the rotation phase of the rotator and being a current component becomes small, which generates a torque in the rotator;
• and
• an outputter configured to output a signal, which indicates that a value of an excitation current component of the drive current is equal to or smaller than a threshold value, when the value of the excitation current component of the drive current detected by the detector is equal to or smaller than the threshold value in a condition that the second mode is executed and a value corresponding to the rotating speed of the rotator is larger than a predetermined value, the excitation current component being a current component represented in the rotating coordinate system and being a current component that affects an intensity of a magnetic flux passing through the winding.