Canon Kabushiki Kaisha

Yuta Nito

Tomohiro Kawamoto

An apparatus according to the aspect of the embodiments includes a phase determiner configured to determine a rotational phase of a rotor, a speed determiner configured to determine a rotational speed of the rotor, a controller having a first control mode for controlling the motor by supplying constant currents to windings, and a discriminator configured to discriminate whether a rotation of the motor is abnormal based on the rotational speed when the rotational speed corresponding to a command speed is equal to or higher than a predetermined value in a state where the controller is controlling the motor in the first control mode. When a signal output from the discriminator indicates that the rotation of the motor is abnormal, the controller stops the motor. When the signal output from the discriminator indicates that the rotation is not abnormal, the controller continues a drive of the motor.

Motor control apparatus, sheet conveyance apparatus, and image forming apparatus

An image forming apparatus according to the present disclosure includes a power supply circuit, a driving circuit, an opening/closing unit, a first switch configured to switch to a connected state and a disconnected state, at least one processor including a first mode for executing vector control for controlling the driving circuit and a second mode for controlling the driving circuit. The at least one processor is configured to determine a rotational phase using a detected current and a set control value, to control the driving circuit, to execute discriminating a type of the motor based on the detected current in the second mode, and to set the control value based on a result of the discriminating. The result based on the detected current in a state where the first switch is in the disconnected state is not used to set the control value.

Image forming apparatus

A motor control device includes a driving circuit, a generator configured to generate a pulse-width modulation (PWM) signal, a resistor, an amplifier, a detector configured to detect a driving current flowing through a winding based on the signals output from the amplifier, a phase determiner configured to determine a rotational phase using the driving current detected by the detector and a control value set in advance, a controller configured to control the driving current based on a torque current component so that a deviation between the rotational phase and an instruction phase becomes small, and a setting unit configured to set the control value based on both a local maximum value and a local minimum value of the driving current flowing through the winding by a voltage applied to the winding based on the PWM signal of which a duty cycle is set to a predetermined value.

Motor control device and image forming apparatus

A motor control device includes a phase determiner, a detector, and a controller configured to control the driving current so that a deviation between a value of a torque current component of the driving current detected by the detector and a target value of the torque current component is reduced, and perform field weakening for weakening an intensity of magnetic flux through the winding. In a state where a value corresponding to a rotational velocity is greater than a first predetermined value, the controller sets a degree of the field weakening to a first degree in a case where the value of the torque current component is greater than a second predetermined value, and sets the degree of the field weakening to a second degree smaller than the first degree in a case where the value of the torque current component is smaller than the second predetermined value.

Motor control device, sheet conveying apparatus, and image forming apparatus

A sheet conveyance apparatus includes a connection member to connect or separate a motor to drive a conveyance roller, where a motor rotor has a rotation phase and a motor winding includes a driving current controlled by a controller. Per control by the controller, a value of a torque current component of a detected driving current becomes a target value of the torque current component and a value of an exciting current component of the detected driving current becomes a target value of the exciting current component. The controller can cause a deviation between a rotor target phase and a determined rotation phase to decrease, cause magnetic flux passing through the winding to be weaker than a magnetic flux of the rotor, and cause the magnetic flux to be stronger than that passing through the winding in a first period.

Sheet conveyance apparatus and image forming apparatus

A sheet conveying apparatus for conveying a sheet includes a conveyance roller, a motor, a phase determiner, and a controller. The phase determiner determines a rotor rotation phase of the motor that drives the conveyance roller to convey the sheet. The controller controls so that a value of a rotor torque current component becomes a target value of the torque current component and controls so that an excitation current component value becomes a target value of the excitation current component, and controls to reduce a deviation between a command phase and the determined rotation phase. The controller controls so that a magnetic flux penetrating through a winding is weaker than a magnetic flux of the rotor, and so that a magnetic flux penetrating through the winding in a second period is stronger than the magnetic flux penetrating through the winding in the first period.

Sheet conveying apparatus and image forming apparatus

A motor control apparatus operates in a first control mode in which the values of a torque current component and an excitation current component are controlled so that the difference between an instruction phase and a rotation phase is decreased and a second control mode in which constant current is supplied to a winding of a motor. The second control mode is switched to the first control mode if the rotation speed is varied from a value lower than a first threshold value to a value not lower than the first threshold value in the second control mode and the first control mode is kept even if the rotation speed is varied from a value not lower than the first threshold value to a value that is not lower than a second threshold value and that is lower than the first threshold value in the first control mode.

Motor control apparatus, sheet conveying apparatus, image forming apparatus

A motor control apparatus that performs a drive control of a motor includes a current detector configured to detect a driving current flowing in a winding of the motor, a calculator configured to calculate an estimated value indicating a rotational position of a rotor of the motor by an estimation computation based on a value of the driving current detected by the current detector, and a corrector configured to correct the estimated value of the rotational position based on a rotation amount of the rotor in a predetermined period from a start of the estimation computation by the calculator until completion of the estimation computation. In addition, a controller controls the driving current flowing in the winding of the motor so that a deviation between the estimated value corrected by the corrector and an instructed value indicating a target position of the rotor is reduced.

Motor control apparatus and image forming apparatus

A driving device of a rotating polygonal mirror which stops supply of a driving current or reduces output of the driving current in a state where the driving current is supplied to a driving motor, and detects a period of an FG signal based on a detected waveform output from a detection element in the state where the driving current is stopped.

Driving device of rotating polygonal mirror and image forming apparatus including the driving device

A light emission apparatus includes a detection unit, a first drive unit, and a second drive unit. The detection unit detects the state of a detection element. The first drive unit controls the light amount of a light beam to be emitted by a first light emitting element based on the state of the detection element detected by the detection unit. The second drive unit controls the light amount of a light beam to be emitted by a second light emitting element based on the state of the detection element detected by the detection unit.

Light emission apparatus, optical scanning apparatus having light emission apparatus, and image forming apparatus

A method for generating a BD signal and identifying a reflection surface after a polygonal mirror has reached approximately constant rotation speed increases time to start image formation because the step of generating the BD signal is needed. An image forming apparatus identifies a reflection surface on which a light beam is incident by using the period of an FG signal.

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Matsudo, Japan

Yuta Nito