Image forming apparatus

An image forming apparatus comprising:

• a first roller configured to convey a sheet;
• a second roller configured to be adjacent to the first roller and installed on a downstream side from the first roller in a conveyance direction to which the sheet is conveyed;
• an image forming unit configured to form an image on the sheet;
• a motor configured to drive the first roller;
• a phase determiner configured to determine a rotation phase of a rotor of the motor;
• a controller configured to control a drive current flowing through a winding of the motor to reduce a deviation between a command phase representing a target phase of the rotor and the rotation phase determined by the phase determiner;
• a current detector configured to detect the drive current flowing through the winding;
• and
• a discriminator configured to determine a type of the sheet conveyed by the first roller based on a value of the drive current detected by the current detector in a state in which the sheet is deflected while being conveyed by the first roller and not conveyed by the second roller,
• wherein a conveyance path through which a sheet conveyed by the first roller passes is bent between the first roller and the second roller, and
• wherein the discriminator determines the type of the sheet conveyed by the first roller based on a value of the drive current detected by the current detector in a state in which the sheet is deflected by not being conveyed by the second roller but being conveyed by the first roller along a bending portion at which the conveyance path is bent.

An image forming apparatus comprising:

• a conveyance roller configured to convey a sheet;
• an abutment member configured to be installed in a downstream side from the conveyance roller in a conveyance direction to which the sheet is conveyed and be contacted by a leading edge of the sheet conveyed by the conveyance roller;
• an image forming unit configured to form an image on the sheet;
• a motor configured to drive the conveyance roller;
• a phase determiner configured to determine a rotation phase of a rotor of the motor;
• a controller configured to control a drive current flowing through a winding of the motor to reduce a deviation between a command phase representing a target phase of the rotor and the rotation phase determined by the phase determiner;
• a current detector configured to detect the drive current flowing through the winding;
• a discriminator configured to output a signal indicating a type of the sheet conveyed by the conveyance roller based on a value of the drive current detected by the current detector;
• a setting unit configured to set information of the sheet conveyed;
• and
• a notification unit configured to provide notice to a user based on the signal output from the discriminator,
• wherein the discriminator outputs a signal indicating the information of the sheet conveyed by the conveyance roller based on a value of the drive current detected by the current detector in a period in which the sheet is deflected by being conveyed by the conveyance roller to the conveyance direction in a state in which the leading edge abuts on the abutment member, and
• wherein, in a case that the information of the sheet set by the setting unit is different from the information of the sheet indicated by the signal output from the discriminator, the notification unit notifies that a sheet corresponding to the set information of the sheet is different from the sheet being conveyed.

An image forming apparatus comprising:

• a first roller configured to convey a sheet;
• a second roller configured to be adjacent to the first roller and installed on a downstream side from the first roller in a conveyance direction to which the sheet is conveyed;
• an image forming unit configured to form an image on the sheet;
• a motor configured to drive the first roller;
• a phase determiner configured to determine a rotation phase of a rotor of the motor;
• a controller configured to control a drive current flowing through a winding of the motor to reduce a deviation between a command phase representing a target phase of the rotor and the rotation phase determined by the phase determiner;
• a current detector configured to detect the drive current flowing through the winding;
• a discriminator configured to output a signal indicating a type of the sheet conveyed by the first roller based on a value of the drive current detected by the current detector;
• a first setting unit configured to set information of the sheet to be conveyed;
• and
• a second setting unit configured to set a setting value of the image forming unit,
• wherein a conveyance path through which a sheet conveyed by the first roller passes is bent between the first roller and the second roller,
• wherein the discriminator outputs a signal indicating the information of the sheet conveyed by the first roller based on a value of the drive current detected by the current detector in a state in which the sheet is deflected by not being conveyed by the second roller but being conveyed by the first roller along a bending portion at which the conveyance path is bent, and
• wherein, in a case that the information of the sheet set by the first setting unit is different from the information of the sheet indicated by the signal output from the discriminator, the second setting unit changes the setting value of the image forming unit to a setting value corresponding to the sheet indicated by the signal output from the discriminator.

An image forming apparatus comprising:

• a first roller configured to convey a sheet;
• a second roller configured to be adjacent to the first roller and installed on a downstream side from the first roller in a conveyance direction to which the sheet is conveyed;
• an image forming unit configured to form an image on the sheet;
• a motor configured to drive the first roller;
• a phase determiner configured to determine a rotation phase of a rotor of the motor;
• a controller configured to control a drive current flowing through a winding of the motor to reduce a deviation between a command phase representing a target phase of the rotor and the rotation phase determined by the phase determiner;
• a current detector configured to detect the drive current flowing through the winding;
• a discriminator configured to output a signal indicating a type of the sheet conveyed by the first roller based on a value of the drive current detected by the current detector;
• a setting unit configured to set information of the sheet conveyed;
• and
• a notification unit configured to provide notice to a user based on the signal output from the discriminator,
• wherein a conveyance path through which a sheet conveyed by the first roller passes is bent between the first roller and the second roller,
• wherein the discriminator outputs a signal indicating the information of the sheet conveyed by the first roller based on a value of the drive current detected by the current detector in a state in which the sheet is deflected by not being conveyed by the second roller but being conveyed by the first roller along a bending portion at which the conveyance path is bent, and
• wherein, in a case that the information of the sheet set by the setting unit is different from the information of the sheet indicated by the signal output from the discriminator, the notification unit notifies that a sheet corresponding to the set information of the sheet is different from the sheet being conveyed.

An image forming apparatus comprising:

• a first roller configured to convey a sheet;
• a second roller configured to be adjacent to the first roller and installed on a downstream side from the first roller in a conveyance direction to which the sheet is conveyed;
• an image forming unit configured to form an image on the sheet;
• a motor configured to drive the first roller;
• a speed determiner configured to determine a rotation speed of a rotor of the motor;
• a controller configured to control a drive current flowing through a winding of the motor to reduce a deviation between a command speed representing a target speed of the rotor and the rotation speed determined by the speed determiner;
• a current detector configured to detect the drive current flowing through the winding;
• and
• a discriminator configured to determine a type of the sheet conveyed by the first roller based on a value of the drive current detected by the current detector in a state in which the sheet is deflected while being conveyed by the first roller and not conveyed by the second roller,
• wherein the image forming unit includes:
• an image bearing member configured to bear a toner image,
• a development unit configured to develop the toner image on the image bearing member, and
• a transfer unit configured to transfer the toner image developed on the image bearing member by the development unit to the sheet,
• wherein the second roller is a roller for conveying the sheet in accordance with a transfer timing at which the transfer unit transfers an image to the sheet,
• wherein the controller controls the motor to deflect the sheet in such a manner that the first roller conveys the sheet in the conveyance direction in a state in which a leading edge of the sheet abuts on the second roller being in a stopped state, and
• wherein the discriminator determines the type of the sheet conveyed by the first roller based on a value of the drive current detected by the current detector in a period in which the first roller deflects the sheet.

An image forming apparatus comprising:

• a first roller configured to convey a sheet;
• a second roller configured to be adjacent to the first roller and installed on a downstream side from the first roller in a conveyance direction to which the sheet is conveyed;
• an image forming unit configured to form an image on the sheet;
• a motor configured to drive the first roller;
• a speed determiner configured to determine a rotation speed of a rotor of the motor;
• a controller configured to control a drive current flowing through a winding of the motor to reduce a deviation between a command speed representing a target speed of the rotor and the rotation speed determined by the speed determiner;
• a current detector configured to detect the drive current flowing through the winding;
• and
• a discriminator configured to determine a type of the sheet conveyed by the first roller based on a value of the drive current detected by the current detector in a state in which the sheet is deflected while being conveyed by the first roller and not conveyed by the second roller,
• wherein a conveyance path through which a sheet conveyed by the first roller passes is bent between the first roller and the second roller, and
• wherein the discriminator determines the type of the sheet conveyed by the first roller based on a value of the drive current detected by the current detector in a state in which the sheet is deflected by not being conveyed by the second roller but being conveyed by the first roller along a bending portion at which the conveyance path is bent.

An image forming apparatus comprising:

• a conveyance roller configured to convey a sheet;
• an abutment member configured to be installed in a downstream side from the conveyance roller in a conveyance direction to which the sheet is conveyed and be contacted by a leading edge of the sheet conveyed by the conveyance roller;
• an image forming unit configured to form an image on the sheet;
• a motor configured to drive the conveyance roller;
• a speed determiner configured to determine a rotation speed of a rotor of the motor;
• a controller configured to control a drive current flowing through a winding of the motor to reduce a deviation between a command speed representing a target speed of the rotor and the rotation speed determined by the speed determiner;
• a current detector configured to detect the drive current flowing through the winding;
• a discriminator configured to output a signal indicating a type of the sheet conveyed by the conveyance roller based on a value of the drive current detected by the current detector;
• a setting unit configured to set information indicating the type of the sheet to be conveyed by the conveyance roller;
• and
• a notification unit configured to provide notice to a user based on the signal output from the discriminator,
• wherein the discriminator outputs the signal based on a value of the drive current detected by the current detector in a period in which the sheet is deflected by being conveyed by the conveyance roller to the conveyance direction in a state in which the leading edge abuts on the abutment member, and
• wherein, in a case where the type of the sheet indicated by the information set by the setting unit is different from the type of the sheet indicated by the signal output from the discriminator, the notification unit notifies that the type of sheet indicated by the information set by the setting unit is different from the type of the sheet being conveyed.

An image forming apparatus comprising:

• a first roller configured to convey a sheet;
• a second roller configured to be adjacent to the first roller and installed on a downstream side from the first roller in a conveyance direction to which the sheet is conveyed;
• an image forming unit configured to form an image on the sheet;
• a motor configured to drive the first roller;
• a speed determiner configured to determine a rotation speed of a rotor of the motor;
• a controller configured to control a drive current flowing through a winding of the motor to reduce a deviation between a command speed representing a target speed of the rotor and the rotation speed determined by the speed determiner;
• a current detector configured to detect the drive current flowing through the winding;
• and
• a discriminator configured to output a signal indicating a type of the sheet conveyed by the first roller based on a value of the drive current detected by the current detector,
• wherein a conveyance path through which a sheet conveyed by the first roller passes is bent between the first roller and the second roller, and
• wherein the discriminator outputs the signal based on a value of the drive current detected by the current detector in a state in which the sheet is deflected by not being conveyed by the second roller but being conveyed by the first roller along a bending portion at which the conveyance path is bent.

A sheet conveying apparatus comprising:

• a first roller configured to convey a sheet;
• a second roller configured to be adjacent to the first roller and disposed on a downstream side from the first roller in a conveyance direction to which the sheet is conveyed;
• a motor configured to drive the first roller;
• a phase determiner configured to determine a rotation phase of a rotor of the motor;
• a controller configured to control a drive current flowing through a winding of the motor to reduce a deviation between a instructed phase indicating a target phase of the rotor and the rotation phase determined by the phase determiner, based on a torque current component for generating torque on the rotor which is represented in a rotating coordinate system based on the rotation phase determined by the phase determiner;
• a current detector configured to detect the drive current flowing through the winding;
• and
• a discriminator configured to output a signal indicating a type of the sheet conveyed by the first roller based on a value of the torque current component of the drive current detected by the current detector in a state in which the sheet is deflected while being conveyed by the first roller and not conveyed by the second roller.

A sheet conveying apparatus comprising:

• a first roller configured to convey a sheet;
• a second roller configured to be adjacent to the first roller and disposed on a downstream side from the first roller in a conveyance direction to which the sheet is conveyed;
• a motor configured to drive the first roller;
• a phase determiner configured to determine a rotation phase of a rotor of the motor;
• a speed determiner configured to determine a rotation speed of the rotor;
• a controller configured to control a drive current flowing through a winding of the motor to reduce a deviation between a instructed speed indicating a target speed of the rotor and the rotation speed determined by the speed determiner, based on a torque current component for generating torque on the rotor which is represented in a rotating coordinate system based on the rotation phase determined by the phase determiner;
• a current detector configured to detect the drive current flowing through the winding;
• and
• a discriminator configured to output a signal indicating a type of the sheet conveyed by the first roller based on a value of the torque current component of the drive current detected by the current detector in a state in which the sheet is deflected while being conveyed by the first roller and not conveyed by the second roller.