Abstract: A control device includes a controller that determines, based on physical property information corresponding to physical property of a recording sheet and read information on an image evaluated as abnormal through reading of an image on the recording sheet by a reading section on a recording sheet conveyance path, a process condition under which an image forming section performs image forming on the recording sheet.

Abstract: A driving device includes: a first motor that transmits power to a rotation shaft of a conveyance roller for conveying a paper sheet; a second motor that transmits power to the rotation shaft of the conveyance roller; and a motor controller that controls rotational speeds of the first and second motors by changing a control value, wherein the motor controller controls the control value of the first motor at multiple steps at a time of acceleration or deceleration and changes the control value of the second motor according to a change range of the control value of the first motor in synchronization with a timing when the control value of the first motor is changed.

Abstract: A motor drive device controls driving of a plurality of motors that rotate a common drive shaft, and includes: a motor drive device that outputs the same drive power to each motor of the plurality of motors, and includes a motor drive controller that controls the drive power, using a rotation speed detection signal of a motor of the plurality of motors as a feedback signal; and a controller that determines a drive abnormality from the rotation speed detection signal of the motor or the drive power of the motor, wherein the controller determines a motor abnormal state and an overloaded state, from the drive power of the motor.

Abstract: A motor drive apparatus drives and controls a plurality of motors that rotate a common drive shaft. The motor drive apparatus includes a motor drive hardware processor that outputs equal drive power to each of the plurality of motors, and manipulates the drive power with a rotational speed detection signal of any one of the plurality of motors as a feedback signal. The feedback signal is switched based on conditions such as responsiveness and efficiency.

Abstract: An image forming device includes a resist roller feeding a sheet of paper toward an image forming unit; a first detector arranged upstream of the resist roller in a feeding direction to detect a front edge of the sheet of paper; a first calculator computing a first misalignment amount of the sheet of paper based on detection results by the first detector; a corrector correcting misalignment of the sheet of paper based on the computed first misalignment amount; a second detector arranged downstream of the resist roller in the feeding direction to detect a position of an end of the sheet of paper in a widthwise direction; a second calculator computing a second misalignment amount of the sheet of paper based on detection results by the second detector; and an adjuster adjusting a correction amount by the corrector based on the computed second misalignment amount.

Abstract: A driving device includes: a first motor that transmits power to a rotation shaft of a conveyance roller for conveying a paper sheet; a second motor that transmits power to the rotation shaft of the conveyance roller; and a motor controller that controls rotational speeds of the first and second motors by changing a control value, wherein the motor controller controls the control value of the first motor at multiple steps at a time of acceleration or deceleration and changes the control value of the second motor according to a change range of the control value of the first motor in synchronization with a timing when the control value of the first motor is changed.

Abstract: A fixing device includes a first fixing section, a second fixing section, the first fixing section and the second fixing section forming a fixing nip therebetween, a nip width adjusting section capable of adjusting a nip width of the fixing nip, a rotation speed detecting section that detects a rotation speed of the second fixing section, and a hardware processor that controls the nip width adjusting section to make the nip width equal to a predetermined reference nip width.

Abstract: A fixing device includes a first fixing section, a second fixing section, the first fixing section and the second fixing section forming a fixing nip therebetween, a nip width adjusting section capable of adjusting a nip width of the fixing nip, a rotation speed detecting section that detects a rotation speed of the second fixing section, and a hardware processor that controls the nip width adjusting section to make the nip width equal to a predetermined reference nip width.

Abstract: An image forming apparatus that controls to cut off exciting currents supplied to a plurality of motors to drive conveyance roller pairs after a leading end of a paper sheet is brought in contact with a registration roller pair, and, when cutting off the exciting currents, cut off the exciting current for at least one of the motors at a different timing from the other motors.

Abstract: An image forming apparatus includes: an image holder that holds a toner image; a transferer that is disposed opposite to the image holder so as to be in contact with the image holder and transfers the toner image from the image holder onto a recording sheet that is going through a contact part where the transferer contacts the image holder, by applying a transfer voltage between the transferer and the image holder; a first power source that applies a voltage of a first polarity to the image holder; and a second power source that applies a voltage of a second polarity, which is reverse to the first polarity, to the transferer.

Abstract: An image forming apparatus that controls to cut off exciting currents supplied to a plurality of motors to drive conveyance roller pairs after a leading end of a paper sheet is brought in contact with a registration roller pair, and, when cutting off the exciting currents, cut off the exciting current for at least one of the motors at a different timing from the other motors.

Abstract: An image forming apparatus includes: an image holder that holds a toner image; a transferer that is disposed opposite to the image holder so as to be in contact with the image holder and transfers the toner image from the image holder onto a recording sheet that is going through a contact part where the transferer contacts the image holder, by applying a transfer voltage between the transferer and the image holder; a first power source that applies a voltage of a first polarity to the image holder; and a second power source that applies a voltage of a second polarity, which is reverse to the first polarity, to the transferer.

Abstract: An image forming system includes: an image forming apparatus that forms an image on a sheet; one or more sheet carrying devices successively disposed on the downstream side of the image forming apparatus; and a control device that controls the image forming apparatus and the one or more sheet carrying devices based on a job that designates a page configuration containing a page order and sheet types, wherein the sheet carrying device includes a bypass conveyance path along which the sheet output from an upstream device is conveyed toward a downstream device, and a sheet tray unit that temporarily stores the sheet output from the upstream device and discharges the sheet toward the bypass conveyance path, and the control device divides the job into sheet types and determines a printing order of the divided sheet types and sheet types to be stored in the sheet carrying device.

Abstract: An image forming system includes: an image forming apparatus that forms an image on a sheet; one or more sheet carrying devices successively disposed on the downstream side of the image forming apparatus; and a control device that controls the image forming apparatus and the one or more sheet carrying devices based on a job that designates a page configuration containing a page order and sheet types, wherein the sheet carrying device includes a bypass conveyance path along which the sheet output from an upstream device is conveyed toward a downstream device, and a sheet tray unit that temporarily stores the sheet output from the upstream device and discharges the sheet toward the bypass conveyance path, and the control device divides the job into sheet types and determines a printing order of the divided sheet types and sheet types to be stored in the sheet carrying device.

Abstract: A fixing apparatus comprises a fixing nip width adjustment unit configured to adjust the fixing nip width of a fixing nip portion; a braking force generation motor configured to generate an effective braking force in the direction to hinder rotation of an upper pressure roller; and a control unit configured to perform restore control for rotating the upper pressure roller and a lower pressure roller by driving a drive motor and speed keeping control for keeping the rotational speed of the braking force generation motor no higher than a predetermined speed during the restore control in a non-fixing period in which the fixing nip width adjustment unit is controlled to decrease the fixing nip width smaller than in a fixing period and a braking force is applied to the fixing side member by the braking force generation motor.

Abstract: An image forming apparatus performs a serviceman call detection mode during its idling time. In this time, a control portion controls upper and lower pressuring rollers to be clamped, controls a driving motor, and controls a change-over mechanism to switch a braking motor off. A torque detection portion detects a torque value Y of the driving motor at this time. The control portion then controls the upper and lower pressuring rollers to be clamped, controls the driving motor, and controls the change-over mechanism to switch the braking motor on. The torque detection portion detects a torque value Z of the driving motor at this time. The control portion subtracts the torque value Y from the torque value Z to calculate a difference value. The control portion determines that the braking motor is broken down when the difference value does not exceed the threshold value.

Abstract: An image forming apparatus comprises a drive motor configured to rotate the lower pressure roller, a torque generation unit for generating a braking force in the direction to hinder rotation of a fixing belt in order to adjust the differential speed between the surface speed of the fixing belt and the surface speed of the lower pressure roller, and a control unit for adjusting the braking force generated by the torque generation unit. The control unit adjusts the braking force generated by the torque generation unit to decrease if the rotational torque of the drive motor is larger than a predetermined target torque, and increase if the rotational torque of the drive motor is smaller than the predetermined target torque.

Abstract: A fixing apparatus included in an image forming apparatus includes a fixing heater that performs heat fixing, a control unit that controls the fixing heater based on control patterns, a temperature sensor that detects temperature of the fixing heater, and a voltage detection unit that detects a voltage that is applied to the fixing heater. In each control pattern, turn-on period of the fixing heater and turn-off period of the fixing heater are set according to a control cycle of a half cycle duty control. The control unit controls the switching unit to turn on or off the fixing heater using a combination of the control patterns each satisfying a standard for preventing a flicker during each control period of time that is integral multiplication of the control cycle according to the temperature of the fixing heater and the voltage value allied to the fixing heater.

Abstract: A fixing apparatus included in an image forming apparatus includes a fixing heater that performs heat fixing, a control unit that controls the fixing heater based on control patterns, a temperature sensor that detects temperature of the fixing heater, and a voltage detection unit that detects a voltage that is applied to the fixing heater. In each control pattern, turn-on period of the fixing heater and turn-off period of the fixing heater are set according to a control cycle of a half cycle duty control. The control unit controls the switching unit to turn on or off the fixing heater using a combination of the control patterns each satisfying a standard for preventing a flicker during each control period of time that is integral multiplication of the control cycle according to the temperature of the fixing heater and the voltage value allied to the fixing heater.

Abstract: A fixing apparatus includes an upper pressure roller, a fixing belt, a lower pressure roller which cooperates with the upper pressure roller and the fixing belt for forming a fixing nip portion which holds and conveys a sheet with a toner image therebetween; a drive motor which rotates the lower pressure roller; a plurality of motors each of which is capable of generating a braking force in the direction to hinder rotation of the upper pressure roller and an assist force in the direction to assist rotation of the upper pressure roller; a torque generation unit which generate an effective braking force in the direction to hinder rotation of the fixing side member as a combination of the braking and assist forces; and a control unit which switches the motor used to generate the braking force among the plurality of motors in accordance with a predetermined condition.