Abstract: A sheet conveyance apparatus includes: a speed detection roller that detects a conveyance speed of a sheet by coming into contact with the sheet being conveyed and being driven to rotate; and a hardware processor that performs temperature control to make an ambient temperature of the speed detection roller a predetermined temperature.

Abstract: The image forming apparatus includes a crimping/release mechanism that switches between a crimping position where a transfer nip is formed and a release position where the intermediate transfer belt and the photosensitive drum are separated from each other, by moving at least one primary transfer section of a plurality of primary transfer sections provided facing a plurality of photosensitive drums respectively, and a processor that performs color misregistration adjustment when a combination of image forming units used for image formation is changed.

Abstract: A sheet conveyance apparatus includes: a speed detection roller that detects a conveyance speed of a sheet by coming into contact with the sheet being conveyed and being driven to rotate; and a hardware processor that performs temperature control to make an ambient temperature of the speed detection roller a predetermined temperature.

Abstract: Provided is an image forming apparatus including an image carrier, a transfer unit, a driver, a hardware processor, an adjustment mechanism, and a speed detector. The hardware processor sets a command value. The hardware processor performs a constant-torque control based on a constant-speed drive torque detected in a constant-speed control. In the constant-torque control, the hardware processor performs a feedback control to set a reference value to an average speed of the driver during passage of a first sheet and calculate a difference from an average speed during passage of a subsequent sheet so as to derive the command value. The hardware processor determines whether a load torque increase, its factor, and/or its influence exceeds a threshold, and forcibly sets the reference value to a speed detected while a pressure between the transfer unit and the image carrier is reduced by the adjustment mechanism from the pressure during image transfer.

Abstract: The present invention provides a recording medium detecting device, an image forming device, an image forming system, a recording medium detecting method, and a non-transitory recording medium storing a computer readable program capable of detecting a grain direction of a recording medium. A recording medium detecting device has: a sensor capable of detecting a recording medium from a first detection direction and a second detection direction different from the first detection direction; and a control unit. The control unit determines a grain direction of a recording medium from first surface property data obtained when the recording medium is detected from the first detection direction and second surface property data obtained when the recording medium is detected from the second detection direction.

Abstract: Provided is an image forming apparatus including an image carrier, a transfer unit, a driver, a hardware processor, an adjustment mechanism, and a speed detector. The hardware processor sets a command value. The hardware processor performs a constant-torque control based on a constant-speed drive torque detected in a constant-speed control. In the constant-torque control, the hardware processor performs a feedback control to set a reference value to an average speed of the driver during passage of a first sheet and calculate a difference from an average speed during passage of a subsequent sheet so as to derive the command value. The hardware processor determines whether a load torque increase, its factor, and/or its influence exceeds a threshold, and forcibly sets the reference value to a speed detected while a pressure between the transfer unit and the image carrier is reduced by the adjustment mechanism from the pressure during image transfer.

Abstract: An image forming apparatus includes the following, a pair of first conveying rollers, a pair of second conveying rollers, a driver which rotates and drives the second conveying rollers by a command value; and a controller which is able to control the driver to perform constant speed control to rotate the pair of second conveying rollers at a constant speed and to perform constant torque control to rotate the pair of second conveying rollers at a constant torque. When the constant torque control is performed, the controller starts the constant torque control with a predetermined initial torque. Based on sheet interval torque detected in a sheet interval term in which the pair of second conveying rollers do not sandwich and convey a sheet after the first sheet reaches the pair of second conveying rollers, the controller corrects the initial torque and calculates a command value for the next sheet.

Abstract: An image formation device for executing a printing job to form a toner image on a record sheet includes: an operation panel configured to move between a first position at which the operation panel protrudes from a front of a device body and a second position at which the operation panel is retracted to a device body side with respect to the first position. The device further includes an acquisition device configured to obtain state information indicating a state of the device body; and a hardware processor configured to determine, based on the obtained state information, whether the state of the device body is a state requiring a user access to the device body or a state of accessing to the device body. The device retracts the operation panel to the second position when a determination result is positive.

Abstract: A fixing apparatus includes: a fixing member including a heater as a heat source; and a hardware processor that uses pulse width modulation (PWM) control to control power supplied to the heater; wherein the hardware processor changes a duty of the PWM control within a half cycle of an input current of the PWM control.

Abstract: An image forming apparatus: acquires, before start of current supply to electric elements including heater, information indicating rated power of the heater and total consumption power of the electric elements excluding the heater; subtracts the total consumption power from upper power limit of the apparatus, and calculates maximum power not exceeding the rated power and remaining power thus subtracted; obtains duty ratio based on assumption of current supply corresponding to the maximum power according to pulse modulation, and determines whether the duty ratio falls within predetermined range; and controls, when the duty ratio falls within the range, drive circuit to supply alternating current by pulse modulation method, and when the duty ratio falls outside the range, to supply the alternating current by phase control method that temporarily interrupts the supply of the alternating current to the heater in half cycles of the alternating current.

Abstract: An image forming apparatus: acquires, before start of current supply to electric elements including heater, information indicating rated power of the heater and total consumption power of the electric elements excluding the heater; subtracts the total consumption power from upper power limit of the apparatus, and calculates maximum power not exceeding the rated power and remaining power thus subtracted; obtains duty ratio based on assumption of current supply corresponding to the maximum power according to pulse modulation, and determines whether the duty ratio falls within predetermined range; and controls, when the duty ratio falls within the range, drive circuit to supply alternating current by pulse modulation method, and when the duty ratio falls outside the range, to supply the alternating current by phase control method that temporarily interrupts the supply of the alternating current to the heater in half cycles of the alternating current.

Abstract: An image formation device for executing a printing job to form a toner image on a record sheet includes: an operation panel configured to move between a first position at which the operation panel protrudes from a front of a device body and a second position at which the operation panel is retracted to a device body side with respect to the first position; an acquisition device configured to obtain state information indicating a state of the device body; and a hardware processor configured to determine, based on the obtained state information, whether the state of the device body is a state requiring a user access to the device body or a state of accessing to the device body and to retract the operation panel to the second position when a determination result is positive.

Abstract: An image forming apparatus drives and rotates at least one of a photosensitive drum and a transport roller with use of a stepping motor in a multi-phase excitation mode. The image forming apparatus includes: a constant-voltage control unit controlling the stepping motor by applying a constant voltage for each phase; a constant-current control unit controlling the stepping motor by regulating an amount of current for each phase by a chopping control; a measuring unit measuring a chopping count of each phase on a per-step basis; a chopping count determination unit determining whether the chopping count of each phase is less than or equal to a predetermined count; and a control switching unit causing the constant-voltage control unit to control the stepping motor when the chopping count determination unit determines affirmatively, and causing the constant-current control unit to control the stepping motor when the chopping count determination unit determines negatively.

Abstract: An image forming apparatus includes an induced voltage detection portion configured to detect an induced voltage Vk in a motor; and an engagement/disengagement completion time detection portion configured to detect an engagement completion time and a disengagement completion time based on the induced voltage Vk detected by the induced voltage detection portion. The engagement completion time is a time at which engagement of a clutch is actually completed. The disengagement completion time is a time at which disengagement of the clutch is actually completed. A control portion determines a command timing based on any one of the engagement completion time and the disengagement completion time detected by the engagement/disengagement completion time detection portion, the command timing being a time at which a command is given to the clutch to perform an engaging operation or a disengaging operation.

Abstract: An image forming apparatus includes an induced voltage detection portion configured to detect an induced voltage Vk in a motor; and an engagement/disengagement completion time detection portion configured to detect an engagement completion time and a disengagement completion time based on the induced voltage Vk detected by the induced voltage detection portion. The engagement completion time is a time at which engagement of a clutch is actually completed. The disengagement completion time is a time at which disengagement of the clutch is actually completed. A control portion determines a command timing based on any one of the engagement completion time and the disengagement completion time detected by the engagement/disengagement completion time detection portion, the command timing being a time at which a command is given to the clutch to perform an engaging operation or a disengaging operation.

Abstract: An image forming apparatus drives and rotates at least one of a photosensitive drum and a transport roller with use of a stepping motor in a multi-phase excitation mode. The image forming apparatus includes: a constant-voltage control unit controlling the stepping motor by applying a constant voltage for each phase; a constant-current control unit controlling the stepping motor by regulating an amount of current for each phase by a chopping control; a measuring unit measuring a chopping count of each phase on a per-step basis; a chopping count determination unit determining whether the chopping count of each phase is less than or equal to a predetermined count; and a control switching unit causing the constant-voltage control unit to control the stepping motor when the chopping count determination unit determines affirmatively, and causing the constant-current control unit to control the stepping motor when the chopping count determination unit determines negatively.

Abstract: While a recording sheet is passing through a fixing nip formed between a heating roller 41 having a heating layer and a pressing roller 42 pressed against the roller 41, a coil 43 is exited by high-frequency power from a power source and causes the layer to generate heat. An unfixed image on the recording sheet is fixed by the heat. The power source detects a zero cross timing of a rectified alternating current, detects an instantaneous value at a point a predetermined period after the zero cross timing, calculates an effective power of the alternating current based on the instantaneous value, and controls the output power to be a desired value determined based on the effective power and the surface temperature of the roller 41. Thus power input to the power source can be quickly detected and power output to the coil can be quickly and stably controlled.

Abstract: While a recording sheet is passing through a fixing nip formed between a heating roller 41 having a heating layer and a pressing roller 42 pressed against the roller 41, a coil 43 is exited by high-frequency power from a power source and causes the layer to generate heat. An unfixed image on the recording sheet is fixed by the heat. The power source detects a zero cross timing of a rectified alternating current, detects an instantaneous value at a point a predetermined period after the zero cross timing, calculates an effective power of the alternating current based on the instantaneous value, and controls the output power to be a desired value determined based on the effective power and the surface temperature of the roller 41. Thus power input to the power source can be quickly detected and power output to the coil can be quickly and stably controlled.

Abstract: Provided is an image forming apparatus capable of selecting a user who requires information on the image forming apparatus to post the information to the user. An image forming apparatus capable of being connected to a network, includes: usage history recording unit recording a usage history of a user who has executed a job on the image forming apparatus; determining unit selecting a user to whom information on the image forming apparatus is posted based on a usage history recorded in the usage history recording unit; and posting unit posting information on the image forming apparatus to a user terminal of the selected user.