An image forming apparatus includes: a motor; a temperature detector; a conveyor; a sheet detector; and a controller configured to perform: (a) controlling a conveying speed of the sheet; (b) determining whether a paper jam has occurred; and (c) determining, when the paper jam has occurred, whether a torque shortage has occurred. The torque shortage is shortage of a torque occurring during conveyance of the sheet. When the torque shortage has occurred, and the paper jam is resolved and conveyance of the sheet is resumed, the controller performs in the (a) controlling: controlling, when an ambient temperature detected by the temperature detector is higher than a predetermined temperature, the conveying speed to become a first conveying speed; and controlling, when the ambient temperature is lower than or equal to the predetermined temperature, the conveying speed to become a second conveying speed slower than the first conveying speed.

An image forming apparatus includes a sheet storage, a sheet feed roller, an image forming device, a fixing device, a motor, a sensor, and a controller having a processor. The sheet storage is configured to store a sheet. The sheet feed roller is configured to feed the sheet stored in the sheet storage into the conveyance path. The image forming device is configured to form an image on the sheet. The fixing device includes a fixing belt and a pressure roller abutting on an outside of the fixing belt, and is configured to fix the image formed on the sheet. The motor is configured to drive and rotate the fixing belt by rotating the pressure roller. The sensor is configured to measure the drive current in the motor. The processor is configured to control a conveyance speed of the sheet based on the measured drive current.

A transfer device includes a plurality of photoconductors, a belt, a plurality of primary transfer rollers and control circuitry. The plurality of primary transfer rollers is disposed for the plurality of photoconductors, respectively. The plurality of primary transfer rollers brings the belt into contact with or separate the belt from the plurality of photoconductors. The control circuitry causes at least one of the plurality of primary transfer rollers to press against a corresponding at least one of the plurality of photoconductors to shift a printing mode.

An image forming apparatus includes an image forming unit configured to form an image on a sheet based on a mode selected from a plurality of modes having different image forming speeds; a memory configured to store first data for a first mode included in the plurality of modes, the first data indicating a correspondence for the first mode between a type of the sheet and the image forming speed, and second data for a second mode included in the plurality of modes, the second data indicating a correspondence for the second mode between a type of the sheet and the image forming speed; a display; and a controller configured to: determine a first image forming speed for the first mode from the first data based on the type of the sheet; and determine a second image forming speed for the second mode from the second data.

An image forming apparatus includes an image carrier that is capable of holding an image on a surface thereof while rotating, an image forming unit that forms the image on the image carrier, a transfer unit that transfers the image from the image carrier to a medium while rotating, a transport unit that circulates as the transfer unit rotates and that transports the medium to a transfer region while holding the medium, and a control unit that changes a timing at which the image forming unit forms the image in accordance with variation in a ratio of a rotation velocity of the transfer unit to a rotation velocity of the image carrier.

An image forming apparatus includes an image forming device, a driving device, an external temperature detector, an internal temperature detector, a work amount detector, and control circuitry. When a temperature detected by the external temperature detector is lower than a temperature threshold, the circuitry shifts to a first restriction state based on a work amount and temporarily stops drive of the image forming device for a period every time the amount reaches a threshold. When the temperature is not lower than the temperature threshold, the circuitry shifts to a second restriction state based on an internal temperature. In the second state, in a case where the internal temperature is higher than a first threshold, the circuitry performs an intermittent operation of repeating a pause state and a printing state, until the internal temperature falls to be equal to or lower than a second threshold being lower than the first threshold.

A motor control apparatus includes: a current supply unit configured to supply a coil current to a plurality of coils of a motor by controlling a voltage to be applied to the plurality of coils, based on a first command value of an excitation current and a second command value of a torque current; and a control unit configured to control the first command value based on a rotation speed of a rotor of the motor, wherein the control unit is further configured to control, when the rotation speed of the rotor is lower than a first threshold value, the first command value to cause the excitation current to be larger than zero, and control the second command value to supply the torque current in accordance with a load of the rotor.

According to at least one embodiment, a failure prediction server includes an interface, a memory, and a processor. The interface is configured to communicate with equipment including a component that deteriorates over time. The memory is configured to store measurement data acquired from the equipment. The processor is configured to set a monitoring start condition for failure prediction in the corresponding equipment based on the measurement data acquired as initial data from the equipment, accumulate the measurement data acquired from the equipment in the memory after the monitoring start condition is satisfied, and predict a failure of the component based on the measurement data accumulated in the memory.

An image forming apparatus includes a rotatable photosensitive member, a charging member, a developing device, a transfer member, a brush, a driving source and a control portion. The control portion controls the driving source to execute an image forming process in which image formation to the recording material is executed and a non-image-forming process in which the photosensitive member is driven to rotate other than the image forming process. The non-image-forming process between a first recording material and a second recording material to which the image formation is executed following the first recording material is defined as a first non-image-forming process, and the non-image-forming process between the second recording material and a third recording material is defined as a second non-image-forming process. The control portion determines a time of the second non-image-forming process based on a history information correlating with a usage amount of the photosensitive member and a time of the first non-image-forming process.

An image forming apparatus includes: a rotatable transfer cylinder with a first groove formed in an outer portion thereof in a rotational radial direction that causes an image to be transferred to a recording medium when it passes along an outer surface of the transfer cylinder; a rotatable fixing cylinder that has a second groove formed in an outer portion thereof in a rotational radial direction, that causes the image transferred to the recording medium to be fixed thereto when the recording medium passes along an outer surface of the fixing cylinder; a loop-shaped circulating member that is wrapped at least around the transfer and fixing cylinders, that circulates in response to rotations of the transfer and fixing cylinders; a recording medium holding member supported by the circulating member, disposed in the first groove when the holding member passes along the transfer cylinder and disposed in the second groove when the holding member passes along the fixing cylinder; first and second driving units that rotate the transfer and fixing cylinders respectively; and that is configured such that a ratio of a moment of inertia of the fixing cylinder to an output torque of the second driving unit is set to be greater than a ratio of a moment of inertia of the transfer cylinder to an output torque of the first driving unit.