To develop a conventional coupling for transmitting a driving force.

A coupling member is provided with a supporting portion for movable supporting a driving force receiving portion for receiving a driving force.

An image forming device continuously forming an image according to a job in a conveying direction of along continuous paper includes: an image formation section forming the image according to the job on the continuous paper; an interval setting section setting a job interval of the image according to the job, which is continuously formed by the image formation section, on the basis of an operation from a user; an image forming process switching section switching two states of a state where the image formation section forms a color image and a state where the image formation section forms a monochromic image; and a switching determination section determining whether or not the two states are switched on the basis of a comparison result between the job interval set by the interval setting section and a paper conveying distance according to a switching time required for switching the two states.

If an inputted job requires switching from a single-color mode to a multicolor mode, an image forming apparatus switches from the single-color mode to the multicolor mode during a relatively long processing waiting time out of processing waiting times between preceding pages and succeeding pages, before a page in the job for forming a multicolor image.

A power supply apparatus to supply power to an image forming device, the power supply apparatus includes an amplifier to amplify an input AC power by a general amplification or a double amplification, a converter to receipt the input AC power amplified by the general amplification or the double amplification and output a DC power with a determined size. A controller control applying the general amplification or the double amplification to the converter, in response to an operating mode of the image forming device.

An automatic document feeder, which is included in an image reading device and an image forming apparatus, includes first and second document trays, a document output tray, a document conveying passage, multiple document conveying bodies, a drive source, a detector, and a controller. The multiple document conveying bodies include a document holding and conveying body to convey and hold the original document sheet on the second document tray. On detection of the original document sheet on the second document tray while conveying a different original document sheet from the first document tray, the controller stops feeding the different original document sheet, causes the different original document sheet downstream from the document holding and conveying body in a document conveying direction to be conveyed to the document output tray, and stops the drive source after the different original document has been conveyed to the document output tray.

An image forming system includes a detection unit to detect a recording material, having an image formed thereon by an image forming unit, placed on a processing tray, a staple unit, a discharge unit, and a discharge tray. A first mode of the system is to discharge the recording material conveyed from the image forming unit to the discharge tray via the processing tray and a second mode involves waiting for instruction for executing. When the detection unit detects the recording material inserted into the processing tray in the second mode, and a recording material first mode conveying instruction is issued in a state of waiting for the executing instruction after the recording material detection, a discharge operation is performed to discharge the recording material inserted into the processing tray to the discharge tray without the staple unit executing staple processing on the recording material inserted into the processing tray.

Provided is an image reading apparatus including: a line sensor including three light receiving element arrays arranged at a predetermined interval in a sub-scanning direction, and being configured to read an image of an original by the respective light receiving element arrays to generate read data representing the read image, the three light receiving element arrays each including light receiving elements for receiving red light, blue light and green light. These elements are arranged in a main scanning direction; and a reading control board. The reading control board is configured to acquire the read data obtained by the respective light receiving element arrays from the line sensor, to sort a plurality of pieces of read data for every pixel of the same color, and to detect an abnormal pixel that does not exist in the image of the original for each color.

An image forming apparatus includes: an electrophotographic photoreceptor that includes an electroconductive substrate, an undercoat layer which is provided on the electroconductive substrate and has electrostatic capacitance per unit area of from 2.5×10.sup.−11 F/cm.sup.2 to 2.5×10.sup.−10 F/cm.sup.2, and a photosensitive layer provided on the undercoat layer; a charging unit; an electrostatic latent image forming unit; a developing unit; an intermediate transfer member; a primary transfer unit that primarily transfers the toner image formed on the surface of the electrophotographic photoreceptor, onto the surface of an intermediate transfer member, while providing a primary transfer current value of from 80 μA to 160 μA; and a secondary transfer unit that secondarily transfers the toner image transferred onto the surface of the intermediate transfer member, onto a surface of a recording medium.

An image forming apparatus includes: a main casing; a drum cartridge; a toner cartridge; a display; and a controller. The drum cartridge is attachable to and detachable from the main casing. The drum cartridge includes a photosensitive drum and a drum memory. The toner cartridge is attachable to and detachable from the drum cartridge. The toner cartridge includes a toner memory. The controller is configured to: determine whether an error occurs in the drum cartridge through a communication with the drum memory; determine whether an error occurs in the toner cartridge through a communication with the toner memory; and when determining that an error occurs in the drum cartridge and determining that an error occurs in the toner cartridge, display on the display an error relating to the drum cartridge in preference to displaying on the display an error relating to the toner cartridge.

Method of heating control includes preheating a heater to a first target temperature when an image forming device is powered on, is woken up from sleep, or receives a task to be processed; determining a voltage parameter of the heater or a characteristic of temperature change of a heating process of the heater, under the current environment of the power supply, according to a prior-preheating temperature, a post-preheating temperature, and a time length of the preheating; and according to the voltage parameter or the characteristic of temperature change under the current environment of the power supply, determining a heating start time of a second heating for the preheated heater and triggering the second heating at the heating start time, to allow a temperature of the heater to reach a second target temperature within a set time before an image to-be fixed arrives at the fixing assembly.