An image forming apparatus includes an image bearer, an image forming unit, a toner image detecting unit, and a detection processing unit. The image bearer is configured to bear a toner image. The image forming unit is configured to sequentially form groups of pattern images for a plurality of colors in a sub-scanning direction of the image bearer, each of the groups including pattern images of the same color at a predetermined interval. The toner image detecting unit is configured to detect the pattern images formed on the image bearer. The detection processing unit is configured to recognize whether an interval between adjacent pattern images of the same color corresponds to a set interval, to exclude an image for which the interval does not correspond to the set interval among the detected pattern images.

An image forming apparatus includes a main body, endless belt, photosensitive drums, setting unit, contacting/separating mechanism, transmitting mechanism, and coupling members. The photosensitive drums are disposed in confrontation with the endless belt and are arranged in a first direction. Each photosensitive drum has an axis extending in a second direction perpendicular to the first direction. The setting unit sets the image forming apparatus to a monochrome mode or color mode. The contacting/separating mechanism controls at least one photosensitive drum to contact or separate from the endless in accordance with the set mode. The transmitting mechanism selectively transmits drive power to photosensitive drums. Each coupling member is selectively coupled to the corresponding photosensitive drum and has a coupling axis extending in the second direction. Each coupling member is uncoupled from the corresponding photosensitive drum when the contacting/separating mechanism controls the corresponding photosensitive drum to separate from the endless belt.

An image forming apparatus includes a frame, a drum cartridge mountable to the frame, and including a photosensitive drum and a drum memory in which drum identification information identifying the drum cartridge is stored, and a control unit including a main body memory in which the drum identification information is to be stored. The control unit reads out the drum identification information from the drum memory, determines whether the drum identification information read out from the drum memory coincides with the drum identification information stored in the main body memory, and enables to execute resister pitch measuring processing of measuring variations in printing pitch due to the photosensitive drum. In a case where it is determined that the drum identification information read out from drum memory coincides with the drum identification information stored in the main body memory, the control unit does not execute the resister pitch measuring processing.

The present application discloses an image formation apparatus that can transfer an image into electronic paper using an electronic photography method, and a printing control method for the image formation apparatus. The present electronic paper comprises an electrophoresis layer for displaying an image using an electrophoresis method, a conductive layer, and a film layer for transmitting an image; and the image formation apparatus comprises a communication interface for receiving printing data, an image formation unit for transferring an image corresponding to the printing data, and a processor for controlling the image formation unit.

An imaging device prints in color and monochromatically, such as black-only. It has a plurality of photoconductive drums, one each for black toner and at least one colored toner. The drums contact and rotate with an intermediate transfer member (ITM) to transfer images at a first transfer. During black-only imaging, the photoconductive drum for the black toner rotates with the ITM at process speed while the drum for the at least one colored toner rotates at less than process speed, often substantially less. The technique reduces consumption of colored toner during black-only imaging and minimizes charge build-up on the drum for the colored toner.

An image forming apparatus includes a main body casing having a front side wall having a plurality of cartridge ports and a tray port, each of the plurality of cartridge ports extending in a first direction and being aligned in a second direction; a reading scanner unit provided above the main body casing; and a sheet discharging unit configured to discharge a sheet and positioned between an upper side wall of the main body and the reading scanner unit. The apparatus further includes a sheet feeding unit positioned below a door provided on the front side wall; a plurality of toner cartridges which are attached to the plurality of cartridge ports; and a plurality of photosensitive drums being detached from the main body casing in the second direction, each of the plurality of toner cartridges being spaced apart from the plurality of photosensitive drums in a third direction.

An image forming method includes forming an image with a toner using a photoconductor in which an intermediate layer and a photosensitive layer including a charge generating layer and a charge transport layer are formed overlying an electroconductive substrate, wherein the ionization potential of the surface of the photoconductor and the ionization potential of the surface of the toner satisfy the following relations 1 and 2,

|Ip (the surface of the photoconductor)Ip (the surface of the toner)|5.53 (eV) Relation 1

5.45 (eV)Ip (the surface of the photoconductor)5.53 (eV) Relation 2

where Ip (the surface of the photoconductor) represents the ionization potential of the surface of the photoconductor and Ip (the surface of the toner) represents the ionization potential of the surface of the toner.

An image forming apparatus includes a plurality of photosensitive members; a scanner unit including light sources, a rotatable polygonal mirror, and reflecting members; and a fixing portion. Parts of the laser beams emitted from the light sources are reflected by the rotatable polygonal mirror toward the fixing device side, and rest parts of the laser beams are reflected by the rotatable polygonal mirror toward a side opposite from the fixing device side. Of the parts of the laser beams reflected by the rotatable polygonal mirror toward the fixing device side, the laser beam reflected toward the reflecting member provided at a position remotest from the rotatable polygonal mirror travels downward relative to a horizontal direction. A rotational axis of the rotatable polygonal mirror is inclined relative to a vertical direction.

An image forming apparatus includes a transfer belt, a plurality of endless rotational bodies, an image forming device, a pattern sensor, and processing circuitry. The image forming device forms correction patterns including a first pattern as a straight line pattern orthogonal to a conveyance direction of the correction patterns and a second pattern as one of a straight line pattern orthogonal to and an oblique line pattern inclined with respect to the conveyance direction. The processing circuitry causes the image forming device to form the correction patterns using a correction value such that the second pattern included in one correction pattern on the transfer belt is same in color and shape as the second pattern included in at least one correction pattern of a preceding correction pattern and a following correction pattern in the conveyance direction with respect to the one correction pattern.

An image forming apparatus includes a voltage adjustment portion having a voltage adjustment member connected to a contact member contacting an endless belt, the voltage adjustment portion changing a current flowing from a current supply member contacting the belt at a position different from a position, at which an image bearing member contacts the belt with respect to a rotating direction of the belt, to the voltage adjustment member via the belt according to a control signal input from a control portion outputting a control signal, thereby changing a size of a transfer potential to transfer a toner image borne by the image bearing member onto the belt at a part at which the belt contacts the image bearing member.