An image forming apparatus includes: an exposure head including a light emitting portion that includes a first electrode layer including a plurality of electrodes that are two-dimensionally arranged in a main scanning direction and a sub-scanning direction, a light emitting layer stacked on the first electrode layer, and a second electrode layer through which light is transmissible; and a controller configured to control a voltage applied to each of the plurality of electrodes in such a way that the light emitting layer emits light, in which the plurality of electrodes for forming an identical pixel are arranged in such a way that the electrodes partially overlap each other when viewed from the rotation direction, and an inter-centroid distance of the plurality of electrodes in the rotational axis direction is equal in the rotational axis direction, and d3=W1/n (n is a natural number of 2 or more), in which W1 [mm] is a width of the electrode in the rotational axis direction, n is the number of electrodes for forming the identical pixel, and d3 [mm] is the equal inter-centroid distance in the rotational axis direction.

An image-forming apparatus includes a generating unit that generates correction data for correcting an unevenness in light amount of an exposure head using a read image of a correction chart, and a correction unit that corrects image data for image formation based on the correction data. The exposure head includes light-emitting chips, each of which includes light-emitting elements. The correction chart includes a plurality of regions arranged in a direction, a first reference mark located on one side of the regions, and a second reference mark located on the other side of the regions. The generating unit determines partial regions respectively formed by the light-emitting chips within the regions based on positions of the first and second reference marks in the read image of the correction chart, and generates the correction data based on a result of measurement on the partial regions.

An image forming apparatus includes: a photoconductor that rotates about a first axis; an exposure portion that includes a substrate that includes a plurality of light emitting portions for exposing a surface of the photoconductor, and a support portion for supporting the substrate, and that moves between an exposure position where the photoconductor is exposed and a retracted position where the photoconductor is retracted from the exposure position; and a rotational member that has a second axis along the first axis, and that moves the exposure portion between the retracted position and the exposure position by rotation about the second axis.

A process unit includes a rotatable image bearer, an optical writing head to expose the image bearer within an maximum exposure range in an axial direction of the image bearer, a developer bearer, spacers disposed in axial end portions of the image bearer to determine a position of the optical writing head relative to the image bearer and slidingly contact the image bearer, a cleaner disposed downstream from the developer bearer in an image bearer rotation direction, and a remover to slidingly contact the axial end portion of the image bearer to remove a substance adhering thereto. In the axial direction, inner ends of the spacers are positioned inside a toner layer range of the developer bearer extending beyond a largest sheet width. The remover is disposed downstream from the cleaner and crossing a line extending from the inner end of the spacer perpendicularly to the axial direction.

An image forming apparatus includes: a photoconductor that rotates about a first axis; an exposure portion that includes a substrate that includes a plurality of light emitting portions for exposing a surface of the photoconductor, and a support portion for supporting the substrate, and that moves between an exposure position where the photoconductor is exposed and a retracted position where the photoconductor is retracted from the exposure position; and a rotational member that has a second axis along the first axis, and that moves the exposure portion between the retracted position and the exposure position by rotation about the second axis.

An electrophotographic image forming apparatus, which utilizes a line head in which a plurality of light-emitting elements is arranged as a light source, includes at least one controller having at least one processor and at least one memory. The controller is configured to obtain print data to perform printing, perform halftone processing for the obtained print data, generate a plurality of pieces of correction information for correcting variations of light amount on a photosensitive body by light radiated from the plurality of light-emitting elements, and correct the print data for which the halftone processing has been performed by using the correction information. The correction information includes various profiles for correcting the variations of light amount.

An image forming apparatus includes an exposure head including a light emitting portion that includes a first electrode layer including a plurality of electrodes that are two-dimensionally arranged in a rotation direction and a rotational axis direction of a photosensitive member, a light emitting layer stacked on the first electrode layer, and a second electrode layer through which light is transmissible; and a controller configured to control a voltage applied to each of the plurality of electrodes in such a way that one pixel is formed by controlling the voltage applied to the plurality of electrodes arranged at different positions in the rotation direction, in which the plurality of electrodes are arranged in such a way that a pitch of the plurality of electrodes included in the first electrode layer in the rotation direction is an integer multiple of a resolution of an image formed by the image forming apparatus in the rotation direction, and the integer is greater than one.

An aspect of the present disclosure relates to an OLED chip that includes: a light emitting region where a plurality of light emitting devices is two-dimensionally arranged on a surface of a substrate; and a contact region disposed outside the light emitting region. Each of the plurality of light emitting devices includes a second electrode which is continuous over the plurality of light emitting devices, the light emitting region has a long side extending in a first direction and a short side extending in a second direction intersecting the first direction, and an end of the second electrode in the first direction has a portion non-parallel to a third direction perpendicular to the first direction.

A process unit includes a rotatable image bearer, an optical writing head to expose the image bearer within an maximum exposure range in an axial direction of the image bearer, a developer bearer, spacers disposed in axial end portions of the image bearer to determine a position of the optical writing head relative to the image bearer and slidingly contact the image bearer, a cleaner disposed downstream from the developer bearer in an image bearer rotation direction, and a remover to slidingly contact the axial end portion of the image bearer to remove a substance adhering thereto. In the axial direction, inner ends of the spacers are positioned inside a toner layer range of the developer bearer extending beyond a largest sheet width. The remover is disposed downstream from the cleaner and crossing a line extending from the inner end of the spacer perpendicularly to the axial direction.

An image forming apparatus includes a light emitting chip and at least one processor. The light emitting chip includes a plurality of light emitting elements, a DAC outputting a voltage corresponding to a setting value, and a circuit unit that supplies a current to the plurality of light emitting elements based on the voltage. At least one processor is configured to set the setting value such that one light emitting element included among the plurality of light emitting elements emits light of a predetermined amount, and correct image data pieces that respectively correspond to the plurality of light emitting elements based on first correction data for correcting amounts of light respectively emitted by the plurality of light emitting elements. The circuit unit supplies a current to each of the plurality of light emitting elements based on the corrected image data pieces.