Plural write control units independently control plural print mechanisms corresponding to plural toner colors. A controller stores a setting value for each page into a first memory area. Plural second memory areas respectively correspond to the plural write control units. Further, one write control unit among them transfers the setting value from the first memory area to the second memory area of this write control unit, and applies the setting value stored in the second memory area and causes the corresponding print mechanism to print a page image. Another write control unit among them transfers the setting value to the second memory area of this write control unit from the second memory area of another write control unit among them, and applies the setting value stored in the second memory area and causes the corresponding print mechanism to print a page image.

A digital printing system having a linear printhead includes corrections for in-track position errors. A data processing system implements a method for determining an in-track position function which includes printing a test target including a plurality of alignment marks, automatically analyzing a captured image of the printed test target to determine a measured in-track position for each of the alignment marks, comparing the measured in-track positions for the alignment marks to reference in-track positions to determine measured in-track position errors, and determining an in-track position correction function responsive to the measured in-track position errors. The in-track position correction function specifies in-track position corrections to be applied as a function of cross-track position. A corrected digital image is determined by resampling an input digital image responsive to the in-track position correction function.

An image forming apparatus includes a casing in which multiple units are disposed. The casing has a front wall having a first opening and a stepped wall having a second opening. In the casing, an exposure unit is disposed in front of an image forming unit, above the first opening, and above a sheet loading section, and a fixing unit is disposed above the image forming unit. The exposure unit is disposed with a first gap between the exposure unit and the image forming unit, and the fixing unit is disposed with a second gap between the exposure unit and the image forming unit. The first gap and the second gap constitute a ventilation channel for distributing outside air flowing into the casing through the first opening to the second opening.

An image forming apparatus includes the following: an image forming portion; a first metal side plate and a second metal side plate provided opposite each other with respect to the image forming portion; an antenna for communicating with external equipment; a housing including a top cover that is provided above the first metal side plate and the second metal side plate in a vertical direction, and a side cover that is provided on an outer side opposite to an inner side where the image forming portion is provided with respect to the first metal side plate, wherein the image forming apparatus further includes a support member provided on the first metal side plate, the support member including a housing support portion that supports at least one of the top cover and the side cover, and an antenna support portion that supports the antenna.

An image forming apparatus is provided. The image forming apparatus includes an image former to change a transfer condition while printing a calibration chart in which patches of different colors are repeatedly arranged in a sub-scanning direction, a scanner to scan the printed calibration chart, and a processor to determine an image defect under each transfer condition using the scanned calibration chart, and to set a transfer condition of the image former based on the determined image defect.

An image forming apparatus, having first, second, and third photosensitive drums, a first developing cartridge including a first developing roller, a second developing cartridge including a second developing roller, a third developing cartridge including a third developing roller, an exposure device, a conveyer, and a moving mechanism, is provided. The first developing roller, the second developing roller, and the third developing roller are arranged in the recited order from upstream to downstream in a moving direction for the sheet to be conveyed. When the second developing roller is at the separated position thereof, the second developing cartridge coincides with a light path of the laser beam for scanning the first photosensitive drum. When the third developing roller is at the separated position thereof, the third developing cartridge coincides with a light path of the laser beam for scanning the second photosensitive drum.

An image forming apparatus includes an image forming section, a driving unit and an operation unit. The image forming section includes one or more image forming units. The driving unit generates driving force. The operation unit selectively performs a first operation and a second operation. The first operation is an operation to change over from a coupled state of the one or more image forming units and the driving unit, which the driving force is transmitted to the one or more image forming units, to a released state of the one or more image forming unit and the driving unit, which the driving force from the driving unit is not transmitted to the one or more image forming units. When the second operation is performed, the released state is maintained.

An image forming apparatus includes a main assembly, a grip, a first guiding member, and a second guiding member. The grip is linearly movable between a first position accommodated inside the main assembly and a second position projecting from the main assembly. The grip has a projection of resin material projecting downwardly from a lower surface of the grip. The first guiding member is provided above the grip to guide the movement of the grip, and the second guiding member is provided below the grip and configured to guide the movement of the grip together with the first guiding member. The second guiding member is provided with an engaging portion projecting from an upper surface of the second guiding member and capable of engaging with the projection to restrict movement of the grip toward the second position when the grip is in the first position.

A digital printing system having a linear printhead includes corrections for in-track position errors. A data processing system implements a method for determining an in-track position function which includes printing a test target including a plurality of alignment marks, automatically analyzing a captured image of the printed test target to determine a measured in-track position for each of the alignment marks, comparing the measured in-track positions for the alignment marks to reference in-track positions to determine measured in-track position errors, and determining an in-track position correction function responsive to the measured in-track position errors. The in-track position correction function specifies in-track position corrections to be applied as a function of cross-track position. A corrected digital image is determined by resampling an input digital image responsive to the in-track position correction function.

An image forming apparatus includes a plurality of photosensitive drums respectively corresponding to a plurality of colors to print, on a recording medium, color chart of a plurality of vertical lines in a sub-scanning direction to a main scanning direction of the recording medium and to be arranged at intervals along the main scanning direction. A vertical line of the plurality of vertical lines includes at least two colored sub-lines to be formed by corresponding at least two photosensitive drums. A processor is to perform a correction in non-linear color registrations in the main scanning direction using an image of the color chart.