Image processors are provided for respective groups formed by grouping of images, the order of which is sequential when images respectively having overlapping portions corresponding to the same portion of an object are arranged so as to be adjacent to each other, and concurrently perform processing to detect combining-position information for combining an image in a group and an image adjacent to the image without any positional displacement by image-matching. The combining-position information between images belonging to different groups is respectively transferred, via combination-information transferring paths, between the image processors and between the image processors.

A scanner includes a generator that synthesizes output of a first sensor group and output of a second sensor group where the image data overlaps in part, and generates image data; and a controller that controls the second sensor group to synthesize and output the output of n photoelectric conversion elements at positions based on the relative positions of the first sensor group and second sensor group.

An image reading device includes linear image sensors that are arranged so that adjacent image sensors include an overlapping region in which portions of reading regions of the adjacent image sensors overlap in a main scanning direction, and a buffer unit for read image data. Image data of each overlapping region are generated by synthesizing first image data obtained by a first linear image sensor and second image data obtained by a second linear sensor, the first linear image sensor and the second linear sensor being adjacent in the main scanning direction. Image data of the predetermined line is generated based on image data in which the image data of each overlapping region are excluded from the image data stored in the buffer unit and the image data of each overlapping region. The processing is repeatedly executed in a sub-scanning direction.

An image forming apparatus includes a conveyor, an image former, and a reading device. The conveyor conveys a medium in a conveyance direction. The image former forms an adjustment pattern on one side of the medium conveyed by the conveyor. The reading device downstream from the image former in the conveyance direction reads the adjustment pattern on the one side of the medium conveyed by the conveyor to generate read data. The adjustment pattern includes a first line segment and a second line segment that extend in directions different from each other and each are inclined with respect to the conveyance direction.

An image forming apparatus includes a conveyance part, an image forming part, a sheet detection sensor, a sensor unit, and a controller. The sheet detection sensor, in which a plurality of sensor blocks each with a plurality of sensor elements mounted thereon at specified intervals are arrayed in a sheet width direction, detects an edge position in the sheet width direction on a basis of scanning image data formed by reading of the sheet. The controller is enabled to execute a calibration of inserting, into the scanning image data, interpolation pixels for compensating an error between an edge position detected by the scanning image data and an actual edge position.

An image forming apparatus includes a conveyance part, an image forming part, a sheet detection sensor, a sensor unit, and a controller. The sheet detection sensor, in which a plurality of sensor blocks each with a plurality of sensor elements mounted thereon at specified intervals are arrayed in a sheet width direction, detects an edge position in the sheet width direction on a basis of scanning image data formed by reading of the sheet. The controller is enabled to execute a calibration of inserting, into the scanning image data, interpolation pixels for compensating an error between an edge position detected by the scanning image data and an actual edge position.

There is provided a scanner that combines images read by a first sensor array and a second sensor array, in which the first sensor array and the second sensor array have read regions which are overlapped partially, and includes a combining section that combines a straight line as an image of a non-straight line in a case where the straight line which is non-parallel and non-perpendicular in a main scanning direction is read in an overlapped manner by the first sensor array and the second sensor array.

An image reading apparatus includes a support portion, a reading portion, a first cover, a second cover, and a holding mechanism. The first cover moves between a second closed position where the first cover covers the reading portion in a first closed position and a second open position where the first cover opens the reading portion. The second cover moves between a third closed position where the second cover forms a second area of a conveyance path together with the first cover in the second closed position and a third open position where the second cover opens the second area. The holding mechanism prevents the first cover from moving from the second open position to the second closed position and holds the first cover in the second open position when the second cover is in the third open position and the first cover is in the second open position.

An image forming apparatus includes a conveyor, an image former, and a reading device. The conveyor conveys a medium in a conveyance direction. The image former forms an adjustment pattern on one side of the medium conveyed by the conveyor. The reading device downstream from the image former in the conveyance direction reads the adjustment pattern on the one side of the medium conveyed by the conveyor to generate read data. The adjustment pattern includes a first line segment and a second line segment that extend in directions different from each other and each are inclined with respect to the conveyance direction.

There is provided a scanner that combines images read by a first sensor array and a second sensor array, in which the first sensor array and the second sensor array have read regions which are overlapped partially, and includes a combining section that combines a first read image read by the first sensor array and a second read image read by the second sensor array and a correction section that corrects an image after a combining based on a degree of displacement of a reading position of the document.