An image forming apparatus includes an image formation unit, a detection unit, a storage unit, and a control unit. When the detection unit outputs a second output value when a second recording material, which is different from a first recording material is detected, in a state where the storage unit stores a first output value output by the detection unit upon detection of the first recording material, the control unit controls an image forming condition based on at least the first output value if a differential value between the first output value and the second output value is smaller than a predetermined threshold value and controls the image forming condition based on the second output value without using the first output value if the differential value is greater than the predetermined threshold value.

In one example, a document scanner has a fixed-position scan bar and a built-in translatable calibration target. The scan bar has a linear array of imaging elements aimed in an imaging direction. The calibration target is spaced apart from and parallel to the linear array, and has a planar surface orthogonal to the imaging direction spanning the length of the linear array. The target is translatable during a calibration in a direction in a plane of the surface.

An image forming apparatus includes: a photosensitive member; an exposure unit configured to divide one pixel into a plurality of pixel pieces and perform exposure on a pixel piece-by-pixel piece basis, to form an electrostatic latent image on the photosensitive member; a determination unit configured to determine, based on image data, an isolated pixel surrounded by blank pixels in the electrostatic latent image; a selection unit configured to select a correction target pixel from the blank pixels surrounding the isolated pixel; and a correction unit configured to correct the image data so as to expose a pixel piece of the correction target pixel.

A reading apparatus that reads an image formed on a document while transporting the document, the reading apparatus includes a first reading section that reads, as a read image, one of specularly reflected light or diffusely reflected light which is reflected from the document on a reading glass through which the moving document passes, and a second reading section that reads, as a read image, the other of the specularly reflected light or the diffusely reflected light which is reflected from the document on one side of a transport path through which the document is transported.

An image reader used as a back surface reading unit includes LEDs, a first mirror, a second mirror, a third mirror, a lens, and a CCD inside a housing. The first mirror, which first reflects light reflected from the document, is positioned farther away from the document reading position than other reflecting mirrors (i.e. the second mirror and the third mirror) in an optical axis direction of the optical path connecting the document reading position and the first mirror.

When a feeding apparatus of a first type is connected to a first mounting surface, a processor outputs, to the feeding apparatus of the first type via a first signal terminal, a control signal. When the feeding apparatus of the first type is connected to a second mounting surface, the control unit outputs, to a feeding apparatus of a second type via a second signal terminal, a control command for controlling the feeding apparatus of the first type. When the feeding apparatus of the first type is connected to the second mounting surface, the feeding apparatus of the second type outputs, to the feeding apparatus of the first type via another signal terminal, a control signal based on a control command for controlling the feeding apparatus of the first type outputted from an image forming apparatus.

A reading apparatus includes a transport unit, a multi-feed detection unit, a reading unit, and a controller. When a multi-feed of the document is detected by the multi-feed detection unit, the controller multi-feeds causes the transport unit to discharge, downstream of the transport path, a multi-fed document for which the multi-feed is detected and then temporarily stops the transport, stores multi-fed page information indicating a page number of the multi-fed document, restarts the transport after the temporary stop, and after the reading unit reads a remaining document whose page succeeds a page of the multi-fed document, performs a re-reading process including the transporting and the reading of the multi-fed document, respectively, and inserts, based on the multi-fed page information, second read data acquired by the reading in the re-reading process into first read data acquired by the reading completed before the re-reading process.

An image processing apparatus includes a document table, an image reading portion, a cover portion, a presser sheet, and a sheet winding portion. The presser sheet is provided on the cover portion, and contacts the document on the document table when the cover portion is positioned at the closing position. The sheet winding portion allows a first portion of the presser sheet to extend along the document table while holding a second portion of the presser sheet in a wound state. The sheet winding portion can feed the second portion when an external force is applied to the first portion. In the cover portion, a retreat space is formed so that the first portion of the presser sheet and a portion of the second portion fed from the sheet winding portion can retreat into the retreat space.

An image reading device includes: a scanner glass; photo-sensors arranged at intervals in a main scanning direction to read a document conveyed in a sub-scanning direction; an adjuster that adjusts the size of an overlapping area between a first and second image obtained by neighboring photo-sensors, the overlapping area constituting a first area of the first image and a second area of the second image; a superimposing portion that shifts either one of images of the first and second area to the other one; a judgment portion that judges whether the images having different focal depths exist based on the degree of matching between the first and second area; and a detector that detects a foreign body on the scanner glass platen by detecting a continuous image stretching in a document conveying direction in both of the images having different focal depths, if the images having different focal depths exist.

An estimated image data calculator is configured to calculate, as estimated image data, for each of image data of respective colors outputted from an imaging element, on the basis of a pixel value of a first pixel on one of two lines adjacent to each other in the image data, and a pixel value of a second pixel on the other of the two lines and adjacent to the first pixel, image data of a non-reading region between a reading region in a document corresponding to the one of the two lines and a reading region in the document corresponding to the other of the two lines. A pixel value correcting unit is configured to correct at least one of the pixel value of the first pixel and the pixel value of the second pixel on the basis of the estimated image data.