An image reading apparatus determines an inclination amount corresponding to an inclination angle of a leading edge of an original document in a conveyance direction, and determines the length of the original document in the conveyance direction. The image reading apparatus sets a first value as a set value in a case that the length of the original document is a first length and sets a second value larger than the first value as the set value in a case that the length of the original document is a second length shorter than the first length. If the inclination amount is smaller than the set value, inclination correction for correcting the image represented by the image data is performed such that the inclination amount is reduced, and if the inclination amount is larger than the set value, the inclination correction is not performed.

A document feeder includes a mode selector, at least two document sensors, and a feeding determiner. The mode selector receives selection of either a normal mode for feeding documents having the same size or a mixed loading mode for feeding documents having different sizes. The document sensors are arranged at an interval in a width direction of the documents, and detect the documents. The feeding determiner performs, based on results of the detection by the document sensors, a size determination to determine a size of a document being fed and a skew determination to determine whether or not the document being fed is skewed. The feeding determiner performs the skew determination when the normal mode has been selected and performs the size determination when the mixed loading mode has been selected.

An image reading apparatus has: electrodes that come into contact with a medium during transport; charge detection circuits, each of which corresponds to one of the electrodes; a reader, and a controller. The controller executes inclination inference processing for calculating the inclination of the medium with respect to a transport path as an inferred inclination value according to a signal from each charge detection circuit, inclination detection processing for deriving the inclination of the medium with respect to the transport path as a detected inclination value according to the result of reading by the reader, and correction value deriving processing for storing a correction value based on the difference between the detected inclination value and the inferred inclination value in a storage section. In inclination inference processing with the correction value stored in the storage section, the inferred inclination value is calculated in consideration of the correction value.

An example image scanning device includes an image sensor to scan a manuscript, a memory, and a processor to generate a scan image corresponding to the manuscript, perform rotation processing for the generated scan image using a scale factor, perform scaling processing for the rotated scan image, and store the scale-processed scan image in the memory.

An image forming apparatus includes a first detector, a second detector, and a determination section. The first detect detects a first skew angle of a sheet. The second detector is located downstream of the first detector and detects a second skew angle of the sheet. The determination section determines whether or not to stop conveyance of the sheet based on the first skew angle and the second skew angle.

A position detection device includes a background member, a reader, and processing circuitry. The background member has a higher absorption characteristic in an invisible wavelength region than in a visible wavelength region. The reader opposite the background member irradiates a recording medium having a mark and the background member with light of a visible wavelength to output a visible image or with light of an invisible wavelength to output an invisible image. The processing circuitry is configured to: detect an end position of the recording medium and a position of the mark on the recording medium from a read image output from the reader; and select the visible or invisible image as the read image used for position detection, according to an absorption characteristic of a color material forming the mark read by the reader and an absorption characteristic of the recording medium in the invisible wavelength region.

A belt transfer type multi-function device includes a control device performing controlling such that an image to be printed on paper already caught between a transfer roller and the belt roller is printed, and if printing should not be performed on a next paper, movement of the next paper is stopped on a transfer path before the next paper is positioned between the transfer roller and the belt roller, the image already transferred on the transfer belt is deleted in a state in which the next paper is stopped on the transfer path, and the next paper in a stopped state is ejected as a blank paper through a ejection port along the transfer path, so that the image already transferred to the transfer belt, which is to be printed on the next paper along the movement direction of paper, is not printed on the next paper.

An image reading apparatus includes a feeding roller that includes a first roller and a second roller provided at an interval in a width direction intersecting a medium feeding direction, and feeds a sheet from a placing section; and a skew detection section that detects skew of the sheet fed from the feeding roller. Skew is corrected by giving a difference between a rotation speed of the first roller and a rotation speed of the second roller with respect to at least one of the relevant sheet detected by the skew detection section and subsequent sheets fed following the relevant sheet based on a skew amount in the sheet.

A document reading apparatus has a first scanning unit that can scan in a document conveyance direction and determines a document reading position, and a guide plate provided in a position that sandwiches the document being conveyed with the first scanning unit. On a facing surface of the guide plate relative to the first scanning unit, a first color section to which a white sheet is attached and a second color section having a sheet metal color (e.g. gray) of the guide plate are formed in the document conveyance direction. The document reading position corresponds to a position facing the second color section when a document is read in a crop mode.

An image reading apparatus acquires first control data regarding generation of first rectangular image data that includes a whole of a document area corresponding to a document within a reading area of read image data. The image reading apparatus acquires second control data regarding generation of second rectangular image data that does not include a background area not corresponding to the document within the reading area of the read image data and includes at least a part of the document area.