An image reading device includes a tray, a paper feed roller that conveys a sheet, a first sensor that detects a front end and a rear end of the sheet, a second sensor that detects the front end of the sheet, and a scanner that reads an image on a front side of the sheet and reads an image on a back side of the sheet. A controller determines a first time duration that elapses from the detection of the front end of the sheet by the first sensor to the detection of the rear end of the sheet by the first sensor and operates the scanner to read the image on the back side of the sheet over a second time duration equal in length to the first time duration. The second time duration begins after the front end of the sheet is detected by the second sensor.

A reading device includes: plural transport rolls that transport a document along a transport path, include a discharge roll disposed on a most downstream side of the transport path, and rotate and do not rotate in synchronization with one another; an opening and closing unit that exposes or covers an upstream portion of the transport path; plural detectors that are provided apart from one another along the transport path, detect a transported document, and include a discharge detector that is disposed on a most downstream side of the transport path and is disposed on an upstream side relative to the discharge roll in a document transport direction; a reader that reads an image formed on a transported document in a downstream portion of the transport path; and a controller that stops the plural transport rolls once upon occurrence of a document jam inside a device body by controlling the transport rolls and rotates the transport rolls for only a predetermined period in a case where the discharge detector is detecting no document and a length of a document is equal to or longer than a threshold length.

An information processing apparatus includes a memory storing instructions and a processor to execute the instructions to perform operations. Four sides of a document included in captured image data are detected. Lengths of the detected four sides of the document are calculated. The operations further include determining which of a plurality of predefined paper sizes corresponds to the document based on the calculated lengths of the four sides. The determined corresponding paper size is set as a document size of the document.

An image reading device includes a tray, a paper feed roller that conveys a sheet, a first sensor that detects a front end and a rear end of the sheet, a second sensor that detects the front end of the sheet, and a scanner that reads an image on a front side of the sheet and reads an image on a back side of the sheet. A controller determines a first time duration that elapses from the detection of the front end of the sheet by the first sensor to the detection of the rear end of the sheet by the first sensor and operates the scanner to read the image on the back side of the sheet over a second time duration equal in length to the first time duration. The second time duration begins after the front end of the sheet is detected by the second sensor.

An image forming apparatus includes an image forming unit to form an image onto a sheet based on an image forming condition, a conveyance roller to convey the sheet in a first conveyance path, a sheet discharger to discharge the sheet conveyed in the first conveyance path, and a sensor to read, in a second conveyance path branched from the first conveyance path, a test image formed on the sheet. In addition, a tray receives the sheet discharged via the second conveyance path, and a controller generates the image forming condition based on a reading result of the sensor. The controller executes first control of controlling the image forming unit to form a first test image and second control of controlling the image forming unit to form a second test image.

An automatic document feeder includes a document loading detector, a document feeder, a document guide, a guide width measurer, a document width acquirer, a guide shift determiner, a document skew detector, a skew determiner, a warning display information generator, and a display. When a detected skew of a document is determined to be unallowable, the document feeder stops a feeding of the document. The warning display information generator generates a warning content about a feed trouble that stopped the feeding of the document, and the generated warning content about the feed trouble is displayed on the display.

Printers capable of determining a media type of a media and associated methods are provided. An example method includes scanning a media with a verifier associated with the printer to generate at least two consecutive windows of the media. The example method further includes determining a vertical length of a captured image based on a comparison of image characteristic values captured in the at least two consecutive windows. The example method further includes determining a media characteristic associated with the media based at least on the captured image and the vertical length and one or more stored media profiles. The example method further includes calibrating the printer based on the media characteristic.

A document conveyance device includes a sheet feeding tray, a conveyance mechanism, a discharge tray, a document pressing member and a supporting mechanism. The document pressing member comes into contact with an upper face of the document discharged from a conveyance path and presses the document downward. The supporting mechanism is configured to be provided in the sheet feeding tray, to support the document pressing member, to allow a shifting of the document pressing member according to an operation for shifting the document pressing member in a discharge direction of the document or an opposite direction to the discharge direction and to inhibit the shifting of the document pressing member against a force applied to the document pressing member by the discharged document.

An image reading system includes an image reading apparatus including a transport unit configured to transport a document from a bundle of cut documents one by one, a reading unit configured to read an image of the transported document, and a reading control unit, and an external control unit included in an external device coupled to the image reading apparatus, wherein an inclination correction process that corrects an inclination of the image of the document, a size determination process that determines a size of the image as a standard for the bundle of documents, and a size correction process that corrects the size of the image of the document to a specific size determined by the size determination process are performed.

An image processing apparatus 1 obtains displacement amounts of patterns formed on front and back sides of a recording sheet respectively, and performs correction of an image formation position based on the displacement amounts. The image processing apparatus 1 calculates the lengths of the sides of each of the front and back sides of a recording sheet by detecting the intersection points of the surrounding edges of the recording sheet with reference to the image data of the each of the front and back sides. A magnification error is calculated based on the lengths of the sides corresponding between the front and back sides. A correction amount is then calculated based on the calculated magnification error in order to make the lengths of each side match each other. Displacement amounts of the positions of the patterns is obtained after correction based on the correction amount.