An image forming apparatus includes a stack portion having recording materials, an image forming unit, a basis weight detection unit, an operating sound detection unit, and a mode selection unit. The basis weight detection unit detects a recording material basis weight based on an ultrasonic wave. The operating sound detection unit detect an abnormality of a generated operating sound. The mode selection unit selects, for each recording material fed to the image forming unit, between transmitting to the basis weight detection unit a first instruction for detecting the recording material basis weight and transmitting to the operating sound detection unit a second instruction for detecting the operating sound abnormality. In determining an interval at which each second instruction is transmitted, the mode selection unit determines the interval so that the interval and a cycle, in which properties of recording materials on the stack portion are repeated, do not continuously coincide.

An image forming apparatus for forming an image on a sheet, includes an image forming unit configured to form the image on the sheet, a double-sided conveyance path through which the sheet with the image formed on a first surface passes before the image forming unit forms an image on a second surface opposite to the first surface, a guide member having a contact portion configured to contact one end of the sheet in the width direction of the sheet, the guide member being provided on the double-sided conveyance path, and a reversing roller pair forwardly and reversely rotatable, configured to convey the sheet to the double-sided conveyance path during a reverse rotation, the reversing roller pair having a drive shaft, and a first roller and a second roller coaxially disposed on the shaft, rotatable with the shaft, wherein the second roller is disposed at a position more away from the contact portion than the first roller in the axial direction of the shaft, the second roller having a larger outer diameter than the first roller.

An image forming apparatus includes an image forming unit, a discharge unit, a double-sided conveyance path, a sheet plate, a skew correction unit, and a frame. The discharge unit discharges a sheet having an image from the image forming unit. The double-sided conveyance path conveys the sheet again to the image forming unit. The sheet plate restricts a position of an end, in a sheet width direction, of the sheet. The skew correction unit obliquely conveys the sheet to abut the sheet end. The frame determines a position of the sheet plate and includes a first positioning portion to position a sheet plate first positioned portion and a second positioning portion to position a sheet plate second positioned portion with the skew correction unit between the first and second positioned portion. The first positioning portion faces the first positioned portion and the second positioning portion faces the second positioned portion.

A sensor unit is at least partially disposed in a region below an upper end of a reversing roller, above a lower end of a second rotary member, and outside a duplex conveying path.

A printing apparatus selectively executes a first print control in which an image is printed on a sheet for which a single-sided printing is instructed after an image has been printed on a first surface of a last sheet of sheets for which a double-sided printing is instructed and which correspond to pages before a page corresponding to the sheet for which the single-sided printing is instructed, and a second print control in which printing on a first surface of a number of sheets, within a predetermined number of pages after a page corresponding to a sheet for which the single-sided printing is instructed, for which the double-sided printing is instructed and which correspond to pages after the page corresponding to the sheet on which the single-sided printing is instructed, is performed prior to printing of the sheet on which the single-sided printing is instructed.

Disclosed are a duplex document copying system and a method thereof applied to a manual operation for a document. A scanning device is connected to a processing device. The processing device stores one or more block pixel thresholds. After the scanning device obtains first scanning data and second scanning data from scanning the document, the processing device compares pixel difference information between the first scanning data and the second scanning data with the one or more block pixel thresholds to calculate a similarity between the first scanning data and the second scanning data so as to avoid repeated scans. In this way, it avoids the manual errors and outputting the repeatedly scanned document, thereby improving overall work efficiency and saving resources.

System and method for adaptively switching a print mode from duplex to simplex. In one embodiment, a processor monitors memory to detect a duplex page followed by multiple contiguous simplex pages. The processor estimates a first time for the duplex sheet corresponding to the duplex page to traverse a duplex media path for switching from a duplex print mode to a simplex print mode. The processor also estimates a second time for simplex sheets corresponding to the multiple contiguous simplex pages to traverse the simplex media path in the simplex print mode, and estimates a third time for the simplex sheets to traverse the duplex media path in the duplex print mode. If the third time is less than a sum of the first time and the second time, the processor modifies the instructions to print the multiple contiguous simplex pages in the duplex print mode.

An image forming apparatus includes a main casing including an image forming unit and a discharge tray, and an optional device configured to be removably attached to the main casing. The main casing includes a conveying path through which a sheet is conveyed from the image forming unit, a discharge path through which the sheet is conveyed toward one of the discharge tray and the optional device, the discharge path diverging from the conveying path, and a return path including a first path through which the sheet is conveyed temporarily out of the main casing via an opening formed in the main casing, and a second path through which the sheet is conveyed toward the image forming unit. The first path diverges from the conveying path. The second path diverges from the first path. The optional device is disposed closer to the discharge tray than the opening.

A printing apparatus having a copying function includes a document feeder that feeds a document, an image reading section that scans the document fed from the document feeder and generates image data of the document, a printing section that performs printing on paper in accordance with the image data, and a controller. The controller performs an avoidance process of avoiding performing the printing in which a size of a sheet of the document and a size of the paper do not match against an intention of a user, in a case where a setting is made in which the document, on which single-sided printing is performed, is printed on both sides of the paper to perform double-sided printing, and the document includes sheets having different sizes and includes an odd number of successive sheets with an identical size.

An image forming apparatus includes a stack portion having recording materials, an image forming unit, a basis weight detection unit, an operating sound detection unit, and a mode selection unit. The basis weight detection unit detects a recording material basis weight based on an ultrasonic wave. The operating sound detection unit detect an abnormality of a generated operating sound. The mode selection unit selects, for each recording material fed to the image forming unit, between transmitting to the basis weight detection unit a first instruction for detecting the recording material basis weight and transmitting to the operating sound detection unit a second instruction for detecting the operating sound abnormality. In determining an interval at which each second instruction is transmitted, the mode selection unit determines the interval so that the interval and a cycle, in which properties of recording materials on the stack portion are repeated, do not continuously coincide.