An image scanning apparatus includes a controller configured to acquire image data by scanning a document and a particular range of a document pressing surface, detect black edge positions by detecting, from the image data, black pixels having gradation values less than a white gradation value, determine a sheet type of the document based on the gradation values of the black pixels, detect white edge positions by detecting, from the image data, white pixels having gradation values equal to or more than the white gradation value. The controller is further configured to, when the sheet type is a thin paper, detect, as the white pixels, pixels having gradation values equal to or more than a first threshold, and when the sheet type is a thick paper, detect, as the white pixels, pixels having gradation values equal to or more than a second threshold.

An image reading apparatus includes a transport section that can transport original documents along a transport path, a reading section configured to read images of the original documents transported by the transport section, an output controller configured to output data of the original documents read by the reading section, a multi-sheet feed detection sensor configured to detect a multi-sheet feed of the original documents transported by the transport section, and an instruction section configured to issue an instruction to disable multi-sheet feed detection by the multi-sheet feed detection section.

An image reading apparatus capable of recognizing edge portions of an original image with precision is provided. The image reading apparatus uses an image reading unit to scan an original being conveyed and read an image of the original. The image reading apparatus includes an edge information obtaining unit and an edge determining unit. The edge information obtaining unit detects an image of an edge portion of the original image and obtains, for each point in a main scanning direction, edge information, which indicates whether or not an edge portion image is detected at the point in a sub-scanning direction. The edge determining unit conducts detection from at least one of two directions of the main scanning direction to detect a point where a given number of successive edge portion images are detected, and obtains an edge portion based on the detected point.

A sheet conveying system includes: an upstream apparatus provided on an upstream side in a conveyance direction of a paper sheet; a downstream apparatus provided on a downstream side of the upstream apparatus; an upstream conveyor that conveys the paper sheet; an upstream driver that drives the upstream conveyor; a downstream conveyor that receives the paper sheet conveyed from the upstream conveyor, and conveys the paper sheet received from the upstream conveyor; a downstream driver that drives the downstream conveyor; an upstream controller that is connected to the upstream and downstream drivers; and a downstream controller that is connected to the downstream and upstream drivers, wherein the sheet conveying system switches control on the basis of sheet information between first control in which the upstream controller controls the upstream and downstream drivers and second control in which the downstream controller controls the downstream and upstream drivers.

A sheet conveying system includes: an upstream apparatus provided on an upstream side in a conveyance direction of a paper sheet; a downstream apparatus provided on a downstream side of the upstream apparatus; an upstream conveyor that conveys the paper sheet; an upstream driver that drives the upstream conveyor; a downstream conveyor that receives the paper sheet conveyed from the upstream conveyor, and conveys the paper sheet received from the upstream conveyor; a downstream driver that drives the downstream conveyor; an upstream controller that is connected to the upstream and downstream drivers; and a downstream controller that is connected to the downstream and upstream drivers, wherein the sheet conveying system switches control on the basis of sheet information between first control in which the upstream controller controls the upstream and downstream drivers and second control in which the downstream controller controls the downstream and upstream drivers.

A printing control apparatus includes a conveying unit that conveys a document to a reading unit, a detection unit that detects a size of the document before it begins to be conveyed, a detection unit that detects the size of the document after the document begins to be conveyed, and a control unit that performs a copy job using the reading unit and printing unit based on the size of the document detected before it is conveyed in a case where the printing unit starts to print the image data before the reading unit finishes generating image data for one page and performs a copy job based on the size of the document detected after it begins to be conveyed in a case where the printing unit starts to print the image data after the reading unit finishes generating image data for at least one page.

An image reading device includes a contact glass, a first lamp, an image sensor, a first lamp, a light absorbing member, and a second lamp. When reading a document, in a first period, the first lamp is turned on while the second lamp is turned off. In a second period, the second lamp is turned on while the first lamp is turned off. On the basis of first image data obtained by reading in the first period and second image data obtained by reading in the second period, the control unit determines whether each pixel in the first image data is a pixel having read document data or not.

Based on a light-reception result of a light-receiving unit capable of receiving light on a document table and outputting the light-reception result, the end of a document placed on a document table is determined. In accordance with the condition of external light on the document table, the light-receiving unit is controlled so as to change a method of outputting the light-reception result from the light-receiving unit.

An original reading apparatus, including: an original tray on which an original is placed; a conveyance portion configured to convey the original placed on the original tray; a sensor configured to read an original being conveyed by the conveyance portion; and a processor configured to detect an abnormal pixel from image data output from the sensor, wherein the processor is configured to: determine a length of a shadow in a conveyance direction of the original based on the image data, the shadow occurring at a leading edge area of the original; detect a skew feed amount of the original based on the image data; determine a mask area based on the length of the shadow and the skew feed amount; and detect an abnormal pixel from the image data without use of image data in the mask area having been determined.

An image processing apparatus includes a memory, a correction circuit, and a calculation circuit. The memory stores image data of an original image that is moved in a sub-scanning direction with respect to an image sensor. The correction circuit sequentially reads the image data from the memory line by line in the main scanning direction, extracts a pixel in a position corresponding to the inclination, and forms an inclination-corrected line in the main scanning direction to correct the inclination. The calculation circuit calculates an amount of movement of a corner of the original image with respect to the sub-scanning direction before and after correction of inclination of the original image with respect to a main scanning direction. The correction circuit restricts progress of formation of the inclination-corrected line based on the amount of movement. The amount of movement is applied when the inclination of the original image is corrected.