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 control method in a printing apparatus includes printing, by a printing unit, an adjustment image for adjusting a printing position on a sheet, conveying, by a conveying unit, the sheet on which the adjustment image is printed, reading, by a reading unit, an image to generate image data, the reading unit being executable to perform reading by a first reading method for reading an image of a sheet without conveying the sheet or a second reading method for reading the image of the sheet while conveying the sheet, and determining, based on that a type of the sheet on which the adjustment image is to be printed is a specific type, to read the adjustment image by the first reading method.

A method is provided for determining a sheet height of a sheet conveyed by a sheet transportation unit. An optical sensor is used for sensing the surface geometry of the sheet, resulting in a two-dimensional height image of the sheet. The height image has pixels that have a value representing a local height of the sheet. The method comprises the steps of: a) selecting from the height image pixels that have a deviating value; b) substituting the deviating value of a selected pixel by a realistic value that is derived from not selected pixels; and c) determining a sheet height by finding a maximum value from the values of the not selected pixels and the substituted values. Furthermore, a print system is provided that comprises a control unit that is configured to apply the invented method.

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 inspection apparatus which inspects an image determines a type of a printing error based on characteristics of a place where the printing error has occurred, and controls a printing apparatus according to the determined type of printing error.

An image reading device includes a reading member that reads an image of a document at a reading position that is set in a transport path of the document, a skew detector that detects an amount of skew of the document with respect to a transport direction of the document, a distortion detector that detects an amount of distortion in the document that has been read, the amount of distortion being a deviation, from a right angle, of an angle formed by a direction transverse to the transport direction of the document with the transport direction of the document, and an image correcting unit that rotates the image that has been read, in accordance with an amount that cancels the amount of skew detected by the skew detector, and corrects distortion of the read image in accordance with an amount that cancels the amount of distortion.

An image reading apparatus includes: a first size-detecting portion which detects a size of an original disposed on a disposing portion; a conveying portion which conveys the original disposed on the disposing portion to a reading portion, a second size-detecting portion which detects the size of the original to be conveyed by the conveying portion; a controller which calculates an overlap region between a reading region and an original region, with the reading region determined based on a reading size obtained by a obtain portion and the detection of the first size-detecting portion, and the original region determined by the second size-detecting portion; and a notifying portion which makes a predetermined notification based on the information that has been calculated.

The present printing system obtains a transparency of a sheet to be subjected to printing, and based on the obtained transparency of the sheet, restricts execution of post-processing by a discharging portion.

A control method in a printing apparatus includes printing, by a printing unit, an adjustment image for adjusting a printing position on a sheet, conveying, by a conveying unit, the sheet on which the adjustment image is printed, reading, by a reading unit, an image to generate image data, the reading unit being executable to perform reading by a first reading method for reading an image of a sheet without conveying the sheet or a second reading method for reading the image of the sheet while conveying the sheet, and determining, based on that a type of the sheet on which the adjustment image is to be printed is a specific type, to read the adjustment image by the first reading method.

A reading device includes a reader provided with a reading sensor that optically reads a sheet conveyed through a conveyance path, and a hardware processor that controls the reader, in which the reader includes a background section that is disposed to face the reading sensor across the conveyance path, the background section having a background surface serving as a background of the sheet when the sheet is read, and the hardware processor switches the background surface of the background section on the basis of attribute information of the sheet to be conveyed.