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 reader CPU stops a lead motor in a case in which a discharge sensor cannot detect reaching of a leading edge part of an original D even though the original is conveyed by a first amount (L.sub.P3+L.sub.M1) or a second amount (L.sub.P3+L.sub.M2) which is smaller than the first amount from when a lead sensor detects the original, when a reader image processing portion (leading edge detection portion) cannot detect the leading edge part of the original from image data of a first face of the original.

A controller executes area defining processing for defining a middle area and two side areas, and ending processing. In a case where the document leading edge extends parallel to a main scanning direction, the controller executes the ending processing for non-skewed document. In a case where the document leading edge does not extend parallel to the main scanning direction, the controller executes the ending processing for skewed document. In which, the controller determines, in the middle area and the side areas, first, second, and third change positions, respectively, at each of which a type of a target read image data line changes from document data to document cover data, determines, based on the first change position and the second change position, whether a document has a rectangular shape, and ends the reading operation based on the third change position and the determination result as to the document shape.

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.

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.

In an information processing apparatus connected with an image forming apparatus having an image forming unit, the image forming unit includes a first receiver, a light source, a photosensitive member, a rotatable polygon mirror including a plurality of reflection surfaces, a light receiver configured to receive light, an identifier configured to identify a reflection surface to be used for scanning the photosensitive member, and a first outputter. The information processing apparatus includes a second receiver configured to receive the predetermined signal, a corrector configured to correct the image data with correction data corresponding to the reflection surface corresponding to each scan line based on the specific reflection surface, and a second outputter configured to start outputting the image data in response to start of reception of the predetermined signal.

A printer is disclosed, which comprises a frame, an image forming module, a controller, a light guide unit, and an optical detector. The image forming module is disposed opposite to the frame and forms a passage. The light guide unit is disposed in the frame and is connected to the controller. The optical detector comprises an illuminating part and a receiving part. The illuminating part illuminates a beam to the light guide d unit, and the receiving part is for receiving the light.

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.

A control section of a reading device performs skew judgment based on an image of a preceding document scanned by the reading section to determine whether the side edge portion of the preceding document is displaced into a nip region sandwiched between a feed roller and a separation section. When it is determined that the side edge portion of the preceding document is displaced into the nip region and also the detection section, which detects a document placed on the placement section, detects a subsequent document, the control section determines a transport error.

A control unit of a medium feeding apparatus is configured to execute a fault detection process to determine that there is a feeding fault when a movement of a subsequent medium in a feeding direction is detected based on detection information of a movement detection unit within a fault detection period that is set after a trailing edge of a preceding medium is detected based on the detection information of the movement detection unit and before feeding of the subsequent medium is started, and the fault detection period set when a size of the medium in a width direction intersecting the feeding direction is a first size is shorter than the fault detection period set when the size of the medium in the width direction is a second size larger than the first size.