A control unit of an image reading device is configured to execute image correction control after performing a first reading operation of reading a medium while transporting the medium in a first direction, and the image correction control includes a second reading operation of reading the medium while transporting the medium in a second direction opposite to the first direction, and a combination process for combining a first area serving as a part of image data acquired through the first reading operation with a second area serving as a part of image data acquired through the second reading operation to acquire image data of one page.

An image processing apparatus includes an image acquisition section that acquires pieces of image data acquired by performing image reading in a sub scan direction in a unit of a line extending in a main scan direction, an orientation changing section that changes an orientation of each of data images represented by the respective pieces of image data acquired by the image acquisition section, and an image processing section that performs image processing serially on the pieces of image data acquired by the image acquisition section. The image processing section performs the image processing every predetermined number of pieces of image data serving as a predetermined processing unit. The image processing section changes the predetermined processing unit for the image processing to a processing unit different from the predetermined processing unit in a case where the orientation is changed by the orientation changing section.

An image processing apparatus includes a processing unit that shifts plural pieces of pixel data so as to suppress deviation in a sub-scanning direction at the time of image formation; a storage unit that stores the plural pieces of pixel data; and a converting unit that converts addresses of the plural pieces of pixel data such that a predetermined number of pieces of pixel data which are a unit of processing of the shift process are stored in a cache memory used by the storage unit at once.

An image reading apparatus according to the present invention includes: a conveyor which conveys an original in a first direction; a light transmitting member which is provided with coating in a first region of a surface facing the original; a reading unit which reads an image at a reading position of the original through the light transmitting member; and a controller which performs processing on the image and which changes the reading position by moving the reading unit when abnormality is detected in the processing. The coating includes a silicon-containing perfluoropolyether compound. An electrically-conductive member is provided in a second region located on the surface of the light transmitting member, upstream of the first region in a conveyance direction of the original. A contact angle of the coating at a position corresponding to the reading position in the first region is appropriately set.

An image processing device includes a reception unit that receives an input image signal, and a synchronization signal used to generate an output image signal on a basis of the input image signal. In a case in which, after receiving the synchronization signal, the reception unit does not receive a next synchronization signal within a predetermined reception period, the reception unit conducts an automatic reception process that treats the next synchronization signal as being received.

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.

A reading device includes a position reference member and a reader. The position reference member has a reference pattern that includes a line extending in a prescribed direction. The position reference member is configured to relatively move in a direction orthogonal to the prescribed direction. The reader includes a plurality of sensor chips, each of the sensor chips including a plurality of pixels. The reference pattern corresponds to each of the sensor chips of the reader.

A medium conveying apparatus includes a conveyance roller to convey a medium, a DC motor to drive the conveyance roller, a processor to rotate the DC motor, an encoder to output a first pulse signal whose cycle varies according to a rotation speed of the DC motor, and an imaging device to acquire an image acquired by imaging a conveyed medium in response to a pulse of a second pulse signal whose cycle is constant. The processor detects a number of pulses of the second pulse signal included in a predetermined cycle of the first pulse signal, and discards images acquired by the imaging device in the same number of pulses as difference between the detected number of pulses and a reference number, in a next cycle of the predetermined cycle of the first pulse signal, when the detected number of pulses exceeds the reference number.

An image forming apparatus including a photoconductor and a light emitting unit. The image forming apparatus including: a generating unit configured to generate correction data used for correcting a shift in the sub-scanning direction of the latent image to be formed on the photoconductor; a correcting unit configured to correct image data based on the correction data; and a control unit configured to control light emission of the light emitting unit so as to form the latent image on the photoconductor. The generating unit is configured to generate the correction data based on configuration information of the light emitting unit, information indicating time required for causing the plurality of light emitting elements to emit light, and information indicating a rotation speed of the photoconductor.

With reference to a correction value revision parameter table, a periodic non-uniformity correction value corresponding to changed rotational speed is obtained from the correction value revision parameter table, and set as a new periodic non-uniformity correction value corresponding to the rotational speed of a rotary component, and thereby a gradation which is an image formation parameter of image data is corrected.