An image reading apparatus includes: a sensor module which includes a light source and sensors; a reference member for creating black correction data and white correction data; and an image processor. The image processor corrects uneven density of an image resulting from interference of image signals from the sensors, by performing, on the image signals obtained by the sensors, shading correction using black correction data and white correction data. The image processor obtains causes the sensors to obtain image signals of the reference member, and creates the white correction data based on white data, and the black correction data based on intermediate data. At least one of when creating the white correction data and when creating the black correction data, the image processor causes the sensors to obtain image signals of the reference member a plurality of times.

Provided is a scanner having sixteen or fewer sensor chips capable of scanning an A4 document; an optical unit that reduces and focuses an image of an A4 document on the sensor chips; and a generator that synthesizes images of the A4 document read by the sensor chips, and generates image data.

An image scanning apparatus, comprising: a scanning device; a reference member; a correction unit; a controller; and a storage device, the scanning device comprising light receiving elements and a lens array, wherein the controller executes: a preparation process and an executive process, the preparation process comprising: a white reference data obtaining process to obtain white reference data by scanning a white reference original; and a white storing process to obtain white basic data by averaging the white reference data of a particular number of adjoining light receiving elements, wherein the executive process comprises: a reference member data obtaining process to obtain reference member data by scanning the reference member; a lens fluctuation calculation process to calculate fluctuation data of the correction data based on the reference member data; and a correction data generation process to generate the correction data by adding the fluctuation data to the white basic data.

An image forming device, which is included in an image forming apparatus, includes an image reader, a sheet conveyance passage, a transparent body, an opposing body, and multiple curved opposing portions. The image reader is configured to read an image formed on a target object. The sheet conveyance passage is a passage through which the target object is conveyed. The transparent body is disposed between the sheet conveyance passage and the image reader. The opposing body is disposed facing the transparent body on a side opposite the image reader. The multiple curved opposing portions have respective outwardly curving reference planes. The multiple curved opposing portions are sequentially switched and located at a predetermined image reading position at which the multiple curved opposing portions face the transparent body with a gap through which the target object passes the predetermined image reading position.

An image reading device includes a light applying unit that applies light from a light source to a recording medium, a detecting unit that detects the light reflected by the recording medium, a holding member that is movable in a first scanning direction of the light applying unit and holds a calibration member to which the light from the light applying unit is applied, a shaft member that extends in the first scanning direction through the holding member and guides the movement of the holding member in the first scanning direction, and a restricting member that extends in the first scanning direction and restricts rotation of the holding member about the shaft member.

According to an embodiment, an image reading device includes a photoelectric conversion unit, a white reference plate, a rotation unit, and a control unit. The photoelectric conversion unit includes an image reading sensor which converts light from an imaging position into image data. The white reference plate has a reading range which is a white reference value. The rotation unit rotates the photoelectric conversion unit so as to come to an angle at which a plurality of portions in the reading range of the white reference plate become imaging positions. The control unit sets a white reference value using a plurality of pixels on the white reference plate which are read using the photoelectric conversion unit which is rotated using the rotation unit.

A movement unit moves a reading unit in a first direction and a second direction. A control unit controls the movement unit so that the reading unit is positioned in a predetermined region in a case when a transition is made from an operation mode to a non-operation mode and controls the movement unit to cause the reading unit to move from the predetermined region to a position at which a white reference plate can be read in a case when a transition is made from the non-operation mode to the operation mode. The control unit causes movement of the reading unit by the movement unit to stop when a movement amount of the reading unit measured by a measurement unit becomes a movement amount corresponding to a distance from the boundary to a position at which a white reference plate can be read.

A scanner includes a transport mechanism that continuously transports a plurality of documents, a sensor, a control unit that performs correction of a read image which the sensor reads by using a correction value, a calculation unit that calculates the correction value based on a result from which the sensor reads a reference region between the documents, and a storage unit that sequentially stores the correction value in any of a plurality of storage regions, in which the control unit switches the storage region where the correction value used for the correction is read out to the storage region where the calculated correction value is stored, if storing of the calculated correction value is completed.

In an image reader, a controller acquires a set of first black data for each pixel in a line by reading one line worth of image via a light receiver with a light source being turned off when a detector detects that a cover is in an open state. Subsequently, the controller acquires a set of white data for the each pixel in the line by reading a white reference member via the light receiver with the light source emitting light when the detector detects that the cover is in the open state. The controller calculates a set of correction data for the each pixel in the line by subtracting the set of first black data of the each pixel from the set of first white data of the each pixel. The set of correction data is used in a shading correction.

An image forming apparatus, including a reading device and a controller to control the reading device to execute a reading operation, is provided. The controller in the reading operation executes a leading edge detecting process, wherein a leading edge of an original sheet is detected from image data acquired through the reading device; a trailing edge detecting process, wherein a trailing edge of the original sheet is detected from the image data acquired through the reading device; a determining process, wherein one of the leading edge and the trailing edge to be used to correct the image data acquired through the reading device is determined based on conditions of the detected leading edge and the trailing edge; and a correcting process, wherein the image data is corrected by use of the determined one of the leading edge and the trailing edge determined in the determining process.