An image reading apparatus includes a control unit configured to detect occurrence or non-occurrence of multi-sheet feed of a medium based on a reception level signal output by a reception unit in accordance with the received ultrasonic wave. The control unit, after a tip of the medium reaches the positions of the reception unit in a transport path, when the reception level signal is below a predetermined threshold, causes the driving voltage to rise, when an amount of change in the reception level signal in accordance with the rise in the driving voltage is smaller than a reference amount of change, determines that multi-sheet feed is ongoing, and when the amount of change in the reception level signal in accordance with the rise in the driving voltage is greater than the reference amount of change, determines that multi-sheet feed is not ongoing.

An image reading apparatus includes a conveyor configured to convey an original in a conveyance direction; a reader configured to read an image of the original conveyed by the conveyor; and at least one processor configured to: determine, based on the image read by the reader, an inclination amount corresponding to an inclination angle of a side of a leading edge of the original in the conveyance direction, wherein the inclination angle represents an inclination of the side of the leading edge of the original with respect to a width direction orthogonal to the conveyance direction; rotationally correct the image read by the reader by the inclination amount so as to reduce the inclination amount to output a first image in which the rotationally corrected image is included in a case where the inclination amount is smaller than a predetermined amount.

An image processing portion of an image reading apparatus includes an extraction portion that extracts color information, a management portion that manages management color information that is an estimated value of the color information based on a control signal, a determination portion that determines whether or not the color information matches the management color information, and a writing control portion that causes the storage portion to store the pixel data when it is determined that the color information matches the management color information and that does not cause the storage portion to store the pixel data when it is determined that the color information does not match the management color information. When the color information does not match the management color information, the management portion adjusts the management color information to match the color information.

A reading device and an image forming apparatus are provided. The reading device includes an image reading device configured to read an image on a recording medium being conveyed, a background device serving as a background image when the image is read by the image reading device, and a foreign-object detector configured to compare a first read image obtained as the background device is read by the image reading device with a second read image obtained as the background device and the recording medium are read by the image reading device to detect an attached foreign object. The image forming apparatus includes the reading device and an image forming device.

An image reading apparatus (1) includes image sensors (20A, 20B). The image sensor (20A) includes light guides (21A, 22A) guiding light to a reading target (M), a lens body (8A) forming an image of reflected light derived from the light guided by the light guides (21A, 22A) and reflected from the reading target (M), light receiving elements (11A) converting the image of reflected light formed by the lens body (8A) into electrical signals, and a controller (14A) controlling exposure times of the light receiving elements (11A). The image sensor (20B) includes a lens body (8B) forming an image of transmitted light derived from the light guided by the light guide (22A) and transmitted through the reading target (M), light receiving elements (11B) converting the image of transmitted light formed by the lens body (8B) into electrical signals, and a controller (14B) controlling exposure times of the light receiving elements (11B).

A light emitting device includes a light-emitting element row that includes light emitting elements arranged in a row in a main scanning direction, an optical element that is used for forming an electrostatic latent image by focusing light outputs of the light emitting elements and exposing a photoconductor to light and a control unit that controls light emission of the light-emitting element row. The light-emitting element row is divided into groups, and the control unit uniformly corrects a light intensity of each of the light emitting elements included in the groups on a group-by-group basis by a first correction method so as to correct density unevenness in the main scanning direction.

An image forming apparatus includes an image forming unit to perform an image forming process of forming a plurality of test charts having different adhesion amounts of an image forming material on a recording medium. The image forming process includes a transfer process of transferring the image forming material to image forming positions on the recording medium. The image forming apparatus further includes an image reading unit, circuitry, and a storage unit. The image reading unit reads each of the plurality of test charts. The circuitry calculates adjustment values for adjusting images formed at the image forming positions on a first side and a second side of the recording medium depending on adhesion amounts of the image forming material on the first side and the second side based on a reading result of the plurality of test charts by the image reading unit. The storage unit stores the adjustment values.

An image reading apparatus includes an image sensor, a document feeder, and a processor. The document feeder includes a first driving device, a second driving device, a third driving device, a first sensor, and a second sensor. The first driving device includes a pick-up member to move documents from a tray to a document conveying path using a driving force through a first clutch. The second driving device is to move the tray with the documents to a side of the pick-up member using a driving force through a second clutch. The third driving device to move the documents along the document conveying path onto the image sensor using the driving force of the motor. The first and second sensors detect the documents on the document conveying path. The processor controls an operation of the first clutch based on the signals of the first and second sensors.

An image reading apparatus (1) includes image sensors (20A, 20B). The image sensor (20A) includes light guides (21A, 22A) guiding light to a reading target (M), a lens body (8A) forming an image of reflected light derived from the light guided by the light guides (21A, 22A) and reflected from the reading target (M), light receiving elements (11A) converting the image of reflected light formed by the lens body (8A) into electrical signals, and a controller (14A) controlling exposure times of the light receiving elements (11A). The image sensor (20B) includes a lens body (8B) forming an image of transmitted light derived from the light guided by the light guide (22A) and transmitted through the reading target (M), light receiving elements (11B) converting the image of transmitted light formed by the lens body (8B) into electrical signals, and a controller (14B) controlling exposure times of the light receiving elements (11B).

Provided is an image processing apparatus for extracting embedded information from a printed document printed by an electrophotographic method, including: a first obtaining unit configured to obtain first image data by reading the printed document while applying light to the printed document; a second obtaining unit configured to obtain second image data by reading the printed document without applying light to the printed document; a determination unit configured to determine whether a high color density region of which density is higher than a predetermined value is present in the printed document; and a decision unit configured to decide which of the first image data and the second image data to set as image data to be used to extract the embedded information, according to the determination made by the determination unit.