An image reading apparatus includes a light irradiator, an optical system and a photoelectric converter. The optical system includes a reflection mirror unit and an aperture unit. The reflection mirror unit includes first and second reflection areas successively provided in a main scanning direction. The aperture unit includes a light shielding portion and first and second light passing holes for allowing the passage of the light reflected by each of the first and second reflection areas. The photoelectric converter includes a light receiving surface having first and second light receiving areas configured to receive the light passed through each of the first and second light passing holes and successively arranged in the main scanning direction. A length of the light receiving surface along the main scanning direction is set to be equal to or longer than that of the image reading area along the main scanning direction.

An image sensor includes: a lens configured to focus light irradiated toward an object to be read and reflected by the object to be read; a sensor configured to receive light focused by the lens; a sensor board configured to mount thereon the sensor; a board retaining plate, having a casing attachment surface extending in the X direction and a sensor board attachment reference surface that is in contact with the +Y side of the sensor board and is formed in a side surface of the casing attachment surface, and configured to retain the sensor board; and a first casing configured to fix or retain the board retaining plate by fastening of a surface of the casing attachment surface.

In an image reading device, a controller is configured to perform: calculating a ratio between first and second reference data as evaluation data; designating a target light receiving element from a plurality of light receiving elements one by one sequentially; calculating average evaluation data of the target light receiving element by averaging the evaluation data of a second number of light receiving elements located at positions apart every predetermined distance equal to a length of a first number of consecutively arranged light receiving elements; setting an evaluation range of the target light receiving element by adding/subtracting a predetermined value to/from the average evaluation data; determining whether the evaluation data falls within the evaluation range; in response to determining that the evaluation data is out of the evaluation range, revising the second reference data of the target light receiving element; and generating correction data using the second reference data after revision.

An image reading device includes: a sensor module having a light source and a plurality of sensors; a white reference plate; and an image processor that generates correction data to be used for shading correction and performs the shading correction on image signals, using the correction data. The light source is configured to switch between at least a first luminous intensity and a second luminous intensity lower than the first luminous intensity. The image processor acquires intermediate data by causing the plurality of sensors to acquire an image signal of the white reference plate illuminated with the second luminous intensity, generates black correction data, based on the intermediate data, and performs the shading correction, using the black correction data, so that a density unevenness, in an image, caused by interference between image signals from the plurality of sensors.

A lens array includes a flat plate-shaped base part, a plurality of lenses, a plurality of columnar light guiding parts and a plurality of light shielding parts. The lenses are formed on one surface of the base part. The columnar light guiding parts are formed on another surface of the base part at points corresponding to the lenses. The light shielding parts are formed at least on lateral surfaces of the light guiding parts.

An image reading device includes an image processor that generates correction data to be used for shading correction and perform the shading correction using the correction data, and a memory that stores first black correction data to be used for the shading correction in a main scanning direction in a predetermined first position in a predetermined sub-scanning direction. The image processor generates third black data based on an image signal of a second reference plate extending in the sub-scanning direction in a predetermined second position in the main scanning direction, generates black correction data according to the sub-scanning direction based on the first black correction data and the third black data, and performs the shading correction using the black correction data so as to correct density unevenness in the main scanning direction and the sub-scanning direction caused by an interference between image signals from a plurality of sensors.

An image reading device has an image processor that generates correction data to be used for shading correction and performs the shading correction using the correction data. The image processor generates intermediate data with a predetermined density level, generates intermediate data in different positions in the sub-scanning direction based on image signals of a first reference plate and a second reference plate disposed in the different positions, generates first and second black correction data based on the respective intermediate data, generates black correction data according to the sub-scanning direction based on both the black correction data, and performs the shading correction using the black correction data in the respective positions in the sub-scanning direction.

A socket includes a first base member that includes a module mount unit allowing a module including an imaging device and an object to be placed thereon and an electric connector that electrically connects the imaging device to an external apparatus, a second base member having an opening, and an engagement unit that causes the first base member to be engaged with the second base member under a condition that the module placed on the module mount unit is sandwiched by the first and second base members. When the first base member is engaged with the second base member by the engagement unit under a condition that the module placed on the module mount unit is sandwiched by the first base member and the second base member, the electric connector is electrically connected to the imaging device, and the object receives illumination light from a light source through the opening.

An image reading apparatus includes a conveyance unit, a casing, a reading unit, a support shaft, a first cable, and a second cable. The reading unit includes a reading sensor configured to read an image of the sheet conveyed in the conveyance path through the transparent member. The support shaft supports the reading unit in a manner of moving in a moving direction orthogonal to a longitudinal direction of the reading unit. The first cable is connected to a first connecting portion disposed in the reading unit, the first cable being held by the reading unit on one side in the longitudinal direction with respect to the support shaft. The second cable is connected to a second connecting portion disposed in the reading unit, the second cable being held by the reading unit on the other side in the longitudinal direction with respect to the support shaft.

A contact image sensor includes a preset scanning plane used for the surface to be scanned to map to the original copy. The contact image sensor includes: a timing circuit: for self-generating light source control signal LRDT and line scan control signal TRIG1; a lens: for collecting reflected light emitted by a light source reflected by the original copy and emitting the reflected light onto a photoelectric conversion chip for converting received optical signals into electrical signals; and a data processing unit: emitting trigger pulse TRIG according to the encoder transmitting the object to be detected, receiving and processing electrical signals output by the photoelectric conversion chip that has the same size of the photoelectric signal output, ensuring the output stability, dynamic range and sensitivity of the image sensor.