An image reading apparatus includes a first sensor that reads a first area of an image, a second sensor that reads a second area, and a processing circuit that generates a merge image by performing a merge process on first image data acquired by reading by the first sensor and second image data acquired by reading by the second sensor. The processing circuit calculates a correction value having a tendency of approaching zero as being away from an overlap area between the first area and the second area based on a reading result acquired by reading the overlap area by the first sensor and a reading result acquired by reading by the second sensor, and generates the merge image by performing an offset process using the correction value.

An optical line sensor 1 includes an illumination unit 2, a light receiving unit 3, and a pair of holding members 4 separably attached to the light receiving unit 3 at both ends in a main scanning direction. The illumination unit 2 includes fitting portions (protrusions 25) at both ends in the main scanning direction. Each of the holding members 4 includes a fitted portion (hole 41). In a state where the fitting portion and the fitted portion are fitted, the illumination unit 2 is positioned so that the irradiation optical axis of light emitted from the illumination unit 2 overlaps the light receiving optical axis at a position substantially coinciding with a reading line of the light receiving unit 3 and is integrally held with the light receiving unit 3.

An image forming apparatus includes: a scanning unit configured to form an electrostatic latent image on a photoconductor by scanning the photoconductor with one or more scanning beams in a main scanning direction based on an image signal, repetitively in a sub-scanning direction perpendicular to the main scanning direction; a generating unit configured to perform halftone processing on image data to generate the image signal; and a storage unit configured to store correction information. The correction information is set such that start positions of a plurality of scanning lines are linearly displaced to either a negative side or a positive side of the main scanning direction along the sub-scanning direction, in accordance with a direction of a first vector forming a smaller angle with the sub-scanning direction among two vectors in the halftone processing.

Provided is a reading module including a light source, an optical system, and a sensor. The optical system images reflected light of light emitted from the light source to the document, as image light. The sensor converts the imaged image light into an electric signal. The optical system includes a mirror array in which a plurality of reflection mirrors are connected, and a plurality of aperture stops. Neighboring reflection mirrors reflect light at different angles viewed from the main scanning direction.

An image sensor unit includes a light condenser that collects light from a reading target object; an image sensor that receives light and converts the light into an electric signal; an elongated housing that houses the light condenser and the image sensor; and an elongated rigid member attached to a side surface extending in the elongated direction of the housing. The side surface of the housing is provided with an attachment protrusion. The rigid member is provided with an attachment hole that penetrates from a surface facing the side surface of the housing to a non-facing surface on the opposite side, and the non-facing surface of the rigid member is provided with a concave. The attachment protrusion is inserted into the attachment hole, and a part of the attachment protrusion is fit into the concave.

An image reading apparatus includes a first sensor that reads a first area of an image, a second sensor that reads a second area, and a processing circuit that generates a merge image by performing a merge process on first image data acquired by reading by the first sensor and second image data acquired by reading by the second sensor. The processing circuit calculates a correction value having a tendency of approaching zero as being away from an overlap area between the first area and the second area based on a reading result acquired by reading the overlap area by the first sensor and a reading result acquired by reading by the second sensor, and generates the merge image by performing an offset process using the correction value.

There is provided a scanner that combines images read by a first sensor array and a second sensor array, in which the first sensor array and the second sensor array have read regions which are overlapped partially, and includes a combining section that combines a first read image read by the first sensor array and a second read image read by the second sensor array and a correction section that corrects an image after a combining based on a degree of displacement of a reading position of the document.

A method, and document scanner system, for correcting image values recorded by an optical document scanner with multiple color cameras arranged in a staggered configuration with overlap scan areas includes storing color correction values mapped to respective color index values, where a color correction value is computed from a color difference between a first color value and a second color value of the respective overlap sets, and correcting a third color value which is a color value from the second set of color image values by a color correction value which is looked up via a color index value determined from the third color value. Thereby color variations among staggered cameras are corrected.

Provided is a reading module including a light source, an optical system, and a sensor. The optical system images reflected light of light emitted from the light source to the document, as image light. The sensor converts the imaged image light into an electric signal. The optical system includes a mirror array in which a plurality of reflection mirrors are connected, and a plurality of aperture stops. Neighboring reflection mirrors reflect light at different angles viewed from the main scanning direction.

An image sensor unit includes a light condenser that collects light from a reading target object; an image sensor that receives light and converts the light into an electric signal; an elongated housing that houses the light condenser and the image sensor; and an elongated rigid member attached to a side surface extending in the elongated direction of the housing. The side surface of the housing is provided with an attachment protrusion. The rigid member is provided with an attachment hole that penetrates from a surface facing the side surface of the housing to a non-facing surface on the opposite side, and the non-facing surface of the rigid member is provided with a concave. The attachment protrusion is inserted into the attachment hole, and a part of the attachment protrusion is fit into the concave.