An image reading apparatus 300 comprises: the scanner device SD which reads information about a sheet P conveyed on a paper conveying route PP and information about a position, a form and a color of an image formed on the sheet P; a spectrophotometer CI which reads information about a color of an image formed on a sheet P conveyed on the paper conveying route PP; and a support base TR which incorporates the paper conveying route and a motor for conveying a sheet and can be pulled out from a main body together with the paper conveying route and the motor. The scanner device SD is not mounted on the support base TR but fixed to the main body of the image reading apparatus. The spectrophotometer CI is mounted on and fixed to the support base TR, and spaced from the paper transfer route PP by a predetermined distance.

An image forming apparatus includes a light transmitting member provided at a reading position set in a conveyance path and an opposite plate opposed thereto, and a document being conveyed passes between this opposite plate and the light transmitting member. On an opposing surface of the opposite plate to the light transmitting member, a low brightness area, for example, like a gray color and a high brightness area, for example, like a white color, having a higher brightness than the low brightness area are formed adjacent to each other in a conveyance direction of the document. Then, an image reader sets a home position of a scanning unit to a first position or a second position corresponding to either the low brightness area or the high brightness area to read the document passing through the reading position.

An image reading device includes linear image sensors that are arranged so that adjacent image sensors include an overlapping region in which portions of reading regions of the adjacent image sensors overlap in a main scanning direction, and a buffer unit for read image data. Image data of each overlapping region are generated by synthesizing first image data obtained by a first linear image sensor and second image data obtained by a second linear sensor, the first linear image sensor and the second linear sensor being adjacent in the main scanning direction. Image data of the predetermined line is generated based on image data in which the image data of each overlapping region are excluded from the image data stored in the buffer unit and the image data of each overlapping region. The processing is repeatedly executed in a sub-scanning direction.

An image reading device includes linear image sensors that are arranged so that adjacent image sensors include an overlapping region in which portions of reading regions of the adjacent image sensors overlap in a main scanning direction, and a buffer unit for read image data. Image data of each overlapping region are generated by synthesizing first image data obtained by a first linear image sensor and second image data obtained by a second linear sensor, the first linear image sensor and the second linear sensor being adjacent in the main scanning direction. Image data of the predetermined line is generated based on image data in which the image data of each overlapping region are excluded from the image data stored in the buffer unit and the image data of each overlapping region. The processing is repeatedly executed in a sub-scanning direction.

An image is read from a recording medium via first and second optical imaging systems disposed such that respective reading regions partially overlap each other in a principal scanning direction on a reading surface. A sum of distances over which first and second images captured by the first and second optical imaging systems, respectively, are displaced in the principal scanning direction with respect to a reference point included in a region in which the reading regions overlap each other is calculated. First and second distances, over which the first and second images are displaced in the principal scanning direction, respectively, are calculated using the sum and first and second reading angles at which the first and second optical imaging systems, respectively, read the reference point. Positions of the first image and the second image in the principal scanning direction are corrected using the first distance and the second distance, respectively.

An image is read from a recording medium via first and second optical imaging systems disposed such that respective reading regions partially overlap each other in a principal scanning direction on a reading surface. A sum of distances over which first and second images captured by the first and second optical imaging systems, respectively, are displaced in the principal scanning direction with respect to a reference point included in a region in which the reading regions overlap each other is calculated. First and second distances, over which the first and second images are displaced in the principal scanning direction, respectively, are calculated using the sum and first and second reading angles at which the first and second optical imaging systems, respectively, read the reference point. Positions of the first image and the second image in the principal scanning direction are corrected using the first distance and the second distance, respectively.

According to one embodiment, an image reading apparatus includes a light emitting unit, a first carriage, a first photoelectric conversion unit, a first lens, and a second carriage. The light emitting unit irradiates a reading object with light. The first carriage includes a first optical member for guiding reflected light from the reading object. The first carriage is movable in a sub-scanning direction along the reading object. The first photoelectric conversion unit receives the reflected light from the reading object guided through the first optical member and outputs an image signal. The first lens is disposed on an optical path of the reflected light between the first optical member and the first photoelectric conversion unit, and images the reflected light from the reading object on the first photoelectric conversion unit. The second carriage is movable in a main scanning direction orthogonal to the sub-scanning direction along the reading object with respect to the first carriage. The second carriage includes a second optical member for guiding the reflected light from the reading object, a second photoelectric conversion unit that receives the reflected light from the reading object guided through the second optical member to output an image signal, and a second lens that is disposed on an optical path of the reflected light between the second optical member and the second photoelectric conversion unit and images the reflected light from the reading object on the second photoelectric conversion unit at a magnification different from the first lens.

An image reading apparatus includes a line sensor configured to read an image of a target object. The line sensor includes light receiving element arrays arranged at given intervals in a second direction perpendicular to a first direction for a plurality of lines, the plurality of light receiving element arrays each including a first light receiving element configured to receive light of a first color and a second light receiving element configured to receive light of a second color different from the first color, which are arranged in the first direction to form one line. The image reading apparatus is configured to derive a shading correction coefficient for shading correction based on output from the light receiving element arrays that have read a reference white plate, and to identify, as an abnormal pixel, a pixel obtained by reading a foreign matter existing on the reference white plate.

An image reading apparatus includes a line sensor configured to read an image of a target object. The line sensor includes light receiving element arrays arranged at given intervals in a second direction perpendicular to a first direction for a plurality of lines, the plurality of light receiving element arrays each including a first light receiving element configured to receive light of a first color and a second light receiving element configured to receive light of a second color different from the first color, which are arranged in the first direction to form one line. The image reading apparatus is configured to derive a shading correction coefficient for shading correction based on output from the light receiving element arrays that have read a reference white plate, and to identify, as an abnormal pixel, a pixel obtained by reading a foreign matter existing on the reference white plate.

Provided is an image reading apparatus including a line sensor including three line sensors arranged at a predetermined interval in a sub-scanning direction, and being configured to read an image of an original by the respective line sensors, which includes light receiving elements arranged in a first direction, to generate read data representing the read image, the three line sensors each including a first light receiving element configured to receive red light, a second light receiving element configured to receive blue light, and a third light receiving element configured to receive green light, which are arranged in a main scanning direction; and a reading control board. The reading control board is configured to generate a first combined flag obtained by combining results of detecting abnormal images of respective colors and a second combined flag obtained by combining results of detecting abnormal images of the respective colors.