Patent ID: 8570611

Claim:
An image reading apparatus for reading an image formed on an original, comprising: a first image reading unit configured to read an image on a first surface of an original to be conveyed; a first fixing unit configured to fix the first image reading unit to the image reading unit in an original conveying direction; a second image reading unit configured to read an image on a second surface opposite to the first surface of the original; a second fixing unit configured to fix the second image reading unit to the image reading unit in the original conveying direction; wherein each of the first image reading unit and the second image reading unit respectively comprises: a frame having an opening; an image sensor configured to read an image on a reading position of the image sensor, in a main scanning direction; a contact glass configured to guide the original to an original image reading location; a reference member disposed at a location different from the original image reading location; a moving mechanism configured to move the image sensor inside the frame to reciprocate the reading position of the image sensor between the original image reading location and a shading correction data acquisition position on the reference member, in a sub scanning direction; and a driving unit configured to drive the moving mechanism, wherein the frame has the contact glass located in the opening, and has the image sensor, the moving mechanism, and the driving unit disposed inside thereof, and wherein the moving mechanism includes a first transmitting unit configured to transmit power of the driving unit to a support shaft for rotating the image sensor in the sub scanning direction or a second transmitting unit configured to transmit power of the driving unit to a slide cam for causing the image sensor to move in the sub scanning direction.