Patent ID: 8335021

Claim:
An image reading apparatus configured to read an image formed on a side of an original, while conveying the original, comprising: an image reading unit including a contact glass configured to guide the original to an image reading location, a glass holding member configured to hold said contact glass, an image sensor configured to read the image on the original conveyed to the image reading location, through said contact glass, a reference member disposed at a location different from the image reading location on said contact glass, or on said glass holding member, such that an image of said reference member can be read by said image sensor, and a moving mechanism configured to move said image sensor so that said image sensor can respectively read the original conveyed to the image reading location and said reference member, said image reading unit being fixed to a main body of the image reading apparatus; and a driving unit configured to drive said moving mechanism from the outside of said image reading unit to move said image sensor, wherein said moving mechanism comprises a traveling member and an urging member, wherein said traveling member is configured to move said image sensor in a direction different from a longitudinal direction of said image reading unit, and is configured to hold said image sensor such that said image sensor can move between a first position for reading the image on the original and a second position for reading the image of said reference member, wherein said urging member is configured to urge said traveling member such that said traveling member moves said image sensor to one of the first position and the second position, wherein said driving unit comprises a pushing member configured to drive said traveling member from the outside of said image reading unit, and a driving power source configured to cause said pushing member to operate, wherein said driving power source causes said pushing member to operate for driving said traveling member urged by said urging member, whereby said image sensor is moved to the other of the first position and the second position; and wherein said traveling member is slidably engaged with said image sensor and is moved by said pushing member in a direction substantially orthogonal to a direction in which said image sensor is moved, whereby said image sensor is moved to one of the first position and the second position, and in a state where said traveling member is moved in a direction in which traveling member is urged by said urging member, an end portion of said traveling member protrudes from said image reading unit.