Patent ID: 7782505

Claim:
An image reading apparatus comprising: an original feeder configured to feed an original; a first reader configured to read an image on one side of the original fed by said original feeder; a second reader disposed downstream of said first reader in a direction in which the original is fed by said original feeder and configured to read an image on another side of the original fed by said original feeder; and a controller configured to cause said first and second readers to read respective first and second reference objects, and generate first correction data for said first reader and second correction data for said second reader based on the respective first and second reference objects read by said first and second readers, wherein a time period required for reading the second reference object by said second reader and for generation of the second correction data is longer than a time period required for reading the first reference object by said first reader and for generation of the first correction data, and wherein said controller causes said second reader to start reading the second reference object before causing said first reader to start reading the first reference object.