Patent ID: 8456712

Claim:
An image reading apparatus, comprising: a reading section that reads, in a prescribed original reading position using an original reading portion, image light from an original that is irradiated with light from a light source of the original reading portion while being transported in a prescribed transport direction at a prescribed transport speed by an original transport portion, the reading section starting reading an original image after a reading start time set in advance has elapsed since detecting a transport timing of an original on an upstream side in the transport direction relative to the original reading position; and a reading timing adjustment section that adjusts the reading start time using a first mark on an adjustment sheet that has the first mark formed at least at a downstream side edge in the transport direction, the reading timing adjustment section adjusting the reading start time based on a reading timing adjustment time from when a transport timing of the adjustment sheet transported by the original transport portion is detected on the upstream side in the transport direction relative to the original reading position until when the original reading portion reads a position considered to be a downstream side edge in the transport direction in the first mark on the adjustment sheet, and the image reading apparatus correcting a reading start timing of an original based on downstream side edge reading error correction information stored in advance, wherein the light source emits light from at least the upstream side among the upstream side and a downstream side in the transport direction, taking the original reading position as a reference, and the downstream side edge reading error correction information stored in advance indicates a downstream side edge reading error correction time obtained by dividing a width in the transport direction of a shadow at the downstream side edge in the transport direction of the adjustment sheet due to light from the light source by the transport speed.