Patent ID: 8184345

Claim:
An image reading device comprising: an original feeding unit that feeds a sheet-type original to a predetermined reading position; a first carriage including a light source and a first mirror; a second carriage including a second mirror and a third mirror; and a control unit which operates the image reading device in a first mode and a second mode, in the first mode, the control unit causes the image reading device to read image data on the original while moving the original with the first and the second carriages stopped, and in a second mode, the control unit causes the image reading device to read image data on the original by moving the first and the second carriages in a sub-scanning direction while keeping a distance between a reading surface of the original and an optical reading element constant, the control unit further causes, if a predetermined condition is satisfied after reading the original in the first mode, the first and the second carriages to standby at a reading position of the first mode while keeping the light source turned on, and if a next read request is issued within a predetermined time, causes the first and the second carriages to move to a next reading position.