| 摘要 |
PROBLEM TO BE SOLVED: To specify an interruption position with high accuracy without synchronizing a line start signal with an encoder signal.SOLUTION: This image reading apparatus makes a line sensor perform periodic reading operations by inputting periodical line start signals, and on the other hand, performs constant speed conveyance of the line sensor by feedback control based on a target position trajectory. In addition, elapsed time from the start of conveyance control is measured, and a measured value is held as conveyance time Tsp for every input of the line start signals. Then, when a free space in a buffer becomes insufficient and a memory full signal is switched to High, a target position at this point is specified to the interruption position Xsp based on the conveyance time Tsp showing the elapsed time to an input point of the line start signal input immediately before and the target position trajectory. Furthermore, when the memory full signal is switched to Low, time when the line sensor reaches the interruption position Xsp is calculated based on the target position trajectory, and the line start signal is input in the line sensor at the corresponding time. |
