SHEET FEED DEVICE, AND IMAGE READING DEVICE AND IMAGE FORMATION DEVICE PROVIDED WITH THE SHEET FEED DEVICE

摘要

PROBLEM TO BE SOLVED: To exactly determine the abnormal state of a manuscript in a sheet feed device and an image reading apparatus and an image formation device provided with the sheet feed device. SOLUTION: The manuscript feed device 101 is provided with: a liftable manuscript base 1 loaded with the manuscript; a manuscript feed roller 4 for feeding the manuscripts loaded on the manuscript base; a jumping up detection sensor SS1 having a light emission element SS1a arranged at both sides of the manuscript and emitting a light and a light receiving sensor SS1b for receiving the light of the light emission element SS1a; and a control part for setting and memorizing a variable threshold value for detecting the abnormal manuscript based on an output value corresponding to an amount of light receiving of the light receiving sensor at starting of feed of the manuscript every when the manuscript is fed by the manuscript feed roller 5 and determining that the manuscript is the abnormal manuscript when the output value becomes the variable threshold value or less on the way of feeding of the manuscript. COPYRIGHT: (C)2005,JPO&NCIPI