Papierende-Detektionsvorrichtung für Bildlesevorrichtung und Bildlesevorrichtung mit Papierende-Detektionsvorrichtung

摘要

The paper end detection apparatus is incorporated in an image reading apparatus wherein paper image information is read from a paper sheet (40) being transported along a paper transport path (310) by an optical image reading unit (410) at a fixed location along the paper transport path (310). A one-line peak value detection section (171) detects a peak value in one line along a direction perpendicular to the direction in which the paper sheet (40) is transported and a storage section (172) stores a past peak value in one line detected prior to the current peak value detected by the one-line peak value detection section (171). A comparison section (173) compares the current peak value detected by the one-line peak value detection section (171) and the past peak value from the storage section (172) and outputs a result of the comparison as a paper end detection signal. Also disclosed is a leading edge detector which detects start marks (SM1, SM2) on the paper (see fig. 2). <IMAGE>