BAND DETECTION SENSOR AND DETECTION METHOD FOR SAME

摘要

This band detection sensor has: an LED (20) that shines detection light on one surface on a web (W); a photodiode (22) that receives the detection light reflected by the web (W) and outputs a detection signal according to the detected light; and a determination section (46) that discriminates a band (B) on the web (W) on the basis of the detection signal from the photodiode (22). The determination section (46) includes a rising edge determination standard (TN, L1) that expresses the speed of the rising edge of the detection signal, and when changes in the detection signal satisfy the rising edge determination standard (TN, L1), a band signal (SB) that indicates the presence of the band (B) is generated.