DEVICE FOR DETECTING EDGE OF TRANSFERRED MEDIUM

摘要

PURPOSE:To enable judgment whether a transferred medium reaches a specified position on a transfer base or not without being affected by the reflection factor of the top surface of the transferred medium, the form of the transferred medium and the like. CONSTITUTION:A reflection member 16 is built by burying a member having a nature of retroreflection into an area containing a detection position 2b of an outer circumferential surface 2a of a rotary drum 2. A light source 10 and an optical sensor 11 are arranged in proximity so that light emitted from the light source 10 and retro reflected with a reflection member 16 is directed to the light sensor 11. When a tip part 4a of a sensing material 4 to be conveyed does not reach the detection position 2b, the light from the light source 10 is retro reflection by the reflection member 16 to be detected with the optical sensor 11. When the tip part 4a of the sensing material 4 reaches the detection position 2b, the reflection member 16 is covered with the sensing material 4 and light from the light source 10 falls on the top surface of the sensing material 4 to be reflected in a direction differing from the incident direction thereof.