METHOD AND APPARATUS FOR DETECTING END SURFACE OF LAMINATE

PROBLEM TO BE SOLVED: To normally perform the treatment of a sheet material on and after by setting the detection end surface position of a first sensor when the end surface detection position of a first sensor detecting the end surface of the whole of a laminate and that of a second sensor capable of detecting only the end surface of a first material are equal to an end surface position and setting the detection end surface position of the second sensor to the end surface position when both end surface detection positions are different. SOLUTION: A photoelectric sensor 32 detecting the end surface of a steel panel being a first sheet material and that of a laminated steel panel with an opaque film being a second sheet material is provided and an infrared sensor 1 emitting infrared rays passing through the opaque film but not detecting the edge of the opaque film even if the film is protruded from the steel panel but detecting the edge of the steel panel without transmitting through the steel panel is provided in the vicinity of the sensor 32. When the opaque film is not protruded from the steel panel, the detected positions from both sensors 32, 1 coincide with each other and the running position of the laminated steel panel is corrected by the photoelectric sensor 32. Conversely, when the opaque film is protruded from the steel panel, the detection value of the potoelectric sensor 32 becomes large and a running position is corrected corresponding to the positional shift of the steel panels by the infrared sensor 1.