Light reflective photoelectric tape sensor system

Claim 1

IN A MAGNETIC TAPE HANDLER APPARATUS FOR PROCESSING INFORMATION INCLUDING AN INFORMATION PROCESSING STATION, AN OPAQUE TAPE WITH A RADIATION REFLECTIVE STRIP ALONG ONE EDGE OF THE TAPE NEAR ONE OF ITS ENDS MARKING THE BEGINNING OF THE TAPE AND ANOTHER REFLECTIVE STRIP ALONG THE OTHER EDGE OF THE TAPE NEAR ITS OTHER END MARKING THE END OF THE TAPE, A SENSING DEVICE COMPRISING; A FIRST RADIATION DETECTOR DISPOSED ON ONE SIDE OF THE TAPE OVER ONE EDGE THEREOF, A SECOND RADIATION DETECTOR DISPOSED ON SAID ONE SIDE OF THE TAPE OVER THE OTHER EDGE THEREOF, A RADIATION SOURCE POSITIONED ON SAID ONE SIDE OF THE TAPE, A SHIELD DISPOSED BETWEEN THE RADIATION SOURCE AND THE FIRST AND SECOND RADIATION DETECTORS TO LIMIT THE RADIATION ARRIVING AT THE DETECTORS TO THAT FROM THE DIRECTION OF THE TAPE, A MIRROR HAVING A REFLECTIVE SURFACE DISPOSED ON THE SIDE OF THE TAPE OPPOSITE SAID ONE SIDE, WHEREBY IRRADIATION OF SAID FIRST DETECTOR INDICATES THE BEGINNING OF THE TAPE, IRRADIATION OF THE SECOND DETECTOR INDICATES THE END OF THE TAPE, AND IRRADIATION OF BOTH OF SAID DETECTORS INDICATES THE TAPE IS MISSING.