公开(公告)号：DE3741532A1

公开(公告)日：1988-08-18

申请号：DE3741532

申请日：1987-12-08

Applicant: BASF AG

Inventor： BAUR REINHOLD DR ,  KLAUSMANN JUERGEN ,  ECKENFELS ANDREAS ,  KIENTSCH ROLF

IPC: G01N21/89 ,  G01N21/95 ,  G11B5/84

Abstract: By means of a light source (2) on one side of the magnetic tape (1) to be analysed and a photocell (3) on the other side of the tape, the uncoated locations are detected. A first switching signal is formed from the photoelectric current of the photocell in dependence on one threshold value. A further switching signal is generated in dependence on another threshold value and the duration of the photoelectric current, with respect to a section of length. With the two switching signals, the tape drive can be stopped and/or a registration can be activated.