| 摘要 |
<p>PURPOSE:To measure the meandering state of a tape during run in an operating speed continuously, by picking up a tape edge of a magnetic tape during run through enlargment at an image sensor and detecting the displacement of broadwise tape edge. CONSTITUTION:A magnetic tape 12 runs slidingly in contact with the front side of a reflection surface 15 of a photo-reflection member 14 provided between guide rollers 6 and a guide pole 7 at winding side. The upper end edge of the tape 12 is irradiated convergently with a projector 16 to pick up an image at an image sensor 17. The image sensor 17 enlarges the picked-up image, which is formed on a number of photodetectors arranged in a straight line. Thus, the outputs of the photodetectors have a step in level between the tape 12 side and the reflection surface 15, and the position corresponds to the position of an upper end edge A. The output of the image sensor 17 is given to a recorder 20 via a control circuit 18 and a D/A conversion circuit 19. Thus, the meandering of a tape during run can continuously be measured.</p> |
