| 摘要 |
<p>PURPOSE:To make the one way running of a tape electrically possible by forming an optical path part which conducts the light of a light projecting part to a photodetecting part at all times by bypassing a tape running path between the light projecting part and the photodetecting part thereby transmitting a tape rewinding inhibition signal at all times from the photodetecting part. CONSTITUTION:A lamp 10 for light projection is disposed in the central part of the F half of a cassette 1, and a photodetecting part 16 is disposed on the side of a supply side reel facing an opening window 14. An optical fiber 18 is adhered between the light projecting part and the photodetecting part and the light of the light projecting part is conducted at all times to the photodetecting part, whereby the rewinding of the magnetic tape is stopped and the exertion of abnormal tension upon the magnetic tape is prevented.</p> |
