| 摘要 |
PROBLEM TO BE SOLVED: To make performable a servo tracking based on pattern information by forming a pattern having a prescribed shape on a thin film section provided between a supporting body and a back coating layer. SOLUTION: Thin film sections 6 and 6 are provided on the surface, which is opposite to a magnetic layer 4 of a supporting body 2, in the longitudinal direction of a magnetic tape 1 over the entire length of the tape 1 while holding a linear thin film non-forming section 7 to form the pattern having a prescribed shape. The width W of the section 7 is set in the range of 5 to 500μm. The sections 6 and 6 are made from a material such as aluminum having a high reflectivity and a thickness T is set in the range of 3 to 100 nm. When a servo tracking is conducted, laser beams are made incident on the section 7. If no reflection light beam is detected, it is judged that an appropriate on-track condition is achieved. If the laser light beams are deviated either to the right or to the left and made incident on the sections 6, a photodetector detects the reflected light beams, transforms the beams into electrical signals, transmits the signals to a servo tracking processor, judges it to be an off-tracking condition and an appropriate process is conducted.
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