| 摘要 |
<p>PURPOSE:To detect six mode positions by two detection elements and to obtain the information at mode transfer time by making the magnetizing pattern of the cylindrical permanent magnet of the position detecting device of a tape recorder narrow and steep at its magnetizing width. CONSTITUTION:A head 11 is moved by mounting it on the substrate 12 of the head moving part of a tape recorder, a cylindrical permanent magnet 13 is abutted to the side part of this substrate 12 and held rotatably by the advance and retreat of the substrate 12. Magnetizing is executed on this permanent magnet 13 in the order of N pole, N pole, O (unmagnetized), S pole, S pole and O at 60 deg. pitch and the magnetic field generated by this permanent magnet 13 is detected by 1st and 2nd detection elements 14, 15. A Hall element is used for this detection element 14, 15 and the detection element 15 is arranged at the position apart at 120 deg. for the center of the permanent magnet 13 from the detection element 14. Six mode positions are then detected by two detection elements 14, 15 to enable a correct mode detection.</p> |
