| 摘要 |
PURPOSE:To attain spot erasion at a desired area of a magnetic tape by setting an erasion head opposite to the position of a reproduction head, having contact between the erasion head and a minute area of a recorded magnetic medium where the erasion of noise, etc. is desired and securing a fixed space between a magnetic material and an erasion head to demagnetize the magnetic tape. CONSTITUTION:An impulsive noise position is detected by a reproduction head 6, and the position of a magnetic medium where noise is recorded is stopped on a reproduction head. A spot erasion button is operated while holding the magnetic medium between a tape shifter and a tape pad 9 so that the noise recorded area of a tape does not shift onto the head 6. Thus the noise position of the magnetic medium is shifted to obtain contact with the magnetic field generated positions of spot erasion heads provided at the front of the head 6 and the rear side of the magnetic medium. An erasion head 7 for spot demagnetization consists of a wide gap (g) and applies a high frequency current to a coil 7a for time t1 with gradual increment and decrement. Then the magnetic field of the erasion head performs a demagnetizing action within a gentle magnetic field. |
