| 摘要 |
PURPOSE:To erase still picture information with a video signal recording and reproducing magnetic head, by constructing a pad to be contacted with a magnetic sheet of a magnetic material having a high magnetic permeability and performing winding treatment on the pad, and then, generating AC magnetic fields in the pad and magnetic head by impressing an alternating current upon them. CONSTITUTION:A recording head 4 is fitted to a head base 6. A pad 5 is positioned to one surface of a magnetic sheet 3 by means of positioning pins 8 and pad pressing fittings 9 with a prescribed clearance being maintained between the pad 5 and recording head 4. At the time of erasion, the pad 5 is excited by an alternative current generated by an oscillator 10 which oscillates upon receiving an erasing command from an erasing command terminal 11 and made to flow through a winding 7. Therefore, the recording head 4 is magnetized through the magnetic sheet 3 and vertical magnetic fields are concentrated in the vicinity of the recording head 4, and then, still picture information of the magnetic sheet 3 is erased by the magnetic fields. |
