| 摘要 |
PURPOSE:To obtain a device for executing an erasion and re-recording of an optional track by a simple constitution, without providing an erasion exclusive head, by executing an erasion by supplying an alternating current whose direction is inverted at every one rotation of a magnetic sheet, to a magnetic head. CONSTITUTION:When a trigger pulse outputted from an erasion start trigger pulse generating circuit 1 is inputted to a start trigger pulse input 22 of a reading-out circuit, the reading-out circuit 2 starts an operation, and outputs an address designating signal to an address bus 31 of a memory 3. The memory 3 outputs a digital value corresponding to a designated erasing current to a data bus 41, and a D/A converter 4 converts the digital value to a corresponding analog current and outputs it to an amplifier 5. Accordingly, a current corresponding to the contents of an address designated at present of the memory 3 flows to a magnetic head 7. On the other hand, the reading-out circuit 2 increases or decreases the address successively, whenever a PG pulse is inputted at every one rotation of a magnetic sheet. Accordingly, by storing digitally a current pattern for obtaining a good erasion characteristic in the memory 3, a desired erasing current pattern is obtained. |
