| 摘要 |
PURPOSE:To simplify the structure of a head device greatly by reading and writing information by providing an auxiliary magnetic pole made of a soft magnetic material around the external circumference of a rotary body through a tape bus by winding a coil. CONSTITUTION:An auxiliary magnetic pole 9 made of a soft magnetic body, such as ferrite, is provided, opposite the main magnetic pole 7 of a rotary body 2, covering more than the half of the external circumference 2a of the rotary body 2, and this auxiliary magnetic pole 9 is wound with a coil 9a. To write information on a magnetic tape 5, the coil 9a is driven for the production of magnetic flux between the auxiliary magnetic pole 9 and main magnetic pole 7, and the tape surface is magnetized vertically. To read the information, magnetic flux produced by the tape 5 is detected by magnetic poles 7, 7 and 9 and a reproduced signal is led out via a coil 9a. Consequently, it is unnecessary to bury the magnetic head in the rotary body 2 and a rotary transformer for signal transfer is therefore unnecessary, thereby simplifying the structure greatly. |
