| 摘要 |
PURPOSE:To use a high track density device together with a conventional low track density device by providing a means for varying the effective width erased on a magnetic recording medium, so that it can be realized easily to appropriate the medium between devices whose track density is different from each other by switching an erasing head. CONSTITUTION:Recording and reproducing of track density of 48TPI and 96TPI are realized by one head assembly body, and 1, 3a and 4a are a recording and reproducing head core set to track width for 96TPI, an erasing head core energized at the time of recording by 96TPI and 48TPI, and its erasing gap, respectively. 3b is an erasing head core energized only at the time of recording by 48TPI, has an erasing gap 4b and is placed at the outside of the erasing head core 3b. In case when it is used for 48TPI, at the time of recording, the erasing head cores 3a, 3b are energized simultaneously and recording is executed by the recording and reproducing head core 1, as shown in the figure (b). In case when it is reproduced by a 48TPI exclusive machine, a noise component is not reproduced in a reproducing head of wide width, deterioration of a signal-to-noise ratio is suppressed to about half, and it is in a range having no problem, as a 48TPI exclusive machine. |
