| 摘要 |
PURPOSE:To improve an S/N and to prevent a detecting error by using an erasing head as a servo exclusive-use, setting the track width of the erasing head to the width having a value equal to a track pitch and making sufficiently small the track width of a reading and writing head. CONSTITUTION:Servo data 3-5 are recorded and reproduced with a gap 1 of an erasing head having a track width equal to a track pitch, and data 6 and 7 are recorded and reproduced with a gap 2 of a reading and writing head having a track width sufficiently narrower than the track width of the erasing head. Since servo data are widely written, when either of the servo data 3 and the servo data 5 is used, a minimum effective track width 8 is greatly widened. Thus, the S/N is improved. |
