| 摘要 |
PURPOSE:To obtain always correct servocontrol or sector information by providing track width and either or the servocontrol information or sector information or the combination thereof in the form of holes or arrays of nonmagnetic parts to a substrate or magnetic film of a magnetic recording medium. CONSTITUTION:The hole arrays 11, 12... conformed to the servocontrol information are formed at every track width w in conforming to the w to part of the magnetic film on the substrate 1. The medium moves in an arrow direction and the hole arrays have the width equal to an intertrack gap g. The row holes 11, 12... are otherwise provided preliminarily to the substrate 1' and the magnetic film 2 is superposed thereon, then the holes are formed to the film 2 as well, or part of the magnetic film 2 on the substrate 1 is made nonmagnetic and the arrays 11', 12... are formed. Such patterns are indeliable and remain even if a magnetic head tends to erase the same accidentally during use and therefore, the always correct servocontrol information or sector information is obtd. The recording medium is thus formed by using a photomask as well as an etching soln., laser etching or a method for immersing the substrate in an aq. Cr2O3 soln. to make the magnetic film nonmagnetic.
|
