198334 ⎘
Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups - or by different subgroups of group ; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording and a beam of light for reproducing, e.g. light-induced thermomagnetic recording, Kerr effect reproducing; Disposition or mounting of transducers relative to record carriers Arrangements of transducers relative to each other, e.g. coupled heads, optical and magnetic head on the same base
Sub-classes:Systems and methods for increasing data rate and storage density in 3-dimensional optical data storage media
#2Systems and methods for increasing data rate and storage density in multilayer optical discs
#3Magnetic disk device and method of controlling magnetic head
#4Devices for optical near-files second surface recording