198339 ⎘
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 with provision for moving or switching or masking the transducers in or out of their operative position Access of indexed parts
Sub-classes:OPTICAL DISK AND OPTICAL DISK DRIVE DEVICE
#2Optical disk and optical disk drive device
#3Optical disk, optical disk access device and access method
#4Optical disk and optical disk drive device
#5Head position control method, head position control device, and disk device
#6Optical disc drive
#7Disc apparatus
#8Recording medium recording medium reproduction method recording medium reproduction device unique identification recording method and recording medium recording device
#9Reproduction method and apparatus, and recording method and apparatus
#10Optical disk and optical disk drive device
#11Optical disk and optical disk drive device