New MSR method for high density read only memory disks

A new MSR-ROM method for high density recording utilizes the difference in coercivity between "rough" and "smooth" areas in a disk. This method is advantageous for mass production and for the compatibility with erasable magneto-optical recording using MSR. A recording density of 5 Gbit/inch/sup 2/ is expected in this method, the same as the double mask type MSR technique in rewritable disk. This paper describes the principle of MSR-ROM and the results of a basic experiment.