Physical characteristics and format of a two-inch-diameter magneto-optical disk system with 3-GB capacity

A small and high-density rewritable optical disk has been anticipated for mobile devices. A two-inch-diameter magneto-optical disk system, which adopts a DWDD (domain wall displacement detection) and sampled servo technique, was reported in a previous work (T. Shiratori et al, J. Magn. Soc. Jpn., vol. 22, supp. no. S2, pp. 47-50, 1998; M. Birukawa et al, Proc. MORIS2002). This paper describes the embossed-pit structure, a new 1-bit-distributed address format (1-bit DAF), the data format, and the physical characteristics of the disk, which allows a capacity of 3 GB.