Optical Disk Family
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01
A family of optical disks are constructed and arranged such that each disk has its data surface located at about the same plane relative the optical head. In this way, focusing excursions of the head are of about the same magnitude for all types of disks. The types of disks contemplated are read-only, write-once, and combination read-only and write-once. With this arrangement, the optical head's lens is servo- centered for all members of the disk family. The combination of read- only and write-once allows the system to have on line large amounts of read-only data (permanent data) as well as a large amount of rewritable data at the same time without changing disks. Fig. 1 shows a portion of a side view of an air-incident disk which includes preformed read-only data 10 and a write-once surface 11.