Optical method for digital data storage and reproduction - using data blocks arranged on spiral track producing small guiding or circumscribed segment

摘要

A revolving recording disc has a light beam guided over it. The storage layer is physically changed by the light beam in accordance with the data, or changes the light beam. Data blocks are arranged on a spiral track, so that a small guiding segment between data blocks, or a circumscribed segment is produced. The lengths of a unit measured in degrees, and consisting of a data block and guiding segment, or of a date block and the circumscribed segment, are equal and such that each spiral turn has the same odd number of units. The spiral is divided in sectors containing only data blocks or only guiding segments. Radial spacing between guiding segments is twice that between data blocks.