Magnetic-optical disc memory system and apparatus for switching header and data information
AssigneeHitachi, Ltd.
InventorsAtsushi Saitoh, Toshimitsu Kaku
Life of this patent
Estimating the term…
Abstract
A magnetic-optical disc memory system wherein header information items which include sector marks indicating initial positions of sectors, track Nos., and sector Nos. are previously provided on a magnetic-optical disc in the form of embossed pits and wherein data information items are written in the form of magnetic signals in data areas other than the header areas. Photodetectors detect the header information and the data. The operation of switching outputs from the photodetectors is controlled in accordance with a timing based on the point of time at which a sector mark signal has been detected from the output of the photodetector which detects the header area.
Claims4
A magnetic-optical disc memory system wherein header information items including sector marks indicative of initial positions of sectors, track numbers and sector numbers are written at predetermined areas on a magnetic-optical disc in the form of embossed pits and wherein data information items are written in the form of magnetic signals in areas other than the predetermined areas on the magnetic-optical disc for the header information items;
- said system comprising:
- means to detect the header information;
- means to detect the date information;
- means to detect sector marks from an output of the header information detection means;
- and
- a switching circuit for selecting one of the header information and the data information based on a sector mark detection signal generated from the secotr mark detection means.
Dependencies are inferred from the claim text.