Patent ID: 6563779
Filing Date: 2003-05-13
Classification: G11B

Abstract:
An optical data storage system comprising:an optical storage medium having a format hologram grating structure that defines a plurality of tracks thereon, wherein said optical medium includes a format hologram grating structure recorded therein, said format hologram grating structure defines a plurality of radially spaced cylindrical shells, said radially spaced cylindrical shells defining said plurality of tracks; an optical head positioned to focus a light beam on one of said plurality of tracks; and a tracking error signal generator configured to compensate for errors detected from said format hologram grating structure, said tracking error signal generator including a first lens positioned in a path of a beam returning from said optical storage medium, a pinhole positioned in said path after said first lens, a second lens positioned in said path after said pinhole, a split detector positioned in said path after said second lens, and differencing circuit operatively coupled to first and second halves of said split detector.