Other

Siros Technologies, Inc.

Shunichi Nishimura

Mark E McDonald

Andrew J Daiber

Michael V Morelli

Sergei L Sochava

Sanjoy Ghose

Jiro Yoshinari

Hideki Hirata

Lambertus Hesselink

Takuya Tsukagoshi

Naoki Hayashida

Herman Ferrier

Matthew Lipson

Tokuyuki Honda

Thomas Kridl

LeRoy A Volz

James R Amble

Tokyuki Honda

Lambrerrtus Hesselink

An optical information storage system using optical storage media including multiple data layers or stacks wherein each of the multiple data stacks has a storage density comparable to a conventional single layer optical disk. The optical data storage system comprises an optical medium having a single dedicated servo layer and multiple data stacks which each contain an embedded servo format, a servo laser beam positioned to maintain a first focus point on the dedicated servo reference layer, a read-write laser beam positioned to maintain a second focus point on one of the data stacks, a first, dedicated servo system which provides focus and tracking error correction according to error signals generated from the dedicated servo layer, and a second, embedded servo system which provides focus and tracking error correction according to error signals generated from the data stacks. The dedicated servo layer, in different embodiments of the invention, may be positioned either below or above the data stacks in the optical medium, or interposed between data stacks. The data stacks may comprise discrete physical data layers or &ldquo;virtual&rdquo; data layers defined by a format hologram. The servo and read-write lasers may differ in wavelength and/or polarization.

Optical data storage system with multiple layer media

An optical information medium comprising at least two data layers for bearing recorded information, and a servo layer for bearing tracking servo, information which is independently formed from the data layers; wherein the medium is used with a recording or reading system wherein a data beam for recording or reading the data in the data layer and a servo beam for reading the tracking servo information in the servo layer are used, and the servo layer is read by the servo beam that had passed through the data layer; and a filter layer is disposed between the data layer and the servo layer, and the filter layer exhibits higher absorption to the data beam than to the servo beam.

Optical information storage medium

Growing community of inventors

Tokyo, Japan

Shunichi Nishimura