Multiple data surface optical data storage system
AssigneeInternational Business Machines Corporation
InventorsMargaret E. Best, Hal J. Rosen, Kurt A. Rubin, Timothy C. Strand
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Abstract
An optical data storage system comprises a multiple data surface medium and optical head. The medium comprises a plurality of substrates separated by a light transmissive medium. Data surfaces are located on the substrate surfaces which lie adjacent a light transmissive medium. The data surfaces are substantially light transmissive. The optical head includes an aberration compensator to allow the head to focus onto the different data surfaces and a filter to screen out unwanted reflected light.
Claims17
An optical data storage system comprising:
- an electromagnetic radiation source for producing an electromagnetic radiation beam;
- an optical medium having a plurality of data surfaces;
- a focus device for focussing the electromagnetic radiation beam to a selected one of the data surfaces;
- an optical detector for receiving a return electromagnetic radiation beam from the medium and generating a focus error signal responsive thereto;
- and
- a focus control device connected to the focus device, the focus control device comprising a peak detector for detecting a peak in the focus error signal and a controller for counting the peaks detected by the peak detector and determining the data surface on which the electromagnetic radiation beam is focused.
An optical data storage system comprising:
- a laser for producing a light beam;
- an optical disk medium having a plurality of data surfaces;
- a rotation device connected to the disk medium for rotating the disk medium;
- a focus device for focussing the light beam to a selected one of the data surfaces;
- an optical detector for receiving a return light beam from the medium and generating a focus error signal responsive thereto;
- and
- a focus control device connected to the focus device, the focus control device comprising a peak detector for detecting a peak in the focus error signal and a controller for counting the peaks detected by the peak detector and determining the data surface on which the light beam is focussed.
Dependencies are inferred from the claim text.