Browse Prior Art Database

Optical Band Recording

IP.com Disclosure Number: IPCOM000115938D
Original Publication Date: 1995-Jul-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 4 page(s) / 83K

Publishing Venue

IBM

Related People

Voegeli, O: AUTHOR

Abstract

Disclosed is an optical band-recording system that utilizes (1) in order to achieve a multiplication of data rate and improvements in storage density.

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Optical Band Recording

      Disclosed is an optical band-recording system that utilizes (1)
in order to achieve a multiplication of data rate and improvements in
storage density.

      Fig. 1 shows a band recording system where data is written and
read in-parallel on m=5 contiguous tracks, D sub 1 ... D sub m,
using m write transducers W sub 1 ... W sub m and m read transducers
R sub 1 ... R sub m.  Recorded bands, B, are separated by guard
bands GB which also contain a pre-recorded servo track S.  The write
and read transducers, either separate or combined, are a linear array
of solid-state lasers with integrated monitor diodes and frontal beam
deflectors (2,3).  The servo transducer, R sub s, produces an error
signal  that varies with the array's misregistration relative to the
servo track.  In a preferred embodiment the reflective recording
medium serves as frontal mirror of the laser cavity.  The laser's
rear facet has high reflectivity (just enough transmission for proper
operation of the monitor diode), its frontal facet is transparent.
Data is written by a hole burning method which alters the
reflectivity  of the recording medium.  Data is read by the monitor
diode which responds to the modulation of the laser's efficiency by
the varying reflectance of the recording medium.

      Fig. 2 shows a read channel arrangement that advantageously
utilizes the parallelism of this band recording system.  The m read
channels, C sub 1 to C sub m are constructed such that crosstalk
signals from neighbor tracks are subtracted (4) from the home track
signal.  The cancellation servo, CS, determines the subtraction
function according to the transducer's transverse se...