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Browse Prior Art Database

Single-Sided Advanced Write-Once Optical Media

IP.com Disclosure Number: IPCOM000117075D
Original Publication Date: 1995-Dec-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Best, ME: AUTHOR [+2]

Abstract

The invented structure consists of a hard-coat protective layer on a phase change WORM disk. The hard coat whose thickness is in a range from a few &mu.m to about 20&mu.m has been shown to affect very little on the performance (CNR and jitter) for practical usage.

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Single-Sided Advanced Write-Once Optical Media

      The invented structure consists of a hard-coat protective layer
on a phase change WORM disk.  The hard coat whose thickness is in a
range from a few &mu.m to about 20&mu.m has been shown to affect very
little on the performance (CNR and jitter) for practical usage.

      Commercially-available phase-change WORM disks which are being
used as double-sided disks were overcoated with hard-coat lacquer
with a thicknesses of 5&mu.m and 15&mu.m.  Dynamic testing was
performed by using the Nakamichi tester (7.5m/s, 3T and 8T patterns,
P[R]=1.2mW, 830nm, NA=0.52).  The Figure shows a structure of the
single-sided WORM medium that was tested.  In this case, a hard-coat
protective layer is overcoated over a phase-change WORM disk.
              Figure   Single-sided WORM disk structure
                         HARD-COAT LACQUER
                      PHASE CHANGE WORM MEDIA
                      POLYCARBONATE SUBSTRATE

      The carrier-noise ratio (CNR) with and without hard coat was
found to be nearly the same for 3T and 8T.  The jitter for the
uncoated and 5&mu.m thick-coated disks was nearly the same but it
increased a little for the 15&mu.m disk, though it is still
acceptable for a current product (note: the jitter for the 15&mu.m is
still lower than that of a standard ablative disk for both 3T and
8T).  It should be mentioned th...