Appeal No. 2003-0709
Application No. 09/332,240
- a recording layer of a phase-change material which is able to
record amorphous marks when in the crystalline state, the
recording layer forming an annular recording area with an inner
and an outer radius,
- a second dielectric layer,
- a metal mirror layer,
characterized in that the recording layer has a gradually
increasing thickness from the inner to the outer radius.
The examiner relies upon the following reference as evidence
of obviousness:
Sato (JP '827) JP 3-216827 Sep. 24, 1991
(Japanese patent)
Appellants' claimed invention is directed to an optical
information medium for rewritable recording by means of a laser-
light beam. The medium comprises, inter alia, a recording layer
of a phase-change material that forms an annular recording area
having an inner and an outer radius. Also, the recording layer
increases in thickness from the inner to the outer radius.
According to appellants, "by shaping the recording layer in this
manner the increase in the relative linear velocity of the
recording layer is readily compensated for by increasing the
crystallization rate of the recording layer" (page 5 of Brief,
first paragraph). Also, the present specification demonstrates
that "with increasing radial distance r from the center of the
disc, the CET [complete erasure time] of the recording layer
-2-
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