Appeal No. 2000-1243
Application 08/826,112
[f]or dielectric layers a different n/k relationship is
necessary as compared to metals. A high reflection is
created by a completely different mechanism -
interference instead of conductivity. The condition is
n>2.9 (for reflectivity >30%) with k as small as
possible.
Most dielectric layers easily reach the extinction
coefficient k smaller IE-3 at 635nm but only a few of
them have a refractive index higher than 2.9 at 635nm.
In addition, most materials fail because of massive
absorption in the UV. . . .
Dubs at 2, 1st col. Dubs also describes using a dielectric
material as the semi-reflective layer in a hybrid DVD/CD-ROM:
Dielectrics . . . are attractive because they have very
low absorption and, utilizing the interference
mechanism, may be used to realize a "Hybrid" disc.
This disc combines a conventional CD-ROM information
layer with a semitransparent DVD layer. The thickness
of this semireflective layer is adjusted to realize
semireflective conditions at the DVD wavelength while
acting as an antireflective film at 780nm. This
semireflective layer is therefore invisible in a
conventional CD-ROM player.
Id. However, Dubs does not indicate that antimony sulfide, which
is not mentioned at all, has the requisite index of refraction
and extinction coefficient to function as a semireflective layer.
Consequently, while Dubs cures the second deficiency noted above
with respect to Nagashima and Horikago, viz., their failure to
show that one skilled in the art would have understood the
relationship of the index of refraction and the extinction
coefficient to a material's suitability for use as a
semireflective film, Dubs does not cure the first deficiency,
14
Page: Previous 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Next
Last modified: November 3, 2007