Appeal No. 1998-0495
Application No. 08/324,540
of an applied field whereas the other liquid crystal's white
state appears with an electric field.
In addition, Lloyd states (column 7, lines 2-8) that the
cell may be slightly modified for utilization of twisted
nematic liquid crystal. Thus, Lloyd implies that the skilled
artisan would know that slight variations may be necessary to
employ a different type of liquid crystal and that such an
artisan would know how to modify the cell to accommodate the
alternative material. Furthermore, Doane discusses (column 1
and column 2, lines 7-16) all of the benefits of PDLC,
including uniformity in cell thickness, simplicity of
preparation and cell fabrication, improved brightness since
polarizers are not required, and improved responsive features.
Accordingly, we agree with the examiner that it would have
been obvious to one skilled in the art to substitute PDLC for
the liquid crystal of Lloyd.
Appellant further asserts (Brief, page 12) that it was
previously thought that the voltages available with a wafer
based active matrix were not high enough for PDLC. However,
the claims are directed to a device, not a driving method.
For such a device, Doane suggests the obviousness of using
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