We have developed a 3D optical modeling of fringing
field in small and reflective color pixels. The optical modeling
includes a LC electromechanical analysis and an optical
reflectance calculation. The simulated optical reflectance was
expressed in both the color coordinate and in the pixel array,
so it was easier to quantify and locate the color leakage. The
simulated optical reflectance agreed well with the experimental
ones. With this 3D optical analysis as a tool, we could
minimize the color fringing field with respect to the pixel
arrangement, rubbing direction, and LC mode. The color purity was improved from 32% NTSC level of the strip pixels
to 47% of the delta pixels, to 51% of the optimal rubbing
direction, and to 63% of the low-leakage MTB mode. The
relation of the color fringing field with pixel size and thickness
of color filter were also studied. The color purity was
generally reduced when the pixel size was reduced. But with
a low-leakage LC mode, the color purity could still be maintained
at 54% NTSC level even when the pixel size was
reduced to 9 m. This suggested that the CF-LCOS microdisplays
were feasible for very high-resolution display applications.