  Radio-quiet gamma-ray pulsars like Geminga may account for a number of the
unidentified EGRET sources in the Galaxy. The number of Geminga-like pulsars is
very sensitive to the geometry of both the gamma-ray and radio beams. Recent
studies of the shape and polarization of pulse profiles of young radio pulsars
have provided evidence that their radio emission originates in wide cone beams
at altitudes that are a significant fraction (1 -10%) of their light cylinder
radius. Such wide radio emission beams will be visible at a much larger range
of observer angles than the narrow core components thought to originate at
lower altitude. Using 3D geometrical modeling that includes relativistic
effects from pulsar rotation, we study the visibility of such radio cone beams
as well as that of the gamma-ray beams predicted by slot gap and outer gap
models. From the results of this study one can obtain revised predictions for
the fraction of Geminga-like, radio quiet pulsars present in the gamma-ray
pulsar population.
