Generally, the present invention relates to an apparatus for reducing
astigmatism in a projection system that is particularly well suited to
reducing astigmatism in LCD projection systems. A projection system
includes a light source to generate light, conditioning optics to
condition the light from the light source and an imaging core to impose
on image on conditioned light from the conditioning optics to form image
light. The imaging core includes a polarizing beamsplitter and at least
one imager, and at least one element in the imaging core is adapted to
reduce astigmatism in the image light. The astigmatism may arise in the
polarizing beamsplitter. A projection lens system projects the
astigmatism-reduced image light from the imaging core.