Patent ID: 7329006

Claim:
An image generating unit for a projection system, comprising: an imaging core comprising at least a first imager, at least a first polarizing beamsplitter and a color combining unit, the color combining unit being substantially free of astigmatism, the first imager being capable of modulating illumination light incident thereon to produce first image light, the first image light being directed from the first imager to the color combining unit via the polarizing beamsplitter, wherein the first polarizing beamsplitter comprises a polarization sensitive film disposed between covers, at least one of the covers having a first refractive index higher than a second refractive index of the polarization sensitive film; and an astigmatism-reducing element disposed on a path of the first image light comprising a sheet of material lying between the covers of the polarizing beam splitter, the sheet of material having a third refractive index higher than the first refractive index.