Patent ID: 7355796

Claim:
A windshield for manipulating optical polarization in a head-up display system, the head-up display system comprising a projection light source, the windshield comprising: a first polarization manipulating layer operable to transform a polarization state of light; a thin film layer adjoining the first polarization manipulating layer; a second polarization manipulating layer adjoining the thin film layer, the second polarization manipulating layer being operable to transform a polarization state of light; and a transparent substrate layer adjoining the second polarization manipulating layer; wherein a first material interface is defined by the thin film layer and the first polarization manipulating layer, a second material interface is defined by the thin film layer and the second polarization manipulating layer, the first and second material interfaces each being operable to transmit and reflect a portion of the light from the projection light source; and wherein the first and second polarization manipulating layers each comprise half wave retarders.