Abstract: Off-axis total internal reflection Fresnel lenses and projection screens are disclosed that, when combined, enable construction of projection assemblies for rear-projection-type screen devices (e.g., projection television systems) that are thinner, provide easier handling and maintenance, and have improved contrast, focusing, and resolution when compared with conventional projection screen devices. The off-axis Fresnel lens comprises a plurality of concentric, outwardly-extending, total internal reflection-type prism facets, the top side of which may be aspherical. Embodiments of the invention also include projection screens having at least one diffuser and one lenticular lens. In addition, one or more opaque layers may be used to improve contrast. The various components, e.g., the fresnel lens, the diffuser, the lenticular lens(es), the opaque layer(s), etc. are all combined, or connected, in such a way as to eliminate substantially all air gaps within the connections.

Abstract: The present disclosure provides optical devices having an asymmetric viewing area imparting improved optical properties to the device.

Abstract: The present disclosure provides optical devices having an asymmetric viewing area imparting improved optical properties to the device.

Abstract: An off-axis Fresnel lens is disclosed that, when combined with a rear projection screen (comprising, e.g., a lenticular lens, a diffuser, or both), enables construction of rear-projection-type screen devices (e.g., projection television systems) that are thinner and have improved contrast and resolution when compared with conventional projection screen devices. The off-axis Fresnel lens comprises a plurality of concentric, outwardly-extending, total internal reflection-type prism facets. Each facet, in turn, comprises top and bottom sides, one or both of which may be flat or outwardly convex. Embodiments of the invention may also include concentric opaque sections that are disposed between successive prisms, between the prism base and the output surface of the Fresnel lens, and/or between the output surface of the Fresnel lens and the input surface of the projection screen in order to improve contrast. Contrast may also be enhanced by laminating the Fresnel lens to the projection screen.

Abstract: The present invention is directed to an off-axis fresnel lens comprising an input surface and an output surface. In one embodiment, concentric, outwardly-extending total internal reflection-type prism facets are disposed on the input surface, each facet comprising a top side being outwardly convex, and a bottom side being substantially flat. In other embodiments, the top side may be substantially flat and the bottom side outwardly convex, or both the top and bottom sides may both be flat. The above embodiments may further comprise a generally opaque layer disposed on the area of the input surface on each side of the facets, or as a generally opaque and horizontal louver between the prism facets and the output surface. The generally opaque layer may also be disposed between the prism facets and output surface, the generally opaque layer having generally transparent portions through which incoming light rays reflected off the top side of each facet may pass.