Abstract: The present invention is directed to illumination structures useful in display systems for projection video and television devices performing with high efficiency and good color rendition. Such illumination sources include a light source having an inner and outer envelope with plane mirrors within the outer envelope to direct reflected light, a light source providing randomly polarized light with polarizing structure for passing a desired polarization of the polarized light, and an arc lamp having at least two arcs for supplying uniform illumination in two dimensions. These illuminating structures enable significantly improved illumination in the appropriate projection video and television systems.

Abstract: A front projection screen has lenticules separated by grooves. A black plastic structure having protruding black ribs is aligned with the lenticules so that the ribs protrude into the grooves with clearance on both sides. For a front projection screen the base from which the ribs protrude is shaped to conform to the shape of the tips of the lenticules and is light absorbent. Preferably, the structure is a molded plastic manufactured by the same tooling and replication techniques which produce the lenticular array.

Abstract: Display systems useful for projection video and television systems are provided to perform with high efficiency and good color rendition. In these systems, color may be provided, as one example, by various light valves, such as liquid crystal displays. Each of the liquid crystal displays are positioned at equal path distances from an illuminating subsystem, and have equal path distances from the light valves to a projection subsystem. This enables optimum illumination of each of the light valves. Various embodiments of arranging the light valves, as well as providing illumination are described.

Abstract: A one-piece projection screen with improved overall efficiency and contrast, the elimination of corner illumination deficiencies and undesirable image artifacts. The optical power of the screen is divided between two or more surfaces acting as Fresnel lenses, and the region or medium separating the surfaces has a different index of refraction than that of the mediums upstream or downstream of the surfaces. The preferred embodiment of the projection screen includes a diffuser and a lenticular array downstream of the surfaces.

Abstract: LCD color television front projection screen has a rear vertically oriented lenticular lens array, the sidewalls of the lenticules steeply inclined to achieve total internal reflection of rays from a projected image into tip regions of the lenticules, an external reflective surface behind the array for reflecting the projected rays back into an audience field in front of the screen, and black masking between the lenticules for absorbing ambient rays.

Abstract: Color television rear projection screen having a front vertically oriented lenticular lens array, a circular Fresnel lens component with an infinite second conjugate, and a horizontally oriented linear Fresnel lens component with a finite second conjugate, the screen having improved luminance uniformity.