Rear end projection system employing aspherical lenses

A character projection unit for projecting images of characters disposed on a film in a spatial array, including, a plurality of light sources mounted in a spatial array corresponding to the spatial array of the characters on the film, the light sources constituting filament lamps at least some of which have misaligned filaments,

• a plurality of condensor lenses having oppositely disposed first and second lens surfaces, the condensor lenses being mounted in front of the light sources in a spatial array corresponding to the spatial array of the light sources,
• a first plurality of projection lenses having oppositely disposed first and second lens surfaces, the projection lenses being mounted in front of the condensor lenses in a spatial array corresponding to the array of the light sources,
• means for mounting the film at a position intermediate the plurality of condensor lenses and the plurality of projection lenses, and
• a second plurality of projection lenses disposed in front of the projection lenses in the first plurality, the projection lenses in the second plurality having aperture stops of limited dimensions,
• the light sources, the condensor lenses and the projection lenses in the first and second pluralities forming a plurality of separate and individually complete projection systems within a confined volume,
• the plurality of the individual condensor lenses being formed as a unitary condensor lens plate,
• the first plurality of the individual projection lenses being formed as a first unitary projection lens plate,
• the second plurality of the individual projection lenses being formed as a secondary unitary projection lens plate,
• a screen disposed at a position forward of the projection lenses in the second plurality,
• each of the complete projection systems including one of the individual condensor lenses in the plurality and corresponding ones of the individual projection lenses in the first and second pluralities,
• at least a particular one of the lens surfaces of each of at least one of the condensor lenses and the projection lens in the first plurality being aspheric to provide for the focusing of the light from the misaligned filaments of said filament lamps light sources on the film and to assure the passage of substantially the entire images from the film through the apertures of limited dimensions in the projected lenses in the second plurality and to provide for the focusing of the images on the screen.