Color image reader having a lens and prism incorporated into a single unit

Claim 1

A color image reading apparatus comprising a light source adapted to move relative to an original document whereby said document is illuminated, a mirror means for reflecting light from the illuminated document to a lens, said light source being disposed on a first side of the optical axis of said lens, said lens focusing the reflected light to form an image, a prism disposed in the optical axis of said lens, said prism separating the reflected light into a plurality of color lights, and a plurality of photo-electric conversion means corresponding in number to the plurality of color lights, said prism having surfaces for diverting said color lights to said plurality of photo-electric conversion means to form a plurality of color images, said plurality of color lights being diverted in substantially the same direction so that said plurality of photo-electric conversion means are disposed on a second side of the optical axis of said lens, said lens and said prism being assembled as a single unit comprising: said lens incorporated into a lens housing, said prism, a stop means for positioning said prism, said stop means being fixed to said lens housing and being adapted to come into contact with an edge of said prism, a light projecting end surface of said lens housing adapted to come into contact with a first surface of said prism, said first surface including said edge, and a prism fixing means capable of being coupled with said lens housing, said prism fixing means fixing a second surface of said prism, said second surface being opposite said edge.