Color beam splitter using air-spaced prisms

This invention relates to color scanners. More specifically, this invention relates to color scanners having beam splitters that separate multi-wavelength light into component parts. Color scanners that separate multi-wavelength light into color components having substantially equal optical path lengths. An colorscanner includes a first prism that receives multi-wavelength light, internally reflects a first component and passes second and third components into a first gap. A first reflector reflects the second and third components back into the first prism. The component parts then pass into a second prism that internally reflects the first and second component parts but passes the third component into a second gap. A second reflector reflects the third component part back into the second prism. A third prism then receives the color components, internally reflects the third component part, and passes the first and second component parts into a third gap. A third reflector reflects the first and second component parts back into the third prism. A fourth prism then receives the color components, internally reflects the second and third components, and passes the first component into a fourth gap. A fourth reflector then reflects the first component part back into the fourth prism. The color components then exit from the fourth prism.