A color filter includes a plurality of color pixels, and a first hologram diffracting an incident light beam into a first diffraction-resultant light beam. The color filter also includes a second hologram diffracting the first diffraction-resultant light beam into a second diffraction-resultant light...http://www.google.ca/patents/US5894359?utm_source=gb-gplus-sharePatent US5894359 - Color filter and color display apparatus
