Patent ID: 6619802
Filing Date: 2003-09-16
Classification: G02B,G03H,H04N

Abstract:
A multi-stripe scrolling apparatus comprising:a white light source; a lens system including a total internal reflection beam splitter having an internal surface exhibiting a critical angle of total internal reflection; a movable array of holographic elements including a plurality of first holographic elements for producing a first color, a plurality of second holographic elements for producing a second color substantially different from the first color, and a plurality of third holographic elements for producing a third color substantially different from the first and second colors; and a light valve, each of the first, second, and third holographic elements being configured such that white light arriving at a respective one of the first, second, and third holographic elements from a respective arrival direction produces a beam of substantially monocolor light of a respective one of the first, second, and third colors, that leaves said respective one of the first, second, and third holographic elements in a respective departure direction that differs by a predetermined angle from the respective arrival direction, the predetermined angle being the same for the first holographic elements as for the second and third holographic elements, the white light source, lens system including beam splitter, movable array, and light valve being physically disposed relative to one another such that: light from the white light source enters the beam splitter and impinges at a first angle of incidence to the internal surface that is greater than the critical angle, so that the light from the white light source is reflected from the internal surface and is directed to the respective ones of the first, second, and third holographic elements; and said beams of substantially monocolor light leaving respective first, second, and third holographic elements reach the beam splitter and impinge at a second angle of incidence to the internal surface that is less than the critical angle, so that said beams of first, second, and third color light are not reflected from but pass through the internal surface to form alternating bands of light of the first, second, and third colors that scroll across the surface of the light valve when the movable array is moving.