Patent ID: 6384979
Filing Date: 2002-05-07
Classification: G02B,G02F

Abstract:
Color display apparatus comprising a spatially uniform distribution of at least first and second types of prism structure, wherein:(a) said first type of prism structure further comprises: (i) a first prism; (ii) a first color filter positioned to filter light incident upon a first facet of said first prism, said first color filter having a first selected spectral absorption characteristic; (iii) a first member having a second selected spectral absorption characteristic, said first member movable with respect to a second facet of said first prism between: (1) a first position in which said first member is in optical contact with said second facet, producing a first absorptive state in which total internal reflection of light rays at said second facet is reduced as a function of wavelength in accordance with said second selected spectral absorption characteristic; (2) a second position in which said first member is not in optical contact with said second facet, producing a first reflective state in which light incident upon said second facet is totally internally reflected toward a third facet of said first prism; (iv) a second member having a third selected spectral absorption characteristic, said second member movable with respect to said third facet of said first prism between: (1) a third position in which said second member is in optical contact with said third facet, producing a second absorptive state in which total internal reflection of light rays at said third facet is reduced as a function of wavelength in accordance with said third selected spectral absorption characteristic; (2) a fourth position in which said second member is not in optical contact with said third facet, producing a second reflective state in which light incident upon said third facet is totally internally reflected toward and through said first color filter; (b) said second type of prism structure further comprises: (i) a second prism; (ii) a second color filter positioned to filter light incident upon a first facet of said second prism, said second color filter having a fourth selected spectral absorption characteristic; (iii) a third member having a fifth selected spectral absorption characteristic, said third member movable with respect to a second facet of said second prism between: (1) a fifth position in which said third member is in optical contact with said second facet of said second prism, producing a third absorptive state in which total internal reflection of light rays at said second facet of said second prism is reduced as a function of wavelength in accordance with said fifth selected spectral absorption characteristic; (2) a sixth position in which said third member is not in optical contact with said second facet of said second prism, producing a third reflective state in which light incident upon said second facet of said second prism is totally internally reflected at said second facet of said second prism; (c) said spectral absorption characteristics are selected such that, for any selected set comprising proximate ones of all of said types of prism structure, controlled movement of said members between particular selected combinations of said respective positions causes said set to reflect light having an average spectral reflectance characteristic corresponding to any one of three independent colors; and, (d) no one of said independent colors is obtainable by mixing any other two of said independent colors.