Patent ID: 6295173
Filing Date: 2001-09-25
Classification: G02B,H04N

Abstract:
A configuration for spectral color division of light and recombination of light and simultaneous spectral color division and recombination of reflected divided light wherein reflection occurs even under a change of polarization of the light, the configuration comprising:a first prism (1) with two first prism faces (3,5) which form a first prism angle (a) between them;a second prism (7) with two second prism faces (9,11) which define a second prism angle (.beta.);with one first (3) and one second (11) prism face being disposed parallel and opposite one another with no air gap therebetween and the two angles (.alpha.,.beta.) with respect to the opposing faces (3,11) being disposed opposite to each other in the configuration, and wherein further;light of a first spectral range (R), substantially incident perpendicularly on the other (5) first prism face, after entering the first prism (1) and double reflection (19,21) leaves the first prism;light of a second (G) and third (B) spectral range, substantially perpendicularly incident on the other (5) first face, passes substantially unreflected through the first prism (1);light of the second spectral range (G) after leaving the first prism (1) and entering into the second prism (7) and double reflection (21,23) leaves the second prism (7);light of the third spectral range (B) passes substantially unreflected also through the second prism (7);and wherein;between the opposing first and second prism faces (3,11) a thin film layer system (21) is provided, whose angle-dependent reflection is matched to the first and second prism angle (.alpha.,.beta.), such that light propagating from said first prism, of the first spectral range (R) and at an angle of incidence at least approximately equal to the first prism angle (.alpha.) is at least largely reflected, and light incident at this angle of incidence (.alpha.) and still propagating from said first prism and of the second and third spectral range (G,B) is at least largely transmitted, light of the second spectral range (G), propagating from said second prism and at an angle of incidence (2.beta.-.alpha.) which is at least approximately equal to the difference between twice the second prism angle (2.beta.) and the first prism angle (.alpha.) is at least largely reflected.