Patent ID: 6404550
Filing Date: 2002-06-11
Classification: G02B,H04N

Abstract:
An optical element comprising:a plurality of first transparent members each having a first incident surface and a first exit surface substantially parallel to each other, first and second film forming surfaces substantially parallel to each other and making a prescribed angle with said first incident surface and said first exit surface, a polarization splitting film formed on said first film forming surface, without adhesive material therebetween and a reflecting film formed on said second film forming surface without adhesive material therebetween, and a thickness; a plurality of second transparent members each having a second incident surface and a second exit surface parallel to each other, said plurality of second transparent members being alternately arranged with and secured to said plurality of first transparent members at said first and second film forming surfaces across said polarization splitting film and said reflecting film respectively so that said second incident surfaces are aligned with said first incident surfaces to form an incident plane and that said second exit surfaces are aligned with said first exit surfaces to form an exit plane; and adhesive layers between said second transparent members and said polarization splitting films and between said second transparent members and said reflecting films, respectively, and wherein at least one of a thickness of the adhesive layers and thicknesses of said first and second transparent members are adjusted to make intervals between said polarization splitting films and said reflecting films substantially constant throughout the optical element; whereby incident light entering through the first incident surface of each first transparent member is directed upon and split by the associated polarization splitting film into first and second components, the first component being directed towards and reflected by the associated reflecting film towards the associated first exit surface without passing through any adhesive layers, and the second component passing through the associated polarization splitting film and out the second exit surface of an immediately adjacent second transparent member while passing through only one of the adhesive layers.