摘要 |
As a polarization beam separating device constituting a projection device, a thin-film multilayer film (reflective polarizer) is used. The thin-film multilayer film is composed of a plurality of alternately stacked layers including layers having a refractive index in a predetermined direction and a refractive index in a direction perpendicular to the predetermined direction, the refractive indices being almost equal to each other, and layers having different refractive indices in a predetermined direction and in a direction perpendicular to the predetermined direction. The use of the reflective polarizer makes it possible to reflect linearly polarized light polarized in a first direction and to transmit linearly polarized light polarized in a second direction, which is perpendicular to the first direction, with respect to light of almost all wavelengths in the visible region. As a result, the contrast of an image to be projected can be improved.
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