| 摘要 |
<P>PROBLEM TO BE SOLVED: To attain a long life polarization conversion element even when a λ/2 wavelength plate made of an organic film is used, a polarization conversion unit using the same, and a projection device. <P>SOLUTION: A polarization conversion element includes: a light incident surface 11 and a light emission surface 12 approximately in parallel with each other; a plurality of translucent units 13 sequentially joined to the light incident surface 11 at predetermined angles; a polarization separation film 14 and a reflection mirror film 15 alternately provided among the translucent units 13, is provided with: polarization separation means 10 for separating a light flux made incident on the light incident surface 11 into two kinds of polarization light fluxes with different polarization directions to be emitted from the light emission surface; a polarization rotary element 40 for rotating the polarization direction of at least one polarization light flux among the two kinds of polarization light fluxes to be aligned with the other polarization light flux; and a heat radiation transparent substrate 30 one principal plane of which the polarization rotary element 40 is formed and which has heat conductivity higher than that of the polarization rotary element, in which the heat radiation transparent substrate 30 is joined to the light emission surface 12 of the polarization separation means 10 by an adhesive layer 20 which is mainly composed of an inorganic material on the other principal plane. <P>COPYRIGHT: (C)2012,JPO&INPIT |
