Polarization converting element, polarization converting unit, and projection-type imaging device

摘要

A polarization separating element is configured to include a translucent substrate formed of a crystal material having birefringent properties and optically rotatory power and a polarization separating portion formed on the incidence-side surface of the translucent substrate so as to transmit a P-polarized light beam and reflect an S-polarized light beam. A reflecting element that reflects the S-polarized light beam reflected by the polarization separating portion is disposed so as to be separated approximately in parallel to the translucent substrate. A predetermined function is set such that the P-polarized light beam having passed through the polarization separating portion and been incident to the translucent substrate is converted so as to be parallel to the polarization plane of the S-polarized light beam so that the P-polarized light beam is output as the S-polarized light beam.