Polarization conversion element, polarization conversion element array, and projection display device using the polarization conversion element or the polarization conversion element array

摘要

PROBLEM TO BE SOLVED: To provide a polarized light converting element and golarized light converting element array which can extract circular polarized light which has the same rotating direction with high light utilization efficiency, and the projection type display device which uses the polarized light converting element or polarized light converting element array. SOLUTION: This device is equipped with a 1st lens part which converges natural light, cholesteric liquid crystal 3 which reflects circular polarized light in one rotating direction of the converged light and transmits circular polarized light in the other rotating direction, a reflection optical element 2 which is provided with an opening part O passing the converged light and reflects the circular polarized light reflected by the cholesteric liquid crystal 3 in the opposite rotating direction, and a 2nd lens part 4 on which the light transmitted through the cholesteric liquid crystal without being reflected by the reflection optical element 2 is made incident. Consequently, the incident natural light is converted into circular polarized light in the same rotating direction and then projected.