| 摘要 |
PURPOSE:To improve the brightness on a screen by providing a means, which divides an incident light into a parallel component and a vertical component, and a polarization plane rotating means where twisted nematic liquid crystal is arranged to rotate the plane of polarization at 90 deg.. CONSTITUTION:A polarizing beam splitter 12 divides the light incident from a light source 11 into a P component (parallel component) and an S component (vertical component), and twisted nematic liquid crystal (TN liquid crystal) 13 rotates the plane of polarization at 90 deg.. That is, TN liquid crystal 13 is given to a pair of substrates so that axes of uniaxial orientation treatment cross at 90 deg., and molecular axes of nematic liquid crystal packed between this pair of substrates form a 90 deg. helical structure between one and the other substrates, and the incident polarized light is rotated along this helical structure. The polarized light made incident as the P component is rotated at 90 deg. and is emitted as the P component as the result. Thus, the light use efficiency is practically improved twice. |
