Multi-layer diffraction type polarizer and liquid crystal element

摘要

A liquid crystal element including a liquid crystal cell that has transparent substrates having electrodes and a liquid crystal layer sandwiched between the substrates, the liquid crystal cell having a retardation value for a linearly polarized light having a wavelength of lambda incident and transmitting through the liquid crystal cell, the retardation value changing from R₁ to R₂ (R₁>R₂>0) when a first voltage V₁ applied between the electrodes is changed to a second voltage V₂ (V₁<>V₂). The liquid crystal element also includes a phase plate having a retardation value R for a linearly polarized light having the wavelength of lambda, the retardation value R satisfying a relation R+R_v=mxlambda (m: integer) with a retardation value R_v generated by a third voltage satisfying R₁>=R_v>=R₂.