Patent ID: 7079202

Claim:
A liquid crystal element comprising: a liquid crystal cell comprising 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 λ incident and transmitting through the liquid crystal cell, the retardation value changing from R 1 to R 2 (R 1 >R 2 >0) when a first voltage V 1 applied between the electrodes is changed to a second voltage V 2 (V 1 ≠V 2 ); and a phase plate having a retardation value R for a linearly polarized light having the wavelength of λ, the retardation value R satisfying a relation R+R v =m×λ (m: integer) with a retardation value R v generated by a third voltage satisfying R 1 ≧R v ≧R 2 .