Reflective ferroelectric liquid crystal display and projection system

Abstract

A major disadvantage of known reflective displays consists in the fact that they ideally have a switching angle of ±45° in the so-called symmetric mode. With the liquid crystal mixtures known to date, this is not possible without hysteresis effects occurring even at small switching angles and resulting in the switching time being increased to an impermissible extent. The invention relates to a novel reflective, ferroelectric display which can be actuated without DC voltage and has a maximum switching angle α which is ±22.5°. The liquid crystal display according to the invention is distinguished in particular by the fact that a further birefringent element is arranged between the two plates bounding the birefringent liquid crystal layer. In a first category of liquid crystal displays according to the invention, this additional birefringent element is a transparent plate having an optical path difference Δn·d≈λ/4, which is arranged after the liquid crystal layer in the direction of the light incidence, in particular between said layer and the mirror.

Dependencies are inferred from the claim text.