Patent attributes
A retarder comprising a substrate, a first optically anisotropic layer formed of a composition comprising a rod-like liquid-crystal compound substantially generating a phase difference of π at 550 nm, and a second optically anisotropic layer formed of a composition comprising a rod-like liquid-crystal compound substantially generating a phase difference of π/2 at 550 nm is disclosed. At least either one of the rod-like liquid-crystal compounds is denoted by Formula (I) Q1-L1-A1-L3-M-L4-A2-L2-Q2: where Q1 and Q2 denote polymerizable groups; L1 to L4 denote single bonds or divalent linking groups provided that at least either of L3 and L4 represents —O—CO—O—; A1 and A2 denote C2-20 spacer groups and M denotes a mesogen group; and an in-plane slow axis of the second layer and an in-plane slow axis of the first layer cross substantially at 60 degrees.
