Patent ID: 8647726

Claim:
An optical element comprising a polarizer and a liquid crystal layer which are attached to each other by means of an adhesive layer including an active energy ray-curable adhesive composition in a cured state, the adhesive composition including a radically polymerizable compound containing a hydroxyl group and a cationically polymerizable compound, the liquid crystal layer having a difference between in-plane refractive index in a slow axis direction and in-plane refractive index in a fast axis direction of 0.05 to 0.2 and a thickness of 0.5 μm to 2.0 μm, and satisfies the following Equation 1: X<8% Equation 1 wherein X represents a percentage of a variation in a phase difference value of the liquid crystal layer obtained after keeping the optical element at 80° C. for 100 hours, relative to the initial phase difference value of the liquid crystal layer of the optical element.