The liquid crystal display device and an optical element, and methods for their preparation

A liquid crystal display device includes two substrates, a liquid crystal layer sandwiched between the substrates and two alignment films, each being provided on one surface of associated one of the substrates so as to face the liquid crystal layer. The device defines multiple picture elements. At least one of the two alignment films is made of a polymer material that includes a main chain, an atomic group having a bond that is selectively cut when exposed to an actinic ray and a side chain bonded to the main chain via the atomic group. The polymer material with the side chain can give a pretilt angle of greater than 85 degrees but 90 degrees or less to liquid crystal molecules. The polymer material without the side chain can give a pretilt angle of 2 degrees to 15 degrees to the liquid crystal molecules.