. . . . . . "Examples of the stretched film include birefringence films obtained by stretching a suitable polymer such as polycarbonates, norbornene resins, polyvinyl alcohols, polystyrenes, polymethyl methacrylates, polypropylenes, and other polyolefins, polyarylates, and polyamides; aligned films formed from liquid crystal materials such as liquid crystal polymers; and aligned layers of a liquid crystal mate" . .