Optical device, labeled article, optical kit and discrimination method

摘要

Increased is the variety of changes of an image in accordance with observation conditions displayed on an optical device including a solidified liquid crystal material. An optical device includes a layered structure including a recess-forming layer with light-transmitting property, a main surface of which includes one or more recess-forming regions each provided with first grooves equal in longitudinal directions to one another and adjacent to one another in a direction crossing the longitudinal directions, and a liquid crystal layer supported by the main surface and made of a solidified liquid crystal material, and a reflection layer facing the layered structure.