| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical member in which identification information which is difficult to discriminate at first sight is applied to an optical functional surface in a strong configuration.SOLUTION: In an optical member 10, a plurality of optical units 12 respectively are provided with a plurality of slopes 14 and 15 each of which has a function for transmitting or reflecting rays of light are periodically arrayed. A plurality of microstructures 1 each having an area equal to or more than 4 μmand equal to or less than 0.04 mm, and a depth or height equal to or more than 1 μm and equal to or less than 5 μm are arrayed on each of the plurality of slopes 14 and 15. Reflected rays of light reflected when the slopes 14 and 15 to which the microstructures 1 are applied are irradiated with the rays of light do not function as information for identification only with reflected rays of light reflected when the microstructures are irradiated with the rays of light from at least only one direction, and the reflected rays of light in each direction reflected when the microstructures are irradiated with rays of light from at least two directions are read and processed by an arithmetic operation so as to determine authenticity of being information for identification. |
