Radio tag antenna structure for an optical recording medium and a case for an optical recording medium with a radio tag antenna

Abstract

An antenna comprises a dielectric member, an antenna pattern formed on one surface of the dielectric member, and a ground pattern formed on the other surface of the dielectric member. A part or the whole of the antenna is implanted in a dielectric layer on the side from which a laser beam does not come in of an optical recording medium symmetrically having a metal layer reflecting the laser beam and the dielectric layer, thereby to provide a radio tag antenna structure for an optical recording medium which is simple, is small-sized, and can secure necessary reading performance.

1 . A case for an optical recording medium which has a dielectric layer and a metal layer and is attached an antenna for a radio tag to a portion of said dielectric layer on which said metal layer is not formed, said case comprising: 
 a dielectric member disposed on an inner surface of said case at a position corresponding to a position at which said antenna is attached when said optical recording medium is contained in said case.