SYSTEM FOR NONCONTACT DISCRIMINATION OF OBJECT, ESPECIALLY METAL OBJECT

摘要

PURPOSE: To provide a system used to discriminate, especially a metallic body like a gas cylinder. CONSTITUTION: This system is equipped with a reader 20 for electronic labels, and the reader 20 is equipped with plural transmitter receivers 21 for electromagnetic waves. Those transmitter receivers 21 are shifted in angle from one another around the center axis, so that some of lines 27 of magnetic flux generated by at least one transmitter receiver 21 form a loop by running in the coil of the antenna of a label along its axis X irrespective of the relative direction when the reader is arranged nearby the label. The label is equipped with a sheet made of a non-magnetic conductive material, arranged in parallel to the antenna, opposite the antenna so as to form a reflection screen for electromagnetic waves.