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AssigneeMitsubishi Materials Corporation
InventorsTakeshi Soe, Masami Miyake, Minoru Nakazato, Kouichi Ishiyama
Estimating the term…
The resonance frequency of a resonant circuit section does not change even if the surface of an article whose theft is monitored is formed of any material. An antitheft tag mounted on the article (11) whose theft is monitored includes a resonant circuit section resonating with the radio wave having a particular frequency and transmitted from a transmitting antenna. An electromagnetic shield layer formed of an insulating material is interposed between the mounting surface of the article and the resonant circuit section. The electromagnetic shield layer may be formed of ferrite powder or soft magnetic powder which has a particle size of 10 μm or less and plastic or rubber or may be formed by laminating a first layer composed of a composite material and a second layer composed of plastic or rubber. Preferably, the soft magnetic powder is any of amorphous alloy, Permalloy, soft magnetic iron, silicon steel, Sendust alloy and Fe—Al alloy.
An antitheft tag which is mounted on an article the theft of which is monitored and which includes a resonant circuit section configured to resonate with radio waves having a particular frequency that are transmitted from a transmitting antenna, comprising:
Dependencies are inferred from the claim text.