The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 14, 2015
Filed:
Nov. 16, 2011
Satoru Sugita, Tochigi, JP;
Toshiaki Yokota, Miyagi, JP;
Yoshimi Takahashi, Miyagi, JP;
Katsuhisa Orihara, Tochigi, JP;
Satoru Sugita, Tochigi, JP;
Toshiaki Yokota, Miyagi, JP;
Yoshimi Takahashi, Miyagi, JP;
Katsuhisa Orihara, Tochigi, JP;
DEXERIALS CORPORATION, Tokyo, JP;
Abstract
An antenna device, capable of stable communications without increasing a space of the entire device by keeping a resonance frequency substantially constant even if the temperature changes, includes: an antenna circuit having an antenna coil with an electrically connected capacitor; the coil receiving a magnetic field transmitted from a reader/writer at a predetermined oscillation frequency; the circuit becoming communicable when inductively coupled to the reader/writer; and a magnetic sheet formed at a position superposed on the coil to change its inductance, wherein the coil has a temperature characteristic in which the inductance is changed with a temperature change, and the sheet has a temperature characteristic of changing the inductance to achieve a characteristic inverse to the inductance change with the temperature change in a predetermined use temperature range, and substantially matching a resonance frequency of the circuit with the oscillation frequency in the use temperature region.