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:
Sep. 08, 1998
Filed:
Mar. 21, 1997
Shoshichi Saitoh, Tochigi, JP;
Masahiro Fujimoto, Tochigi, JP;
Katsuhisa Orihara, Tochigi, JP;
Susumu Yanagibori, Tochigi, JP;
Sony Chemicals Corporation, Tochigi, JP;
Abstract
A battery-free non-contacting information card of a relatively simple arrangement which prevents an IC chip or the like from being destroyed by an excess voltage. This non-contacting information card includes a resonance circuit (3) for receiving a carrier signal (e.g., FSK signal) modulated on the basis of information supplied from a card reader/writer (2), an information processing systems (5), (6), (7) for obtaining information from the carrier signal and a rectifier systems (13) for obtaining a voltage by rectifying the carrier signal, wherein the non-contacting information card can be operated by the voltage obtained at the output side of the rectifier circuit (13). The resonance circuit (3) includes a variable capacitive element (3d). A resonance frequency of the resonance circuit (3) is varied by varying the capacity value of the variable capacitive element (3d) in response to the voltage value obtained at the output side of the rectifier circuit (13) to thereby make the voltage value obtained at the output side of the rectifier circuit (13) substantially constant.