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:
Jan. 26, 1999
Filed:
Oct. 25, 1996
Kabushiki Kaisha Tokai-Rika-Denki-Seisakusho, Niwa, JP;
Abstract
A transmitting and receiving system including, a transponder always maintains a transmission function even if circuit constants of circuit elements are deviated or such circuit constants are shifted in association with temperature changes. The transponder includes a transponder coil electromagnetically coupled to an antenna coil through which a response signal is transmitted, a resonance capacitor, a main modulation circuit including a first modulation capacitor, and a supplemental modulation circuit including a second modulation capacitor whose static capacitance value is different from that of the first modulation capacitor. A response signal is transmitted in changing an impedance of a transmitting and receiving portion by the main modulation circuit when a question signal is received and by the supplemental modulation circuit when a correction command signal is received.