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:
Jun. 14, 2005
Filed:
Sep. 19, 2000
Applicants:
Joji Nakane, Nara, JP;
Tatsumi Sumi, Takatsuki, JP;
Inventors:
Joji Nakane, Nara, JP;
Tatsumi Sumi, Takatsuki, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka-fu, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03D001/24 ; H03D001/04 ;
U.S. Cl.
CPC ...
Abstract
In a contactless IC card that performs envelope detection on an ASK-modulated carrier wave and demodulates the carrier wave to recover data piggybacked thereon, demodulation is suspended during periods where there is no possibility of a change of a data value (from data 0 to data 1, or from data 1 to data 0) in the digital data piggybacked on the carrier wave. In so doing, incorrect data recovery can be prevented even when noise arises in power supply voltage waveform due to power consumption of an internal memory or the like.