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. 17, 1997
Filed:
Jun. 20, 1995
Tadayori Makino, Tokyo, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An IC card device capable of transmitting identification data to an inquiring unit without involving interference even when a plurality of IC card devices stay in the vicinity of the inquiring unit over a certain time. As the IC card device approaches the inquiring unit, the field intensity of a signal received by a receiver circuit incorporated in the IC card device increases. When it is determined that the field intensity exceeds a preset threshold level, a reception level determination circuit reads out identification data from a memory. A transmitter circuit transmits repeatedly the identification data signal to the inquiring unit. When the number of times the identification data is transmitted reaches a preset number, a counter stops the transmitting operation of the transmitter circuit. When it is determined by a reception level determination circuit that the field intensity exceeds the preset threshold value, a timer causes the receiver circuit to stop reception of the signal transmitted from the inquiring unit for a predetermined period.