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:
Oct. 11, 1994
Filed:
Jun. 03, 1993
Tokimec Inc., Tokyo, JP;
Abstract
When a control section of a data carrier discriminates a command from a reader/writer, either one of two kinds of pseudo random signals is returned in accordance with a bit 0 or 1 of response data. When two autocorrelation values obtained by correlation arithmetic operations are simultaneously equal to or greater than a predetermined threshold value, the reader/writer determines that a communication has been executed with two or more data carriers, so that an error warning, an access stop, a retry, or the like is executed. The reader/writer compares the autocorrelation peak value obtained from the pseudo random signal from the data carrier with a threshold value. When it is equal to or greater than the threshold value, the reading operation is executed. In the reading operation of continuous data bits from the data carrier, the reader/writer selects the minimum value from among the autocorrelation peak values of the bits obtained by the correlation arithmetic operations and stores the selected minimum value. When the minimum memory value is smaller than a threshold value, it is determined that data could not correctly be read, so that an error is indicated.