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:
May. 13, 1997
Filed:
Jun. 21, 1995
Tokimec, Inc., Tokyo, JP;
Abstract
A response permission command is transmitted from a reader/writer, thereby setting all of data carriers to a response possible state. Subsequently, a data return command is transmitted, thereby returning data for collation on a bit unit basis. The reader/writer transmits a data collation command of, for example, bit 0 to each of the data carriers when recognizing the return of the data in which bits 0 and 1 mixedly exist. When an own return bit coincides with a collation bit, each of the data carrier judges that the collation succeeds and returns a next bit for collation. When they don't coincide, however, a state of the data carrier is switched to a response inhibition state. By repeating such processes with respect to all of the bits of the data for collation, only one data carrier finally remains in a response possible state and generates an access permission command, thereby performing the reading or writing operation. When the operation is finished, the state is switched to an access inhibition state by an access inhibition command. The processes from the transmission of the response permission command are again repeated for the remaining data carriers.