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:
Dec. 03, 1991
Filed:
Jun. 19, 1989
Toshio Takizawa, Tokyo, JP;
Hiroharu Hirata, Tokyo, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
An IC card reader/writer has frequency mode identifying means for determining whether or not an IC card loaded thereon has an identifiable frequency. When the frequency mode of the IC card is identifiable, clock frequency determining means reads frequency data representative of an operating clock frequency out of the IC card to determine an operating clock frequency particular to the card. Based on the determined operating clock frequency of the IC card, frequency setting means converts reference clock pulses being generated by reference clock generating means into clock pulses which match the clock frequency of the IC card, and feeds those clock pulses to the card. The reader/writer is capable of producing clock pulses the frequency of which is variable in matching relation to the frequency of operating clock pulses of an IC card.