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. 19, 1998
Filed:
Nov. 01, 1996
Shuzo Fujioka, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Mitsubishi Electric Semiconductor Software Co., Ltd., Hyogo, JP;
Abstract
A noncontact IC card, a card reader/writer, and a card system, for surely detecting a start flag, thereby reducing a communication error rate and achieving higher communication reliability. The noncontact IC card has a control unit, which includes a CPU, ROM, RAM, etc., and it further has a 1-bit flip-flop (F/F) connected between a receive circuit and the control unit. According to a program of the control unit, data are received one bit at a time, and a UART is set ready for receiving when a bit pattern of the start flag is detected. A card reader/writer is equipped with a control unit which includes a CPU, ROM, RAM, etc. The control unit inserts 1-byte dummy data '00.sub.H ' between a trigger signal and the start flag at the time of transmission. A card system has a card reader/writer and a noncontact IC card. The card reader/writer is provided with a control unit, a transmitting antenna, which includes a series resonance circuit, and a switching circuit, which is connected between a receiving antenna and a receive circuit. Further, the noncontact IC card is provided with a 1-bit flip-flop (F/F), which is connected between the receive circuit and the control unit.