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:
Jan. 23, 2001
Filed:
May. 15, 1998
Kouichi Uesaka, Yokohama, JP;
Yoshihiko Hayashi, Setagaya-ku, JP;
Takashi Suga, Yokohama, JP;
Masami Makuuchi, Yokohama, JP;
Ryozo Yoshino, Hadano, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The present invention provides a reader and/or writer for performing both the supply of operating power to an IC card and transmission of a communication signal to the IC card or transmission and reception thereof to and from the IC card, wherein a main coil or a spiral antenna for generating an electromagnetic field for the two or at least power supply, and auxiliary coils or spiral antennas for generating magnetic fields opposite in phase to the electromagnetic field generated by the main coil or spiral antenna to thereby restrain the intensity of the electromagnetic field in the distance are provided side by side.