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:
Aug. 26, 1986
Filed:
May. 01, 1984
Yuichi Morikawa, Mitaka, JP;
Hirohiko Sato, Iruma, JP;
Eiichi Amada, Kokubunji, JP;
Toshiro Suzuki, Hachiouji, JP;
Hirotoshi Shirasu, Yokohama, JP;
Hiroshi Kuwahara, Kodaira, JP;
Nippon Telegraph & Telephone Public Corporation, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In an interface circuit which couples a two-wire line of bidirectional transmission and unidirectional four-wire receiving and transmitting lines; in order to permit the interface circuit to operate in adaptation to the fluctuation of an impedance with the two-wire line side viewed from the four-wire receiving line, the four-wire receiving line is provided with a plurality of filters and a group of switches for selecting the filters, an output of the four-wire transmitting line is compared with outputs obtained by scanning the filters, and the filter providing the minimum output difference in the comparisons is selected and connected.