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. 12, 1989
Filed:
Aug. 10, 1988
Hiroshi Mano, Hino, JP;
Masayuki Tsurusaki, Hino, JP;
Yoshikazu Sano, Hino, JP;
Junichi Shiomi, Hino, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
In a digital key telephone system through which extension-to-extension calls can be made and incoming calls can be transferred between a master main installation and plural slave main installations, the master and slave main installations are interconnected through digital interface units provided for each installation in order to transmit and receive speech data and control data in digital code between the installations. The digital interface unit of the master main installation first designates an address of the slave main installation to which data are to be transmitted before data transmission, while the digital interface unit of the slave main installation receives data transmitted from the master main installation after address designation. Further, the addresses of the slave main installations can be designated together or separately.