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. 28, 1991
Filed:
Oct. 10, 1989
Applicant:
Inventor:
Hiromi Katagawa, Fukuoka, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M / ; H04M / ;
U.S. Cl.
CPC ...
379234 ; 379235 ; 379257 ; 379283 ;
Abstract
Instead of setting the type of a dial signal for a central office line connected to a private branch exchange to either a DTMF signal or a pulsed signal externally of the private branch exchange, the line is acquired and a DTMF signal is transmitted from the private branch exchange to the line so that the line is recognized as a dial line for the DTMF signal when a dial tone coming from the line disappears but as a dial line for the pulsed signal when the dial tone does not disappear. Results of recognition are set in the private branch exchange and the type of the dial signal for the line is set automatically in accordance with the results.