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:
Oct. 07, 2003
Filed:
Nov. 18, 1999
Koichi Yamamoto, Fukuoka, JP;
Toshihiko Sakata, Fukuoka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A telephone system capable of judging kinds of various signals (line input signals) obtained through a line is disclosed, that enables reduction of the number of parts, detection with high accuracy, reduction of a mounting area, and reduction in costs. The telephone system includes an A/D converter for making A/D conversion of the line input signal such as a CPC signal, a bell signal, and a usage state signal indicating a telephone line usage state to output a digital line input signal, and a frequency analyzing unit for making frequency analysis of the digital signal converted by the A/D converter, and the central processing unit judges the kind of the line input signal based on a result of the frequency analyzing unit.