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. 04, 2004
Filed:
Oct. 21, 1999
Applicant:
Inventor:
Koji Goto, Tokyo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M 3/00 ; H04M 5/00 ;
U.S. Cl.
CPC ...
H04M 3/00 ; H04M 5/00 ;
Abstract
A frequency deviation detecting apparatus for detecting frequency deviation of a dual tone multiple frequency (DTMF) signal includes frequency deviation analyzers for analyzing a received signal for frequency components proximate fixed frequencies in analytical blocks, each analytical block having a length that ensures the precision required for detecting the frequency deviation. Each of the analytical blocks of the deviation analyzers partially overlays an adjacent block so that analysis by at least one analytical block is ensured within a minimum duration of a DTMF signal.