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:
Mar. 24, 1992
Filed:
Jun. 14, 1989
Applicant:
Inventors:
Assignee:
Siemens Aktiengesellschaft, Munich, US;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
375 26 ; 379361 ;
Abstract
A harmonic tone having an amplitude which is significantly lower than a fundamental audible tone is superimprosed on the audible tone to drown out quantization noises for audible tones transmitted in digital telecommunications exchange systems.