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. 09, 1984
Filed:
Oct. 06, 1981
Applicant:
Inventors:
Philip D Wasserman, Cupertino, CA (US);
Terry R Seaver, San Jose, CA (US);
Assignee:
Anderson Jacobson, Inc., San Jose, CA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ; H04R / ;
U.S. Cl.
CPC ...
179 / ; 381 94 ; 381112 ; 179 / ;
Abstract
A technique for reducing the nonlinear frequency characteristics of a carbon granule microphone of the type generally used in telephone handsets wherein a tone outside the voice range is applied to the microphone simultaneously with the audio signal desired to be transmitted. This technique has particular advantages with telephone modems, especially those where the sending and receiving frequencies are hamonically related.