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. 05, 1999
Filed:
Nov. 07, 1996
Karl W Rabe, Chapel Hill, NC (US);
Ericsson, Inc., Research Triangle Park, NC (US);
Abstract
A radiotelephone having a wave guide for channeling sound energy from a speaker to the ear of a person utilizing the radiotelephone. The wave guide is disposed adjacent the speaker and acts to direct sound energy from the speaker to the vicinity of a person's ear. The wave guide comprises an elongated wall structure having inlet and outlet end portions and a varying cross-sectional area that varies in a uniform and repeating manner between maximum and minimum values. This elongated wave guide with its varying cross-sectional areas forms an acoustical low-pass filter that efficiently transmits and propagates low frequencies, that is frequencies in the range of 300 Hz to 3,000 Hz.