Patent · US Expired

Telephone apparatus for use in a conference room

US4078155A · kind A · utility

29Cited by
4References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 17, 1977
Grant dateMar 7, 1978
Priority date
Expiry dateJan 17, 1997

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04R1/22
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A telephone apparatus for use in a conference room has a housing, with a vertical central axis, with a loudspeaker at the upper end, coaxial with the vertical axis, and a microphone at the lower end. The loudspeaker faces upward with an unrestricted outlet and is omnidirectional in output. The microphone faces downward and is coaxial with the vertical axis, being sensitive only to airborne vibration only. The microphone is surrounded by an inclined surface extending outwardly and upwardly at an angle of about 30.degree., and has an omnidirectional sensitivity. The housing is supported with the microphone inlet about 1/2 inch above a surface, which can be the surface of a base member attached to the housing. The minimal peripheral distance from the center line of the speaker to the center line of the microphone, around the housing, is about 15 inches, for good acoustic separation. A resonator can be attached to the microphone inlet.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.