Patent · US Expired

Headphoning

US4455675A · kind A · utility

223Cited by
3References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 28, 1982
Grant dateJun 19, 1984
Priority date
Expiry dateApr 28, 2002

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04R1/1066
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

Headphones have a small cavity between the diaphragm and the ear canal with a microphone in the cavity closely adjacent to the diaphragm providing a feedback signal that is combined with the input electrical signal to be reproduced by the headphones to provide a combined signal that is power amplified for driving the diaphragm.

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