Earphone
US4646872A · kind A · utility
251Cited by
3References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1985 |
| Grant date | Mar 3, 1987 |
| Priority date | — |
| Expiry date | Oct 30, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R1/225
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An earphone having a housing, a speaker unit accommodated in the housing and a duct formed in the housing to pass sound emanated from the rear surface of the speaker unit and in which a mesh subjected to water repellent treatment is provided within the duct.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.