Thin speaker having an enclosure within an open portion and a closed portion
US4899390A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1987 |
| Grant date | Feb 6, 1990 |
| Priority date | — |
| Expiry date | Sep 15, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R7/04
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A speaker which is thin but which is capable of providing high-fidelity reproduction and ensuring a suitable level of sound pressure even when it is brought close to a wall. A closed chamber is formed behind one part of a diaphragm mounted in an enclosure, and an open chamber is formed behind another part of the diaphragm. At least one voice coil drive unit is connected to the diaphragm. The phase difference between sounds radiated from the front and rear surfaces of the diaphragm is increased as large as possible by using an acoustic duct for the sound radiated through the open chamber, thereby minimizing cancellation of sounds and improving the sound pressure level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.