Methods and apparatus for controlling the output of moving armature transducers
US6389145B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1998 |
| Grant date | May 14, 2002 |
| Priority date | — |
| Expiry date | Jul 24, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R11/06
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A moving-armature transducer assembly suitable for use as an alerter in a portable telephone. The assembly includes a transducer housed in an enclosure including first and second acoustical chambers. A first sound emitted from a front hole on a front side of the transducer is propagated through the first acoustical chamber and emitted from a first port of the assembly. A second sound emitted from a rear hole on a rear side of the transducer is phase-shifted by the second acoustical chamber acting in combination with a second port or ports on the assembly to have a phase coinciding with the phase of the first sound. The second sound then combines with the first sound, reinforcing the first sound and producing a combined sound having an increased level and bandwidth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.