Handheld device loudspeaker system
US7346315B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 2004 |
| Grant date | Mar 18, 2008 |
| Priority date | — |
| Expiry date | Sep 19, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2499/11
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Loudspeaker systems for handheld devices (2400, 2500) such as cellular telephones (100, 1400, 1600, 1900) are provided. The loudspeaker systems include at least one omnidirectional monopole loudspeaker (404, 1504, 1802, 1918, 1920) and at least one dipole loudspeaker (402, 1502, 1804, 1914, 1916). Filtering is used to compensate for differences between electric-to-acoustic signal transfer functions of the loudspeakers in order to achieve destructive interference of emitted audio in one direction and reinforcement in another direction. Various loudspeaker systems that are reconfigurable from directional mode, to omnidirectional mode are provided. Filtering is also used to add a frequency dependent phase to one signal in order to alter a direction of maximum sound pressure level. Two monopole-dipole pairs can be used to produce a stereo effect. The monopole and dipole loudspeakers can be housed in a detachable loudspeaker accessory (200).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.