Sound-based proximity detector
US6925296B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 2001 |
| Grant date | Aug 2, 2005 |
| Priority date | — |
| Expiry date | Nov 21, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M1/6016
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A proximity detector for use in a mobile telephone having at least a microphone and a loudspeaker operatively connected to a signal processor is presented. The proximity detector includes data processing and control modules having a module for controlling the signal processor for activating the loudspeaker to reproduce an acoustic control signal. A correlator correlates a control signal received directly by the microphone and a control signal being reflected from a user of the telephone and then received by the microphone to determine the distance between the telephone and the user. A signal level controller controls the signal processor to vary the signal level of an audible signal reproduced by the loudspeaker proportionally to the determined distance between the telephone and the user.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.