Monolithic optical autocompensation read-out circuit for distance dependent loudness control in mobile phones
US7260422B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 10, 2003 |
| Grant date | Aug 21, 2007 |
| Priority date | — |
| Expiry date | Mar 21, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit and method are given, to realize a loudness control for mobile phone earpieces and speakers with the help of a proximity sensor, which is realized as an infrared photo-electric guard circuit, where only very few external parts are needed. As a novelty here, the necessary photo sensors are integrated onto a single chip. To form the photodiodes within a single IC together with the other circuit elements are much less expensive. Using the advantages of that solution the circuit of the invention is manufactured with standard CMOS technology and only very few discrete external components. This solution reduces also power consumption and manufacturing cost.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.