Non-video path data collection device
US5881360A · kind A · utility
36Cited by
5References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 11, 1995 |
| Grant date | Mar 9, 1999 |
| Priority date | — |
| Expiry date | Oct 11, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/60
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system performs audio matching to determine the channel to which a television set is tuned. In one embodiment, the system feeds two audio signals to primary and secondary windings of an audio transformer, and employs an output signal taken from a center tap on the primary winding to determine whether the audio signals match. In another embodiment, the system detects transitions of the two audio signals, produces a pulse for each transition, and compares the pulses to determine whether the signals match.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.