Auxiliary video data slicer with multi-mode peak detection for determining sync and data slicing levels
US5561469A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 28, 1994 |
| Grant date | Oct 1, 1996 |
| Priority date | — |
| Expiry date | Nov 28, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/0355
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An auxiliary video data slicer for extracting auxiliary video information from a video signal includes a peak detector. The peak detector determines a peak amplitude of horizontal sync pulses that are included in the video signal and a peak amplitude of a run-in-clock (RIC) waveform that is included in an auxiliary information component of the video signal. A variable threshold level for the peak detector is varied in a first range to detect the peak amplitude of the sync pulses. A threshold voltage for detecting the leading edge of sync pulses is derived from the peak amplitude of the sync pulses. The location of the RIC waveform within a video line interval is determined in response to detection of a sync pulse edge. The variable threshold level of the peak detector is varied in a second range to detect the peak amplitude of the RIC signal. A data slicing threshold level for extracting auxiliary video information is derived from the peak value of the RIC signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.