Signal matching signal substitution
US4733301A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 26, 1987 |
| Grant date | Mar 22, 1988 |
| Priority date | — |
| Expiry date | Jun 26, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/812
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A signal matching signal substitution system includes a tuner for selectively receiving signals in respective television channels with an input gain control for controlling the signal output level of the tuner. The system substitutes television signals in a substitute channel in lieu of normal signals in a normal channel selected by a viewer. The system has a component for determining the input signal level of currently received signals in a currently received channel and generating a current amplitude signal. A set point generator is responsive to the current amplitude signal corresponding to the normal channel most currently received for providing a set point for the output signal level. A gain control signal generator is responsive to the set point and the signal output level for generating a gain control signal maintaining the output level at the set point. The set point may be set at a predetermined fixed level when the current amplitude signal corresponding to the most current normal channel is relatively high and is set at progressively lower levels when the current amplitude signal corresponding to the most current normal channel is below a transition level. The set point a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.