Television signal decoder with improved architecture
US5136368A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 24, 1991 |
| Grant date | Aug 4, 1992 |
| Priority date | — |
| Expiry date | Jan 24, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S348/914
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a new television signal decoder architecture, a mixer switches between two inputs, A and B, using an envelope function C, according to the relationship: Ouput=A*C+B(1-C), where A is either the composite television signal input in normal operation or a first test signal memory in test signal generation operation, and B is either a fixed blanking level in normal operation or a second test signal memory in test signal generation operation. A test signal generator and blanking sequencer provides the test signals to the two test signal memories and an envelope control signal to the envelope generator telling it when and in which direction to supply the transition envelope to the mixer. A variable electrical length front end is created by a microprocessor that recalls from its memory the timing associated with a particular composite video source and directs a timing circuit to wait an appropriate amount of time before releasing a frame of video stored in a FIFO buffer memory to the rest of the decoder. A bus is shared by sync signals and signals from diagnostic points of interest and is alternatively controlled by the sync generation circuitry during normal operation and the microproc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.