Noise reduction circuit for a video signal
US4563704A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 16, 1982 |
| Grant date | Jan 7, 1986 |
| Priority date | — |
| Expiry date | Jun 16, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/911
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A noise reduction circuit comprises a lowpass filter supplied with a luminance signal having a noise component of an input video signal, for eliminating a high-frequency component including the noise component, a first circuit for subtracting an output signal of the lowpass filter from the luminance signal, in a state where a rise in the level of the luminance signal is delayed by a predetermined time .tau. from the start of a rise in the output of the lowpass filter, where the output signal of the lowpass filter has a rise time .tau., and a second circuit for amplitude-limiting a subtracted output of the first circuit and subtracting the amplitude-limited output from the luminance signal, to obtain a luminance signal eliminated of the noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.