Digital noise reducing apparatus for a video signal processing recording reproducing apparatus
US4677487A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 1984 |
| Grant date | Jun 30, 1987 |
| Priority date | — |
| Expiry date | Oct 17, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/911
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital noise reducing apparatus improves the signal to noise ratio (S/N) of a luminance signal of a video signal reproduced from a recording medium. This apparatus includes: an analog to digital (A/D) converting circuit for converting the luminance signal into a digital luminance signal; a digital delay circuit for delaying the digital luminance signal by one horizontal scanning period (1H); a first calculating circuit for calculating the difference between the digital luminance signal and the delayed digital luminance signal; a limiting circuit for limiting the amplitude of an output signal of the first calculating circuit, and a second calculating circuit for subtracting a signal output which is from the limiting circuit from the digital luminance signal. The apparatus operates to reduce noise at the line offset frequency of the luminance signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.