Spot arrest system
US4261014A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 3, 1979 |
| Grant date | Apr 7, 1981 |
| Priority date | — |
| Expiry date | Dec 3, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N3/32
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A spot arrest system modulates cathode ray tube beam scanning speed in accordance with compressed and noise-processed image enhancement signals derived from video signal transitions. A generator provides first derivative type image enhancement signals which are compressed by a log amplifier. The log amplifier tends to equalize the amplitude of the image enhancement signals for various video transitions at an optimum amplitude. The signals are then applied to a noise processor which attenuates image enhancement signals which do not correlate to first derivatives of the corresponding video signals. In the noise processor, a multiplier receives as one input the compressed image enhancement signals and receives as another input control signals based on first derivatives of the video signals. The noise-processed signals are then coupled to the cathode ray tube to modulate the beam scan speed. Additionally, beam current may be modulated inversely with respect to the beam scan speed modulation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.