Deflection control apparatus for a beam index color cathode ray tube
US4287531A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 1979 |
| Grant date | Sep 1, 1981 |
| Priority date | — |
| Expiry date | Nov 19, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/24
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Deflection control apparatus is disclosed for a beam index color television receiver of the type which includes a cathode ray tube adapted to display a video picture in response to a received color television signal. The beam index cathode ray tube is provided with index stripes which are scanned by the electron beam as the beam scans a raster across the display screen of the tube. A detector detects when the respective index stripes are scanned by the beam so as to produce an index signal, the frequency of which varies from a predetermined frequency value when the scanning speed of the beam varies. An oscillator generates an oscillating signal that is synchronized with the index signal, and a phase locked loop, which includes a comparator for comparing the index signal to the oscillating signal so as to produce a control signal as a function of the difference therebetween, adjusts the frequency of the oscillating signal in accordance with that control signal. The television receiver also includes a switching arrangement which is responsive to the oscillating signal to switch color information signals for the purpose of modulating the beam. The deflection control apparatus includes…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.