Brightness control network in a video signal processor with AC coupled output stages
US4598316A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 31, 1983 |
| Grant date | Jul 1, 1986 |
| Priority date | — |
| Expiry date | May 31, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/57
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Brightness control apparatus for a video signal processing system wherein the video signal is pre-conditioned to establish a prescribed reference level during image blanking intervals. The prescribed reference level is afterwards further modified by adding a black-going pulse component to the video signal during the blanking intervals. The magnitude of the added pulse component is adjusted in accordance with the setting of an adjustable brightness control to control the brightness of images displayed by an image display device included in the system. Controlled video signals are AC coupled to an intensity control electrode of the display device by a DC restoration circuit which responds to the magnitude of the added blanking interval pulse component, for establishing the DC bias of intensity control electrode and thereby image brightness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.