Video system including apparatus for deactivating an automatic control arrangement
US5847773A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 1996 |
| Grant date | Dec 8, 1998 |
| Priority date | — |
| Expiry date | Jan 3, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/4854
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A projection television system includes an automatic contrast control section for controlling the amplitude of the luminance signal in response to the peak value of a luminance-representative image component signal in order to prevent white-spot blooming. Circuitry is provided for deactivating the automatic contrast control section when a user sets the contrast control level above a given threshold level, e.g., corresponding to the maximum contrast control level. As a result white-spot blooming is inhibited in order to ensure sharp images for a contrast control range below the given threshold level while allowing maximum white image components to be produced (at the expense of white spot blooming) when the contrast control level is set above the threshold level, depending on the preference of the user.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.