System and method for adjusting white balance of projector type color display device
US5287173A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1992 |
| Grant date | Feb 15, 1994 |
| Priority date | — |
| Expiry date | Nov 18, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/73
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system for adjusting the white balance of a projector type color display device is shown. The color display device includes three single color cathode ray tubes from which single color beams are projected onto a screen to form a colored image on the screen. The white balance adjusting system comprises a first device for feeding one of the three cathode ray tubes with all white signal to cause the same to project a single color image on the screen; a second device for detecting a luminance value of the single color image on the screen; a third device for deriving luminance values of the other single color images from the detected luminance value; and a fourth device for controlling the selected cathode ray tube in such a manner that the derived luminance values are put in a tolerance which is provided for dealing with a noise of the second device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.