Feedback control device for photo-colorimetric parameters for a light box with color LEDs
US7804478B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 29, 2004 |
| Grant date | Sep 28, 2010 |
| Priority date | — |
| Expiry date | Feb 20, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG09G2380/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The field of the invention is that of light boxes used for illuminating optical-valve displays, especially matrix liquid-crystal displays (or LCDs). The illumination from light boxes can at the present time be produced by light-emitting diodes that emit in various spectral bands so as to reconstruct white illumination. For a number of applications, in particular aeronautical applications, it is necessary to maintain the photometric and colorimetric characteristics of this illumination independently of the environmental and ageing conditions of the components. The invention provides an electronic feedback control device for maintaining the photometric and colorimetric characteristics of this illumination at given setpoint values without introducing disturbing optoelectronic devices into the light box. Several possible technical solutions are described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.