Laser-driven television projection system with attendant color correction

US5440352A · kind A · utility

Assignee

• Schneider Rundfunkwerke Aktiengesellschaft · DE

Inventors

• Christhard Deter · Hermsdorf, DE
• Dirk Loeffler · Brahmenau, DE

Key dates

• Filing date: Feb 18, 1994
• Grant date: Aug 8, 1995
• Expiry date: Feb 18, 2014

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04N9/67
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

A television projection system for generating picture points of a television picture has at least three light sources which may be controlled in intensity for light signals (R.sub.L ', G.sub.L ', B.sub.L ') of different wavelengths, wherein the hue of each picture point is fixed by means of color value signals (R, G, B) in a first base system which may be represented in a CIE diagram by corner points of a hue region which are defined via wavelengths of screen phosphors. The wavelengths of the light signals determine a second base system which shares a common range of hues with the first base system. Further, an input circuit is provided for generating at least three electrical signals which are proportional to the color value signals (R, G, B) or contain a mixture thereof, and a control device is provided for controlling the light sources. The control device can be triggered by the signals of the input circuit and has a circuit which can transform every hue from the first base system into the second base system via a matrix. In addition, the shortest wavelength of the light sources is 470 nm or less and the other wavelengths of the light sources are so determined that the common ra…