Patent ID: 6239832
Filing Date: 2001-05-29
Classification: H04N

Abstract:
Apparatus for the conversion of colour film images to corresponding electrical signals, the apparatus comprising:a cathode ray tube which is provided with a phosphor for producing light, the phosphor being composed of at least two phosphor components, each phosphor component having a distinct spectral output;primary photodetector means arranged to detect the light produced by the phosphor of the cathode ray tube, after said light has been modulated by a film, said primary photodetector means further being arranged to produced primary electrical signals which include information about the colour content of the detected light;secondary photodetector means arranged to detect light produced by the phosphor of the cathode ray tube, which light has not been modulated by the film, and to produce secondary electrical signals which include information about the colour content of the detected light corresponding to the emission from each phosphor component of said phosphor; andprocessing means for adjusting the primary electrical signals with reference to the secondary electrical signals.