COLOUR PICTURE DISPLAY TUBE

摘要

13 A deflection colour selection system for a single beam channel plate display tube. Within an envelope of a display tube there is provided a laminated dynode channel plate electron multiplier (16) having channels whose exit apertures are conveniently aligned in columns. An apertured extractor electrode (36) is mounted on and electrically insulated from an output face of the electron multiplier (16), the apertures (42) in the extractor electrode (36) being aligned with a respective channel. A luminescent screen (14) is spaced from the extractor electrode (36), the screen (14) comprising a repeating pattern of phosphor elements (R, G, B) adapted to luminesce in different colours, each pattern comprising one of each type of phosphor element only. A current multiplied electron beam (34) exiting from an aperture in the extractor electrode is deflected onto an associated pattern of phosphor elements by pairs of first (38) and second (40) deflector electrodes insulated electrically from each other and the extractor electrode, the first (38) and second (40) deflector electrodes being disposed as pairs between each column of apertures (42) in the extractor electrode (36). All the first (38) electrodes are interconnected as are the second (40) electrodes. By having pairs of electrodes (38, 40) a good resolution is obtainable and misalignment errors between the electron multiplier (16) and the screen (14) can be corrected electrically.