| 摘要 |
PURPOSE:To achieve improved image quality and improved high resolution letter quality by arranging first and second magnetic field controllers in the direction of the tube axis and specifying the relationship between the distance (l) between the field controllers and the distance (Sg) between electron beams. CONSTITUTION:First magnetic field controllers 10B and 10R are apart from a second magnetic field controller 10G by a given distance (l) in the direction in which the beam travels. The first controllers 10B and 10R are located toward the deflection york and the second controller 10G is located toward a cathode 11. The symbol 12 represents a line of magnetic force leaking from the deflection magnetic field produced by the deflection york. The first controllers 10B and 10R are used to increase the vertical raster size of a central beam 5G and the second controller 10G is used to decrease the vertical raster size of the central beam 5G thereby making the vertical raster size of the central beam 5G coincide with that of side beams 5B and 5R. The distance (l) is specified by beam distance (Sg) and is adjusted according to formula 6>l/Sg>1 desirably formula l/Sg-3. |
