| 摘要 |
PURPOSE:To correct shape deformation of electron beams, by providing a correction yoke in contact with a tube wall outside the tube corresponding to a position where the 4th grid is located. CONSTITUTION:A correction yoke 26 is provided in contact with a tube wall outside the tube corresponding to a location near a main electronic lens L toward the tube axis of a cathode-ray tube 1, i.e., a location where the 4th grid G4 is located. The correction yoke 26 is of guadruple pole construction the same as an electromagnetic convergence device 4 to constitute a guadruple electronic lens. The magnetic field by the yoke 26 is opposite to that produced by the convergence device 4. Further, the correction magnetic field of mis-convergence can be zeroed on an X axis (abscissa) including the center of screen of the cathode ray tube 1. |
