METHOD AND DEVICE FOR LANDING CONTROL OF COLOR PICTURE TUBE

摘要

PURPOSE:To shorten the landing control time by providing an annular coil having a face passing the center and set in parallel to the tube axis between a deflecting device and an electron gun and moving and revolving the landing point of an electron beam by the action of a magnetic field. CONSTITUTION:A magnetic field generator 12 consisting of three pairs of annular coils 13 is set between a deflecting device 9 and an electron gun of a color picture tube. The planar direction of the coil 13 passing its center is set in parallel to the direction of tube axis. The coils 13 which are opposite to each other on the basis of the tube axis are connected to each other so that the currents of both coils flow in the same direction. A magnetic field is generated by flowing a current 15 to a pair of coils 13, and the landing point of an electron beam 11 is forcibly shifted by a fixed degree. The current of the coil 13 is switched by a switching device 14, and the mislanding 16 is revolved toward a phosphor dot 1a at the center. Then a purity magnet 10 is controlled to set a prescribed degree for the mislanding 16. The same control is carried out by shifting the device 9 toward the tube axis.