ELECTROMAGNETIC FOCUS AND ELECTROSTATIC DEFLECTION-TYPE CAMERA TUBE

摘要

PURPOSE:To reduce false signals and improve the efficiency and uniformity of a bias light by providing a ring-like member with its inner diameter nearly equal to the outer diameter of a cylindrical electrode and its outer diameter nearly equal to the inner diameter of a glass tube body on the outer periphery of the final cylindrical electrode of an electron gun. CONSTITUTION:A ring-like member 31 with its inner diameter nearly equal to the outer diameter of a cylindrical electrode 3 and its outer diameter nearly equal to the inner diameter of a glass tube body 1 is provided on the outer periphery of the cylindrical electrode 3. A return beam 13 is returned to the cylindrical electrode 3 or ring-like member 31. At this time, a contact spring 15 and a spot welded point 16 portion generated when the electrode of an electron gun 2 is assembled which generate many reflection beams are covered by a ring- like member 31. Therefore, reflection beams 14 are remarkably reduced, and the false signal image is so much improved that the false signal image of the cylindrical electrode 3 and the false signal image on a scan screen are barely visible. Thereby, the false signal can be remarkably reduced.