Cathode-ray tube

摘要

In the structure of the present invention, there can be provided a cathode ray tube in which deviation in the trajectory of the electron beams by the leakage magnetic field from the mask frame (1) is decreased by using a polygonal mask frame (1) in which the relative magnetic permeability of longer side members (31) out of two side members adjacent to each other at the joint portion of the mask frame (1) is the same as or larger than the relative magnetic permeability of the other side members (21). Thus, the significance of the present invention in industrial terms is large.