PURPOSE: To eliminate an open circuit and perform reliable welding by fitting a conductive support body so that its top is positioned lower than two cathode sleeves, depressing a heater leg section from above with plate-like support pieces, and bringing the support pieces in contact with the top of the support body for laser welding.
CONSTITUTION: A conductive support body 13 penetrates through a cylinder body 2 fixed to a cathode support cylinder 1 and is fitted with adhesive glass 4 so that its top is positioned lower than the lower end of a cathode sleeve 6. In addition, sleeves 6, 6 are fixed through the upper ends of support pieces 5, 5 fixed inside the support cylinder 1. A base metal body 7 coated with an electron emitting material is fixed to the enveloping top surface of the sleeve 6. A heater 8 is inserted in the sleeve 6, a heater leg section 8A is pushed down with a plate-like support piece 10, and the support piece 10 is brought into contact with the top of the support body 13. Under this condition, laser rays are illuminated from above the support piece 10 to weld the support piece 10 to the support body 13, then laser rays are illuminated to the contact section between the support piece 10 and leg section 8A from above the support piece 10, thus reliable welding can be performed with no open circuit.
NAKAYAMA SHIYOUJI
TAKANASHI YUKIO
