CATHODE-RAY TUBE AND PROCESS FOR PRODUCING THE SAME

摘要

A cathode-ray tube having an electron gun including a main focusing lens made of a helical high-resistance material, and a process for producing the same. The method of forming a helical high-resistance body on the inner surface of a glass tube comprises the steps of making (31) a hole in the central portion of the glass tube and attaching a sealing ring by fritting to carry out electrical connection to both ends of the glass tube, coating (35) the glass tube with a paste of a high-resistance material obtained by compounding glass powder having a softening point lower than an annealing temperature of the glass tube with ruthenium oxide, forming (37) a helical structure on a film of the high-resistance material after it has been dried, and baking (38) the resultant product at a temperature of 420 DEG C - 550 DEG C, whereby a helical high-resistance body having a resistance value of 0.8 G OMEGA - 100 G OMEGA is formed.