公开(公告)号：DE1589231A1

公开(公告)日：1970-09-10

申请号：DE1589231

申请日：1967-04-20

Applicant: MATSUSHITA ELECTRONICS CORP

Inventor： MIZUNO HIDEO ,  YAMASHITA KATSUYUKI ,  IWATA KOSHI ,  SUITA AKUTSU HIDEO ,  MORIGUCHI EIJIRO ,  KAMIYA SHIGERU ,  IGA ATSUSHI ,  TAWARA YOSHI

IPC: H01J61/073 ,  H01J1/14

Abstract: 1,178,052. Cathode materials and processing. MATSUSHITA ELECTRONICS CORP. 12 April, 1967 [20 April, 1966], No. 16719/67. Heading H1D. A discharge tube, more especially a low pressure Hg fluorescent lamp, has cathodes coated with emissive material comprising the oxides of Ba, Sr and Ca together with, in a proportion of from 0À05-10% by weight of the oxides, a substance having the composition of: {(1-x)Fe : xCo} 2 By where 0À15 # x #0À6 and 1 # y # 1À15, i.e. consisting principally of Fe-Co borides, the mixture of borides and 0 xides further containing, in a proportion of from 1-8% by weight of the oxides, one or more of the high melting point metals selected from the group comprising Zr, Hf, Nb and Ta. Initially, with the oxides present as carbonates, the emissive mixture may be suspended in a butyl acetate solution of nitrocellulose and applied to double or triple W coil supports and the resulting coated coils may then be heated during the degassing of the tube to convert the carbonates to oxides. Fluorescent lamps incorporating such cathodes reduce the interference noise to 15dB or less and the blackening of the tube envelope is held at an acceptable level. A number of specific examples of the composition of the emissive mixture are given.