DIFF Subgroup
H01J 19/20 Supports for the emissive material
Introduced: September 1968
Full Title
Full titles differ between systems:
IPC:
Details of vacuum tubes of the types covered by group > Electron-emitting electrodes; Cathodes > Thermionic cathodes > Cathodes heated indirectly by an electric current; Cathodes heated by electron or ion bombardment > Supports for the emissive material
CPC:
Details of vacuum tubes of the types covered by group H01J21/00 > Electron-emitting electrodes; Cathodes > Thermionic cathodes > Cathodes heated indirectly by an electric current; Cathodes heated by electron or ion bombardment > Supports for the emissive material
No child classifications to compare. This is a leaf node in both IPC and CPC.