IPC Subgroup
H01J 21/36 Tubes with flat electrodes, e.g. disc electrode
Introduced: September 1968
Last revised: January 2006
Full Title
Vacuum tubes > Tubes with flat electrodes, e.g. disc electrode
Classification Context
- Section:
- ELECTRICITY
- Class:
- ELECTRIC ELEMENTS
- Subclass:
- ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS