Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Publication of NL246837ApublicationCriticalpatent/NL246837A/xx
H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
H01J1/02—Main electrodes
H01J1/13—Solid thermionic cathodes
H01J1/20—Cathodes heated indirectly by an electric current; Cathodes heated by electron or ion bombardment
H01J1/22—Heaters
H—ELECTRICITY
H01—ELECTRIC ELEMENTS
H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
H01J17/00—Gas-filled discharge tubes with solid cathode
H01J17/02—Details
H01J17/04—Electrodes; Screens
H01J17/06—Cathodes
H01J17/063—Indirectly heated cathodes, e.g. by the discharge itself