.~ Generating gas or vapor within an envelope, or coating by vapor, gas, mist or smoke within the envelope {12}
20
.~.~ Filament heating
DEFINITION
Classification: 445/20
Filament heating:
(under subclass 9) Method which includes supplying current to the conducting cathode, anode or grid structure of the lamp or discharge device so as to cause thermally warming.
SEE OR SEARCH CLASS
313, Electric Lamp and Discharge Devices,
549, for electric lamps and electric space discharge devices which are provided with a getter or a gas or vapor generating material and which have combined therewith means for heating the getter or the gas or vapor generating material.
