Description
Class F21K : LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
Subclass 2/04: Light sources using luminescence (luminescent materials C09K 11/00; selection of luminescent materials for light screens F21V 9/16; using excitation by radioactivity G21H 3/02, H01J 65/06, H01J 65/08; transforming the wavelength of the light of gas- or vapour-discharge lamps by luminescence H01J 61/42; electroluminescent light sources H05B 33/00) using triboluminescence; using thermoluminescence