| F21K | NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR |
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Note(s) In this subclass, it is desirable to add the indexing codes of subclasses F21W and F21Y [2016.01] |
Descriptions for F21K and notes/indexes are displayed on this screen.