| 摘要 |
PROBLEM TO BE SOLVED: To provide a reflecting layer for a reflection type fluorescent lamp which can send out visible radiation in the desired direction from a lamp by converting ultraviolet rays into the visible radiation by a phosphor coating film by returning them inside the lamp through a phosphor layer after the visible radiation and the ultraviolet rays are efficiently and effectively reflected. SOLUTION: A reflecting layer 20 containing a blend ofγalumina andαalumina, is arranged between a light transmissive envelope 10 and a phosphor layer 22. The alumina blend is composed ofγalumina of 7 to 80wt.% andαalumina of 20 to 93wt.%, and much preferably, it is composed ofγalumina of 30 to 40wt.% andαalumina of 60 to 70wt.%. A covering quantity of the reflecting layer is not less than 5mg/cm<2> , and preferably, 6 to 8mg/cm<2> . The reflecting layer is particularly suitable for an electrodeless fluorescent lamp.
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