Fluorescent lamp having reflective layer
AssigneeHitachi, Ltd.
InventorChuryo Kodama
Life of this patent
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Abstract
The present invention relates to a fluorescent lamp of the reflective layer type comprising a first phosphor layer and a second phosphor layer laminated partially on the first phosphor layer. The first phosphor layer is formed on the entire face in the circumferential direction of the inner wall of a glass tube, and the second phosphor layer is formed on the first phosphor layer at a certain coating angle along the axial direction of the glass tube. The average particle size of the phosphor constituting the first phosphor layer is different from the average particle size of the phosphor constituting the second phosphor layer. In the fluorescent lamp of the reflective layer type having this structure, a high illuminance can be obtained.
Claims10
A fluorescent lamp of the reflective layer type comprising a glass tube, a first phosphor layer formed on the entire face of the inner wall of said glass tube and a second phosphor layer formed on said first phosphor layer at a certain reflection angle along the axial direction of said glass tube, wherein the average particle size of a phosphor constituting said first phosphor layer is at least 3 .mu.m, the average particle size of a phosphor constituting said second phosphor layer is at least 6 .mu.m and the average particle size of the phophor constituting said first phosphor layer is smaller than the average particle size of the phosphor constituting said second phosphor layer.
Dependencies are inferred from the claim text.