Fluorescent lamp with envelope grooves
AssigneeDuro-Test Corporation
InventorsJoel Shurgan, Donald P. Northrop, Gordon D. Coplein
Life of this patent
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Abstract
A low pressure discharge lamp, particularly a fluorescent lamp, having a plurality of separate and continuous grooves along its length each of which is formed for 360.degree. around the envelope. The groove configuration maintains a generally arcuate cross-section of varying radius to thereby alter the wall recombination rate of the plasma ions with the phosphor. In the embodiments where the cross-section of the envelope as deformed by the groove is non-circular, the invention also acts to increase the plasma arc stream length thereby changing the electrical and luminous properties of the lamp. A method and apparatus for making the grooves using a plurality of heat sources is also described.
Claims10
A fluorescent lamp comprising an elongated cylindrical envelope of vitreous material, cathode means at each end of the envelope, a phosphor on the inner wall of said envelope and means within said envelope for producing an arc stream discharge when a voltage is applied across said cathodes, said cylindrical envelope being formed with a plurality of depressed grooves to interact with the arc stream discharge, each of said grooves extending around a major portion of the cylindrical envelope surface and being separate and independent of each other, the areas of the envelope without the grooves defining an overall cylindrical shape for the envelope.
Dependencies are inferred from the claim text.