Patent ID: 8629608
Filing Date: 2014-01-14
Classification: H01J

Abstract:
1. A mercury vapor discharge lamp, comprising: a sealed, substantially light-transmissive envelope having an inner surface; at least one discharge source; a fill comprising mercury and an inert gas sealed inside the envelope; a phosphor coating disposed upon at least a portion of the inner surface of the envelope, the phosphor coating defining an inwardly-facing surface, the phosphor coating comprising a phosphor composition that includes phosphor particles, wherein the inwardly-facing surface of the phosphor coating defines voids that have a maximum dimension; and a protective coating on the inwardly-facing surface of the phosphor coating, the protective coating being substantially transparent to UV light of 254 nm wavelength, the protective coating being configured to inhibit collision of Hg ions with phosphor particles in the phosphor coating, wherein the protective coating comprises inorganic particles, and wherein a diameter of the inorganic particles of the protective coating exceeds the maximum dimension of the voids in the inwardly-facing surface of the phosphor coating.