Patent Number: 6,294,871

Title: Ultraviolet and visible filter for ceramic arc tube body

Abstract: A ceramic arc tube for a metal halide discharge lamp is soaked in a dopant solution. The dopant solution includes a salt of a UV-absorbing additive, such as europium, cerium, or titanium. The salt is converted to the oxide form of the UV-absorbing additive during sintering of the arc tube. Lamps fabricated using the doped arc tubes filter UV from light emitted from the discharge without appreciably absorbing light in the visible range. The UV retained in the lamp causes the lamp to run at a hotter temperature, improving light output.

Inventors: Scott; Curtis E. (Mentor, OH), Laska; H. Michael (Willoughby, OH), Kaliszewski; Mary Sue (Lyndhurst, OH), Rappensberger; Csaba F. (Dunakeszi, HU)

Assignee: General Electric Company

International Classification: H01J 61/00 (20060101); H01J 61/30 (20060101); H01J 61/82 (20060101); H01J 017/16 ()

Expiration Date: 09/25/2018