1983 Philips HPL-B 80W Comfort

In 1983 Philips released its HPL Comfort, a range of high-pressure mercury lamps coated with a blend of multiply-doped yttrium vanadate and cerium-doped yttrium aluminate (YAG) phosphors for the production of a warm-white light with an improved light color quality. While the first phosphor is an improved red-emitting material, YAG is a yellow-orange-emitting phosphor with a strong optical absorption in the blue end of the spectrum, a feature which is critical for lowering the color temperature of the light emitted by the mercury discharge.

While the first product range of HPL Comfort lamps included elliptically-shaped mercury lamps rated from 50 to 400 W, two new 50 and 80 W globe-shaped models were also added. The HPL-B Comfort, shown here, was intended for a use in decorative luminaires where the lamp is in direct view. Its thick phosphor coating and large bulb results in a very low surface luminance, which is critical to limit glare and prevent visual discomfort. However aesthetically pleasing these globe mercury lamps appeared compared to the standard elliptical models, the commercial demand for HPL-B lamps did not meet expectations and Philips eventually phased out this particular model in 1988, only five years after its introduction (the standard version remained in production). This is now one of the rarest model in Philips’s HPL family of fluorescent mercury lamps.