LOW-PRESSURE MERCURY VAPOUR DISCHARGE LAMP

摘要

: Low-pressure mercury vapour discharge lamp having a colour rendering index Ra of at least 80, having a luminescent layer which emits in the three wavelength ranges from 430 ro 490 nm, from 520 to 565 nm and from 590 to 630 nm, the emission in the range from 590 to 630 nm being mainly derived from a rare earth metal oxide which is activated by trivalent europium. The luminescent coating comprises an oxysulphide of yttrium and/or lanthanum, activated by trivalent europium as an additional redluminescing component, which oxysulphide constitutes from 2 to 10% by weight of the luminescent coating.