| abstract |
A low-pressure mercury vapor discharge lamp, having a glass envelope, whose inner side is provided with a layer of luminescent material and a light-transmitting layer of conducting tin oxide provided between this luminescent layer and the glass envelope. The tin oxide layer is provided with a light-transmitting protective layer of one or more of the colorless oxides of the elements from the secondary groups in column 4 and 5 of the periodical system, e.g. titanium dioxide or zirconium dioxide. |