ENVELOPE FOR SMALL-DIAMETER FLUORESCENT LAMP AND SMALL-DIAMETER FLUORESCENT LAMP

摘要

PROBLEM TO BE SOLVED: To provide a small-diameter fluorescent lamp envelope allowing the fabrication of a small-diameter fluorescent lamp highly resistant against solarization via the use of tungsten as lead-in metal, and a small-diameter fluorescent lamp fabricated by using the envelope. SOLUTION: A glass composition is made to contain at least one of TiO2 , PbO and Sb2 O3 as a fluorescent lamp envelope. In this case, tubular glass having an outer diameter equal to or less than 5.2mm and wall thickness equal to or less than 0.6, formed out of boro-silicated glass having a linear expansion coefficient between 34×10<-7> / deg.C and 43×10<-7> / deg.C at a temperature between 30 deg.C and 380 C is used as the fluorescent lamp envelope.