Patent ID: 6890235

Claim:
Method of manufacturing a multi-tube fluorescent discharge lamp, wherein the finished lamp comprises a first glass tube, a second glass tube, which is slightly larger than the first glass tube; two cathode portions, and phosphor; said method comprising the steps of: a) forming an isolator nearby the middle of the first glass tube; b) perforating through-holes nearby the both ends of the first glass tube; c) coating phosphor on an outer surface of the first glass tube; d) coating phosphor on an inner surface of the second glass tube; e) installing two cathode portions, each includes a pair of electrodes, a pipe, a stem and a hole, at respective the both ends of the first glass tube; f) fusing the two ends of the first glass tube with the cathode portions; g) installing the first glass tube into the second glass tube in coaxial; h) fusing the two ends of the first glass tube and the second glass tube; i) drying the phosphor layer and sealing one of the pipe by heat; j) injecting Hg as several mg into the discharge chamber from the other opening pipe; k) vacuuming the discharge chamber front the other opening pipe; l) filling Ar gas as several hundreds Pa in pressure into the discharge chamber; m) sealing the other opening pipe; n) agitating the liquid Hg into vapor Hg; o) installing two bases to respective ends of the discharge tube.