Patent ID: 7164223

Claim:
A multi-tube fluorescent discharge lamp, comprising: a total of N multiple number of glass tubes, each of different caliber and arranged in a coaxial structure within each other; an isolator near a middle section of an innermost first glass tube and extending to an (N−1)th glass tube; plural-numbered through-holes near both sides of the isolator at odd-numbered glass tubes starting from the innermost first glass tube to the (N−1)th glass tube, and around ends of even-numbered glass tubes starting from an inner second glass tube to an (N−2)th glass tube; a pair of cathodes placed at both ends of the innermost first glass tube; phosphor layers on inner and outer surfaces of the glass tubes starting from the inner second glass tube to the (N−1)th glass tube, on the outer surface of the innermost first glass tube and on the inner surface of the Nth glass tube; and both ends of all glass tubes being sealed to form a succession of interconnected discharge chambers provided in a state of vacuum and comprising mercury (Hg).