Patent ID: 7339314

Claim:
A multi-ringed fluorescent lamp comprising: a multi-ringed bulb including a plurality of ring glass bulbs in each of which a plurality of straight tube portions and a plurality of bent portions are formed alternately on a same plane, by bending partially a glass tube having an outside tube diameter of from 12 to 20 mm into a rectangular shape so that opposite ends of the glass tube terminate with the straight tube portions located adjacently to each other, said ring-shaped glass bulbs being placed concentrically on the same plane and connected to each other through a bridge connection portion to form a single discharge path, and a gap between adjacent bent portions of the ring glass bulbs being formed to be larger than a gap between adjacent straight tube portions thereof and having a maximum value of from 6 to 15 mm; a phosphor layer formed on an inner surface of the multi-ringed bulb; a pair of electrodes provided in opposite ends of the discharge path of the multi-ringed bulb; and discharge medium filled in the multi-ringed bulb is filled.