Hot cathode fluorescent lamp and electrode for fluorescent lamp

Abstract

A long-life hot cathode fluorescent lamp can include a pair of parallel lead wires that can be arranged at each end of a tube. A coiled filament can be connected at its opposite end portions to the lead wires. The coiled filament can have two long pitched regions in which a coil pitch is longer than regions outside of the long pitched regions. Emitter can be located in a region defined between the two long pitched regions. Shape characteristics and intensive current flow obtained by the presence of the long pitched regions can form the origins of discharge near the boundaries between long and short pitched regions. Accordingly, stable discharge can be achieved with the origins of discharge located at ends of the emitter. As a result, the hot cathode fluorescent lamp is allowed to have a long life and stable light emission characteristics.

Dependencies are inferred from the claim text.