Magnetic arc spreading fluorescent lamp with protective envelope

摘要

An arc discharge device such as a fluorescent lamp comprising a lamp envelope having an inner phosphor coating. An arc spreading assembly is disposed in or in close proximity to the lamp envelope. The lamp envelope is of an oval or elliptical cross-section and the major axis is a multiple of the minor axis of the lamp's cross-sectional shape. The lamp envelope is strengthened mechanically and protected against atmospheric pressure by being enclosed in an evacuated outer cylindrical protective envelope.