Lighting unit and electrodeless low-pressure discharge lamp and discharge vessel for use in said lighting unit

摘要

A lighting unit comprises an electrodeless low-pressure discharge lamp (10) and an electric supply (60) for the lamp. The lamp is provided with a discharge vessel (20) having a radiation-transmitting enveloping portion (21) and a recessed portion (24). The discharge vessel encloses a discharge space (27) in a gastight manner and contains an ionizable filling. The lamp also is provided with a coil (30) positioned in the recessed portion for generating a high-frequency magnetic field so as to maintain an electric discharge in the discharge space. The enveloping portion (21) of the discharge vessel is provided with a radiation-transmitting, electrically conducting layer (22) at a surface facing the discharge space (27). This layer is electrically connected to a lead-through member (42) which issues to the exterior of the discharge vessel. The lead-through member is a metal tube which forms at least a portion of a tubular projection (46, 42, 47). The discharge vessel of the lighting unit can be manufactured comparatively easily and can have a comparatively compact construction.