Compact fluorescent lamp having a partitioned envelope, and method of

Abstract

The envelope of a single-ended fluorescent lamp is provided with an inserted partition assembly that forces the arc discharge to follow a tortuous path which is longer than the envelope, thus reducing the size of the lamp and providing a concentrated light source which is suited for use in lighting fixtures that are designed for incandescent type lamps. The inherent tendency of the arc to bypass the partition is overcome by seating the end of the partition assembly against a soft gasket of porous material (preferably fibrous in structure) that is located at the sealed end of the envelope and constitutes a barrier to the discharge which blocks the direct arc-path between the adjacent electrodes. The porous gasket is part of a diaphragm assembly and, since it is permeable to gases and vapors, it does not interfere with the evacuation of gaseous impurities and water vapor from the envelope when the lamp is being manufactured. Potential arc-leakage paths along the envelope-partition interface are sealed by a filling of phosphor deposited along such regions during lamp manufacture. The porous gasket preferably comprises a pad of felt-like inert material that extends completely across the interior of the envelope, or one which has a central opening and is of annular shape and held in place by a pair of suitable planar members--one of which is seated against a flanged end of the partition assembly. The envelope, partition, diaphragm and electrode components are assembled in a manner which prevents oxidation of the tungsten wire electrodes and also permits the organic binder, solvent constituent, etc. to be removed from the phosphor coatings without contaminating the electrodes.