Display panel having improved mercury assembly

Abstract

The panel comprises a gas-filled envelope formed by a base plate and a face plate hermetically sealed together by a ring of fusible sealing material. The interior of the envelope includes a display area which consists of glow cathodes and one or more anodes. Adjacent to the display area and near one end of the panel is provided a source of mercury which comprises a glass capillary tube containing a droplet of mercury. The mercury capillary tube is supported by a generally C-shaped insulating layer which is formed when the ring of fusible sealing material is formed, and of the same material. This C-shaped layer, like the sealing ring, is in contact with, and lies between, the base plate and face plate. The glass capillary is embedded at one end and at about its midpoint in this seal material, with the opposite end being free and unsupported. The free end of the capillary can be shattered by a laser to release mercury vapor into the panel envelope. The small spacing between the capillary and both the base plate and face plate prevents mercury droplets held inside the C-shaped layer from entering the display area of the panel, and, after the initial opening of the capillary, during which droplets might appear, no further droplets will leave the capillary, due to capillary adhesion, and only mercury vapor will be emitted.