Mercury capsule assembly for display panel

#At the present time, mercury vapor is provided in the gas atmosphere of all gas discharge display devices to minimize cathode sputtering. The mercury is introduced into such devices from a glass capsule held within the glass tubulation secured to the envelope. At a selected time in the manufacture of the panel, the glass capsule is shattered and mercury vapor enters the envelope through a hole therein. When such a mercury capsule is used with a flat display panel, the tubulation has to be specially shaped with a constricting portion to hold the mercury capsule in place. Such a tubulation is expensive.

#In addition, in manufacture of the panel, first, the tubulation is sealed off below the mercury capsule, and then, after the mercury has been released therefrom, that portion of the tubulation is removed. This is an undesirable extra step in the manufacturing process.

#In addition, with a glass capsule of this type, globules of mercury usually remain in the tubulation after the capsule has been opened, and some of this mercury can enter the panel through the hole in the envelope when the panel is handled, and such mercury can cause shorts inside the envelope.

#FIG. 1 is a schematic plan view of a display panel embodying the invention;

#FIG. 2 is a sectional view of a portion of the panel of FIG. 1 showing a mercury carrier embodying the invention; and

#FIG. 3 is a plan view of the carrier of FIG. 2.

#Apparatus embodying the invention is useful with substantially any type of device which is to contain mercury vapor and into which the mercury is introduced from a carrier in a glass tubulation secured to the device. For purposes of illustrating the invention, a display panel of the type known as a PANAPLEX panel is shown schematically in the drawings and is described in relatively general terms. Devices which may use the invention are described in greater detail in U.S. Pat. No. 3,868,535.

#Referring to the drawings and to FIGS. 1 and 2, a display panel 10 embodying the invention includes a base plate 20 of glass, ceramic, or the like, which carries a plurality of groups of cathode electrodes 30 in the form of segments, shown schematically, which are adapted to be energized in different combinations to display characters, as is well known in the art. The base plate also carries leads for the cathode electrodes and suitable insulating means as required; however, these are not shown, to simplify the drawings. The panel 10 also includes an anode electrode (not shown) for each group of cathode electrodes, and, in one arrangement, the anodes comprise thin films of tin oxide, formed on the lower surface of the face plate 50. The base plate and face plate are hermetically sealed together with a suitable gas-filled space between them to form the panel envelope. A glass tubulation 60, of well known shape, is secured to the base plate of the panel in alignment with a hole 70 in the base plate which communicates with the interior of the envelope.

#According to the invention, mercury is introduced into the panel 10 from a mercury carrier or capsule 80 known as a giver-getter. This capsule, shown in FIGS. 2 and 3, comprises a generally cup-shaped ring which carries, in the cup portion, a mercury amalgam 90 from which mercury vapor can be released by the application of heat. The carrier 80, which is relatively thin and has a diameter somewhat smaller than the largest diameter of the tubulation, is embedded in a mass 100 of fibrous insulating material, such as Fiberfrax, and the assembly is loosely mounted within the tubulation. Of course, this is done before the tubulation is secured to the lower surface of the base plate. Thus constructed and positioned, the metal mercury carrier 80 itself does not touch the glass wall of the tubulation, but is insulated therefrom by the Fiberfrax material.