With respect to the arc tube array-type display of this type, those disclosed in Japanese Patent Application Laid-Open No. 2003-86141 and Japanese Patent Application Laid-Open No. 2003-86142 have been known. FIGS. 17 and 18 show these examples. FIG. 18, which is a partial cross-sectional view of FIG. 17, shows a state in which a display device is cut in a direction orthogonal to the length direction of the arc tube of a display device.
In this arc tube array-type display, a display panel is constituted by a number of arc tubes 1 (arc tube array) aligned in parallel with one another, which are sandwiched by a pair of flat-plate supporting members 31 and 32 made of glass, resin, or the like. Moreover, another structure has been known in which transparent film sheets are used as the supporting members. In the arc tube 1, a red phosphor layer R, a green phosphor layer G and a blue phosphor layer B are placed, with a discharge gas being sealed therein.
In the display device of this type, a discharge is generated inside the arc tube, and electrodes used for discharging are formed on arc tube array opposing faces of the supporting members, with the electrodes being made in contact with the surface of the arc tube.
With respect to these electrodes, normally, address electrodes (also referred to as data electrodes) A are arranged along each of arc tubes on the arc tube array opposing face of the supporting member 32 on the back surface side, and a number of paired display electrodes X and Y, used for face-discharging, are arranged on the arc tube array opposing face of the supporting member 31 on the front surface side (display surface side) in a direction intersecting the address electrodes A. Each of the display electrodes is formed by a transparent electrode 12 made of an ITO film or a SnO2 film or the like and a bus electrode 13 made of a metal film. Each of the address electrodes A is made of a metal film.
Upon conducting a display process, the Y electrodes of the paired display electrodes are used as electrodes for scanning, and a light-emitting area is selected by generating an address discharge at an intersecting portion between the Y electrode and the address electrode A. Next, by utilizing a wall charge formed on the tube inner face of the corresponding area by the address discharge, a display discharge (also referred to as a holding discharge or a sustain discharge) is generated at the paired electrodes X and Y so that the displaying process is carried out. Thus, as indicated by an arrow in FIG. 18, red light 33, green light 34 and blue light 35 are emitted from the arc tube 1. The address discharge is an opposing discharge generated inside the arc tube 1 between the Y electrode and the address electrode A that face each other with the arc tube 1 being sandwiched in between, and the display discharge is a face discharge generated inside the arc tube 1 between the two display electrodes X and Y that are placed on the plane in parallel with each other. With this electrode layout, a plurality of light-emitting areas (unit light-emitting area) are formed in the length direction of the arc tube.
In the arc tube array of this electrode layout, however, since the display discharge is prepared as a face discharge, a high discharging voltage is required. Moreover, the phosphor layer is formed on the back surface side of the inside of the arc tube, and since the area of the face discharge is apart from this phosphor layer, vacuum ultraviolet rays to be used for exciting are not sufficiently supplied to the phosphor layer. Moreover, since two display electrodes are placed at a single light-emitting area on the front surface side of the arc tube array, the light-shielding rate becomes greater, resulting in a low light-emitting efficiency.
Moreover, due to irregularities caused by deviations in the tube diameter of the arc tubes or the like, an insufficient adhesion between the display electrode and the arc tube tends to occur to cause deviations in the discharge starting voltage for each of the light-emitting areas, resulting in problems of a failure to ensure a large operational margin and the like.
Here, in the case of a PDP (Plasma Display Panel) of a type in which cells are formed by separating a discharge space formed between the pair of substrates using partition walls, which is different from the structure of the above-mentioned arc tube array-type display device, a PDP described in Japanese Patent Application Laid-Open No. 2000-331615 has been known as a patent relating to the present invention. This PDP has a structure in which display electrodes are arranged on a side face of each of partition walls.
The present invention has been devised in consideration of such circumstances, and scan electrodes and paired display discharging electrodes are installed in a separate manner so that the paired display discharging electrodes are installed on the side face of the arc tube to provide a four-electrode structure; thus, the discharging voltage can be reduced and the light-emitting efficiency can be improved.