NL8502734A - DISPLAY PANEL WITH A GAS DISCHARGE AND METHOD OF MANUFACTURING THIS. - Google Patents

Description

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Display pan.ee! with a gas discharge and method of manufacturing it.

The manufacture of a gas discharge display device has historically been accomplished with one by one type of operation. That is, separate gas substrates and / or ceramic substrates are provided on which the conductor tracks are pressed and then the dielectric masks are pressed over the conductor tracks and into the openings in the conductor tracks for the cathode electrodes, the cathode materials form an interface with the gas discharge medium pressed thereon and all this then baked and cured. Such "10" devices are then usually assembled using a gas filler tube, but in some cases devices are made without a tube where there is a final hermetic seal of two spaced apart substrates obtained using a non-15 molten sealing frame, evacuating the entire unit and refilling with an elevated temperature and then heating the assembled parts spaced between the electrode elements while holding the gas in the composition until the glass parts become soft are to a sealing temperature to result in a fusion sealing of the frame member and thereby to a final device assembly. This method is difficult and extensive and does not lend itself to a large production of individual display elements.

US Pat. No. 2,142,106 discloses a gas discharge display device with small glass plates carrying formed cathode elements and individual anode elements stacked as plates with the 8502 734 V i - 2 spacing between the plates sealed to the circumference to prevent electrode action on one another, leaving a small opening at one point in the circumference by not applying the sealing operation here and providing a connection to the main gas chamber formed by an overarching glass envelope or balloon. In U.S. Patent 2,142,106, the balloon is then deflated and refilled with the gas at an appropriate pressure with the suction and refilling treatments extending through and through the opening to the individual gas chambers formed in the spaced located plates in which the opening is then filled with a suitable sealing material through which the gas can penetrate during the suction and filling operation and wherein this separate sealing element or plug is then sealed by a heating element or an electronic bombardment or other sealing measure.

The invention provides a direct and marked improvement over the sealing technique in US Pat. No. 2,142,106, the invention taking over part of the technique from this US Patent and extending it to a process for manufacturing thousands of discrete discrete panel elements with gas discharge in a manner which has hitherto not been possible and with tolerance factors which are considerably greater than in the prior art. A glass rod that is practically free of leaves and generally formed according to the circumference of the gas chamber is melted on the two substrate surfaces in an air environment. There is a small gap or gap between the ends of the bar. Large numbers of the device can be stacked in trays with a small glass rod bridging the ends of the rod and held in place by the opposite substrate. The rod seal or plug is slightly smaller in diameter to fit snugly between opposing substrate surfaces with a melting temperature 8502734 * * - 3 - which is slightly below that of the formed rod.

Both materials, however, have an optical quality and edge surfaces that are practically bladder-free. This loose rod seal or stop allows simultaneous evacuation (also under firing conditions if desired) and refilling with any desired gas composition of large numbers of individual devices with a single operation.

In the prior art, when making sections of display panels with electrodes 10 and a gaseous discharge, in particular alphanumeric displays, the individual conductor paths are first printed and baked on the substrate, and then the mask and the cathode element electrodes, for example, wherein those elements which are in direct conductive contact with the gas are pressed and cured and wherein the cathode elements are pressed through the openings in the dielectric mask. According to the invention, instead of using a ceramic substrate, simple inexpensive glass substrates are used. The conductor elements that form the cathode electrodes that interface with the gas medium are first used and cured at relatively higher temperatures to ensure that those conductor segments or elements that form the cathodes of the device have a good hard surface to wrap around the gas interface minimize spraying issues and improve the discharge properties of such devices. In the sealing operation as described above, it has also been found that the use of screens on seal materials in an unmelted state is not as desirable as the use of a preformed bar element 30 made of glass with optical fiber properties, i.e., no blowing which deform and tear the seal when heated and / or evacuated.

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The typical and classic way to manufacture gaseous discharge devices is to bake the devices under vacuum to remove entrapped gaseous impurities from the interior surfaces of the device.

5 Baking under vacuum is a very time-consuming and expensive method.

According to another feature of the method of the invention, the several thousands of devices piled on trays are placed in a vacuum chamber.

The vacuum is brought over the device without heating to remove practically all free impurities from the individual gaseous discharge devices, then, at an ambient temperature, the gas fill is admitted to the processing chamber and thereby each individual gaseous discharge element is filled at chamber or ambient temperature. This ensures proper gas ratios and eliminates the need for accurate high temperature calibration of the gas fill. Then, after the gas fill has been introduced into the devices, they are heated by Calarod heaters within the chamber to effect the melting of small sealing elements into the openings as described above. This technique thereby avoids the long time between filling and heating the chamber, reducing a production path of thousands of devices in a single chamber to no more than 6 hours before pumping, heating and refilling with the gas and the like . Since this sealing process takes place at a pressure slightly below that of the environment and since the volume of the gas in the vacuum chamber may be greater than the cumulative gas volume contained in the devices, there is sufficient heating at a slightly negative pressure condition to ensure proper cleaning of the device under less than perfect vacuum condition and at significantly reduced costs and processing times. According to another feature of the 8502734 * 5 invention, small capsules containing mercury are activated by the use of a laser beam. To this end, the device is provided with windows that are transparent to laser beams in each of two glass substrates, allowing the use of a laser beam to effectively break the mercury capsule without damaging the device itself.

Finally, in the prior art, connections between the anode electrodes and external connections with operating voltages were made by means of small metal clamps between two substrates.

According to the invention, a conductive epoxy resin is introduced * between the clamp ends of the anode electrodes and the printed conductor ends on the cathode plate. According to the invention, this epoxy resin is carefully cured to ensure that bubbles do not come into contact with the anode elements which would tend to cause hot spots and break the anodic connections.

According to the invention, a large number of cathode substrate electrodes and mask constructions are printed and baked on a single glass plate, the electrodes being pressed and dried / cured at a higher temperature and then a mask applied and electrical cross-joints cured at lower temperatures. Upon completion of the manufacture of the electrode and the dielectric mask structures and the cross joints, the glass plate is simply notched and separated to form separate back side substrates and electrode mask structures which are then assembled together with a similarly shaped anode plate construction. Individual devices are then assembled together using a pre-formed sealing bar having a slit in the sealing structure and a mercury releasable capsule that can be actuated by a laser beam. In forming the devices, the gas is passed through the narrow slit left open in the seal construction, the slit being closed with a short sealing rod and why degassing and gas filling occurs during the final gas filling step. With this method, a large number of devices in a range of 1000-5000 can be manufactured in a relatively short time.

The invention will be elucidated on the basis of the drawing in the following.

Figure 1 shows a glass substrate on which is printed a first conductive pattern shown in its upper left corner, the dashed lines indicating the locations of a large number of other such patterns not shown in the figure.

Figure 2 shows the glass plate of figure 1 on which the first dielectric mask is printed (a black colored dielectric but indicated in white in figure 2).

Figure 3 is the plate shown in Figure 2 with the crossover guides printed on the mask of Figure 3 connecting the different elements shown, it being understood that the same printing has taken place with respect to the other substrate elements shown in Figure 3 .

In figure 4 a further dielectric printing is effected over the crossing elements of figure 3.

Figure 5 is an exploded view showing the order of assembling the various components in a device ready for filling and sealing operations in a multi-product process.

Figure 6 is a top view of a fully assembled device.

Figure 7 is an enlarged sectional view showing the placement of the sealing bar bridging the gap 8302 734 * * - 7 - to the now molten sealing frame.

Figure 8 shows the mercury capsule in place with a laser beam aimed thereon to destroy it.

Figure 9 shows a map of the working scheme 5 showing the individual printing and curing operations used in manufacturing the device.

Figure 1 shows a glass plate 10 which in a typical example can be only thick glass of 25 cm - 30 cm with individual cathode electrode patterns printed thereon 11 - 1/11 - 2, 11 - N and cathode period elements 12 - 1, 12 - N.

Each cathode pattern forms a digit position, the indicated embodiment being for a nine digit numerical display (n - 9). It will be noted that the invention applies equally to an alphanumeric segment format as well as a cross-point matrix representation. These elements have cathode electrode segments 13A, 13B, etc. which, in the embodiment of the invention, form the cathode electrode elements defining the glow discharge portions of the display. It will be noted that certainly of these cathode pieces such as 13A, for example, has a further direct conducting portion 14 - A which runs to a conductor strip 15 - A. An embodiment according to the invention are all corresponding segments 13 - A in all digit positions 11-1 , 11-2 ____ 11 - N, electrically interconnected, some of which are directly interconnected in the initial electrode printout shown in Figure 1. For example, the central rod piece 13 - C is indicated as a horizontal piece of electrode and through a conductor member 14 - C connected to a strip 15 - C.

Alternate strips are also being printed at this time for subsequent connection to the anode elements to be described later. Likewise, the cathode electrode 13 - B in the digit location 11-1 is connected to each cathode piece indicated by the number B by means of a conductor part 14 - B and thereby with a strip 15 - B.

However, in accordance with the indicated 65 27 2734 i * - 8 embodiment, some cathode segments are not directly connected to conductors extending to the individual strip elements 15. In the illustrated embodiment, a first dielectric mask element 16 shown in Figure 2 is printed across 5 conductor segments leaving gaps or passages such as 18-1, 18-2, 18 - N and 19 - 1, 2, 19 - N and 20 - 1.20 - N, 21 - 1, 21 - N and 22 - 1, through 22 - N, which are all aligned with underlying conductor parts or regions. These passages are simply openings or gaps 10 left in the dielectric mask or layer 16.

In addition to the passages or openings left open for crossover connections, which will be described later in connection with Figure 3, it will be noted that the individual cathode segments 13 - A, 13 - B etc. and their periods are 12 - 1 .. .. 12 - N, be left open. As previously described, no further conductive material is applied to these cathode elements because they are cured at a higher temperature thereby rapidly cooling and / or providing smooth surfaces for the discharge itself. However, the intersecting 20 passages 18-1 ... 18 - N, 19 - 1 - N, 20-1 ... 20 - N and 22 - 1 ... 22 - N are left open so that the geleter material is printed is able to make electrical contact with the conductor elements exposed by the passages in a manner as shown in Figure 4. These form the electrical crossover connections shown in the pattern of Figure 3. It will be noted that conductor patterns can be designed to eliminate or minimize the printing of such crossover passages. It will be appreciated that while the dielectric mask is shown as a bit it is a black mask for brightly illuminating the glow discharges in the cathode pieces and that the cathode material appears as white or silver colored and is basically silver in a suitable means of transport. Clear or translucent areas of glass are also shown in dotted lines. The anode glass substrate could be 8502 734 • * · t - 9 - naturally translucent.

In addition to the openings or passages to establish the crossover connections and in addition to the opening to allow the cathode pieces 5 to be sensed, a pair of windows 25A and 25B are provided in direct conductive contact with the gas so that the glass substrate 10 directly is visible through these openings 24 and 25.

These openings are for the purpose of which will be described in more detail below. * 10 In Figures 1 and 2, an unknown registration mark is indicated in which the registration marks are simply marks printed in dielectric material on the substrate 10 and each subsequent printing on the substrate 10 when dielectric material is printed to ensure registration thereof. Similarly, # further printing of the registration marks is made to ensure that correct registrations are obtained. The term printing is mainly used for stencil screen printing etc. but other forms of printing can be used.

As shown in Figure 3, the crossing connection of the road 19-1 to road 19 - N is indicated by the number 30, with the crossings connecting the roads 18-1 ... 18 - N being indicated by 31. Likewise, the crossover guides 32, 33 and 34 are guided prints on the dielectric. The printing operations are simply screening or otherwise applying the conductive material directly to the dielectric surfaces of the substrate with the conductive material entering the passages and making electrical contacts with the pre-printed conductor. It will also be noted that a few projections 36 and 37 are also printed on the conductor only for the purpose of establishing the crossover connections between the conductor elements as indicated.

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It will be noted that the conductive cathode pieces remain exposed for each of the digit positions, and these elements, in fact, continue to receive the temperature treatments (albeit at low temperatures) 5 to cure the dielectric layer 16 and the individual crossover layers, as indicated.

In a final printing operation, the final dielectric layer is applied over the crossover while maintaining windows 25a and 25B. The purpose of this final printing is, as is well known, to avoid any glowing of conductor regions or parts that are not desirable to glow.

In Figure 9, it should be noted that an important step in the method just described in the manufacture of the back substrate is that the electrodes constituting the cathode pieces for display are printed in an initial printing operation. This electrode is cured in step 5 as shown in Figure 9 at a much higher temperature than that which could be accomplished in the prior art for manufacturing devices having the features of the invention. In other words, by first pressing the cathode pieces and curing them at a much higher temperature to provide an improved cathode gas interface, the mask printed at a later time can be cured at lower temperatures without adversely affecting the conductive properties of the various conductor elements used in providing external connections for the device. As shown in Figure 9, the initial mask is printed in a two-step operation, first printing the mask for the first time, drying the mask and then curing the mask.

A second mask printing, drying and curing operation is then applied but it will be noted that it can be performed in a single step. In some cases, the mask can be manufactured 3502 734 5 *. 11 are like a film and transferred to a substrate. However, it is important to ensure that the mask has a sufficient thickness so that the slit adjacent the cathode pieces is separated by a physical boundary of dielectric material.

Thus, the second step is an important assurance that the dielectric between the ends of individual cathode sections is large enough to provide a limit that avoids or minimizes shorting between adjacent cathode sections.

The printing of the crossings is performed with the same conductive material as used in the first printing operation of conductive material and it will be noted that at least the conductive material is dried and then cured at higher temperatures. This material is a frit-based thick film paste mainly of silver. The third mask printing movement, although it could be limited to simple printing over the crossings, was in fact a full printing since this further ensures a sufficient boundary between the individual cathode pieces on the substrate. Thus, in order to additionally be able to press, dry and cure the cathode electrodes at sufficiently high temperatures (where a typical transport oven is about 15 meters long, 30 cm per minute, where there are about 15 heat zones with a maximum temperature of 100 ° C), to ensure a good, clean, smooth silver surface for the cathode electrode, pressing the cathode electrodes in a first printing step allows to build sufficient boundaries in the masked areas between the individual cathode pieces to allow the possibility of of conductive connections between the individual cathode elements due to spraying, etc., thereby increasing the operating life of the device.

As indicated in block 18 of Figure 9, the device is written along the dashed lines and separated to provide separate backside substrates indicated in Figure 5, as element 50. Element 50 is identical to 3502 734-12 - the various elements 50 which are shown in figure 4.

In Figure 5 now, the rear side substrate is indicated as element 50 identical to the rear side substrate shown in Figure 4. In Figure 5, an anode substrate 51 5 is also shown, with individual anode elements 52 - 1, 52 - 2, 52 - N printed thereon. wherein there is one such anode electrode for each digit position and adapted to overlie the individual cathode pieces and the cathode period element 12-1 at a given digit position. The anode conductors 10 are translucent tin oxides that have been printed and baked on a single thick glass substrate 53. It will be noted that the printing and baking of these conductors can be performed according to a raw material method very similar to printing the back substrate with the cathode elements.

The use of tin oxide as a translucent anode element is conventional in the art and will not be described in detail here except to say that the method of printing large numbers of devices on a thin glass substrate is useful for providing devices on 20 large scale.

The top substrate on the anode plate 51 is connected to the bottom substrate by means of a sealing member or member 55 formed so that its ends 56 and 57 are spaced from about 6 mm to about 1 mm. The sealing element 55 is simply placed on the black masked dielectric element and held in place by drying unmelted dielectric. At the same time, small spacer bars 58 and 59 at each end of the device are temporarily held in place in the same manner by gluing as by using unmelted dielectric.

The spacer bars 58 and 59 consist of a hard glass composition with a higher softening temperature that the sealing element 55. The sealing element 55 is made of a kind of optical fiber glass with no bubbles in it and which has a 8502 734-13 - melting or sealing temperature below the melting point of the glass substrate 10 and the spacer bars 58 and 59 (a sealing temperature of about 450 ° C is used). Additionally, a small mercury capsule 60 is held in place above the window 25A by a white unmelted dielectric having essentially the same composition as the dielectric forming the mask but containing no pigment. The object of using a white unmelted dielectric is that laser power used to break the capsule 60 is not absorbed by the black dielectric to form heat in the black dielectric thereby destroying the device. Also for this reason, a pair of windows 25A and 25B are provided.

After the sealing element 55 and the spacer bars 58 and 59 and the mercury capsule 60 have been placed in the device, the anode plate 51 is placed over these elements and placed on a weight. The entire device is passed through a heating furnace to melt or connect the sealing element 55 to the anode plate 51 and the back substrate plate 50. The resulting device is shown in Figure 6 and it will be noted that there is a narrow gap 65 so that the interior of the the gas chamber is accessible. A glass rod 66 with a diameter approximately the same as the spacer rods 58 and 59 is simply placed in the gap or cavity between the rear substrate plate 50 and the anode plate 51 and forms the glass stopper shown in block 23 in Figure 9. __

It will be noted that the spacer bar elements 58 and 59 need not be in the gas chamber as formed or in the locations indicated. They may be parallel to the horizontal tracks of the seal 55, parallel to all four tracks between display positions for larger displays (see U.S. Patent 3,499,167). And even externally the chamber and parallel to the 8502 734 \ - 14 - # »c, horizontal and / or vertical tracks of the sealing element 55.

In fact, the spacer element may have a circumferential pattern which is a twin of the sealing element 55 and only slightly larger or smaller. The only size criterion of the spacer element is that it determines the discharge gap and is of a glass type with a high melting temperature and a fiber softening point below that of the sealing element 55.

As shown in Figure 6, alternating contact strips 15 are connected to the cathode electrode 10 on the cathode plate 50 and the intermediate ones are connected by means of an extruded conductive silver epoxy connector 70-1, 70-2 as an improvement over the known state of the art with metal plug connections previously used for this purpose. It is important to cure the epoxy at a temperature such that no bubbles are formed. Bladders tend to form concentrations of streams in the oxidized tin coatings thereby damaging or destroying the compound therefor.

As shown in Figure 8, the mercury capsule 20 60 is a filamentous glass tube (with an outer diameter of 0.4 mm) which can transmit laser energy. It is arranged between a window 25A of the cathode plate 50 and a transparent portion of the anode plate 51 (which can also be referred to as a "window") and held in place for a composition 25 by a white dielectric. The aluminum or copper block serves as a heat sink and should not be very reflective for safety reasons. Instead of a glass capsule, it can be any other radiant energy driven device, such as a SAES type 150 capsule from the SAES-30 company from Italy.

• The gas fill can be a mixture of neon and argon such as 99.5% neon and 0.5% argon. As usual, radioactive crypton (crypton 85) can be added to the fill mixture to reduce the operating voltage. It will be noted, however, 8502 734 - that there are two unused contact strips 15 that could be used to operate a sustain discharge as is also common in the art.

In a preferred embodiment, the edges 75 and 76 on the plates 50 and 51 form a slot or notch to receive the sealing bar or the plug 60.

This allows simple mechanical holding of the spacer in its desired position during the degassing and gas filling operation. If desired, the upper horizontal path of the sealing element 55 may be located closer to the edge so that as the fabric softens, the sealing material of the element 55 will be flattened as shown in Figure 8 and the rod 60 is held in place by an adhesive. such as an unmelted dielectric. However, the sealing element 55 may be flattened in cross section and, as before, slightly thicker than the spacer bars. The panel is assembled with the sealing bar 66 in the notch or gap bridging the ends of the sealing element 55, the panels stacked in stainless trays with the port or spacing 65 up and the glass bar 66 in place. There is a high temperature glass slide (not shown) located between the bottom edge of the anode plate 51 to maintain proper relationship between the anode and the cathode plates when heating the sealing rod 66 is performed.

The sealing element 55 is a blow-free glass to avoid "worm-like" holes therein with a glass with an optical fiber such as Coming type 7570 glass 0.22 "OD rod and formed as shown in FIG. 5 which works satisfactorily and relatively low temperature of about 450 ° C. The glass stopper or rod 66, which is placed over the opening or port 65, has a fiber softening point that is below that of the sealing element 55, a similar glass with a fiber softening point that is 20 to 30 ° lower is satisfactory.

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The gas treatment in the evacuation of the system, the introduction of the correct gas at room temperature at the correct pressure of about 120 Torr, and heating the sealing rod so that it closes the enclosure with the desired gas condition. In the system described above, the cycle lasts 6 hours with 2000 devices per cycle. Each room can be large enough to handle 5000 devices. The cycle can be reduced to Ü hours. When the devices cannot be sealed, they are simply reprocessed. The gas from the system is recovered by running two chambers in parallel. After the sealed devices have been removed from the gas processing system, each is applied under a laser which is projected through a window into the device to break the capsule and release mercury from the casing. As is known in the art, some panel aging time can be performed to release the mercury.

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Claims (19)

1. A method of manufacturing a gas discharge information display panel wherein a pair of rigid plate elements define parallel planar interfaces of a gas discharge chamber between which interfaces to display information is generated by a number of discrete gas discharges between selectively energized electrodes, characterized in that a number of information display panels are manufactured simultaneously, all of which are sealed by applying a glass fusible element to one of the substrate elements in a pattern defining the lateral interfaces of the gas discharge chamber and of a port for evacuating and gas filling the chamber together with a spacer for determining the discharge gap, which spacer is fusible at a temperature higher than the melting temperature of the glass fusible element, the substrates being brought together with the necessary spacing to provide 15 sealable panel assemblies to shape? some of the sealable panel assemblies are placed in a common chamber for heating and vacuum treatment; all sealable panel assemblies in the common chamber are heated to a temperature sufficient to melt the fusible glass element and weld the assembled plate elements to one; the gas discharge chambers of all display panels in the chamber are successively evacuated and filled with gas through the ports; and then a molten stopper is applied to each of the ports to trap the gas in the panels. O 8502734 / M193-10-7-83 ___L. -18- _:::: =. = 2. *, Method according to claim 1, characterized in that the glass fusible element is a frit which is screen printed on the rigid plate elements. 3. Method according to claim 1, characterized in that the melted stopper is formed from a melted stopper element in the form of a glass rod. A method according to claim 3, characterized by the stopper wherein the sealable panel assemblies are stacked next to each other with the fixed glass stopper elements aligned with each other and pressure applied to the stack at least during the heating which the panel assemblies in the contiguous stack. 5. A method according to claim 1, characterized in that the application of the vacuum and the refilling with the gas filling takes place at a temperature which is approximately the operating temperature of the device. t θ 6. A method according to claim 3, characterized in that the filling gas has a pressure below atmospheric pressure and is introduced into the chamber containing the stacked panel devices for a sufficient time during the application of heat to melt the material. glass sealing element over the slit and to shut off the gas in the panel. 7. A method according to claim 3, characterized in that the stopper element is held in place prior to the application of heat by the facing surfaces of the rigid plate elements. A method according to claim 1, characterized in that the panel devices are stacked vertically with the gate for evacuation and filling facing upwards. A method according to claim 8, characterized in that one of the rigid bodies is shorter in the vertical direction than the other and in stacking a non-fusible holding member is in place to displace the shortest of the rigid elements obstruct. A method according to claim 1, characterized in that, a, u * - - £ - / 9 - in each of the bodies a laser energy transparent window is formed which windows face each other in the panel assembly, which a mercury donor is placed in the windows, and that after sealing the port for vacuum and filling, a burst of laser energy is directed through one of the windows to cause the release of mercury into the gas chamber. A method according to claim 10, characterized in that the mercury donor is contained in a glass capsule 10 which is transparent to laser energy. Method according to claim 1, characterized in that the gas discharge information display panel on one rigid substrate plate element comprises anode electrodes and on an opposite substrate plate element cathode electrodes, contact strips on one of the substrate elements, including contact strips integrally connected to the electrodes present thereon, the plate elements being connected by a sealing member which defines a gas discharge chamber with the plates, the plate with the contact strips 20 having an overhanging portion carrying the contact strips, and an electrically conductive and blow-free extrusion between the plates electrically connect the electrodes on the other substrate to at least one of the contact strips on the overhang after applying the molten glass stopper to the port for evacuation and filling. Method according to claim 12, characterized in that the electrically conductive, blow-free extrusion consists of silver incorporated in an expoxy carrier, which is extruded between the two plates on site of the selected contact strips. A method according to claim 12, characterized in that the cathode elements printed on the glass substrate lie in the plane of the substrate, a short distance between each of the elements, and wherein the printing of the dielectric on the substrate provides sufficient thickness to form a sputtering obstacle between the cathode elements having the short O 8502734 -JP spacing. 15. The method of followers of claim 1, characterized in that in coordination with the gas discharge panel there is provided a laser energy activatable generator with at least one laser energy transparent window in one of the substrate elements, wherein the laser energy activatable generator is physically disposed in the gas chamber behind the window, as well as means that hold the donor in place between the window and the opposite substrate and direct a laser beam through the window to activate the laser energizable giver. 16. A method according to claim 15, characterized in that the gas discharge display panel has a discharge gap between the 0.5 mm substrate beams, the donor being formed by a wire glass hollow tube element consisting of 15 for laser energy transfer glass and having an outer diameter less than about 0.05 mm and a selected length, t where the tubular elements are sealed at both ends and filled with elemental mercury, the length of the tubular and the cross-sectional area of a high portion thereof It has been chosen that the tube contains a predetermined amount of mercury in a liquid state. 17. Mercury capsule, characterized by a wire-shaped hollow tube element of glass consisting of a laser energy transparent glass with an outer diameter of less than about 0.5 mm and of a selected length, the tube element being sealed at both ends and filled with elemental mercury, wherein the length of the tube and the surface of the interior cross-section of the tube cavity are selected to contain a predetermined amount of mercury in a liquid state. 6> A method of introducing mercury into a flat gas discharge display panel without a filler tube but with a pair of laser energy transparent windows arranged in opposition to each other in the glass sheets forming the panel, the windows being outside the information display surface of the discharge device and 35 mercury energizer which can be activated by laser energy is placed in the discharge gas medium in the space between the windows transparent to the laser energy, characterized by the emission gas on the discharge gas, »OJ * 8502734 m" ~~ p "——— ... placing the outer surface of one of the windows of an electrically conductive block of metal, directing a beam of laser energy through the other window onto the laser energizable activator to release elemental mercury into the gas medium in the device. A method according to claim 18, characterized in that the electrically conductive block metal is made of aluminum and that the laser energy has a wavelength of about 1 micron. JEV / MR f