DE2137760A1 - Bi Id display device made up of a number of luminescent elements - Google Patents

Description

Γ.-Jjjg ·. ΓΓπ755-ϊϋ «ίΓϊ4 ZeIIeT π 1 ο 77ΡΠ

f. Philips' Gloeilampsnfabriekeo
File No. PHIf- 5020
Registration dated: July 27, 1971

Image display device consisting of a number of luminescent Elements is constructed.

The invention relates to an image display device which is made up of a number of gas discharge tubes, which are closed on one side by a window and with a mixture aua mercury and at least one noble gas are filled while the wall of these tubes is covered with a luminous material and the length of each gas discharge tube is at least twice greater than the dimension perpendicular to the tube in question, where there is an Elaktroda on both sides of each gas discharge tube.

Such an image display device is suitable for Pernaebzwecke ₉ Zaichandarstallungp Z ₀ B ₀ Ziffarn ₉ letters uad bookmarks, füs alaktrischa Grössan and the like _o For diaaam purpose the Lauchtmatarial baatzutas Gasantladungsröh ^ chan des

The device is made to light up by applying a voltage across these tubes.

A design is possible in which all on one side of the Electrodes lying on the discharge tube are individually led to the outside so that the required voltage is supplied to each discharge tube separately. A design is also possible in which the electrodes lying on one side of the discharge tube onto a be connected in certain ways, what with a multitude of discharge tubes means a simplification. The electrodes on both sides of the discharge tube then form e.g. a grid of non-intersecting electrodes, with each electrode of one grid crossing all electrodes of the other grid. In particular, the electrodes of one grid and those of the other grid intersect perpendicularly.

A device of this type is known from US Pat. No. 3,334-269, in which the luminous material on the wall of a discharge tube is made to light up by ultraviolet radiation which is obtained when a voltage difference is applied between the discharge tubes belonging to the discharge tube a discharge electrode in a mixture of mercury and argon occurs "on the basis of the description in the patent specification mentioned, it can be assumed that the ultraviolet radiation is from a glow discharge of the gas discharge. Would eizaugt'warden in beschiiebenan in this Patantsohzift device positive pillars "so look left diaae in normal operation" temparatus venture of lifted ignition switch sohwsa "At a high Teiaparaiias: könnto the Sohaltvosgang light are performed ^ abas la ά®τ eswShaton PatsnissliEift Wisd pishts about

high operating temperature mentioned. This is an advantage of extraterrestrial use Presence of the luminous material on the wall of the discharge tube in column 4 »lines 45 - 49» only mentions that the generated Light is now perceived without the light passing through the phosphor layer is weakened, which 'weakening occurs, when this layer is present on the window} this also indicates does not indicate the presence of a positive column.

In the patent mentioned, the pail of a phosphor layer on the window and the case of a phosphor layer on the wall of the tubes are mentioned as almost equivalent alternatives. If the phosphor layer was present on the window ₉ and if the ultraviolet radiation came from a positive column _{9 it} would be due to the self-absorption of the ultraviolet radiation in the. positive column only a very small part of the ultraviolet radiation causes the phosphor layer on the window, which also indicates the absence of a positive column. Only a small part of the supplied energy is because in a glow discharge srzaugt comparatively little ultraviolet radiation wild _t converted into sieht- · bares light, so that the device has a niedrigan 'efficiency has ₉ which is, in Ainar low brightness Mus since "

The invention is based on dia knowledge ₉ that a arheblich bigger part is sugaführten energy converted into visible light when aina gsössare ultraviolet radiation producing takes place "This is in dex positive column of a suitably selected gas discharge is FAIL ₅ dia in a Gamisch aua Quecke silbes and at least one noble gas takes place ₉ whereby, in order to obtain a positive column, the longitudinal dss Entladungssöfoecbens at least twice as the dimension perpendicular to the relevant one

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Tube is while the gas pressure to the diameter of the discharge tube is adapted.

In getting a positive column, the difficulty arises a relatively high ignition voltage, which "at normal Operating temperature is required. According to the invention, a positive column is formed in the gas discharge tubes, while with the Gas discharge tube a device which reduces the ignition voltage is connected in series. This gate direction contains the gas discharge, which is in open connection with the gas discharge tube, so that diffusion of charge carriers from this device to the Gas discharge tubes can occur. The luminous material is on the wall of the gas discharge tube; thereby it is achieved that the self-absorption of ultraviolet radiation in the positive Column affects the amount of visible light received as little as possible.

The presence of the device for reducing the ignition voltage of the positive column in the gas discharge tube a device for displaying images with great brightness obtained from it sinzalrse elements can be switched on without that high voltages are required, on the one hand it is possible that for each gas inlet area an individual ignition voltage degrading direction is prevalent, while on the other hand it is it is possible that ®ina ainea Aaaab1 or all Gaa discharge tubes common dia ignition voltage hajcabsatzsnde device is available.

In the case of ainnainzalnen the ignition voltage of the positive column The lowering of the device for each gas discharge tube is then E.g. in series with every eistaa gas discharge tube there is a second Gaaentladuagsröhrchan arranged. The length of each of these second

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Gas discharge tube is at most equal to the dimension vertically to the "tube in question. To" both sides of these second gases "charge tubes there is an electrode, the first being Gas discharge tube and the associated second gas discharge tube may have an intermediate electrode common to them. Venn ignited the gas discharge in a second gas discharge tube is, waa with regard to the dimensions with a proportionate small voltage difference takes place, a glow discharge is obtained in connection with the dimensions. The presence this glow discharge has the consequence that in the associated first gas discharge tube at a relatively low level Voltage difference a positive column is obtained.

The mode of operation is now e.g. the following: The voltage difference over a given first gas discharge tube is lower than the ignition voltage, which would be required without further precautions would be, but higher than the ignition voltage that would occur in the presence of a the ignition voltage reducing device is required. If there is a glow discharge in the associated second gas discharge tube is ignited, charge carriers also diffuse the aem Tube into the first gas discharge tube in question, wherein as a result of the diffusion of charge carriers at this voltage difference, a gas discharge is ignited in this first gas discharge tube which is a positive column in relation to the dimensions of the tube and the gas pressure used. This takes place the actual switching process via the second gas discharge tube. Another way of working is that the voltage difference across a certain first gas discharge tube is lower than the ignition voltage, which is the ignition voltage in the presence of a

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degrading device is required. If a glow discharge is ignited in the corresponding second gas discharge tube, charge carriers thus diffuse to this first gas discharge tube; the voltage difference across this first gas discharge tube however, it is too low to ignite a discharge.

When the voltage difference is above this first gas discharge tube until the required ignition voltage is required, a gas discharge is ignited, which is related to the dimensions of the tube and the gas pressure used is a positive SSuIe. The actual switching process takes place via the first gas discharge tube. In particular, it is in series with every first gas discharge tube on the one facing away from the window Side a second gas discharge tube, the length of which is at most equal to the dimension perpendicular to this tube, with aich on both sides of every second gas discharge tubea an electrode is located. In particular, is located between the first gas discharge tube and the second gas discharge tube an electrode common to these two tubes.

In another embodiment, one for each gas discharge tube individual device reducing the ignition voltage of the positive column, this device is then e.g. inside the gas discharge tube appropriate. For this purpose it is at a short distance from the electrode that is not on the side of the window is located, an additional electrode is attached inside the gas discharge tube. The device reducing the ignition voltage will now by an electrode not on the side of the window, which additional electrode and the part of the gas discharge tube lying between these two electrodes. The distance

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between these two electrodes is at most equal to the dimension of the gas discharge tube perpendicular to the tube in question. When a gas discharge is ignited in the relevant part dea Gasentladungaröhrchens which _s is carried out in connection with dan dimensions at a relatively low Spannungsuntsrachied is related to the dimensions of a glow discharge in the batreffenden part dea gas discharge tube obtained The mode of operation is the mode of action described in the preceding paragraph analog. In particular, an additional electrode is now attached to each gas discharge tube, which is at a distance from the electrode ₉ which is not on the side of the window and which is at most equal to the dimensions of the gas discharge tube perpendicular to this tube.

In the two examples described above, it is possible, the electrodes located on one side of the two Entladungsröhrchan, or the additional electrode to be connected together in a particular manner, being ₀ B ₀ form a Gittsr from Aich non-cutting electrodes _β Ea are Z different designs possible, among other things depending on the way in which the switching process is carried out. In the case in which a second gas discharge tube is present and a first and a second gas discharge tube have an electrode in common with them, the grids 2U on the sides of the second gas discharge tube, if the switching process takes place via the second gas discharge tube, consist of non-cutting electrodes ₉ each electrode of its Gittsra crosses all electrodes of the other GittarsjinsbsaondeEe in a vertical direction. The grid on the other side of the first gas discharge tube is made up of electrodes that are not attached to each other.

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These electrodes are e.g. both sides of the second gas discharge tube parallel and are then perpendicular to the electrodes of the other of these grids. this means that the first gas discharge tubes are located between two grids, whereby either the electrodes of one grid are those of the other Cross grids perpendicularly, or the electrodes of one grid are parallel to those of the other grid. In the case where a a second gas discharge tube is present, and a first and a second gas discharge tube have one electrode in common, exist the grid lying on both sides of the first gas discharge tube when the switching process is carried out via the first gas discharge tube takes place, each from non-intersecting electrodes, each electrode of a grid all electrodes of the other grid - especially in the vertical direction - crosses. The grid on the other side of the second gas discharge tube consists of non-intersecting electrodes, e.g. to those of one of the grids on either side of the first gas discharge tube are parallel.

The same applies to cases in which in the discharge tube, in which a positive column is formed, an additional electrode is provided. To sequentially have a gas discharge in two To ignite discharge tubes, of which one of the electrodes belongs to the same wire of a grid, it is necessary to that a separate resistor is arranged in each of the parallel current paths, because otherwise it would be due to the voltage drop The second would not be possible via an effective gas discharge To ignite gas discharge. This is usually done by having all electrodes of a grid outside the actual panel

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be provided with a resistance. The resistance property can be built into the panel itself in other ways by all Electrodes of a grid are coated with a layer of a material of high resistance.

An embodiment in which for a number or for all Gas discharge tube a common device for reducing the ignition voltage is provided, is characterized in that it is ensured that during the operation of the playback device for this gas discharge tube at least during a certain Period a plasma is present. A plasma is to be understood as a mixture of charged gas particles, which in its entirety approximately is electrically neutral. This plasma, which is common to these gas discharge tubes, is generated between a cathode and an auxiliary anode. Different geometries are possible. The cathode and the auxiliary anode may be arranged such that the direction of the Cathode to the auxiliary anode is almost perpendicular to the direction of the gas discharge tube. According to another geometry is located the auxiliary anode is between the cathode and the gas discharge tube. The auxiliary anode does not need all the gas discharge tubes to be common to whom the cathode is common. The luminous material of a certain gas discharge tubea now lights up brought when the voltage difference across this gas discharge tube higher than the operating voltage, while the voltage difference over the gas discharge tube in question is lower than the ignition voltage, which is necessary without further precautions were. Because charge carriers diffuse from the plasma into the gas discharge tube, it is now in the gas discharge tube a sufficient Vorioniaation available to the

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To ignite the discharge in this tube whose luminous material is not made to light up must be, there is a tension lower than that Operating voltage is. In this case the device is switched on by regulating the gas discharge tube Voltage difference. In particular, there is therefore the ignition voltage Degrading device consisting of a cathode and an auxiliary anode, between which at least a part of the gas discharge tube common plasma is generated. Depending on the voltages used, the positive SSuIe between the electrodes becomes both Sides of a gas discharge tube or between the cathode of the plasma and the one on the other side of the gas discharge tube lying electrode generated.

When the electrodes are on each side of the gas discharge tube are connected to one another so that they form grids of non-intersecting electrodes, each electrode of a grid crosses them all Electrodes of the other grid, especially in the vertical direction. It is also possible to have a second gas discharge tube in alignment with each first gas discharge tube between this tube and the plasma to be arranged, on both sides of which an electrode is attached, the first gas discharge tube and the associated second gas discharge tube having a common intermediate between them Have electrode. The total voltage difference upper the first and the associated second gas discharge tube is now always higher than the operating voltage. The switching process does not take place by changing this total voltage difference, but by Change in the voltage of the intermediate electrode, i.e. by Change in the part of the voltage lower boil which is above the second

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Gas discharge tube occurs. This second gas discharge is before η then acts like a kind of valve. The plasma can only be used for the first Gas discharge tubes have an effect that reduces the ignition voltage in which the voltage difference across the associated second gas discharge tube is so great that charge carriers can penetrate into the first gas discharge tube. The result is that the switching process does not take place in the main current path. Preferably is in this case in series with between the gas discharge tubes and the device reducing the ignition voltage a second gas discharge tube for each first gas discharge tube arranged, with an electrode on both sides of every second gas discharge tube.

It should be noted that in U.S. Patent 2,595 * 617 a Image display device is described, which is constructed from a number of gas discharge tubes, the window of which is provided with a luminous material are covered, while a common compartment is provided is in which a reserve of ionized gas or ionized vapor which forms a kind of plasma. Although in this patent the terms "column" and "positive column" are used, it is evident from many passages of the cited patent that that the luminous material under the action of electron excitation is made to light up. For example, it is mentioned in column 12, lines 70, that electrical charges in each cell act locally on the luminous layer. Next is a modulation of the received Brightness by regulating the anode voltage (see column 4, lines 39-41) only possible with electron excitation. Also deliver the gases mentioned in column 3, lines 67 - 68 (mercury vapor, Water vapor and helium) at the low pressure mentioned

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very little ultraviolet radiation. Daa luminous material is located on the window; if ultraviolet radiation were generated, the self-absorption of the ultraviolet radiation in the positive column only a very small part of the ultraviolet radiation reaches the luminous material on the window.

In the device according to the invention, the luminous material is which is located on the wall of a gas discharge tube, decisive for the color of the emitted light. By application A color picture display device is obtained from materials which light up in different colors.

The brightness obtained is further increased if the wall of the gas discharge tube, on which the luminous material is present, has light-reflecting properties.

Some embodiments of the invention are in the drawing and are described in more detail below. Show it

1 shows a cross section through part of a display panel,

FIG. 2 partially in view of a development of the display panel according to FIG. 1,

3 shows in section another type of display panel,

Fig. 4 shows in section still another type of display panel and

5 shows, in section, a further embodiment of a display panel .

Fig. 1 shows a cross section through part of a display panel according to the invention. This panel is made up of a sheet of glass 1, made up of a first grid of parallel wires, one of which the figure shows a wire 2 made from a glass plate 3

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with opening at 4 »5» 6, 7 »8» 9 and 10, from a second grid parallel wires 11, 12, 13, 14, 15, 16 and 17, from a sheet of glass 18 with openings 19, 20, 21, 22, 23, 24 and 25, the right to escape to the openings in the plate 3, from a third grid of parallel wires, of which one wire 26 is shown in the figure is, and composed of a metal cover plate 27, which are connected to the plate 18 above an insulating intermediate part 28 is. The wires of the first grid are countersunk in grooves in the plate 1, while the wires of the second grid and the Wires of the third grid are sunk into grooves in the plate 18. The walls of the openings in the plate 3 are -layered coated with a fluorescent material. The openings in the plates 3 and 18 are filled with a mixture of mercury and at least one Noble gas filled out. The melted pump and filling opening is not shown in the figure.

Fig. 2 shows a development of the display panel, partly in elevation according to Fig. 1. The glass plate 1 is provided with vertical grooves 30, 31, 32, 33 and 34, in which wires 35, 36, 37, 38 and of the first grid. One of these wires corresponds to the wire shown in FIG. 1. The glass plate 3 is provided with openings which are in vertical columns and horizontal rows are arranged and of which a number, namely 40, 4I, 42, 43 »44» 45 »46, 47» 48 » and 50, is shown. The openings in one of the columns correspond a part of the openings 4, 5 »6, 7, 8, 9 and 10 in Fig.1. The glass plate 18 is on one side with horizontal grooves 51 »52, 53, 54 and 55, in which wires 56, 57, 58, 59 and 60 des second grid. These grooves correspond to part of the grooves shown in Fig. 1, which is also the case for these wires and part of the

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Wires 11, 12, 13, H, 15, 16 and 17 in Fig. 1 apply. On the the other side is the glass plate 18 with vertical grooves 61, 62 and 63, in which wires 64 »65 and 66 of the third grid lie. One of these wires corresponds to wire 26 in FIG. 1. An the intersection of the grooves 5 ^ t 52, 53 »54 and 55 on the one hand and 61, 62 and 63, on the other hand, are in the plate 18 openings 67, 68, 69, 70, 71, 72, 73, 74, 75, 76 and 77 attached. The openings in one of the columns correspond to part of the openings 19, 20, 21, 22, 23, 24 and 25 in FIG. 1. Furthermore, the metal cover plate is also shown in FIG 27 and the insulating intermediate part 28 are shown.

In a practical example, the openings in the plates 3 and 18 have a diameter of 1 mm; the length of the openings in the plate 3 is 5 mm and the length of the openings in the plate 18 is 0.5 mm. The openings are filled with a mixture of saturated mercury vapor and argon under a pressure of 7 ^{µm of} mercury column. 1 mm and a width of 0.1 mm. The openings in the plate 3 are coated with a reflective layer of titanium oxide, on which layer a layer consisting of calcium halophosphate is applied. Weisaea light is thus preserved. When this display panel is operated, a voltage difference of 350 V occurs between the wires of the first grid on the one hand and those of the second grid on the other. This voltage difference is not sufficient to ignite a positive column in the openings of the plate 3. If there is a voltage difference of 300 V between a certain wire of the second grid and a certain wire of the third grid, in

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the "relevant opening in the plate 18 due to the geometry the openings ignited a glow discharge. Then diffuse Charge carriers to the corresponding opening in the plate 3, which bring about a reduction in the ignition voltage, so that now with the mentioned Voltage difference of 350 V in the relevant opening a positive column is ignited in plate 3. The fluorescent substance brings the ultraviolet radiation generated in it Opening to light up. The switching process takes place in this case by regulating the voltage difference between the wires of the second grid on the one hand and those of the third grid on the other.

Fig. 3 shows in section another type of display panel. This panel is made of a glass plate 101, made of a first grid of vertical wires, one of which is a wire in the figure is shown, from a glass plate 103 with openings 104, I05, 106, 107, 108, 10? and 110, the end of which is covered with a phosphor layer 111 are coated, from a second grid of horizontal wires 112, II3, II4, 115, 116, "117 and 118, from a glass ring II9, through which a lead wire 120 for an auxiliary anode 121 and 'a Lead wire 122 for an auxiliary cathode 123 are guided, and further constructed from a metal closure plate 124. The wires of the first grid and those of the second grid are in grooves in the Plate 103 sunk. The panel is coated with a mixture of mercury and at least one noble gas filled out. The ignition voltage of the positive Column, which is to be formed in one or more of the openings in the plate, is reduced in this case by the plasma, which is formed at a certain voltage difference between the auxiliary cathode 123 and the auxiliary anode 121. The switchgear

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transition takes place by changing the voltage difference between the wires of the first grid on the one hand and those of the second grid on the other.

Fig. 4 shows in section still another type. Apart from that The same parts of the device reducing the ignition voltage are used as in FIG. 3, with the corresponding reference numerals are designated. The panel contains a glass ring 125 through which a lead wire 126 for an auxiliary anode 127 and lead wires 128 for an auxiliary cathode 129 are passed, and also a

^ metal locking plate 130 The ignition voltage of the positive column, which are formed in one or more of the openings in the plate 103 is to be reduced, is now reduced by the plasma, which at a certain voltage difference between the auxiliary cathode 129 and the auxiliary anode 127 is formed.

Fig. 5 shows in section yet another type of display panel. This panel is made of a glass plate 131, from a first grid of vertical wires, one of which is shown in the figure, made of a glass plate 133 with openings 134 "1" 35 " 136, 137, 138 »139 and 140, the ends of which are covered with a fluorescent layer I4I

W are coated from a second grid of vertical wires, of which a wire I42 is shown in the figure, from a glass plate 143 with openings 144, 145, I46, 147, 148, 149 and I50, which are aligned with the openings in the plate 133 lie, from a third grid of horizontal wires I5I, I52, 153, 154, 155, 156 and I57, from a glass ring 158 through which a lead wire 159 for an auxiliary anode and lead wires 161 for an auxiliary cathode 162 are passed, and further from a metal locking plate 163 built up. The wires of the first grid are countersunk in grooves in the plate 133,

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while the wires of the second and third grids are in grooves in the plate 143 are sunk. The panel is made with a mixture Mercury and at least one noble gas filled in. The ignition voltage of the positive column, which is in one or more of the openings in the Plate 133 is to be formed, is reduced in this case by the plasma, which at a certain voltage difference is formed between the auxiliary cathode 162 and the auxiliary anode 160. The reduction in the ignition voltage of the positive column results only for those openings in plate 133 where the The voltage difference across the associated openings in the plate is so great that charge carriers from the plasma pass through the opening in the plate 143 in the relevant opening in the plate can diffuse into it. The switching process takes place in this case by changing the voltage difference between the wires of the second grid on the one hand and those of the third grid on the other. The gas discharge tubes in the plate 143 act like a kind of valve.

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Claims (6)

- 18 - PHN.5O2O. PATENT PRESENTATIONS ι ft I · / image playback device consisting of a number of gas discharge tubes is thawed, which is closed on each side by a window and with a mixture of mercury and at least a Edelgaa are filled, with the wall of these tubes with a luminous material is coated during the length of each gas discharge tube is at least twice larger than the dimension perpendicular to the tube in question and extends on both sides Each gas discharge tube has an electrode, characterized in that there is a positive column in the gas discharge tube is formed, and that in series with the gas discharge tubes, a device reducing the ignition voltage is arranged. 2. Device according to claim 1, characterized in that in series with each first gas discharge tube on the of the window remote side a second gas discharge tube is arranged, the length of which is at most equal to the dimension perpendicular to the relevant Tube is, with an electrode on both sides of every second gas discharge tube. 3. Device according to claim 2, characterized in that there is between the first gas discharge tube and the second gas discharge tube an electrode is located that is common to the two tubes. 4. The device according to claim 1, characterized in that an additional electrode is attached in each gas discharge tube which is at a distance from the electrode not lying on the side of the window which is at most equal to the dimension perpendicular to the gas discharge tube in question. 2098 0 9/1082 - 19 - ΓΗΝ.5Ο2Ο. 5. "Device according to claim 1, characterized in that the the device reducing the ignition voltage consists of a cathode and an auxiliary anode, between which at least one part the gas discharge tube cfcen common plasma is generated. 6. Apparatus according to claim 5 »characterized in that between the gas discharge tube and the one that lowers the ignition voltage Performed in series with every first gas discharge tube a second gas discharge tube is arranged, where an electrode "on" both sides of every second gas discharge tube is located. ORIGINAL BATHROOM 209809/1082