KR100332312B1 - Fluorescent display tube wherein grid electrodes are formed on ribs contacting fluorescent segments,and process of manufacturing the display tube - Google Patents

Abstract

A substrate, a plurality of anodes formed on the substrate, a fluorescent layer formed on each anode thereof, a cathode located on top of the fluorescent layer generating electrons impinging the fluorescent layer, and at least a portion of a periphery of each of the anodes To this end, it is formed of an electrically insulating material on the substrate, and includes a rib having a higher height from the substrate than the fluorescent layer, and a grid electrode formed on each rib for controlling activation of the fluorescent layer.

Each rib consists of a plurality of layers laminated by screen printing using a paste.

Description

FLUORESCENT DISPLAY TUBE WHEREIN GRID ELECTRODES ARE FORMED ON RIBS CONTACTING FLUORESCENT SEGMENTS, AND PROCESS OF MANUFACTURING THE DISPLAY TUBE}

Background of the Invention

Field of invention

The present invention relates to a vacuum fluorescent display tube and a method of manufacturing the display tube. More specifically, the present invention relates to a rib or rib structure that supports the grid electrode of the display tube and surrounds the fluorescent fragment of the display tube, and a method of manufacturing the rib or rib structure.

Description of related technology

The well-known vacuum fluorescent display tube is selectively activated when a plurality of anodes disposed on a substrate are each covered by a fluorescent layer, and the fluorescent layer collides with electrons generated or liberated from a cathode disposed on the anode, That is, configured to emit light or glow discharge. The fluorescent layer emits light in the cathode direction when impinged by electrons from the cathode, and the image provided by the activated fluorescent layer is visualized from the cathode toward the fluorescent layer (anode). This type of fluorescent display tube can provide a clear image at a relatively low voltage for electron acceleration. In addition, different phosphors used in phosphor layers that emit light of different wavelengths allow color display of the image. Due to these advantages, fluorescent display tubes are widely used as display devices in acoustic devices and instrument panels of automobiles.

In the fluorescent display tube of the type described above, a mesh grid is disposed between the anode and the cathode to control the glow or activation of the fluorescent layer or fragment formed on the anode at different locations on the display screen.

When a constant voltage (acceleration voltage) is applied to a given grid, electrons generated from the cathode are accelerated by the grid and collide with the fluorescent layer just below this grid. However, electrons reaching the grid to which a negative voltage (cutoff bias) is applied will be shielded by the grid, and the fluorescent layer directly below the grid will not glow.

The mesh grid has a suitable spacing between the anode array and the grid and is supported by appropriate legs on the substrate such that each grid extends across an array of anodes consisting of a predetermined number of anodes. The strength of the grid decreases with the increase of the grid area including the anode array, and if the grid is relatively large, the grid is susceptible to thermal deformation. Thermal deformation can be a problem such as reduced luminance and short circuit in the fluorescent layer. In addition, the grid having a mesh structure inevitably blocks a part of the light emitted from the fluorescent layer, so that the luminance of the fluorescent layer is reduced by the grease.

Another disadvantage caused by using the mesh structure is the anode array density, that is, the density of display elements per unit area of the display screen.

More specifically, some of the electrons accelerated by the grid to which the acceleration voltage is applied may leak and collide a portion of the fluorescent layer directly under the adjacent grid to which the negative voltage cutoff bias is applied. In this case, the fluorescent layer which does not need to be glowed can be glowed due to the leaked electrons. In order to avoid such false activation of the fluorescent layer, adjacent arrays of anodes (adjacent arrays of the fluorescent layer) covered with each mesh grid should be spaced apart from each other by a relatively large distance, such as at least 2 mm. This separation prevents the display elements (array of fluorescent layers) from being arranged at high density.

As another type of fluorescent display tube, it is proposed that a planar grid made of an electrically conductive material is formed on the substrate to surround each fluorescent layer. An example of this type of fluorescent display tube is that disclosed in JP-A-3-52945. In the fluorescent display tube disclosed in this publication, as shown in the cross-sectional view of FIG. 10, an anode 122 is formed on a glass substrate 120 in an appropriate pattern, and a fluorescent layer 123 is formed on each anode 122. FIG. Planar grids 121a and 121b are formed on and surround the anode 122.

Such display tubes that do not use a mesh grid do not suffer from the problems caused by the use of the mesh grid, that is, the disadvantages of thermal deformation of the mesh grid, and the reduced luminance of the fluorescent layer due to the shading of the mesh grid.

However, the fluorescent display tube of FIG. 10 has a significant disadvantage. That is, the anode 122 has a fluorescent layer 123 over a distance indicated by " 0 " in FIG. 10 so that the underside of the anode 122 ensures the intended activity of the fluorescent layer 123 over the entire area including the periphery. Have a perimeter of the dummies located outside of the perimeter. In addition, a fairly large space P must be left between them so as to prevent a short circuit between the anode 122 and the grid electrodes 121a and 121b.

The distance "0" and the space "P" necessarily result in a relatively large distance between adjacent fluorescent layers 123 or a relatively large space between adjacent display elements or fragments. Accordingly, the fluorescent display tube of FIG. 10 has the same problem as the known display tube using the mesh grid.

The conventional fluorescent display tube of FIG. 10 also has a disadvantage resulting from a substantially coplanar relationship between the planar grids 121a and 121b and the fluorescent layer 123, which apply the respective acceleration and bias voltages (positive and negative voltages). This inevitably leads to a reduction in the acceleration and shielding effect of the electrons generated from the cathode. This requires static driving of the grid 121. Although dynamic driving or strobing of the grid 121 is possible, a relatively high bias voltage is required for shielding electrons, requiring a high voltage line.

In view of the above disadvantages, a fluorescent display in which an electrically insulating rib is formed on the substrate so as to surround each fluorescent layer and the grid electrode is formed on the top surface of the rib so that the grid electrode is spaced apart from the upper surface of the fluorescent layer in a direction perpendicular to the substrate plane. The tube is being proposed. As an example of such a display tube, JP-A-62-290050 is disclosed. According to this display tube, the function of the grid electrode for accelerating and shielding electrons is relatively improved even when the display elements are arranged at a relatively large density.

In order to form ribs, grid electrodes and fluorescent layers in the above-described display tube, an electrically insulating and conductive layer, which becomes ribs and grid electrodes, is first laminated on a substrate, and an etching mask formed of resist is used on these insulating and conductive layers. Dry etching operation is performed. Selected portions of the insulating and conductive layers not covered with the resist mask are removed by dry etching, while other portions covered with the mask are left, leaving rib and grid electrodes corresponding to the coating of the layer. The rib and substrate then cooperate to form a recess in which the fluorescent layer is formed. To form the fluorescent layer, the recess is filled with a suitable filler having a solid phase at room temperature (eg 1,3,5 trioxane C ₃ H ₆ O ₃ ).

Filler masses filling the recesses are covered with respective fluorescent layers comprising a photosensitive resin (UV-curable resin). The filler mass is then heated to the liquid phase so that the fluorescent layer sinks through the liquid to the bottom of the recess. Subsequently, the filler mass is further heated to the gas phase, leaving only the fluorescent layer (substrate anode layer on the substrate) surrounded by the ribs in the recess. The fluorescent layer is then baked to be exposed to ultraviolet radiation to cure the photosensitive resin and adhered to the substrate (anode layer).

In the above-described manufacturing method of the display tube, an etching mask is disposed on the electrically conductive layer for the grid electrode, and dry etching using glass bead blast is performed through the mask, so that the electrically insulating layer and the conductive layer are not covered with the mask. Remove part of it. Thus, recesses are formed in the stacked conductive and insulating layers. However, the dry etching method using glass bead blasting cannot make the aspect ratio (width / depth) of the recess larger than two. This means that it is difficult to arrange the grid electrode at a sufficiently large level with respect to the fluorescent layer formed in the anode layer on the substrate.

Thus, the space between the grid electrode and the fluorescent layer is not sufficient to allow the grid electrode to accelerate and shield electrons with high stability. Moreover, glass bead blasts tend to damage the anode layer in the final stages of etching resulting in degradation of the anode.

Summary of the Invention

It is therefore a first object of the present invention to provide a fluorescent display tube in which the rib has a sufficient height and the anode can function normally.

It is a second object of the present invention to provide a method of manufacturing a fluorescent display tube which forms a rib having a sufficient height without damaging the anode.

In order to achieve the first object according to the first aspect of the present invention, there is provided a method comprising: (a) a substrate; (b) a plurality of anodes formed on the substrate and with a fluorescent layer formed on each anode; (c) a cathode disposed on the fluorescent layer to generate electrons impinging on the fluorescent layer; (d) using an insulator paste formed of an electrically insulating material on the substrate so as to surround at least a portion of the periphery of each of the anodes, the height from the substrate being greater than the fluorescent layer, each comprising an electrically insulating material; A rib composed of a plurality of layers laminated by screen printing; (e) There is provided a fluorescent display tube having grid electrodes formed on each rib to control activation of the fluorescent layer.

In the fluorescent display tube configured as described above, the ribs are formed of an electrically insulating material on the substrate such that the ribs surround at least a portion of each of the periphery of the anode so that the height from the substrate of each rib is larger than the fluorescent layer. A grid electrode is formed on the top surface of the rib. Further, each rib is a laminated structure composed of a plurality of layers laminated by screen printing using an insulator paste containing an electrical insulating material.

Each layer of rib is generally laminated in turn using an insulator paste containing a solvent and a colorant used to control the viscosity of the insulator paste. When each new rib layer is formed by screen printing on a previously printed layer, the colorants and solvents contained in the insulator paste forming the new rib layer are efficiently absorbed in the entire layer or the lower layer, thus forming a new layer to form a new layer. Hanging or flowing of the applied insulator paste is prevented. Thus, the ribs can be screen printed in the desired shape and dimensions even where the recesses or open spaces are defined by ribs having a relatively large aspect ratio. The anode is also not damaged during the formation of the ribs by screen printing.

According to a first aspect advantageous to the invention, the upper surface of each anode cooperates with the side of the corresponding rib to define a recess or open space.

This recess is filled with a corresponding fluorescent layer formed by screen printing using a fluorescent paste containing a fluorescent substance. The viscous fluid-type fluorescent paste flows into the recess so that the corresponding fluorescent layer is held in contact with the side of the corresponding rib, and the fluorescent paste mass fills the recess without gaps or gaps on the side of the rib. Therefore, the space between adjacent display elements or fragments including each fluorescent layer is reduced, thereby increasing the density of the display elements per unit area of the display screen. Further, the formation of each fluorescent layer by filling the recess with a fluorescent paste facilitates the processing of the display element and reduces the overall manufacturing cost of the display tube. In addition, the flow of fluorescent paste into the recess allows a relatively large tolerance of alignment accuracy of the fluorescent layer to the ribs. This means that some misalignment of the screen printing pattern or plate for the fluorescent layer and ribs is absorbed or controlled by the flow of fluorescent paste from the ribs to the recesses defined therein. Therefore, the screen printing pattern can be easily positioned without requiring high accuracy, thereby facilitating the process of manufacturing the display tube, and thus increasing the yield of the display tube as a final product.

Each rib may be formed to surround the entire periphery of the corresponding anode and fluorescent layer. This arrangement is desirable to protect the fluorescent layer against the influence of grid electrodes provided on adjacent ribs, i.e. to avoid erroneous activation of the fluorescent layer due to leakage electrons accelerated by the adjacent grid electrodes. Therefore, this arrangement can reduce the space between adjacent display elements, which increases the density of the display elements.

Alternatively, the ribs can be formed to surround a portion of the periphery of the anode and the fluorescent layer. This arrangement is also effective to protect the fluorescent layer against the influence of the grid electrode on adjacent ribs.

According to a second advantageous aspect of the invention, the grid electrode is spaced apart from the fluorescent layer by a distance of at least 20 μm in the direction from the substrate toward the cathode. This arrangement allows the grid electrode to properly accelerate or shield electrons at the cathode upon application of constant voltage acceleration and negative voltage cutoff bias, respectively.

According to a third advantageous aspect of the invention the grid electrode has a thickness of 5 to 100 μm. In this case, the grid electrode has an electrical resistance small enough to ensure acceleration and shielding of the electrons. In addition, since the conductor paste used for the grid electrode will not stretch or flow significantly when applied to the rib by screen printing, otherwise a short circuit between the possible grid electrode and the fluorescent layer can be effectively avoided.

According to a fourth advantageous aspect of the present invention, the rib is composed of a plurality of rib structures of a lattice structure spaced apart from each other in a direction parallel to the substrate plane. Each rib structure defines a plurality of rows of square regions each of which is formed by screen printing so that each fluorescent layer is held in contact with each side of each of the rib structures defining each rectangular region. In this case, the grid electrode is composed of a plurality of grid electrode structures of a lattice structure respectively formed on the top surface of the rib structure. This arrangement provides a dot-matrix fluorescent display tube in which the fluorescent layer or fragments are arranged at a high density.

In operation, the phosphor layer is selectively activated to emit light, forming a desired image in the dot matrix, while adjacent anodes are sequentially applied to the voltage line in a time-division manner in a direction parallel to the strobe, ie, the short side of the rectangular display screen. Is optionally connected.

Strobing along the short side of such a display screen is advantageous over strobing along the long side of the screen of a conventional display tube. That is, strobeing along the short side of the screen side increases the duty cycle of the strobe pulses, which in turn increases the luminance of the fluorescent layer. Also, since the dimension of the short side of the rectangular screen is not limited as in a conventional display tube using a mesh grid susceptible to thermal deformation, the overall size or area of the display screen can be significantly increased.

According to a fifth advantageous aspect of the invention, the ribs consist of a plurality of parallel ribs arranged on the substrate and spaced apart at equal intervals, and grid electrodes are formed in each of the upper cross sections of the parallel ribs. In this case, the fluorescent layer is formed by screen printing and arranged in a plurality of parallel rows each arranged between corresponding parallel rib pairs. Each intra-row fluorescent layer is held in contact with opposite sides of the corresponding parallel rib pair. This arrangement also provides a dot-matrix fluorescent display tube in which the fluorescent layer or fragments are arranged at a high density. In operation, the phosphor layer is selectively activated to emit light to form the desired image in the dot matrix while adjacent anodes are sequentially strobe in a direction parallel to the short side of the rectangular display screen. This arrangement therefore has the advantages described above, namely the increased brightness of the fluorescent layer and the increased overall size of the display screen.

According to a second aspect of the present invention there is provided a method of manufacturing a fluorescent display tube constructed in accordance with the first aspect of the present invention as defined above, in order to achieve a second object, which method comprises: Forming a plurality of rib layers by repeating the screen printing operation using the insulator paste and the drying operation after the screen printing operation a predetermined number of times corresponding to the plurality of rib layers so as to be retained; (ii) forming the fluorescent layer by screen printing using a fluorescent paste comprising the fluorescent material such that the fluorescent layer is held in contact with the side of the rib; (iii) forming a grid electrode on the top surface of the rib by screen printing using a conductor paste containing an electrically conductive material.

This manufacturing method has advantages as described above with respect to the display tube itself. In other words, when each new rib layer is formed by screen printing on a previously printed layer, the colorants and solvents contained in the new layer of insulator paste are efficiently absorbed into the entire layer or the lower layer, thus forming a newly applied layer. Slack or flow of the insulator paste is prevented. Therefore, the screen printed rib has the desired shape and dimensions even when the recess or open space defined by the rib has a relatively large aspect ratio. This manufacturing method is also suitable for manufacturing display tubes without damaging the anode during formation of ribs by screen printing.

According to a first advantageous feature of the invention, the step of forming a plurality of rib layers is performed after the anode is formed on the substrate by applying an insulator paste in contact with the anode. This configuration allows the degree of misalignment between the anode and the ribs by making the size of the anode slightly larger than the ribs. This means that the relative positioning of the anode and the rib is relatively easy.

According to a second advantageous feature of the invention, the step of forming the plurality of rib layers comprises the steps of: forming at least one of the plurality of layers before the fluorescent layer forming step is performed, and a predetermined height after the fluorescent layer forming step is executed. Forming another layer of the plurality of rib layer to form a rib having a. In this case, the step of forming the fluorescent layer includes filling the recess defined by at least one of the plurality of rib layers with the insulator paste such that the insulator paste mass contacts the surface of at least one of the plurality of rib layers defining the recess. It consists of

According to this feature, since the fluorescent paste in the form of a viscous fluid flows into the recess, the lump of fluorescent paste fills the recess without any gap or gap with respect to the side of the rib.

Thus, the space between adjacent display elements or fragments including each fluorescent layer is reduced, resulting in an increase in the density of display elements per unit area of the display screen. The flow of fluorescent paste into the recess also allows a relatively large tolerance of the alignment accuracy of the fluorescent layer to the ribs. This means that some misalignment of the screen printing pattern or plate for the fluorescent layer and ribs can be absorbed or received by the flow of mold and paste from the ribs into the recesses defined therein. Therefore, the screen printing pattern can be easily positioned without requiring high precision.

According to an advantageous third feature of the invention, the step of forming the plurality of rib layers comprises forming at least one layer using an insulator paste after the fluorescent layer is formed, while the step of forming the grid electrode comprises at least one rib layer. Forming a grid electrode. Since at least one rib layer is formed after the fluorescent layer is formed, the grid electrodes formed on the ribs are spaced apart from the fluorescent layer by a sufficient distance to electrically insulate the grid electrode and the fluorescent layer from each other to a sufficient degree. In addition, this feature effectively prevents the phosphors from remaining on the surface of the grid electrode, thus avoiding the possibility of otherwise glowing of the phosphor on the grid electrode.

The method further includes simultaneously heating the plurality of rib layers, the fluorescent layer, and the grid electrode. This simultaneous heating step increases the manufacturing efficiency of the display tube.

The ribs may be formed to be spaced apart from the fluorescent layer by a distance of at least 20 μm in the cathode direction from the substrate. This feature allows the grid electrode to properly accelerate and shield electrons from the cathode upon application of constant voltage acceleration and negative voltage cutoff bias, respectively.

The grid electrode may be formed to a thickness of 5 to 100㎛. In this case, the grid electrode has an electrical resistance small enough to ensure the acceleration and shielding of the electrons, and the conductor paste applied to the ribs to form the grid electrode will not stretch or flow significantly, so otherwise possible grid electrode and fluorescent layer between The short circuit of can be effectively avoided.

The invention can be further understood by the following description of the preferred embodiments in conjunction with the accompanying drawings.

Detailed description of the preferred embodiment

1 through 3, there is shown a fluorescent display tube comprising a substrate 1 formed of a suitable glass, ceramic or other electrically insulating material or composite. An insulating layer 2 is formed on the opposite main surface of the substrate 1, and the insulating layer 2 has a thickness thinner than the thickness of the substrate 1 and a through hole penetrating the thickness. As shown in FIG. 3, the wiring conductor pattern 3 is formed on the upper surface of the substrate 1, and more specifically, is formed between the substrate 1 and the insulating layer 2. As shown in FIG. The wiring conductor pattern 3 is partially accommodated in the through hole formed through the insulating layer 2 and in contact with each graphite layer 4 partially received in the corresponding through hole, whereby the wiring conductor pattern 3 Is electrically connected to the graphite layer 4 to lead the wiring pin 13.

The graphite layer 4 is formed by printing in a fixed pattern using a thick film forming paste whose main component is graphite. The paste applied by printing in a predetermined pattern is heated into the graphite layer 4 serving as an anode of the fluorescent display tube.

The pattern defined collectively by the graphite layer or anode 4 is a 7-segment digital letter pattern in the form of the number " 8 " and 7 as shown in the upper right part of FIG. Corresponds to a display element such as a seven-segment analog bar pattern consisting of two parallel bars. Digital character patterns are used for digital display (digits or numbers "0" to "9"), while analog bar patterns are used for physical quantities of analog display. One anode 4 corresponds to one segment of each display element, such as a digital character pattern or an analog bar pattern.

As shown in FIG. 3, the graphite layer 4 is covered by the ribs 6 formed on the insulating layer 2 and covered by the fluorescent layer 5 on the top. The rib 6 is made of an insulating material such as a glass material having a relatively low melting point, and the height of the rib 6 having a height from the insulating layer 2 is sufficiently higher than the upper surface of the fluorescent layer 5. It is formed to be the top. Each rib 6 has a wall thickness of about 50 μm (as shown in the horizontal direction in FIG. 3). The grid electrode 7 is formed on the upper surface of the rib 6 by thick film printing in the same pattern as the rib 6. The grid electrode 7 has a height or thickness of 5 to 100 μm (as shown in the vertical direction in FIG. 3), so that the top surface of each grid electrode 7 is in the upper direction in FIG. It is spaced apart from the upper surface of the appropriate fluorescent layer 5 by an interval of 100 to 150 mu m in the direction toward the cathode 12 shown in FIG. In this arrangement, the grid electrode 7 is electrically insulated from the fluorescent layer 5.

The grid electrode 7 is electrically connected to the pad 11, and the lead wiring pin 13 is connected to the pad 11 through a grid wiring pattern 8 formed by thick film printing on the insulating layer 2. . Each grid electrode 7 for a 7-segment digital character pattern is connected to a corresponding lead wiring pin 13 in one of the lead wires 13 and each grid electrode 7 for a 7-segment analog bar pattern. Is connected to the corresponding lead wiring pin 13.

As is apparent from FIG. 3, each graphite layer or anode 4 and the corresponding fluorescent layer 5 formed thereon are formed such that their peripheral surface is kept in full contact with the side surface of the rib 6. Thus, there is substantially no gap between the fluorescent layer 5 and the corresponding grid electrode 7 in the direction parallel to the plane of the substrate 1, and electrically insulating between the fluorescent layer 5 and the grid electrode 7. Is maintained.

The cathode 12, which is in the form of an electric wire or filament, is directly heated. The wire cathode 12 extends and is supported between a pair of cathode support frames 14 formed on the substrate 1 so as to be located on top of the graphite layer or anode 4. The various elements on the upper surface of the substrate are installed as described above, covered by the lid glass 15, and the internal space defined by the substrate 1 and the glass 15 is sealed by a sealing glass having a low melting point. The fluid is completely sealed and emptied, thereby providing a vacuum fluorescent display tube.

In the operation of the present fluorescent display tube configured as described above, for example, an acceleration voltage of 40 V is applied between the cathode 12 and the selected grid electrode 7 and is also applied between the cathode 12 and the selected anode 4. While the direct heated cathode 12 is heated. As a result hot electrons generated and emitted from the direct heated cathode 12 are accelerated and collide with the fluorescent layer 5 corresponding to the excited anode 4, where the collided fluorescent layer 5 emits light. However, no light is emitted from the fluorescent layer 5 surrounded by the grid electrode 7 to which the cut-off bias voltage of various voltages up to about 10V, for example, the 0V voltage of the cathode 12 is applied. Also no light is emitted from the fluorescent layer 5 covering the anode 4 to which the indicated acceleration voltage is not applied. When the fluorescent display tube is a dynamic drive type, the lead wiring pins 13 connected to the grid electrodes 7 through the grid wiring pattern 8 are sequentially and selectively connected to the acceleration voltage in a time division manner at a predetermined frequency, On the other hand, the lead wiring pin 13 connected to the corresponding fluorescent layer 5 and the anode 4 through the wiring conductor pattern 3 is selectively connected to the acceleration voltage line, and at the same time, the grid electrode 7 is sequentially connected to the acceleration voltage line. By being connected to, predetermined characters such as characters, symbols and graphic representations are displayed by selective excitation of the fluorescent layer 4 (fluorescent segment).

In order to confirm the performance of this fluorescent display tube, the analog display element in the analog bar pattern shown in the upper right of FIG. 2 is tested. These display elements can be used as equalizer displays on acoustic devices. In FIG. 2, upper and lower analog display elements are denoted by U and L, respectively.

The upper and lower display elements U and L are spaced apart from each other by a B interval of 500 μm.

In the test, an acceleration voltage of +20 V was applied to the grid electrode of the upper element U, and a bias voltage of -5 V was applied to the grid electrode 7 of the lower element L. On the other hand, a positive voltage was applied to the anode 4 of all the analog display elements U and L.

In a dark room where no light is seen at all, the visual inspection of such a display device undesirably emits light from the upper segment of the lower display device L adjacent to the upper display device U. FIG. For comparison, a conventional fluorescent display tube using stainless steel mesh grid (thickness: 50 mu m opening ratio: 80%) was tested under the same conditions as the present display tube. In the absence of such a mesh grid, the excited fluorescent segment 5 in the present display tube had a more definite peripheral profile and showed a 12% increase in light intensity over that in a conventional display tube.

Next, referring to the flowchart of FIG. 4 and the schematic views of FIGS. 5A to 5E, a method of manufacturing the fluorescent display tube of FIGS. 1 to 3 will be described. First, the anode plate 20 is prepared as shown in FIG. 5A. The anode plate 20 is formed of a substrate 1, a wiring conductor pattern 3 (not shown in FIG. 5A), and an insulating layer 2 and graphite, which are formed by a thick film printing technique on the substrate 1 in that order. Layer 4. In step P1 of the process shown in FIG. 4, a paste made of an insulating material on the anode plate 20 is applied by thick film printing using a screen printing machine so that the applied paste surrounds the graphite layer 4, thereby lowering the green. Alternatively, the non-heated rib layer 22 is formed as shown in FIG. 5B. This lower green rib layer 22 makes the lower part of the rib 6 when the green rib layer 22 is later heated. Thereafter, the lower green rib layer 22 formed of the insulating paste applied by screen printing is dried until the rib layer 22 is solidified. The insulator paste for the lower green rib layer 22 may be a mixture of inorganic frit, a colorant and an organic solvent such as glass or pigment having a low melting point. Colorants and organic solvents are used to adjust the viscosity of the insulation to promote thick film printing. Lower green rib layer 22 has a thickness of about 30 to 50㎛ after drying. In step P1, printing and drying are repeated two or more times to obtain a dried lower green rib layer 22 of a predetermined thickness formed by overlapping two or more layers or films.

In the following description, the term "thickness" is to be interpreted as meaning the dimension measured in the direction perpendicular to the plane of the substrate 1, otherwise it will be described.

In step P2 of the process of FIG. 4, the main component is a paste made of phosphor so that the applied paste fills the recess defined by the upper surface of the graphite layer 4 and the lower green rib layer 22 surrounding it. Is applied to the graphite layer 4 by thick film printing using a screen printing machine, whereby the green fluorescent layer 24 is formed as shown in FIG. 5C. This green fluorescent layer 24 then produces a fluorescent layer 5 when heated.

This green fluorescent layer 24 made of fluorescent paste is dried until solidified. The fluorescent paste for the green fluorescent layer 24 may be a mixture of well known fluorescent materials such as zinc oxide, a colorant, and an organic solvent used to adjust the viscosity of the paste. The green fluorescent layer 24 has a thickness of about 35 μm after drying.

In step P3 of the process of FIG. 4, the same insulator paste as used in step P1 is applied to the lower green rib layer 22 by thick film printing using the same screen printing machine as used in step P1. In this way, the upper green rib layer 26 is formed as shown in FIG. 5D. This upper green rib layer 26 forms the upper part of the rib 6 when the green rib layer 26 is later heated. The upper green rib layer 26 is then dried until solidified. The upper green rib layer 26 has a thickness of about 70 to 150 mu m after drying.

Printing and drying in step P3 may be repeated two or more times to obtain a dried thick upper green rib layer 26 of predetermined thickness consisting of two or more overlapping layers or films.

In step P4, the green grid electrode layer 28 is formed as shown in FIG. 5E by applying a conductor paste to the upper green rib layer 26 of the rib 6 by thick film printing using a screen printing machine. . This green grid electrode layer 28, when subsequently heated, provides a grid electrode 7. The green grid electrode layer 28 is then dried until it solidifies. The conductor paste may be a mixture of an electrically conductive material such as silver, copper, aluminum, nickel and graphite, an inorganic frit such as glass having a relatively low melting point, and a colorant and an organic solvent used to control the thick film printing ability of the paste. . The conductive material is used in the form of a powder in which the particles are bonded to each other at relatively low temperatures. The green grid electrode layer 28 has a thickness of approximately 10 to 150 mu m after drying. In step P4, printing and drying are repeated two or more times to obtain a dry green grid electrode layer 28 of a desired thickness.

The green layer for the grid interconnection pattern 8 is then an anode on which the lower green rib layer 22, the green fluorescent layer 24, the upper green rib layer 26, and the green grid electrode layer 28 are formed. The screen is printed on the plate 20 and dried. Subsequently, step P5 of FIG. 4 is performed to heat the lamella or laminated green structure on the anode plate 20 at a temperature of about 500 to 600 ° C. so that the lower and upper green rib layers 22, 24 provide ribs 6. The green phosphor layer 24 provides the phosphor layer 5, and the green grid electrode layer 28 provides the grid electrode 7. Accordingly, the substrate 1 is provided with a fluorescent electrode 5 surrounded by the ribs 6 and the grid electrode 7 formed on the ribs 6, so that the periphery of each fluorescent layer 5 has the inner wall surface of the ribs 6. It is in close contact with you.

In the present embodiment of the present invention, the precursor of the rib 6 forms a stack of lower and upper green or non-heated rib layers 22, 26 formed by repeating screen printing and drying operations as described above. Therefore, the ribs 6 can be formed easily and economically. As described above, the insulator paste used to form the green or unheated rib layers 22 and 26 includes a solvent and a colorant used to control the viscosity of the paste. When the upper green rib layer 26 is formed by screen printing on the lower green rib layer 22, the colorant and the solvent contained in the insulator paste forming the upper green rib layer 26 into the lower green rib layer 22. Effective absorption prevents sagging or flow of the newly applied insulator paste forming the upper green rib layer 26.

Therefore, even when the recess defined in the range by the rib 6, that is, the open space has a relatively large aspect ratio, the rib 6 can be screen printed in a desired shape and dimension.

The same is true even if layer 22 and / or layer 26 consist of a film formed of two or more overlapping layers or insulator pastes. The anode 4 is also not damaged while forming the ribs by screen printing.

In this embodiment, the upper end of the rib 6 is spaced apart from the upper surface of the fluorescent layer 5 in the insulator layer 2 toward the fluorescent layer 5 by an appropriate distance. It is made to be formed on the insulator layer 2 so as to surround the graphite layer or the anode 4 and the fluorescent layer 5.

And the grid electrode 7 is provided on the upper surface of the rib 6 so that the grid electrode 7 may be spaced apart from the fluorescent layer 5 in a direction toward the cathode 12 located thereon.

This arrangement causes the electrons generated from the cathode 12 to be accelerated when a positive acceleration voltage is applied, and blocks electrons when a negative bias low pressure is applied. In addition, according to the present arrangement, it is possible to arrange the display elements with a significantly reduced space between adjacent elements while activating the display elements by mistake, ie applying a voltage, thereby increasing the integration degree of the display elements arranged on the substrate 1. It can be greatly improved. Moreover, since a relatively low cutoff bias voltage is required to shield the electrons, the total voltage required for the fluorescent tube is reduced accordingly.

According to the process shown in FIGS. 4 and 5, the fluorescent layer 5 is screen printed on the anode (graphite layer) such that the periphery of each fluorescent layer 5 contacts the edge surface of the surrounding rib 6. Is formed by. In other words, the green fluorescent layer 24 made of a fluid having a viscosity in the form of fluorescent paste for the fluorescent layer 5 has an edge surface and an anode surface of the lower green rib layer 22 providing the lower portion of the rib 6. Is formed to fill a recess defined by the top surface. By this method, it is possible to make the fluorescent layer 5 contact with the ribs 6 without any gap or gap, and to reduce the space between adjacent display elements each consisting of two or more fluorescent layers or fragments. The degree of integration increases.

Further, each rib 6 surrounds the corresponding graphite layer or the entire periphery of the anode 4 and the fluorescent layer 5 so that the adjacent fluorescent layer 5 is protected from the adverse effects of the adjacent grid electrodes 7. That is, the fluorescent layer 5 of one display element is not activated by being influenced or erroneously influenced by electrons escaping from the grid electrode 7 of the surrounding, or neighboring, display element. In this regard, the degree of integration of the display elements on the display tube can also be increased.

In the present fluorescent display tube, the grid electrode 7 has a height of 100 to 150 탆 when measured from the upper surface of the fluorescent layer 4. That is, the upper surface of the grid electrode 7 is separated from the upper surface of the fluorescent layer 5 by a distance of 100 to 150 탆 in the direction of the cathode 12. This arrangement ensures stable acceleration of the electrons coming from the cathode 12 upon application of a positive acceleration voltage and stable blocking of the pendulum upon application of a negative bias voltage.

The grid electrode 7 is selected to a thickness in the range of 5 to 100 μm. If the thickness is smaller than 5 mu m, the grid electrode 7 has a considerably high electrical resistance value, and the function of the grid electrode 7 for blocking electrons is insufficient. If the thickness is larger than 100 mu m, sagging of the conductor paste occurs when the precursor in the form of the green grid electrode layer 28 is formed by printing. The grid electrode 7 having a thickness selected from 5 to 100 μm has a sufficiently low electrical resistance value to allow acceleration and shielding of intended electrons, and shortening of the fluorescent layer 5 due to sagging of the conductor paste during printing. Is prevented.

According to a process comprising steps P1 and P3 of forming the precursor of the lead 6 and step P2 of forming the precursor of the fluorescent layer 5, the ribs are formed on the insulating layer 2 of the substrate 1. It is formed so as to surround each graphite layer, that is, the anode 4, and green fluorescence by printing using a fluorescent paste to fill a recess defined by the surface of each anode 4 and the edge surface of the corresponding rib 6. By forming the layer 24, the fluorescent layer 5 is formed in contact with the inner wall surface of the rib 6. In the screen printing process, the fluorescent type phosphorescent paste is poured into the recess, so that the green fluorescent layer 24 has the entire periphery and lower green ribs of the layer 24 even though the printing pattern is somewhat misplaced with respect to the substrate. The recesses can be filled with no gaps between the edge surfaces of the layer 22. Thus, the fluorescent layer 5 can be formed without any gaps or gaps adjacent to the ribs 6.

In the steps P1 and P3 of the present embodiment, the drying process is performed after the printing process, and the screen printing and the drying process are repeated as many times as desired to form the lower and upper green rib layers 22 and 26. This repeated printing and drying process is more effective in avoiding sagging of the insulator paste than in the case of one drying after one printing to obtain the desired thickness, because the insulator paste is dried every time the printing process is performed. to be. According to this process, the ribs 6 can be formed to have a fairly small wall thickness when measured in a direction parallel to the plane of the substrate 1.

In addition, since the lower and upper green ribs 22, 26 are formed in steps P1 and P3 to surround the graphite layer, i.e., the anode 4, an anode 4 having a size slightly larger than a normal size is formed. The use of the screen printing pattern can avoid remaining gaps or gaps between the ribs 6 and the anode 4, even if the screen printing patterns of the anode 4 and the green rib layers 22, 26 are somewhat offset or misaligned with each other. It should be noted that

That is, the ribs only overlap the periphery of the anode 4 due to the misalignment of the printing pattern.

This means that the tolerance of the alignment precision of the printing pattern of the anode 4 and the rib 6 is relatively large.

It should also be noted that step P2 of forming the precursor of the fluorescent layer 5 is followed by step P1 of forming the lower green rib layer 22, and then step P3 of forming the upper green rib layer 26 is continued. In other words, the green fluorescent layer 24 is formed before the precursor of the rib 6 is formed to have a final thickness. That is, after the green fluorescent layer 24 is formed, the upper green rib layer 26 is formed on the lower green rib layer 22 already formed. This process is useful because it can avoid problems that may occur when the printing plate or pattern of the green fluorescent layer 24 is offset from the printing pattern of the lower green rib layer 22. More specifically, although a portion of the fluorescent paste in the form of a viscous solvent initially applied in step P2 is located on the lower green rib layer 22 already formed due to misalignment of the printing pattern, the viscous solvent in the viscosity is present. Some of the mass may flow into the recess defined in the lower green rib layer 22 due to the fluidity of the mass, and a portion of the solvent mass still remaining on the lower green rib layer 22 may be formed in the upper green rib layer formed in step P3. 26) is covered by. Therefore, this arrangement increases the tolerance range of the alignment accuracy of the fluorescent layer 4 and the rib 6, thereby increasing the yield of the display tube as a final product.

In addition, the green grid electrode layer 28 is formed on the upper green rib layer 26 formed after the green fluorescent layer 24 is formed to facilitate electrical insulation of the grid electrode 7 from the fluorescent layer 5. .

Step P5 comprises several green layers, namely, lower and upper green rib layers 22 and 26 formed in steps P1 and P3; A green fluorescent layer 24 formed in step P2; It should also be noted that it is executed to simultaneously heat the green grid electrode layer 28 formed in step P4.

Thus, the laminated green structure composed of such green layers 22, 24, 26, and 28 is simultaneously heated to a heated composite laminated structure composed of ribs 6, fluorescent layers 5, and grid electrodes 7.

6 to 9 show another embodiment of the present invention.

The reference numerals used in the foregoing embodiments are intended to point to functionally identical elements in this modified embodiment and duplicate descriptions of these elements are avoided for the sake of brevity of expression.

6A and 6B show a plurality of parallel ribs 6 formed on the insulating layer 2 on the substrate 1 such that the plurality of parallel ribs 6 are spaced at equal intervals from each other in the longitudinal direction of the rectangular display screen. One example of a dot-matrix fluorescent display tube is shown. That is, parallel ribs 6 extend in the horizontal direction of the display screen, that is, in a direction parallel to the short side of the rectangular screen. On the top surface of the parallel ribs 6, individual grid electrodes 7 in parallel strip shape are formed. The display tube also includes a wiring conductor pattern 3 formed between the substrate 1 and the insulating layer 2. The wiring conductor pattern 3 includes conductors spaced apart at equal intervals from each other in the horizontal direction of the display screen, that is, in a direction parallel to the parallel ribs 6. The conductor of the pattern 3 extends in the longitudinal direction of the display screen, ie parallel to the long axis of the rectangular screen. The display tube also includes a plurality of graphite layers, ie, anodes 4 arranged in parallel rows between adjacent pairs of parallel ribs 6. The anodes 4 in each row are spaced at equal intervals from each other along a direction parallel to the ribs 6. This anode 4 is electrically connected to the individual conductors of the wiring conductor pattern 3 through individual connectors extending through the through holes formed through the insulating layer 2. The display tube is also formed by screen printing and includes a plurality of fluorescent layers 5 each arranged in a plurality of parallel rows positioned between adjacent parallel ribs 6. The fluorescent layers 5 in each column are spaced apart at equal intervals in the direction parallel to the ribs 6 and cover the individual anodes 4 in the corresponding rows. The fluorescent layer 5 is in contact with opposite sides of the adjacent ribs 6.

In the operation of the display tubes of FIGS. 6A and 6B, a pair of adjacent grid electrodes 7 are selectively connected to the acceleration voltage lines, while the conductors of the conductor pattern 3 are sequentially connected to the acceleration voltage lines in a time division manner. Connected. Located between adjacent grid electrodes 7 currently connected to the accelerating voltage line, the fluorescent layer 5 connected to the voltage line via a conductor pattern is excited to provide an image in the form of a dot matrix. This fluorescent layer 5 corresponds to the dot matrix of the display screen, that is, the image element.

In the second embodiment of the present application, the ribs 6 also have a height higher than that of the fluorescent layer 5, with the result that the grid electrode 7 is located above the fluorescent layer 5. In addition, since the fluorescent layer 5 is formed on each anode, that is, the graphite layer 4 so that both ends thereof are in contact with the side of the adjacent rib 6, this arrangement is also on the other side of the adjacent rib 6 in question. The influence of electrons used to excite the desired fluorescent layer 5 located between adjacent ribs 6 on the adjacent adjacent fluorescent layer 5 can be minimized. Therefore, it is possible to prevent or minimize the leakage of the electrons 5 due to a mistake and excitation of the fluorescent layer, and the degree of integration of the display element per unit area of the substrate 1 may be further increased.

In the dot matrix fluorescent display tube of the present application in which the fluorescent layer 5 is disposed at a high density, a desired image is displayed by selectively exciting the fluorescent layer 5 or applying a voltage, and the anode 4 is a wiring conductor pattern. Through (3) it is continuously connected to the acceleration voltage line. In other words, the display tube of the present application has an anode (A) in the direction in which the fluorescent layer 5 is parallel to the short side of the rectangular display screen, compared to a conventional display tube in which the grid electrode is strobe in a direction parallel to the long side of the rectangular display screen. It is excited by strobing (dynamic drive) 4).

Strobing in a direction parallel to the short side of the screen increases the duty cycle of the strobe pulses strobing the anode 4, so that the light emission of the fluorescent layer 5 is increased accordingly. Further, in the display tube of the present application which does not use the conventional mesh grid, the dimension of the short side of the display screen can be relatively large because the dimension of the short side is not limited by the thermal deformation of the mesh grid. Thus, the display screen has a relatively large overall size or area.

7A and 7B show another type of dot-matrix fluorescent display tube.

In this embodiment, a plurality of rib structures 6 made of a lattice structure are formed on the insulating layer 2 on the substrate 1 so that the rib structures 6 are parallel and spaced apart from each other.

Each rib structure 6 defines two rows of rectangular layers, ie, a rectangular region in which an anode 4 and a fluorescent layer 5 are each formed in sets. A plurality of grid electrode structures 7 are formed on each rib structure 6 so that the top surface of the rib structure 6 is covered with each grid electrode structure 7. For example, the regions defined by the rib structure 6 each consist of a plurality of sets of four rectangular regions, each set consisting of two rectangular regions in one of the two rows and two rectangular regions in the remaining columns. . Each of the four rectangular regions in each set corresponds to one dot in a dot matrix.

The anode 4 in a set of four rectangular regions allows the wiring conductor pattern 3 to be connected so that the four anodes 4 in one set of four rectangular regions are connected to the anodes 4 in the corresponding four rectangular regions of the other set. Through the anode 4 in the remaining set. In this embodiment, the conductors of the wiring conductor pattern 3 connected to the anode 4 are respectively connected to the acceleration voltage lines, while the grid electrode structure 7 is sequentially connected to the acceleration voltage lines. The fluorescent layer 5 formed on the anode 4 which is located in the rectangular region in the grid electrode structure 7 currently connected to the acceleration voltage line and connected to the voltage line is excited to provide an image in the form of a dot matrix.

In the third embodiment of the present application, the rib structure 6 also has a higher height than the fluorescent layer 5, with the result that the grid electrode structure 7 is positioned on the fluorescent layer 5 and the fluorescent layer 5 is used for screen printing. Thereby being formed on the anode 4 and in contact with the wall surface of the rib structure 6. Accordingly, as in the previous embodiment, the present embodiment prevents or minimizes the fluorescent layer 5 from being accidentally excited due to the leakage of electrons, and guarantees an increase in the degree of integration of the display device. Like the second embodiment of FIGS. 6A and 6B, this embodiment ensures that the emission of the fluorescent layer 5 is increased due to the increased duty cycle of the strobe pulse, and thus the dimension of the short side of the display screen is increased. Thus increasing the area of the screen.

Variations of the third embodiment of FIGS. 7A and 7B are shown in FIGS. 8A, 8B and 8C.

In this fourth embodiment, each set of rectangular dot regions in each rib structure 6 is divided into four rectangular subdot regions. More specifically, each rib structure 6 in FIGS. 7A and 7B has an auxiliary cross separator, and each grid electrode structure 7 formed on each rib structure 6 has a corresponding auxiliary cross grid ( 9), the grid divides each of the rectangular dot areas in FIGS. 7A and 7B into four sub-dot areas as well shown in FIG. 8C. These four sub-dot areas collectively define one dot in a dot matrix. In each sub dot area, an anode 4 and a fluorescent layer 5 are provided. The fluorescent layers 5 in the four subdot regions are electrically connected to each other. This arrangement is more effective in preventing the fluorescent layer 5 from being excited by electron leakage by mistake even if the size of the dot is large.

9 is a variation of the embodiment of FIGS. 8A-8C. In the embodiment of Fig. 9, each electrode structure 7 has an auxiliary grid 10 instead of the auxiliary cross grid 9 provided in the embodiments of Figs. 8A to 8C. Each auxiliary grid 10 substantially takes the form of a straight strip that divides each rectangular dot into two subdot areas.

Although the present invention has been described by way of preferred embodiments, it will be appreciated that the details of the described embodiments are not limited and may be implemented differently.

In the described embodiment, the graphite layer or anode 4 is formed before the ribs or rib structure precursors 22 and 26 are formed. However, the lower green rib layer 22 is first formed on the insulating layer 2, and then the precursor of the anode 4 is formed by the lower green rib layer 22 before the precursor of the fluorescent layer 5 is formed. The range can be formed within the defined area.

In the described embodiment, the top surface of the grid electrode 7 has a height of 100 to 150 μm when measured on the top surface of the fluorescent layer 5. However, if the height of the grid electrode 7 from the fluorescent layer 5 is at least 20 μm, the grid electrode 7 accelerates electrons from the cathode 12 when applying an acceleration and bias voltage to the electrode 5. And shielding function.

In the embodiment of FIGS. 1 to 3, a grid wiring pattern 8 is formed on the insulating layer 2.

However, the grid wiring pattern 8 can be formed on the upper surface of the substrate 1 similarly to the wiring conductor pattern 3.

In the described embodiment, the green fluorescent layer 24 is formed in step P2 after the lower green rib layer 22 is formed and before the upper green rib layer 26 is formed. However, after the green fluorescent layer 24 is formed first, the precursor of the rib 6 can be formed by repeating the screen printing and drying operations.

It will be understood that various changes, modifications and improvements can be made by those skilled in the art without departing from the spirit and scope of the invention as defined in the claims that follow.

1 is a partial cutaway perspective view of a fluorescent display tube constructed in accordance with an embodiment of the present invention;

FIG. 2 is a partial plan view of the upper portion of the substrate of the display tube of FIG. 1 showing a display element provided on the substrate;

3 is a front view of a cross section taken along line 3-3 of FIG. 2,

4 is a flowchart illustrating a part of the manufacturing method of the fluorescent display tube of FIGS.

5A-5E are partial schematic diagrams illustrating various green or unfired layers formed by the manufacturing method of FIG.

5A shows an anode plate with such a layer formed,

FIG. 5B shows the lower green rib layer formed in step P1 of FIG. 4,

FIG. 5C shows the green fluorescent layer formed in step P2 of FIG. 4,

FIG. 5D shows the upper green rib layer formed in step P3 of FIG. 4,

FIG. 5E shows the green grid electrode layer formed in step P4 of FIG. 4,

6A is a partial plan view showing a fluorescent display tube according to another embodiment of the present invention in the form of a dot-matrix display;

6B is a partial perspective view of the display tube of FIG. 6A,

7A is a partial plan view showing another form of dot-matrix display according to a further embodiment of the present invention,

FIG. 7B is a partial perspective view of the dot-matrix display of FIG. 7A,

8A is a partial plan view of a dot-matrix display according to a further embodiment of the present invention in which each dot area is divided into four sub-dots by cross separation of an auxiliary grid,

FIG. 8B is a partial perspective view of the dot-matrix display of FIG. 8A,

8C is an enlarged view of a dot region divided by cross separation,

9 is a view corresponding to the dot-matrix of FIG. 7C showing a further embodiment of the present invention;

10 is a front view partially showing a cross section of a conventional fluorescent tube having a planar grid electrode.

Claims (5)

Forming at least one of the plurality of layers constituting each rib by screen printing using an insulator paste comprising an electrically insulating material; A recess defined by at least one of the plurality of layers of each rib is filled with a fluorescent paste, and a surface of at least one of the plurality of layers of each rib in which the mass of fluorescent paste partially defines the recess Forming a fluorescence by screen printing using a fluorescent paste comprising a fluorescent material to be in contact with the substrate; Forming another rib having a predetermined height from an upper surface of the fluorescent layer by forming another one of the plurality of layers of each rib on at least one of the plurality of layers by screen printing using the insulator paste. step; And Forming a grid electrode on the top surface of the rib by screen printing using a conductive paste comprising an electrically insulating material, Forming the grid electrode is performed so as to have a thickness of 5 to 100 μm on the grid electrode, (a) a substrate, (b) a plurality of anodes formed on the substrate, (c) a fluorescent layer formed on each of the anodes, and (d) a cathode located above the fluorescent layer that generates electrons impinging upon the fluorescent layer (e) ribs formed on the electrically insulating material on the substrate, the ribs having a higher height from the substrate than the fluorescent layer, and (f) grid electrodes formed on each rib to control activation of the fluorescent layer. Method of manufacturing a fluorescent display tube comprising a. The method of claim 1, further comprising simultaneously heating the plurality of layers constituting each of the ribs, the fluorescent layer, and the grid electrode. The method of claim 1, wherein forming another one of the plurality of layers of each rib is performed such that the rib is spaced apart from the fluorescent layer at a distance of at least 20 μm from the substrate in the direction of the cathode. Way. Forming at least one of the plurality of layers constituting each rib by screen printing using an insulator paste comprising an electrically insulating material; A recess defined by at least one of the plurality of layers of each love is filled with a fluorescent paste, and a surface of at least one of the plurality of layers of each rib in which the mass of the fluorescent paste partially defines the recess Forming a fluorescent layer by screen printing using a fluorescent paste comprising a fluorescent material to be in contact with the substrate; Forming another rib having a predetermined height from an upper surface of the fluorescent layer by forming another one of the plurality of layers of each rib on at least one of the plurality of layers by screen printing using the insulator paste mold. step; And Forming a grid electrode on the top surface of the rib by screen printing using a conductive paste comprising an electrically insulating material, Forming at least one of the plurality of layers constituting each of the ribs and forming another one of the plurality of layers, each of the ribs surrounding the entire periphery of a corresponding one of the anodes, A plurality of rib structures of a lattice structure, wherein the rib structures are spaced apart from each other, and each of the rib structures is in contact with a side surface of each of the rib structures defining each of the fluorescent layers, each of which defines a rectangular region. Each of which is executed to define a plurality of rows of square regions formed by screen printing; The forming of the grid electrode is characterized in that the grid electrode is performed to be composed of a plurality of grid electrode structures of the grid structure, respectively formed on the top surface of the rib structure, (a) a substrate, (b) a plurality of anodes formed on the substrate, (c) a fluorescent layer formed on each of the anodes, and (d) a cathode located above the fluorescent layer that generates electrons impinging upon the fluorescent layer (e) ribs formed on the electrically insulating material on the substrate, the ribs having a higher height from the substrate than the fluorescent layer, and (f) grid electrodes formed on each rib to control activation of the fluorescent layer. Method of manufacturing a fluorescent display tube comprising a. Forming at least one of the plurality of layers constituting each rib by screen printing using an insulator paste comprising an electrically insulating material; A recess defined by at least one of the plurality of layers of each rib is filled with a fluorescent paste, and a surface of at least one of the plurality of layers of each rib in which the mass of fluorescent paste partially defines the recess Forming a fluorescent layer by screen printing using a fluorescent paste comprising a fluorescent material to be in contact with the substrate; Forming another rib having a predetermined height from an upper surface of the fluorescent layer by forming another one of the plurality of layers of each rib on at least one of the plurality of layers by screen printing using the insulator paste. step; And Forming a grid electrode on the top surface of the rib by screen printing using a conductive paste comprising an electrically insulating material, Forming at least one of the plurality of layers constituting each of the ribs and forming another one of the plurality of layers, wherein the ribs surround a portion of the periphery of each of the anodes, the ribs are arranged on the substrate and Executed to consist of a plurality of parallel ribs equally spaced from each other; Forming the grid electrodes is performed such that the grid electrodes are respectively formed on top surfaces of the parallel ribs; Forming the fluorescent layer, wherein the fluorescent layer is arranged in a plurality of parallel rows, each of the columns disposed between corresponding pairs of the parallel ribs, and wherein each of the fluorescent layers in the row of the corresponding pair of parallel ribs Characterized in that it is carried out in contact with the opposing surface; (a) a substrate, (b) a plurality of anodes formed on the substrate, (c) a fluorescent layer formed on each of the anodes, and (d) a cathode located above the fluorescent layer that generates electrons impinging upon the fluorescent layer (e) ribs formed on the electrically insulating material on the substrate, the ribs having a higher height from the substrate than the fluorescent layer, and (f) grid electrodes formed on each rib to control activation of the fluorescent layer. Method of manufacturing a fluorescent display tube comprising a.