JP3418319B2 - Fluorescent display tube - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a grid electrode structure of a fluorescent display tube.

[0002]

2. Description of the Related Art A phosphor layer is fixed on a plurality of anodes provided on a display surface of a substrate, and electrons generated from a cathode located above the display surface in a vacuum space collide with the phosphor layer. There is known a fluorescent display tube of a type in which the fluorescent layer is caused to selectively emit light by being made to do so. In such a fluorescent display tube, since the surface of the phosphor layer against which the electrons generated from the cathode collide is located on the display side, the operating voltage is low and the display is clear, and the phosphor layers with different emission colors are prepared. By doing so, it is possible to display in color, and is therefore widely used as a display component for audio equipment and dashboards of automobiles.

[0003]

As a kind of the above-mentioned fluorescent display tube, a mesh-like grid for controlling the light emission of the phosphor layers on the anodes at a plurality of places provided on the display surface of the substrate is used instead. Then, a rib-shaped wall protruding from the periphery of the anode of the substrate so as to surround the phosphor layer and a grid electrode provided on the top of the rib-shaped wall are provided for each light emission unit (light emission group). There is proposed a type in which a grid electrode positioned higher than the above controls the light emission of the phosphor layer. For example, this is the fluorescent display tube described in JP-A-62-290050. In such a fluorescent display tube, thermoelectrons emitted from the filament functioning as a cathode are applied to a grid electrode located at the top of the rib-shaped wall at a relatively low positive acceleration voltage of about several tens of volts. As a result, the phosphor layer positioned on the anode is accelerated and collided, and the phosphor layer surrounded by the grid electrode emits light, so that the dynamic drive is suitably performed.

Therefore, according to the fluorescent display tube of this type, the mesh-shaped grid electrode is fixed to the display surface by the leg portions 80 provided at a plurality of places as shown in the fixing structure of FIG. Since 82 is not used, it is not necessary to provide a grid pad 84 for fixing the leg portion 80 and energizing the leg portion 80 at a position outside the phosphor layer 20 on the display surface, and an area that does not contribute to light emission (dead space).
Can be made smaller. In addition, since the phosphor layers are separated from each other by the rib-shaped wall below the rib grid electrode, some of the electrons that have passed through the mesh-shaped grid electrode 82a to which the acceleration voltage is applied are adjacent to the phosphor layer. Since leakage light emission due to incidence on the phosphor layer 20 located below the mesh-shaped grid electrode 82b to which the erase voltage is applied cannot occur, leakage light emission of the phosphor layer 20 at the boundary between the light emitting units can be prevented. The mutual spacing can be made sufficiently small to reduce the area that does not contribute to the display in this respect as well. Incidentally, in order to prevent such leakage light emission when the mesh grid electrode 82 is used, it is necessary to make the mutual spacing of the phosphor layers 20 large, for example, about 2 (mm) or more.

However, even the rib grid electrode having the above advantages is applied to a fluorescent display tube having various display pattern shapes, and a new problem in pattern design and driving becomes clear. It was That is, the rib grid electrode is provided at a position surrounding the phosphor layer to form an electric field above the phosphor layer to control electrons. Therefore, for example, Japanese Patent Laid-Open No. 8-1
As described in Japanese Patent No. 38593, etc., in a pattern such as "O" or "P" including a closed curve, it is necessary to provide a rib grid electrode also on the inner peripheral side surrounded by the closed curve. However, as illustrated in FIG. 2 for the character pattern “O”, when it is connected to the rib grid electrode 88 located on the outer peripheral side in part to energize the rib grid electrode 86 on the inner peripheral side, it should be a closed curve. The continuity of the phosphor layer 20 is broken, and the original pattern shape cannot be obtained. For example, when the size of the pattern is sufficiently large with respect to the width dimension ds of the connecting portion 90 formed to have a size of about 100 to 140 (μm), the breaks are hardly noticeable and pose no problem. In a pattern with a small character height of about hc = 2 (mm), the design break is too large to be ignored. Incidentally, if the rib grid electrode 86 is not provided on the inner peripheral side, or if the rib grid electrode 86 is provided and is not connected to the rib grid electrode 88 on the outer peripheral side, the negative charges accumulated on the inner peripheral side insulating layer or on the rib grid electrode 86 are not charged. This causes unevenness in light emission.

Further, as shown in FIGS. 3 (a) and 3 (b),
In a large-area solid-state light emission pattern, the phosphor layer 2
It is difficult to obtain a sufficient control function only by providing the rib grid electrode 88 around 0. Therefore, for example, when a positive voltage is applied to the anode 40, the rib grid electrode 88 is
Even if an erasing voltage is applied to, the central portion of the light emitting pattern, which is less affected by the negative electric field formed by it, emits light.
Therefore, in a pattern in which the smaller width dimension dp of the phosphor layer 20 exceeds, for example, 0.4 (mm), ribs 92 in the pattern are projected and formed on the phosphor layer 20 as shown in the figure. It is necessary to finely divide the light emitting pattern by the in-pattern rib grid electrode 94 provided at the same height as the rib grid electrode 88 on the top. Therefore, the phosphor layer 20 cannot be formed with the original design, which impairs the design.

Further, in the rib grid type fluorescent display tube, the negative electric field formed by the rib grid electrode blocks electrons toward the phosphor layer provided on the inner peripheral side thereof. Therefore, the larger the pattern area, the stronger the erasing voltage, that is, the cutoff bias, compared to the case of the mesh grid electrode, and sometimes it is necessary to increase it to about 1.5 times. This cut-off bias is the difference between the cathode potential and the grid electrode potential when it is off, so if the power supply voltage, that is, the potential difference between when the grid electrode is on and when it is off, is the same as the grid electrode potential when it is on. The potential difference from the cathode potential, that is, the accelerating voltage decreases, and the luminance efficiency with respect to the magnitude of the power supply voltage deteriorates. Therefore, considering the brightness, the size of the pattern is also limited to a substantially small range. The power supply voltage of the fluorescent display tube cannot be freely set because it is limited by the withstand voltage of the driver and CPU used, the purpose of use of the fluorescent display tube, and the like.

The present invention has been made in view of the above circumstances, and an object thereof is to make it possible to reduce an area which does not contribute to display, have a high degree of freedom in pattern design, and have a high luminance efficiency. To provide.

[0009]

In order to achieve such an object, the gist of the present invention is that a phosphor layer is fixed on each of a plurality of anodes provided on a display surface of a substrate, and In the above, the electrons generated from the cathode provided above the display surface are controlled by a plurality of grid electrodes provided for each predetermined light emitting unit of the phosphor layer between the phosphor layer and the cathode. a fluorescent display tube of the type for selectively emitting phosphor layer, (a) said plurality of grid electrodes, its said phosphor layer so as to surround each light emitting unit
Along the outer periphery of the phosphor layer higher than the phosphor layer
It is to include a mesh-shaped grid electrode whose peripheral portion is fixed to the top of the peripheral rib-shaped wall protruding by thick film printing and which covers the phosphor layer.

[0010]

Thus, the plurality of grid electrodes of the fluorescent display tube are thicker and thicker than the phosphor layer on the outer peripheral side along the outer peripheral edge so as to surround the phosphor layer for each light emitting unit. It is configured to include a mesh-shaped grid electrode whose peripheral portion is fixed to the top of the outer peripheral rib-shaped wall protruding by film printing and which covers the phosphor layer. Therefore, since electrons are controlled by the mesh grid electrode provided so as to cover the phosphor layer, various inconveniences peculiar to the use of the rib grid electrode, that is, a break in a pattern including a closed curve, or a large gap occurs. Since the inner rib grid electrode is required in the area pattern, the original design is impaired, and the cut-off and
There is no need to increase the bias. Moreover, since the mesh-shaped grid electrode is attached by fixing the peripheral portion to the apex of the outer peripheral rib-shaped wall, the grid pad for fixing the leg portion of the grid electrode is not required and the non-light emitting area is reduced. it can. Further, between the mesh-shaped grid electrode and the phosphor layer, since the phosphor layers belonging to different grid electrodes are separated from each other by the outer peripheral rib-shaped wall, the electrons passing through the grid electrode are adjacent to each other. Leakage emission due to the incidence on the phosphor layer covered with the light cannot occur. Therefore, it is possible to obtain a fluorescent display tube that can reduce the area that does not contribute to display, has a high degree of freedom in pattern design, and has high luminance efficiency.

[0011]

Other Embodiments Preferably, the mesh-shaped grid electrode is fixed to the top of the outer peripheral rib-shaped wall over substantially the entire circumference. With this configuration, since the mesh-shaped grid electrode is fixed to the top of the outer peripheral rib-shaped wall over substantially the entire periphery of the mesh-shaped grid electrode, fluorescent display as in the case of being supported by legs provided at a plurality of locations Thermal deformation due to heat generation during use of the tube is suppressed. for that reason,
Even when the mesh-shaped grid electrode is made larger as the light emitting pattern formed by the phosphor layer becomes larger, it is possible to suppress the occurrence of display defects such as uneven brightness and short circuit due to the thermal deformation. Therefore, the degree of freedom in designing the display pattern is further increased.

Preferably, the fluorescent display tube further includes an outer peripheral electrode provided so as to surround the outer periphery of the outer peripheral rib wall on the display surface of the substrate and connected to the anode. With this configuration, since the outer peripheral electrode having the same potential as the anode is provided on the outer peripheral side of the outer peripheral rib-shaped wall, even if the electrons accelerated by the grid electrode collide with the outer peripheral side of the outer peripheral rib-shaped wall, The electrons are removed by the outer peripheral electrode, and the electrons emitted from the cathode are also positively accelerated and diffused by the outer peripheral electrode. Therefore, negative charges are not accumulated on the surface of the insulator layer on the outer peripheral portion of the outer peripheral rib-shaped wall, and moreover, the electrons emitted from the cathode are positively accelerated and diffused by the outer peripheral electrode. The electron density incident on the body layer becomes uniform, and uneven brightness is suitably eliminated.

Further, preferably, the fluorescent display tube is provided so as to surround the outer periphery of the outer peripheral rib-shaped wall on the display surface of the substrate and has a negative charge removing electrode having a potential similar to that of the cathode. Is further included. With this configuration, since the negative charge removing electrode having the same potential as the cathode is provided on the outer peripheral side of the outer peripheral rib-shaped wall, the electrons accelerated by the grid electrode collide with the outer peripheral side of the outer peripheral rib-shaped wall. Even so, the electrons are removed by the peripheral electrode. Therefore, since negative charges are not accumulated on the surface of the insulating layer on the outer peripheral portion of the outer peripheral rib-shaped wall, the density of electrons incident on the phosphor layer becomes uniform, and uneven brightness is suitably eliminated.

Further, preferably, the fluorescent display tube is
(b) a conductor layer provided on the top of the outer peripheral rib-shaped wall to fix the mesh-shaped grid electrode, and (c) grid wiring connected to the mesh-shaped grid electrode through the conductor layer. It is a waste. With this configuration, a conductor layer for fixing the mesh grid electrode is provided on the top of the outer peripheral rib-shaped wall, and the mesh grid electrode is connected to the grid wiring via the conductor layer. Therefore, since the mesh grid electrode is fixed to the conductor layer and simultaneously connected to the grid wiring through the conductor layer, the grid pad is provided on the display surface, and the mesh grid electrode having the legs is provided. Can be easily electrically connected to each other without directly connecting to the grid pad at the leg portion.

Further, preferably, in the case where the conductor layer and the grid wiring are provided, the grid wiring is provided on the substrate by being covered with an insulating layer, and the fluorescent display tube comprises: Similar to the through hole provided through the insulating layer and in communication with the grid wiring, and the outer peripheral rib-shaped wall erected on the display surface so as to surround the through hole on the outer peripheral side of the through hole. Rib-shaped walls for grid pads of various heights, and the grids in a state of being electrically connected to the conductor layer provided on the top of the peripheral rib-shaped walls.
The grid pad conductor layer provided on the top of the pad rib-shaped wall and the grid pad rib for electrically connecting the grid wiring and the grid pad conductor layer through the through hole And a connection conductor provided on the inner peripheral side of the shaped wall. With this configuration, the grid-pad conductor layer is connected to the grid wiring by the connection conductor provided on the inner peripheral side of the grid-pad rib-shaped wall, so that the mesh-shaped grid electrode is connected to the grid wiring. To be done. Therefore, since it is possible to secure the continuity between the grid electrode and the grid wiring in a small area surrounded by the rib-shaped wall for the grid pad, simply apply the conductor paste from the upper side of the through hole to separate the grid electrode and the grid wiring. The area that does not contribute to the display caused by connecting them can be reduced as compared with the case of connecting them. Note that the rib-shaped wall for the grid pad as described above is provided at a position outside the phosphor layer similarly to the grid pad provided when the mesh-shaped grid electrode is fixed to the leg portion as in the conventional case. The area required for this is sufficiently smaller than the area of the grid pad required for fixing a relatively large leg.

Further, preferably, in the case where the conductor layer and the grid wiring are provided, the anode wiring connected to each of the anodes is provided on the substrate by being covered with an insulating layer, and the grid is provided. The wiring includes a terminal pad electrically connected to a base end portion of a connection terminal extending from the vacuum space to the outside for supplying power to the mesh grid electrode and a conductor layer thereof, and an upper side of the insulator layer. Is to connect in. In this way, since the grid wiring is provided in a state where it is three-dimensionally stacked with the anode wiring through the insulator layer, the number of wirings existing on one plane is reduced and the wirings on the substrate are laid out. And the fluorescent display tube can be easily downsized.

Further, preferably, in the case where the grid wiring is provided on the upper side of the insulating layer as described above, the terminal pad base portion and the outer peripheral rib-shaped wall located on the peripheral portion of the substrate and the terminal pad base thereof. And a protrusion protruding continuously from the peripheral rib-shaped wall at a height similar to that of the outer peripheral rib-shaped wall and connecting to the conductor layer to form the terminal pad and the grid wiring. In this way, a convex conductor layer fixed to the top of the convex portion is included.
With this configuration, the conductor layer is directly connected to the connection terminal via the grid wiring and the terminal pad which are continuously provided on the convex portion protruding at the same height as the outer peripheral rib-shaped wall. Therefore, compared with the case where the heights of the conductor layer, grid wiring, and terminal pads are different from each other,
Since the area required to connect them is reduced,
The fluorescent display tube can be further miniaturized.

Also, preferably, the fluorescent display tube is
(d) Inside the area surrounded by the outer peripheral rib-shaped wall, the phosphor layer is provided at a position not provided with the phosphor layer at the same height as the outer peripheral rib-shaped wall, and the mesh-like shape is provided on the top thereof. It includes an inner rib-shaped wall to which the inner portion of the grid electrode is fixed. With this configuration, the inner rib-shaped wall is provided at a position where it does not interfere with the phosphor layer in the region surrounded by the outer peripheral rib-shaped wall, and the mesh grid electrode is also fixed to the top portion of the inner portion thereof. Therefore, even when the outer peripheral rib-shaped wall surrounds a wide area or is provided in a complicated shape, the inner rib-shaped wall suppresses distortion and vibration of the mesh grid electrode,
The degree of freedom in pattern design is further enhanced.

Preferably, when the above-mentioned inner rib-shaped wall is provided, the top of the inner rib-shaped wall is
An inner conductor layer continuous with the conductor layer provided on the outer peripheral side is fixed. With this configuration, even when the mesh-shaped grid electrode is fixed to the inner rib-shaped wall by a conductor (inner conductor layer) as in the case of fixing the mesh-shaped grid electrode to the top of the outer rib-shaped wall, the light is incident on the inner conductor layer. The generated electrons flow to the grid wiring exclusively through the inner conductor layer and the conductor layer. Therefore, by providing the inner conductor layer in a state where the connection with the conductor layer is disconnected, the electrons flow from the inner conductor layer to the conductor layer through a part of the mesh-shaped grid electrode, which causes It is possible to suppress a problem that a current concentration occurs in a part of the mesh grid electrode to generate heat and the mesh grid electrode is thermally deformed.

Preferably, an auxiliary rib-shaped wall is provided on the outer peripheral side of the mesh-shaped grid electrode so as to surround at least a part of the outer peripheral rib-shaped wall at the same height, and the auxiliary rib-shaped wall is formed. An auxiliary grid electrode having the same potential as that of the mesh grid electrode is fixed to the top portion of the. By doing so, since the rib grid electrode is provided as an auxiliary grid electrode on the outer peripheral side of the mesh grid electrode, a negative electric field formed by applying an erasing voltage to the adjacent mesh grid electrode and the outer circumference Since the negative electric field formed by the negative charges accumulated on the outer peripheral side of the rib-shaped wall is canceled by the auxiliary grid electrode, it is possible to suppress uneven light emission due to the negative electric field. In addition,
Since the mesh-shaped grid electrode is not provided between the outer peripheral rib-shaped wall and the auxiliary rib-shaped wall, even if the auxiliary grid electrode is provided, an increase in the area of the entire grid electrode including the auxiliary grid electrode is suppressed, and the reactive current Growth is suppressed.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings. In the following examples, the dimensional ratios of each part are not necessarily drawn accurately.

FIG. 4 is a perspective view in which a part of the fluorescent display tube 10 according to one embodiment of the present invention is cut away. In the figure,
The fluorescent display tube 10 includes glass, ceramics, and a plurality of fluorescent material layers 20 each having a predetermined light emitting pattern.
A substrate 12 made of an insulating material such as enamel, a glass spacer 14 formed in a frame shape, and a transparent cover glass plate 1
6 and a plurality of anode terminals 18 _P , a plurality of grid terminals 18 _G , and a cathode terminal 18 _K, and these substrates 12, spacers 14, and cover glass plate 1
A vacuum space surrounded by these members is formed by glass-sealing 6 together.

The surface of the substrate 12 covered with the vacuum space functions as a display surface of the fluorescent display tube 10, in which a plurality of phosphor layers 20 are meshed grid electrodes 22a. 22a, 22c, etc. (hereinafter, simply referred to as grid electrode 22 unless otherwise specified) are arranged in a state of being covered by a plurality of units. Each of the plurality of phosphor layers 20 constitutes a light emitting unit capable of emitting light at the same time for each of the plurality of phosphor layers 20 covered by one grid electrode 22, and has a predetermined position for each light emitting unit. In common with each anode terminal 18 _P via an anode wiring 34 described later.
Respectively connected to. In addition, the grid electrode 22
Are connected to the respective grid terminals 18 _G through the grid wirings 26 provided on the display surface.

A pair of filament supporting frames 30 (only the one on the right side is shown) provided with the cathode terminals 18 _K are fixedly provided at both ends of the substrate 12, respectively. A thin wire (filament) -shaped cathode 32, which functions as a direct-heating cathode, is stretched between them so as to be at a predetermined height position parallel to the longitudinal direction of the substrate 12 and separated from the display surface of the substrate 12. ing. The cathode 32 is composed of, for example, a tungsten wire on the surface of which an oxide solid solution of an alkaline earth metal having a low work function such as (Ba, Sr, Ca) O 3 is fixed as an electron emission layer.

Therefore, the thermoelectrons emitted from the filament 32 are accelerated by the grid electrode 22 to which a positive voltage (acceleration voltage) of, for example, about 20 (V) is applied to the zero (V) filament 32. Therefore, if a positive voltage is also applied to the phosphor layer 20 covered by the grid electrode 22, thermionic electrons collide with the phosphor layer 20 to cause the phosphor layer 20 to emit light. Even if a positive voltage is applied to the body layer 20, if a negative bias voltage (cutoff bias = negative erasing voltage) of about several volts is applied to the filament 32 on the grid electrode 22 that covers it, The thermoelectrons do not reach the phosphor layer 20 and the phosphor layer 2
0 does not emit light. Therefore, in the state where thermoelectrons are emitted by the electric current flowing through the filament 32,
When a positive voltage is applied to a desired one of the phosphor layers 20 in synchronism with the positive voltage being sequentially applied to the grid electrode 22, so-called dynamic driving causes light emission in a desired pattern. The display is done. In this case, since the grid electrode 22 is provided so as to cover the phosphor layer 20, the electron flow toward the phosphor layer 20 becomes substantially uniform over the entire surface, and light emission with uniform and substantially uniform brightness is achieved. Display is obtained.

5 (a), 5 (b), and 5 are enlarged views showing the main part of the light emitting pattern provided on the display surface with the grid electrode 22 removed from the phosphor layer 20. The electrode structure and the like on the substrate 12 will be described in detail with reference to FIG. 6 in which the grid electrode 22 is provided on the phosphor layer 20 in a portion corresponding to the VI-VI cross section of (a). The grid electrode 22 has a mesh or mesh structure in a ladder mesh pattern having a uniform opening distribution, as shown in FIG. 5 (b) while maintaining its mutual positional relationship. It is produced by subjecting a thin metal plate made of stainless steel or the like having a uniform thickness of about 50 (μm) to etching treatment or the like. In addition, as shown in FIG. 5A, the phosphor layer 20 includes a plurality of rectangular phosphor layers 20s having various sizes, "TRACK", "STEP", and "MON".
It is composed of a plurality of phosphor layers 20c, etc., each having an English letter shape of "O" and "STEREO".

On the other hand, as shown in FIG. 6, on the display surface of the substrate 12, for example, a thick film conductor paste is printed and baked by a screen printing method, or an aluminum thin film is vapor-deposited and etched. Anode wiring 3 having a thickness of about 15 (μm) or several (μm) so that it is connected to the anode terminal 18 _P and passes under the phosphor layer 20.
4 are formed. Moreover, on the anode wiring 34,
An insulator layer 38 having a predetermined thickness of about 30 to 40 (μm) and provided with a through hole 36 penetrating in the thickness direction is fixed. The insulator layer 38 is formed by applying a thick film insulating paste made of, for example, low melting point glass and a coloring pigment by a screen printing method and baking the paste. On the insulator layer 38, an anode 40 having a pattern similar to that of each phosphor layer 20 is formed at a position where it is electrically connected to the anode wiring 34 through the through hole 36. The anode 40 is a thick film paste containing graphite as a main component in a predetermined pattern for 20 to 30 (μ
It is printed and baked to a thickness of about m). The phosphor layer 20 is formed, for example, by printing a thick film phosphor paste on the anode 40 to a thickness of about 15 to 30 (μm).

On the insulator layer 38, the plurality of phosphor layers 20 covered by the respective grid electrodes 22 are surrounded by each unit, that is, the phosphor layer 20 and the anode 4 are surrounded.
The outer peripheral rib-shaped walls 44 made of an insulating material having a low melting point glass as a main component are formed along the peripheral edge of the grid electrode 22 at predetermined intervals so as to contact the outer peripheral edge of the grid electrode 22. It is set up. In addition, at the inner position of each outer peripheral rib-shaped wall 44, a long inner rib-shaped wall 44 is formed so as to individually separate the phosphor layers 20 and the anodes 40 surrounded by the outer peripheral rib-shaped walls 44. The walls 46 are erected on the insulating layer 38 at a predetermined distance from each other. That is, the inner rib-shaped wall 46 is provided at a position where the phosphor layer 20 is not provided in a region surrounded by the outer peripheral rib-shaped wall 44 configured for each light emitting unit so as not to interfere with the phosphor layer 20. The inner rib-shaped wall 46 is made of an insulating material containing low melting point glass as a main component similarly to the outer peripheral rib-shaped wall 44, and has the same height as the outer peripheral rib-shaped wall 44 as shown in the figure. Is. Further, each inner rib-shaped wall 46 is formed continuously with the outer peripheral rib-shaped wall 44 or another inner rib-shaped wall 46 at both ends thereof. Therefore, the phosphor layer 20 is entirely surrounded by the outer peripheral rib-shaped wall 44 and the inner rib-shaped wall 46. In the portion provided with the phosphor layer 20c, as shown in FIG. 5A and FIG. 7 showing a cross section taken along line VII-VII in FIG. 5A, the outer peripheral rib-shaped wall 44 and the inner rib-shaped wall 46 are “TRACK” is not provided in a shape along the outer peripheral edge of each of the phosphor layer 20c and the anode 40.
It is provided so as to surround the whole of the plurality of phosphor layers 20c and the anode 40 which constitute them for each unit corresponding to the words such as.

The outer peripheral rib-shaped wall 44 and the inner rib-shaped wall 46 are formed, for example, by printing a thick-film paste made of an insulating material such as low-melting glass or inorganic filler a plurality of times by thick-film printing. W = 0.1-0.5 (m
m) width and h = 0.2 than the insulator layer 38
They are erected at the same time so that the height is about 0.5 (mm). That is, the outer peripheral rib-shaped wall 44 and the inner rib-shaped wall 4
6 distinguishes the portion of the integrally formed rib-shaped wall by the standing position specified in relation to the grid electrode 22, and there is no difference in the configuration other than the provided position. Absent. The minimum value of the distance between the outer peripheral rib-shaped wall 44 and the inner rib-shaped wall 46, that is, the phosphor layer 2
The minimum value of the pattern interval formed by 0 is, for example, about D = 120 to 150 (μm), as shown in the drawing for the mutual interval of the inner rib-shaped walls 46. The width dimension W and the interval D are set so that the pattern density is sufficiently increased in the range where the print formation is easy.

On the tops of the outer peripheral rib-shaped wall 44 and the inner rib-shaped wall 46, conductor layers 48 are simultaneously and continuously formed by printing a thick film conductor paste. In this embodiment, the portion of the conductor layer 48 fixed on the inner rib-shaped wall 46 corresponds to the inner conductor layer. Therefore, the inner rib-shaped wall 46
The upper conductor layer 48 includes the conductor layer 48 on the outer peripheral rib-shaped wall 44.
An accelerating voltage is applied to the inner rib-shaped wall 4
The electrons that have entered 6 are guided to the outer peripheral rib-shaped wall 44 exclusively through a path passing through the conductor layer 48 thereabove. The above conductor layer 48
Is a particle-shaped conductive material such as silver, palladium, copper, aluminum, nickel, carbon, etc., fixed to a thickness of 10 to 50 (μm). The conductor layer 48 is fixed to the tops of the rib-shaped walls 46, 48 at several points on the inner side. Therefore, since the rib-shaped walls 44 and 46 and the conductor layer 48 are configured in the same manner as the rib grid electrode described in JP-A-62-290050, the conductor layer 48 serves as a grid electrode. However, since the mesh-shaped grid electrode 22 functions exclusively as a grid electrode in the present embodiment,
Mainly plays a role in fixing it and making it possible to energize it.

The above-mentioned fixing of the grid electrode 22 is carried out, for example, according to the steps shown in FIG. First, in the insulating paste film forming step of step 1,
For example, by using a thick film screen printing method or the like, the thick film insulating paste is repeatedly applied and dried in the pattern shown in FIG.
The unfired insulating paste film generated in 6 is formed. Next, in the conductive paste applying step of step 2,
A thick film conductive paste is applied to the top of the insulating paste film to a predetermined thickness. Then, before drying, while the conductive paste film maintains a sufficiently high fluidity, the step 3
In the grid electrode placing step, the mesh (grid electrode 22) shown in FIG. 5 (b) prepared in advance by etching is placed, and then in the drying step of step 4, at a temperature of about 100 to 200 (° C.). After drying, in the baking step of step 5, baking is performed at a temperature of about 450 to 550 (° C.). As a result, the insulating paste film is removed from the rib-shaped walls 44, 4
Simultaneously with the generation of No. 6, the grid electrode 22 is fixed to the conductor layer 48 formed by melting and hardening the conductive paste film at the entire periphery and at some positions on the inner side. In this way, the grid electrode 22 has rib-shaped walls 44,
Since they are attached to the top of the ribs 46, ribs are provided in order to keep the grid electrodes 22 in a suitable size such that the grid electrodes 22 are not shaded in the phosphor layer 20 and a sufficiently large viewing angle is secured. The height of the shaped walls 44 and 46 is set within the above-mentioned range.

When mounting as described above,
Since the placed grid electrode 22 is wet by the conductive paste, the position in the plane direction is fixed even before firing based on the surface tension and the viscosity of the conductive paste, and the grid electrode 22 moves during firing. Board 1
Since the conductive paste is cured in a state where it is more thermally expanded than 2, the appropriate tension is applied to it based on the difference in thermal expansion between the grid electrode 22 and the substrate 12.
Therefore, it is not necessary to use mechanical fixing means when attaching the grid electrode 22. However, when the fluidity-imparting component (binder, solvent, etc.) of the conductive paste is absorbed by the unbaked insulating paste film and the fluidity becomes insufficient, and the grid electrode 22 is difficult to fix, the insulating paste film The conductive paste may be applied after firing to form the rib-shaped walls 44 and 46. If it is desired to fix the grid electrode 22 more reliably, the grid electrode 22 may be placed on the conductive paste film and dried, and then the conductive paste may be further applied.

Returning to FIG. 5 (a), the figure and its IX-IX
As shown in FIG. 9 showing the cross section, the outer peripheral rib-shaped wall 44
And the end of the substrate 12 in the width direction between the outer peripheral rib-shaped wall 44 and a thin wire-like connecting portion 50 extending toward the end, and a rectangular terminal continuous with the connecting portion 50. The pad base 52 is provided so as to project from the insulator layer 3838. The connection portion 50 and the terminal pad base portion 52 are also made of the same insulator as the outer peripheral rib-shaped wall 44,
By forming and printing the outer peripheral rib-shaped wall 44 and the inner rib-shaped wall 46 at the same time, they are integrally formed with them at the same height. These connection parts 50
A conductor layer 54 similar to the conductor layer 48 is fixed to the top of the terminal pad base portion 52, and a portion of the conductor layer 54 fixed to the connecting portion 50 is the grid wiring 26. The portions fixed on the terminal pad base 52 constitute the terminal pads 56 to which the grid terminals _18G are pressed and fixed. Therefore, in the grid electrode 22, the conductor layer 48 on the outer peripheral rib-shaped wall 44 that also serves as the fixing, the grid wiring 26 constituted by the conductor layer 54 on the connection portion 50, and the conductor layer 5 on the terminal pad base portion 52.
The grid wiring 26 is connected to the grid terminal 18 _G through the terminal pad 56 composed of four, and the grid wiring 26 is provided on the insulator layer 3838 in a three-dimensionally stacked state with the anode wiring 34. Therefore, although the mesh-shaped grid electrode 22 is used, no pad for fixing the leg portion of the grid electrode is provided on the display surface. In this embodiment, the connecting portion 50
The terminal pad base portion 52 corresponds to the convex portion, and the conductor layer 54 corresponds to the convex conductor layer.

As described above, according to the present embodiment, the plurality of grid electrodes 22 of the fluorescent display tube 10 are provided on the outer peripheral side of the phosphor layer 20 so as to surround the phosphor layer 20 for each light emitting unit. Outer peripheral rib-shaped wall 44 protruding higher than
The mesh-shaped grid electrode 22 is fixed to the top portion of the peripheral edge of the phosphor layer 20 and covers the phosphor layer 20. Therefore, since electrons are controlled by the mesh-shaped grid electrode 22 provided so as to cover the phosphor layer 20, various inconveniences peculiar to the use of the rib grid electrode 22, that is, the closed curve of the phosphor layer 20c are used. "R" including "A"
A break in the character pattern such as "P" or "O" or the need for the in-pattern rib grid electrode 94 in a rectangular pattern having a large area such as the phosphor layer 20s to impair the original design. (In other words, there are no restrictions on design) and there is no need to increase the cutoff bias for larger areas. In addition, since the mesh-shaped grid electrode 22 is attached by fixing its peripheral portion to the top of the outer peripheral rib-shaped wall 44, the grid pad for fixing the leg portion of the grid electrode 22 is not required, and non-light emission is not required. The area can be reduced. Furthermore, the grid electrode 2
2 and the phosphor layer 20, an outer peripheral rib-shaped wall 44
Phosphor layers 20 belonging to different grid electrodes 22
Since they are separated from each other, leakage light emission due to the electrons passing through the grid electrode 22 entering the phosphor layer 20 covered by the adjacent grid electrode 22 cannot occur. Therefore, the area that does not contribute to display is small, the degree of freedom in pattern design is high, and the luminance efficiency is high.

Further, according to the present embodiment, the mesh-shaped grid electrode 22 has an outer peripheral rib-shaped wall 44 over substantially the entire circumference of the peripheral portion thereof.
Since it is fixed to the top of the fluorescent display, thermal deformation due to heat generation during use of the fluorescent display tube 10 such as when supported by legs provided at a plurality of positions is suppressed. Therefore, even when the mesh-shaped grid electrode 22 is increased in size as the light emission pattern formed by the phosphor layer 20 is increased in size, display defects such as uneven brightness and short circuits may occur due to thermal deformation. As a result, the degree of freedom in designing the display pattern is further increased.

Further, according to the present embodiment, the fluorescent display tube 10 is
A conductor layer 48 provided on the top of the outer peripheral rib-shaped wall 44 to fix the mesh-shaped grid electrode 22, and a grid wiring 26 connected to the mesh-shaped grid electrode 22 via the conductor layer 48. Is included.
In this way, the conductor layer 48 for fixing the mesh-shaped grid electrode 22 is provided on the top of the outer peripheral rib-shaped wall 44, and the mesh-shaped grid electrode 22 is connected to the grid wiring 26 via the conductor layer 48. Connected. Therefore, since the mesh-shaped grid electrode 22 is fixed to the conductor layer 48 and at the same time connected to the grid wiring 26 via the conductor layer 48, the mesh-shaped grid is attached to a grid fixing pad or the like provided on the display surface. They can be easily electrically connected without connecting the electrodes 22.

Further, in the present embodiment, the grid wiring 26 is a terminal to which the base end of the grid terminal 18 _G extending from the vacuum space to the outside for electrically feeding the grid electrode 22 is electrically connected. Pad 56 and its conductor layer 4
8 is connected on the upper side of the insulator layer 38. With this configuration, since the grid wiring 26 is provided in a state of being three-dimensionally stacked with the anode wiring 34 formed on the substrate 12 with the insulating layer 38 interposed therebetween, the number of wirings existing on one plane can be reduced. This reduces the number of wiring lines on the substrate 12 and facilitates miniaturization of the fluorescent display tube 10.

Further, in the present embodiment, the terminal pad base 52 located on the peripheral portion of the substrate 12 and the connecting portion 5 connecting the outer peripheral rib-shaped wall 44 and the terminal pad base 52.
0 are projected at the same height as that of the outer peripheral rib-shaped wall 44, and their connecting portions 5 are formed so as to be continuous with the conductor layer 48 to form the terminal pad 56 and the grid wiring 26.
0 and a conductor layer 54 fixed to the top of the terminal pad base 52. Therefore, the conductor layer 48 is connected to the grid terminal 18 _G via the grid wiring 26 and the terminal pad 56 provided on the connection portion 50 and the terminal pad base portion 52 protruding at the same height as the outer peripheral rib-shaped wall 44. Since they are connected, the area required for connecting them is reduced as compared with the case where the conductor layer 48, the grid wiring 26, and the terminal pad 56 are different in height from each other. Further miniaturization is possible.

Further, in the present embodiment, the outer peripheral rib-shaped wall 44 is located inside the area surrounded by the outer peripheral rib-shaped wall 44 formed for each light emitting unit and where the phosphor layer 20 is not provided. And an inner rib-shaped wall 46 to which the inner portion of the mesh-shaped grid electrode 22 is fixedly attached at the top thereof. By doing so, in the region surrounded by the outer peripheral rib-shaped wall 44, the phosphor layer 2 is formed.
An inner rib-shaped wall 46 is provided at a position where it does not interfere with 0, and the mesh-shaped grid electrode 22 is also fixed to the apex of the inner portion. Therefore, even when the outer peripheral rib-shaped wall 44 is provided so as to surround a wide area as in the present embodiment, the inner rib-shaped wall 46 suppresses the distortion and vibration of the mesh grid electrode 22.

In the present embodiment, the conductor layer 48 corresponding to the inner conductor layer is provided on the top of the inner rib wall 46.
The inner conductor layer 48 is fixed to the top of the outer peripheral rib-shaped wall 44 provided on the outer peripheral side thereof.
It is continuous with. By doing so, even when the mesh-shaped grid electrode 22 is fixed to the inner rib-shaped wall 46 by the inner conductor layer 48 as in the case where the mesh-shaped grid electrode 22 is fixed to the top of the outer peripheral rib-shaped wall 44, the inner conductor layer 48 is fixed. Electrons incident on the grid flow through the inner conductor layer 48 and the conductor layer 48 on the outer peripheral rib-shaped wall 44 to the grid wiring 26. Therefore, the inner conductor layer 48 is provided in a state where the connection with the conductor layer 48 on the outer peripheral rib-shaped wall 44 is cut off, so that the electrons pass from the inner conductor layer 48 through a part of the mesh-shaped grid electrode 22. Flow to the conductor layer 48 on the outer peripheral side, which causes current concentration in a part of the mesh-shaped grid electrode 22 to generate heat, which prevents the mesh-shaped grid electrode 22 from being thermally deformed.

Further, according to the present embodiment, the mesh-shaped grid electrode 22 is fixed on the rib-shaped wall 44 along the entire periphery of the mesh-shaped grid electrode 22 and tension is generated based on the difference in thermal expansion from the substrate 12 at the time of firing. Therefore, the rigidity of the grid electrode 22 itself may be relatively low. Therefore, as compared with the conventional case where the legs 80 are fixed,
Since the aperture ratio of the grid electrode 22 can be increased and the light blocking can be reduced without considering the rigidity, the brightness of the fluorescent display tube 10 can be increased.

Next, another embodiment of the present invention will be described. In the following embodiments, the same parts as those in the above-described embodiments are designated by the same reference numerals and the description thereof will be omitted.

FIGS. 10 (a) and 10 (b) are views for explaining another configuration example of the grid wiring 26 and the terminal pad 56 connected to the grid electrode 22 in the above-mentioned embodiment,
Of these, (a) is a diagram corresponding to FIG. 9 above, and (b)
[Fig. 3] is a plan view of relevant parts in (a). In the figure, on the outer peripheral side of the outer peripheral rib-shaped wall 46, there is formed a "U" -shaped grid pad rib-shaped wall 58 that is continuous with the outer peripheral rib-shaped wall 46 and forms a rectangular closed plane with the outer peripheral rib-shaped wall 46. The conductor layer lead-out rib 60 protruding from the insulating layer 38 is provided upright from the insulating layer 38, and a part of the outer peripheral rib-shaped wall 46 that forms the closed plane. The grid pad rib-shaped wall 58 and the conductor layer leading-out rib 60 are both formed at the same height as the outer peripheral rib-shaped wall 46, and the outer peripheral rib-shaped wall is formed on the top thereof. The conductor layer 48 is formed continuously from the top of the wall 46.
In the present embodiment, the portion of the conductor layer 48 formed on the top of the conductor layer lead-out rib 60 corresponds to the grid pad conductor layer.

Further, in the grid wiring 26 and the terminal pad 56, like the anode wiring 34, a conductor is fixed on the substrate 12 by the thick film screen printing method and the insulating layer 38.
It is formed by being covered by. The grid wirings 26 and the terminal pads 56 are partially exposed by the through holes 36 and the like provided in the insulator layer 38, and the grid wirings 26 pass through the portions (not shown) on the substrate 12 and the terminal pads. Connected to 56. Then, in the closed plane formed by the outer peripheral rib-shaped wall 46 and the grid-pad rib-shaped wall 58 as described above, for example, a conductor paste similar to that used when the conductor layer 48 is formed on the outer periphery. The connection conductor 62 is provided by being filled to the same height as the rib-shaped wall 46 and the like. Conductor layer 4 fixed to the top of the conductor layer lead-out rib 60
8 is electrically connected to the grid wiring 26 by the connection conductor 62 through the through hole 36 provided in the closed plane, whereby the grid electrode 22 passes through the conductor layer 48 and the connection conductor 62. It is connected to the grid wiring 26. Therefore, also in the present embodiment, the conduction between the grid electrode 22 and the grid wiring 26 can be secured in a small area surrounded by the grid pad rib-shaped wall 58.
That is, the grid wiring 26 is not necessarily the insulator layer 38.
Need not be formed on the upper side of the substrate 12, but may be formed on the surface of the substrate 12 as in the present embodiment.

FIG. 11 is a diagram for explaining another example of the electrode structure on the substrate 12 of the fluorescent display tube 10 and is a diagram corresponding to FIG. 6, and FIG. 12 is a plan view of the main part of FIG. It is a figure corresponding to the principal part of the said FIG. 5 (a). In the figure,
An outer peripheral electrode 64 is provided on the outer peripheral side of the outer peripheral rib-shaped wall 44 so as to be in contact with and surround the outer peripheral rib-shaped wall 44. The outer peripheral electrode 64 is connected to the wiring 66 provided on the substrate 12 through the through hole 38, and further connected to the anode wiring 34 common to the anode 40 on the inner peripheral side of the outer peripheral rib-shaped wall 44, for example. ing. Therefore, since the outer peripheral electrode 64 having the same potential as the anode 40 is provided at the outer peripheral side of the outer peripheral rib-shaped wall 44, that is, at the position corresponding to the periphery of the grid electrode 22, the cathode 32 is provided.
Even if the electrons emitted from the outer peripheral rib-shaped wall 44 collide with the electrons emitted from the outer peripheral electrode 64, the electrons are not only removed by the outer peripheral electrode 64, but also the cathode 32
The electrons emitted from the positive electrode are also accelerated and diffused by the outer peripheral electrode 64. As described above, it is possible to use the outer peripheral electrode 64 in combination with the mesh-shaped grid electrode 22, and according to the present embodiment, the outer peripheral rib-shaped wall 4 is used.
4, no negative charge is accumulated on the surface of the insulator layer 38 on the outer peripheral portion of No. 4, and the electrons emitted from the cathode 32 are the outer electrode 6.
4 also positively accelerates and diffuses, so that the electron density incident on the phosphor layer 20 becomes more uniform, and the uneven brightness is further suppressed.

The outer peripheral electrode 64 is the anode wiring 3
Instead of being connected to 4, it may be connected to the cathode 32.
In this case, the wiring 66 corresponds to a cathode wiring, and a negative charge removing electrode having the same potential as the cathode 32 is provided so as to surround the outer periphery of the outer peripheral rib-shaped wall 44 on the display surface of the substrate 12. Even in this way, even if the electrons accelerated by the grid electrode 22 collide with the outer peripheral side of the outer peripheral rib-shaped wall 44, the electrons are removed by the outer peripheral electrode 64. Since negative charges are not accumulated on the surface of the insulator layer 38, the density of electrons incident on the phosphor layer 20 becomes uniform, and uneven brightness is suitably eliminated.

When the outer peripheral electrode 64 is connected to the anode 40 and has the same electric potential as that, the wiring 6 is formed as described above.
6 instead of providing the anode 40 with the outer peripheral rib-shaped wall 44.
The outer peripheral rib-shaped wall 44 may be erected on the anode 40 by extending to the outer peripheral side. Even in this case, the function of the outer peripheral electrode 64 does not change at all. However, in consideration of the fixing strength of the outer peripheral rib-shaped wall 44, it is possible to obtain higher strength by directly standing on the insulating layer 38 than by standing on the anode 40, and therefore, as shown in FIG. It is preferable to adopt the structure described below.

FIGS. 13 (a) and 13 (b) are views for explaining the construction of the main part when the present invention is applied to other light emission pattern shapes, where (a) is a plan view and (b) is ( It is a bb cross section in a). In the figure, a mesh-shaped grid electrode 68 is adjacent to the outer peripheral rib-shaped wall 44 fixed to the top portion, and an auxiliary rib-shaped wall 70 is erected from the insulating layer 38 so as to surround a part of the outer periphery thereof. . The auxiliary rib-shaped wall 70 has a height similar to that of the outer peripheral rib-shaped wall 44 and the like, is connected to the outer peripheral rib-shaped wall 44 at a plurality of points, and the top thereof is continuous from the top of the outer peripheral rib-shaped wall 44. Then, the conductor layer 48 is fixed. In this embodiment, the phosphor layer 20 is provided in each region surrounded by the outer peripheral rib-shaped wall 44 and the inner rib-shaped wall 46 indicated by a broken line in the drawing, and the outer peripheral rib-shaped wall 44 and the auxiliary rib-shaped wall 44 are provided. Between the wall 70 and the phosphor layer 20
Is not provided.

The grid electrodes 68a and 68b are provided with stripe-shaped openings as shown in FIG. This grid electrode 68 is, for example, 50
(μm) is a thin metal film having a thickness of about (3) is produced by performing an etching process, for example, parallel strips 72 of about 0.03 (mm) width dimension arranged in parallel at equal intervals,
It is composed of an edging portion 74 having a similar width dimension which forms the entire contour shape. The grid electrode 68 thus configured is fixed to the top of the outer peripheral rib-shaped wall 44 by the conductor layer 48 at the peripheral portion, that is, the edging portion 74, and as is apparent from FIG. Wall 44
It is not provided at a position between and the auxiliary rib-shaped wall 70. That is, the grid electrode 68 is provided only at a position that covers the phosphor layer 20 provided on the inner peripheral side of the outer peripheral rib-shaped wall 44. Therefore, the conductor layer 48 fixed on the auxiliary rib-shaped wall 70 is always kept at the same potential as the grid electrode 68, but it hardly functions as a grid electrode that accelerates electrons toward the phosphor layer 20. An auxiliary grid electrode for canceling a negative electric field formed by another grid electrode 68 that is provided adjacent to the grid electrode 68 and is applied with an erase voltage during a period when the acceleration voltage is applied to the grid electrode 68 located on the inner peripheral side thereof. Functions exclusively as. Therefore, the negative electric field suppresses the occurrence of uneven light emission in the phosphor layer 20 covered by the grid electrode 68 to which the acceleration voltage is applied.

The peripheral edge of the grid electrode 68 is fixed on the auxiliary rib-shaped wall 70, so that the outer peripheral rib-shaped wall 4 is
Even if a part of the grid electrode 68 is located between the No. 4 and the auxiliary rib-shaped wall 70, the function of the auxiliary grid electrode as described above does not change. Therefore, although the grid electrode 68 may be provided as such, the grid electrode 68 is not required at a position not covering the phosphor layer 20, and the electrons absorbed by the grid electrode 68 and the conductor layer 48 generate a reactive current. Since they are generated, it is desirable that their area be made as small as possible.

FIGS. 15 (a) to 15 (c) are views for explaining still another embodiment. (A) is a plan view, (b) is b in (a).
-B sectional view, (c) is a cc sectional view in (a). In the figure, the light emitting unit covered by the grid electrode 68a is provided with the phosphor layer 20 in a pattern similar to that shown in FIG. 13 (a).
As is apparent from (b), all of the phosphor layers 20 provided on the different anodes 40 have inner rib-shaped walls 46.
However, some of them are electrically separated by simply being printed at a predetermined interval. Therefore, in the section surrounded by the outer peripheral rib-shaped wall 44 and the inner rib-shaped wall 46, four phosphor layers 20 that emit light independently of each other are provided. Since the inner rib-shaped wall 46 is provided in order to suppress the distortion and vibration of the grid electrode 68, it is sufficient to provide the inner rib-shaped wall 46 in a portion necessary for that purpose.
Even when a plurality of phosphor layers 20 that emit light independently of each other are provided in one light emitting unit covered by 8, the plurality of phosphor layers 20 are not necessarily separated from each other by the inner rib-shaped wall 46. You don't have to.

Further, in FIG. 15 (a), the grid electrode 6
The light-emitting unit covered by 8b has an annular non-light-emitting portion, that is, a portion where the phosphor layer 20 is not provided, in the light-emitting pattern, as is apparent from FIG. When the grid electrode 68b is supported at the inner position in such a light emitting pattern, a columnar body 76 independent of the outer peripheral rib wall 44 may be provided upright from the insulating layer 38 as shown in the figure. However, when the conductor layer 78 similar to the conductor layer 48 is provided in order to fix the grid electrode 68b to the top of the outer peripheral rib-shaped wall 44 and at the same time to fix it on the columnar body 76, the conductor is provided via the grid electrode 68b. Since the acceleration voltage is applied to the layer 78, electrons are also absorbed in the layer 78, and the absorbed electrons flow to the conductor layer 48 through the grid electrode 68b. Therefore, when the grid electrode 68b is supported at the inner position by the conductor layer 78 which is not continuous with the conductor layer 48 as described above, the amount of current is reduced to suppress heat generation of the grid electrode 68 due to the current. In order to prevent the thermal deformation, the conductor layer 78
It is preferable to reduce the area of the column, that is, the area of the top of the columnar body 76 as much as possible. Note that when an insulator layer is provided on the columnar body 76 instead of the conductor layer 78 and fixed at the inner position with an insulator, such consideration is not necessary. Further, as shown in the figure, the grid electrode 68b is provided with lattice-shaped openings, but the "mesh-shaped grid electrode" in the claims is not limited as long as the openings are uniformly distributed. The shape of the opening is not particularly limited.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be carried out in still another mode.

For example, in the embodiment, the plurality of grid electrodes 22 and 68 are provided for each light emitting unit composed of the plurality of phosphor layers 20 that emit light independently, but one phosphor layer is provided. It does not matter if the grid electrodes 22 and 68 covering only 20 are included.

In the embodiment, the grid electrode 2
Although the entire circumferences of the peripheral portions of 2, 68 are fixed to the outer peripheral rib-shaped wall 44, it may be possible to fix only a part of the peripheral portion. In addition, in order to sufficiently suppress the distortion and vibration of the grid electrode 22, it is desirable to fix substantially the entire circumference of the peripheral edge portion.

Further, in the embodiment, the outer peripheral rib-shaped wall 4
By providing the conductor layer 48 on the top of No. 4, the grid electrodes 22 and 68 are fixed to the top and at the same time electrically connected to the grid wiring 26 continuously provided on the conductor layer 48. Instead of the conductor layer 48, an insulator layer may be provided on a part or substantially the entire circumference of the top portion, and the grid electrodes 22 and 68 may be fixed to the insulator layer. Even in this case, it is possible to connect to the grid wiring 26 provided in the vicinity by fixing the grid electrodes 22 and 68 and then applying a conductive paste from above.

Further, in the embodiment, the grid electrode 2
Although the meshes of 2, 68 are formed in a ladder shape, a stripe shape, or a lattice shape, the mesh shape (that is, the shape of the opening) is determined in consideration of the aperture ratio, the required area of the grid electrodes 22, 68, and the like. It may be appropriately changed, and for example, may be configured in a honeycomb shape or the like. Further, a substantially mesh-shaped grid electrode may be formed by stretching a wire (metal wire) or the like on the outer peripheral rib-shaped wall 44.

In the embodiment, the mesh-shaped grid electrodes 22 and 68 are provided on all the phosphor layers 20, but the phosphor layers 20 of a pattern shape having a sufficiently small area and not including a closed curve are provided. On the other hand, the rib-shaped wall 4 is formed around it.
It suffices that the conductor layers 48 are provided at 4, 46 and their tops, and need not be covered by the grid electrodes 22, 68. In this case, the conductor layer 48 functions as a rib grid electrode. In the case of a pattern in which the area of the phosphor layer 20 is small and does not include a closed curve, the rib grid electrode can be sufficiently controlled and the original design of the pattern can be maintained.
It is not necessary to provide 2,68.

Further, in the embodiment shown in FIG. 13, only one auxiliary grid electrode (auxiliary rib-shaped wall 70 and conductor layer 48) is provided on the outer peripheral side of the grid electrode 68, but the number of the auxiliary grid electrodes is driven. The number may be appropriately changed depending on the voltage, the pattern density, and the like, and for example, two or more may be provided. Further, in the figure, the auxiliary rib-shaped wall 70 is continuously formed from the outer peripheral rib-shaped wall 44, and the conductor layer 48 is continuously provided at the tops thereof,
Although the acceleration voltage is applied to the auxiliary grid electrode at the same time when the acceleration voltage is applied to the grid electrode 68, the auxiliary grid electrode may be provided independently of the grid electrode 68. When they are independently provided in this way, the auxiliary grid electrodes can be made common to the grid electrodes 68 adjacent to each other.

Although not illustrated one by one, the present invention can be variously modified without departing from the spirit thereof.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a mounting state of a conventional mesh grid electrode.

FIG. 2 is a diagram illustrating a problem of a conventional rib grid electrode.

3A and 3B are diagrams for explaining another problem of the conventional rib grid electrode, in which FIG. 3A is a plan view and FIG.
It is a b sectional view.

FIG. 4 is a perspective view showing a fluorescent display tube according to an embodiment of the present invention with a part cut away.

5 (a) is a diagram showing a light emission pattern shape provided in the fluorescent display tube of FIG. 4 with a grid electrode removed, and FIG. 5 (b) is a view showing the positional relationship between the grid electrodes. It is a figure shown in a state.

6 is a diagram showing a cross section taken along line VI-VI in FIG. 5 (a).

FIG. 7 is a diagram showing a cross section taken along line VII-VII in FIG.

FIG. 8 is a process diagram illustrating a method of attaching a grid electrode.

9 is a diagram showing a cross section taken along line IX-IX in FIG. 5 (a).

10A is a diagram corresponding to FIG. 9 illustrating another example of the connection structure of the grid electrode and the grid wiring, and FIG.
Is a plan view in (a).

FIG. 11 is a view corresponding to FIG. 6 illustrating another embodiment of the present invention, which illustrates a sectional structure of a main part when an outer peripheral electrode is used together.

FIG. 12 is a plan view of FIG.

13A is a plan view for explaining another embodiment of the present invention, and FIG. 13B is a sectional view taken along line bb in FIG. 13A.

14 is a diagram showing a grid electrode used in the embodiment of FIG.

15A is a view for explaining another embodiment of the present invention, FIG. 15B is a sectional view taken along line bb in FIG. 15A, and FIG. 15C is a sectional view taken along line cc in FIG. 15A. It is a figure.

[Explanation of symbols]

12: substrate 20: Phosphor layer 22, 68 grid electrode 26: Grid wiring 32: cathode 40: Anode 44: Perimeter ribbed wall 46: Inner ribbed wall 48: Conductor layer

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoko Matsumoto 2160 Yatsunami, Sanran, Yasu Town, Asakura-gun, Fukuoka Prefecture, Kyushu Noritake Co., Ltd. (56) Reference JP-A-8-45449 (JP, A) Japanese Unexamined Patent Publication No. 8-124503 (JP, A) Actually open 2-140749 (JP, U) Actually open 54-96149 (JP, U) Actually open 61-3659 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 31/15

Claims (4)

(57) [Claims] 1. A phosphor layer is fixed on each of a plurality of anodes provided on a display surface of a substrate, and electrons generated from a cathode provided above the display surface in a vacuum space generate electrons from the phosphor layer. A fluorescent display tube of a type that selectively emits light from the phosphor layer by controlling with a plurality of grid electrodes provided for each predetermined light emitting unit of the phosphor layer between the cathode and the cathode. The grid electrode is provided on the top of the outer peripheral rib-shaped wall projecting by thick film printing higher than the phosphor layer on the outer peripheral side so as to surround the phosphor layer for each of the light emitting units along the outer peripheral edge thereof. A fluorescent display tube comprising a mesh-shaped grid electrode having a peripheral edge fixed and covering the phosphor layer. 2. The fluorescent display tube according to claim 1, wherein the mesh-shaped grid electrode is fixed to the top of the outer peripheral rib-shaped wall over substantially the entire circumference of the peripheral edge. 3. A conductor layer provided on the top of the outer peripheral rib-shaped wall and fixed to the mesh-shaped grid electrode, and grid wiring connected to the mesh-shaped grid electrode via the conductor layer. The fluorescent display tube according to claim 1 or 2. 4. The protrusion is provided at the same height as the outer peripheral rib-shaped wall inside the area surrounded by the outer peripheral rib-shaped wall and at a position where the phosphor layer is not provided. 4. The fluorescent display tube according to claim 1, further comprising an inner rib-shaped wall to which an inner portion of the mesh grid electrode is fixed.