JPH0432132A - Metal wall discharge display tube - Google Patents

Abstract

PURPOSE:To reduce a lost display part by forming a side wall out of a metal of a specified thickness, by forming the side wall from a method plate whose thickness is less than 1mm, putting the end part of the side wall on the side surface of a display glass plate in opposition, and by melting and fixing them through seal glass for sealing them. CONSTITUTION:A metal plate of 0.3mm in thickness is formed out of the alloy of 42 weight % Ni, and 6 weight % Cr-Fe. A thin film process is carried out for hatches 3a, 3b shown in the figure, which are adjoining a side wall part, from a reverse surface, so as to make the thickness after bending process approximately 0.3mm. A positioning groove for a bulkhead is provided, and a thin film process is carried out to make the width approximately 0.6mm. Regarding the shape of the bulkhead 8, it is of the same material as of the side wall, and is made only of the plate of thickness of 0.6mm. Two pieces of bulkhead plates 8 are assembled with each other in a cross by notching, which is then integrated into the groove 3c, and after dielectric powder including glass is electrodeposited thereon, a display glass plate 1 is put on the bulkhead part which is fixed and coated, and thus is lowered, and the side wall part is sealed with seal glass. The discharge display tube thus formed is designed to be of single color, and of picture element pitch of 8mm, while an opening ratio obtained is approximately 80%. This opening ratio is three times as large as, or more than the opening ratio 25% of a conventional display tube of the same design whose seal width is 2mm.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a metal-walled discharge display tube, and more specifically, the present invention relates to a metal-walled discharge display tube, and more specifically, the sidewall is made of metal with a thickness of 1.0 m or less, and the seal width between the display glass plate and the sidewall is The present invention relates to a metal wall discharge display tube which has a small size and is particularly effective for making a large display by arranging a plurality of discharge display tubes in a planar manner.

[Prior Art and Problems to be Solved by the Invention] A discharge display tube requires a gas container, and is usually constructed by sealing a display glass plate, an opposing plate, and a side wall with a sealing glass. When the side wall is low, beads or the like may be mixed into the seal glass to serve as a spacer. Furthermore, a device in which the display glass plate and the side wall are integrated has also been proposed.

In any case, the seal glass consists of the display glass plate, side wall,
Since it is sandwiched between the opposing plate and the side wall and sealed by applying pressure, the sealing surface spreads parallel to the display surface, and this forms the display invalidation section.

FIG. 1 shows a plan view of two discharge display tubes arranged in this manner. In the figure, the peripheral area occupied by the side wall 3 or the seal glass 4 is the display invalidation area 7. Also,
In the figure, one discharge display tube has four picture elements 5 with a picture element interval of 6.
It is configured separately.

FIG. 2 is a partial sectional view of section A in FIG. 1, and is for explaining an example of a conventional discharge display tube. In the same figure, 1
2 is a display glass plate, 2 is an opposing plate, 3 is a side wall, and 4 is a seal glass.

The size of the above-mentioned display ineffective area has little to do with the size of the discharge display tube and is almost constant, so for devices with a small display area, the display ineffective area takes up display space and becomes a huge hindrance. . This is particularly a serious problem in discharge display tubes in which a plurality of discharge display tubes are arranged in a planar manner for large-scale display.

In other words, if we consider a picture element that expresses one color, if the picture element displays only one color, it will consist of one discharge cell, and if it has multiple colors, it will consist of multiple discharge cells such as red, green, blue, etc. Become. In the case of a large-sized display, the picture elements need to be arranged at equal pitches across a plurality of discharge display tubes. Therefore, the interval between the picture elements needs to be at least twice the width of the side wall display ineffective area.

If the ratio of the picture elements to the display surface is defined as the aperture ratio, the larger the width of the sidewall display ineffective portion, the smaller the aperture ratio. If the aperture ratio is small, the brightness of the display surface will be low if the brightness of the picture elements is the same, making it impossible to display a large display, and if the brightness of the picture elements is increased, the driving voltage will increase and the life of the discharge display tube will be shortened.

Further, when the aperture ratio is kept the same, if the width of the side wall display ineffective portion increases, the possible pixel pitch increases, resulting in a disadvantage that only a coarse display is possible.

In conventional discharge display tubes, the width of the side wall display ineffective area is set to 2III! for the reasons described below. Since it was difficult to reduce the temperature to below J, the above-mentioned drawbacks were unavoidable.

There are two things that form this side wall display ineffective part, one is the side wall and the other is the seal glass.

Therefore, to explain the sealing process using this sealing glass, the sealing process involves glass powder whose working temperature is below the temperature at which the display glass plate, opposing plate, and side walls are thermally deformed, and above the temperature at which vacuum evacuation is performed. It is made by heating and melting a powder obtained by mixing a coloring agent and a filler for adjusting thermal expansion. Therefore, the display glass plate, the opposing plate, and the side walls are selected to have similar coefficients of thermal expansion, and the most widely used material at present is to use soft glass as an inexpensive material. Seal glass is made by kneading the above-mentioned powder with a vehicle etc. to form a paste, which is then applied to one or both sides of the sealing position, and pressurizes the sealing surface to adhere tightly before drying or while it is fluid when heated and melted. be done.

There are two requirements for this seal: one is to be airtight, and the other is to withstand the difference in gas pressure between the inside and outside of the discharge display tube, including during evacuation.

In order to be airtight, it is necessary for the seal glass to exist throughout the seal part not only in the width direction but also in the thickness direction, but since the paste seal glass described above does not have good applicability, it is especially important to It is difficult to make it uniform. Therefore, in the conventional seal glass sandwiching type, it is necessary to crush the thick part by applying pressure and spread it across the entire seal gap. The amount of this expansion increases as the variation in coating thickness increases and as the pressure force becomes more uneven.In general, if the seal width is designed to be narrow, the yield will decrease, so conventionally the seal width is set to 2 mm or less. That was difficult.

Next, the resistance to differential pressure between the inside and outside of the tube is determined by the strength of the sealing glass and the adhesive force between the sealing glass and the sealing surface. Since compressive force mainly acts on the seal glass itself, there is no problem in reducing the seal width. However, since tensile force is applied to the adhesive surface, it is necessary to increase the adhesive force. Adhesive strength depends on the wettability and adhesive area of the adhesive surface and seal glass.

Wettability varies depending on dirt on the bonding surface, surface roughness, heating and melting conditions, atmosphere, pressing force, etc., but favorable conditions for these can be determined through appropriate experiments.

In this state, the adhesive force is determined by the adhesive area, and from this point of view as well, the seal width cannot be made too small.

Next, the side wall will be explained. Even if the seal width can be reduced by overcoming the above-mentioned difficulties, if the side wall is thicker than this, it will form an invalid display area. The side walls must withstand the differential pressure between the inside and outside of the discharge display tube. If the height of the sidewall is low, the thickness of the sidewall may be small, but in discharge display tubes that require high brightness for large displays, the discharge space must be large and the height should be several layers or more. is preferable,
The thickness cannot be made that small. Furthermore, as the height increases, it is difficult to make thin sidewalls using conventional glass or ceramics, and even if it were possible to make sidewalls made of such brittle materials, it would be difficult to manufacture sidewalls for discharge display tubes. Since the workability in the process is very poor, it is usually difficult to manufacture products with a thickness of 1 liter or less.

The present invention was developed in view of the above problems, and uses a side wall that is easy to mold, has good workability, and has excellent mechanical and thermal properties, and reduces the display ineffective area even when sealed with seal glass. The purpose is to provide discharge display tubes that can
In particular, it is an object of the present invention to provide something that is effective both in ordinary discharge display tubes and in discharge display tubes used in combination for large-sized displays.

[Means for Solving the Problems] The above object of the present invention is achieved by using metal for the side wall and sealing the display glass plate and the side wall on the side surface of the display glass plate.

That is, the metal wall discharge display tube of the present invention is a discharge display tube in which a display glass plate, an opposing plate, and a side wall are sealed with a sealing glass to form a gas container, and the side wall is made of metal with a thickness of 111 Ill+ or less, The end portion of the side wall is brought into contact with the side surface of the display glass plate, and both are fused and fixed with a sealing glass to be sealed.

The present invention uses metal sidewalls as described above. The metal material used for this metal side wall should preferably have a coefficient of thermal expansion similar to that of the display glass plate used.

Otherwise, there is a risk that the glass will break during the cooling process of the sealing process. For soft glass, 42% by weight Ni-
Preferred examples include 8% by weight Cr--Fe alloy and 50% by weight N1--Fe alloy, and for hard glass, 20% by weight Ni-17% by weight Co--Fe alloy.

The thickness of the metal side wall is 1 m or less, preferably O, L ~ 0.6
It is m. If the thickness exceeds 1#, the display invalid area will become large.
Moreover, if it is less than 0.1 #, the discharge display tube cannot be made larger because it will deform due to the gas pressure difference between the inside and outside of the tube.

The metal may be used as is or may be subjected to various well-known surface treatments. For example, there is oxidation treatment for the purpose of improving wettability with seal glass. Examples of oxidation methods include thermal oxidation, anodic oxidation, oxide sputtering, thermal spraying, and coating. There is also an insulating coating treatment for insulation from the discharge display tube wiring, examples of which include a method generally known as hollow technology, and the above-mentioned methods such as sputtering and thermal spraying. This coating is also effective in improving wettability with seal glass.

As described above, the advantages of using metal for the side wall in the present invention are that it has good mechanical properties, can be made thinner, and that high dimensional accuracy can be achieved in the processed product.

Making the side walls thinner is one of the requirements for reducing the display ineffective portion. If the dimensional accuracy is poor, when a large number of discharge display tubes are arranged side by side, the display ineffective area becomes large. The reason for this is
This is because it is necessary to provide a gap that takes into account variations in each discharge display tube.

This metal side wall is formed, for example, by the following method.

That is, the side wall surrounds the side surface of the discharge display tube, and the side wall may be formed by dividing and assembled by welding, brazing, pressure welding, etc. A method of shaping and molding in one piece is advantageous. When bending is performed, it is advantageous to provide an overlapped portion and join by welding or the like in terms of strength or eliminating gaps. At this time, since the thickness increases when the sidewalls are overlapped in terms of side wall thickness, it is preferable that each overlapped portion be thinned to about 1/2 of the original thickness. The shape of the side wall used in such a discharge display tube is generally rectangular.

Also, when one discharge display tube has multiple picture elements,
A barrier wall is required to separate the discharge cells within the discharge display tube. In a combination discharge display tube for large displays, as can be seen in FIG. 1, it is meaningless to make the partition wall thickness less than twice the side wall thickness. However, since the discharge cell partition wall within one picture element may be thin, the aperture ratio is larger. The partition wall is not related to the differential pressure of the gas, and there is no need to strictly seal the gap, so a very thin partition wall can be used, and a suitable material for this is a metal plate. For example, by combining a plurality of barrier rib plates vertically and horizontally, a large number of lattice-shaped discharge cell separation walls can be formed. An example of such a combination partition plate is shown in FIG. In order to install these partition walls 8 at fixed positions in the discharge display tube, a suitable method is to provide a groove in the inner surface of the side wall and fit the partition plate into the groove.

Note that this partition wall 8 portion forms the picture element interval 6 in FIG.

Further, the side wall can be molded integrally with the opposing plate. The integrated shape is usually box-like, but this can be easily formed from two metal plates by bending or the like. The advantage of this is that sealing of both can be omitted and that the number of man-hours can be reduced compared to molding both separately. Generally, in bending, in order to accurately and easily bend the position, it is preferable to form a groove-like thin wall on the bent portion. The opposing plate usually requires holes for electrodes, electron passage, and gas passage, and holes may be provided in the side wall as described later.

The various types of processing described above can be selected from many processing methods, and external processing, hole processing, and thin wall processing can be easily performed by etching. The advantages of this etching are that the above-mentioned processing can be performed simultaneously, high processing accuracy, the ability to process small to large items with the same equipment, easy processing of multiple pieces, and low mold costs. It has many advantages such as being suitable for small-scale production. This is only possible if the material used is a thin metal.

Depending on the processing method, formed sidewalls may have seams or small gaps due to poor welding, which can be dangerous from an airtight perspective. In order to avoid this risk, the metal surface should be coated with glass or an inorganic dielectric material containing glass while the side wall is being molded, and if necessary, together with the metal opposing plate and the metal partition wall. Although various methods can be employed as the coating method, it is preferable to electrodeposit dielectric powder using a metal material as an electrode. Electrodeposition allows even complex shapes to be coated uniformly, and since the dielectric contains glass, by melting and fixing it, small gaps can be sealed and a highly airtight product can be created. This coating layer becomes part of the sidewall thickness,
Normally, 10 to 200 μm can be effectively used.

Even if the side walls, partition walls, and opposing plates forming the discharge space are made of metal, the discharge characteristics are sufficiently satisfied. The reason for this is that the voltage drop during discharge is limited to the vicinity of the cathode.
This is because each metal part and the electrode need only be separated by a dielectric. The thickness of this dielectric material only needs to be 10 μm or more, so if a metal coated with a dielectric material is used as described above, the construction of the electrode becomes easier.

Furthermore, the metal of the side walls and partition walls coated with a dielectric material can be used as electrodes as they are or with some parts exposed. This is true not only when the discharge indicator has one discharge cell or one common electrode and a plurality of selection electrodes, but also when a plurality of selection plates are arranged in a matrix. It is well known that it can be used as a common electrode.

In the present invention, the seal glass is the same as the conventional one,
It can also be used in the form of a paste. The sealing location between the display glass plate and the side wall is the side surface of the display glass plate. For this purpose, the end portion of the side wall may be brought into contact with the side surface of the display glass plate, and sealing glass may be applied to cover the gap between the two and melted and fixed.

Partial sectional views of the discharge display tube of the present invention constructed in this way are shown in FIGS. 3 to 5 and FIG. 6. Note that the reference numbers are the same as in FIG. 2.

The display glass plate 1 is usually used with a thickness of 2NR or more, and at least about 1 inch in thickness, in order to withstand the pressure difference between the inside and outside of the pipe and for workability. Therefore, a sufficient amount of sealing glass 4 can be applied within the side surface of the display glass plate 1 to seal the display glass plate 1 and the side wall 3, and there is no problem in the workability.

When sealing the opposing plate 2 and the side wall 3, the seal width does not interfere with the display, so the opposite end of the side wall 3 is
It is also possible to bend it into a shape, use the sealing glass 4, and perform sealing using pressure. An example of this is shown in FIG. Of course, as shown in FIG. 4, the end portion of the side wall 3 may be brought into contact with the side surface of the opposing plate 2, and the end portion of the side wall 3 may be sealed with a sealing glass 4 in the same manner as described above.

Such sealing performed on the side surface of the display glass plate does not require pressure to be applied to the sealing glass as in the past, and therefore can be used satisfactorily even with paste-like sealing glass that does not have good applicability.

Further, the adhesive force obtained by this seal is mainly the adhesive force between the side surface of the display glass plate and the seal glass, and between the end surface of the side wall and the seal glass, but if the side wall thickness is small, the adhesive force may be insufficient. The following methods can be cited as countermeasures against this problem.

(1) Apply adhesive to the surface where the side wall and the display glass plate are in contact with each other. Since this adhesive may have a thickness of about 1 to 10μII, it can be inserted within the clearance range where the two are brought into contact with each other. Further, since there is no particular need for airtightness, it is easy to apply an adhesive, and various adhesives can be used. For example, a heat-resistant inorganic adhesive, the same or similar type of sealing glass, etc. are used.

(2) To increase the adhesion area between the side wall and the seal glass. To achieve this, the shape of the side wall to which the sealing glass is applied must be devised. For example, FIG. 5 shows the end portion of the side wall 3, in which the end portion of the side wall 3 is shown as having irregularities, and in FIG. 5(b) as shown in FIG.

(3) Apply sealing glass to the side walls as well. In this case, the thickness of the sealing glass on the side surface must be as thin as possible because it creates an invalid display area. In order to avoid this problem, it is better to make the end of the side wall where the sealing glass is applied thinner than the other parts. Since this part is in contact with the glass, there is no problem with the pressure resistance of the side wall even if it is thin. In this way, even if sealing glass is applied to the side surface of the side wall, sealing can be achieved within the original thickness of the side wall. This also makes it easier to apply the sealing glass even if the shape near the end of the side wall becomes complex as shown in FIG.

Such a partial sectional view is shown in FIG.

By appropriately selecting and combining the above three methods, it is possible to obtain a seal with a sufficiently large adhesive force even if the side wall thickness is thin.

[Function] The present invention seals the display glass plate and the side wall of the discharge display tube substantially within the range of the side wall thickness, and since the side wall is molded with metal, the thickness can be reduced, and the display ineffective area is significantly reduced. can. In addition, since the side walls are made of metal, even complex shapes can be easily machined, and the mechanical and thermal properties are good, making it easy to manufacture discharge display tubes. It also has the advantage that it can be used in almost the same way.

[Example] Hereinafter, the present invention will be specifically explained based on Examples.

Example The shape shown in FIG.
- It was formed from a metal plate made of Fe alloy and has a thickness of 0.8 mm. The opposing plate 2 and the side wall 3 were integral, and the boundary indicated by the - dotted chain line was processed into a thin groove shape for bending. The adjacent parts 3a and 3b indicated by hatching on the side wall are the parts that overlap after bending, and the thickness of 3a after overlapping is about 0.3 m.

3b was thinned from the opposite side. Further broken line 3c
A positioning groove for the partition wall is provided at the position shown in , and the width is approximately 0.6
AM was processed into a thinner wall. The shape of the partition wall 8 is as shown in FIG.
It is a 0.6m thick plate made of the same material as the side walls. The opposing plate 2 was also provided with holes 9 for electron passage.

Although not shown in the same figure, a fifth
Hole drilling and thin wall processing for applying seal glass were performed as shown in Figure (b). The above-mentioned external shape processing, hole processing, and thin wall processing were performed all at once by etching. The side wall 3 integral with the opposing plate 2 was bent at a predetermined position, overlapped at a predetermined position, and the overlapped portion was welded. Next, the two partition plates 8 were combined in a cross pattern using the notches shown in FIG. 8, and were assembled into the grooves 3c. A perspective view of the external shape assembled in this manner is shown in FIG. Dielectric powder containing glass was electrodeposited in the state shown in FIG. 9, and then fixed and coated at 800°C. In this way, the gaps between the metals were completely sealed. A display glass plate was placed on the thus obtained lowered partition wall portion shown in FIG. 9, and the side wall portion was sealed with a sealing glass as shown in FIG. 6.

The discharge display tube was manufactured using the same materials and processes as those for ordinary discharge display tubes, and it was confirmed that the characteristics were sufficient.

This discharge display tube is designed with a single color and a pixel pitch of 8m.
The obtained aperture ratio is about 80%. This resulted in an aperture ratio more than three times that of a normal display tube of the same design with a seal width of 2 m, which had an aperture ratio of 25%.

[Effects of the Invention] As explained above, the metal wall discharge display tube of the present invention, in which the side wall is made of metal with a thickness of 1.0 m or less, and the display glass plate and the side wall are sealed within the thickness of the side wall, enables display. Ineffective areas can be reduced, the aperture ratio of picture elements can be significantly increased, and the picture element pitch can be made finer, especially in large-sized display combination discharge display tubes.

In addition, since the side walls are made of metal, they can be easily processed even if they have a complicated shape, and have good mechanical and thermal properties, making it easy to manufacture discharge display tubes. Furthermore, since the heat conduction is higher than that of glass, heat dissipation is good, and it is also easy to attach heat dissipation fins to the back side, so it is possible to prevent the brightness of the discharge display tube from decreasing due to high temperatures.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the discharge display tube viewed from the display surface, Fig. 2 is a partial sectional view of part A in Fig. 1, Figs.
5(a) and 5(b) are partial sectional views showing an example of processed metal side wall ends used in the present invention, respectively. Figure 7 shows
FIG. 8 is a diagram showing the shape of a full-wall partition wall (plate) used in the present invention; FIG. FIG. 9 is a perspective view of the metal wall discharge display tube according to the present invention, in which the side wall, opposing plate, and partition wall are assembled. 1: Display glass plate, 2: Opposing plate, 3: Partition wall, 4: Seal glass, 8: Partition wall (plate)
.

Claims (1)

[Scope of Claims] 1. In a discharge display tube in which a gas container is formed by sealing a display glass plate, an opposing plate, and a side wall with a sealing glass, the side wall is made of metal with a thickness of 1 mm or less,
A metal wall discharge display tube characterized in that the end portion of the side wall is brought into contact with a side surface of a display glass plate, and both are sealed by melting and fixing them with a sealing glass. 2. The metal wall discharge display tube according to claim 1, wherein the metal side wall is integrally formed from a single metal plate having a thickness of 0.1 to 0.6 mm. 3. The metal wall discharge display tube according to claim 1 or 2, wherein the seal portion at the end of the metal side wall has irregularities and/or holes. 4. The metal wall discharge display tube according to claim 1, 2 or 3, wherein the thickness of the seal portion at the end of the metal side wall is formed to be thinner than other portions. 5. The metal wall discharge display tube according to claim 1, wherein the metal side wall and the opposing plate are integrally formed from a single piece of metal by bending. 6. The metal wall discharge display tube according to any one of claims 1 to 5, wherein at least one of the processing of the outer shape, hole processing, and thinning of the metal side wall is performed by etching. 7. The metal wall discharge display tube according to any one of claims 1 to 6, wherein the discharge display tube has a plurality of discharge cells, and a gold wall plate is used for the discharge cell partition wall. 8. The metal wall discharge display tube according to any one of claims 1 to 7, wherein a groove is provided on the inner surface of the metal side wall to position the partition wall. 9. The metal wall discharge display tube according to claim 1, wherein after the metal side wall is formed, glass powder and inorganic dielectric powder containing glass powder are electrodeposited and fused and fixed. 10. The metal wall discharge display tube according to any one of claims 1 to 9, wherein the metal side walls and/or partition walls are used as electrodes.