JPS60163334A - Assembling of fluorescent character display tube - Google Patents

Abstract

PURPOSE:To heighten the strength against the rise of a grid by placing a low- melting point glass pellet on the fixing area of a grid support and by fixing it through fusion at the time of enclosing it, when the middle part of the grid is fixed on an insulated base plate. CONSTITUTION:A fluorescent character display tube is made up of a positive electrode which has a fluorescent material coated on its electrode pattern formed on an insulated base plate 1, a mesh-like grid 4, a filament, and a cover glass 8. When supporting the grid 4 with the use of frit sealing materials 2 at both ends of the base plate 1 and the middle part 7 of this plate 1, in the middle part, a frit glass pellet 12 (low-melting point glass calcined) is placed on a fixed plate 11 formed by bending a grid support 10, and the grid 4 is fixed by fusing the pellet 12 during the process of enclosing it through a furnace. In this way, it is possible to improve the strength in the direction of the grid 4 rising due to heat generated and reduce the occurrence of ununiformities in the distance to the filament.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Description of the field to which the invention pertains The present invention relates to a method for assembling a fluorescent display tube, and particularly to a method for fixing a grid.

(2) Conventional technology Fluorescent display tubes consist of an anode substrate with fluorescent material activated on an electrode pattern with wiring made of silver or the like on an insulating substrate, a mesh-like grid made of metal, and a tungsten chamber. It consists of a filament coated with a cathode agent such as barium oxide and a cover glass.

The grid has the role of diffusing electrons emitted from the filament to the anode substrate and controlling the blinking of each digit during dynamic drive.
Current flows between the grids, grid losses occur, and the grids generate heat.

Recently, as the uses of fluorescent display tubes have expanded, there has been a growing demand for fluorescent display tubes with larger external dimensions and greater luminance. In addition, the grid loss without supplying +V also increased, and the heat generated by the grid also increased.

Usually, the grid is fixed by an enclosure at both ends of the fluorescent display tube, and the grid expands and deforms when it generates heat.

In large and high-brightness fluorescent display tubes, the amount of deformation of the grid is particularly large, resulting in uneven brightness due to uneven distance between filaments and grids, and in severe cases, filament breakage due to contact short circuit between grids and filaments. An accident occurred.

In order to solve the above-mentioned problems, conventionally, two methods have been used for fixing the central portion of the grid on the anode substrate in large-sized, high-brightness fluorescent display tubes with large grid loss.

The first conventional grid fixing method will be described below with reference to the drawings. Fig. 1 shows an example of a method for preventing deformation of a grid due to thermal expansion using conventional technology, Fig. 2 shows details of a grid fixing part in the center of the grid, and Fig. 3 shows a cross-sectional view of the grid fixing part. show. In the figure, anode substrate 1
On top, a crit sealing material 2 made of low-melting glass for sealing is printed around the anode substrate 10, and at the same time, a fixing frit 3 is entirely printed at the grid fixed position.

On the other hand, the mesh-like grid 4 is fixed to the grid support 5 by spot welding, and the lead terminals 6 and the grid fixing plate 7 are integrally formed with the grid support 5. The grid fixing plate 7 is shaped so that a distance of one foot is maintained between the grid 4 and the anode substrate 1, and the fixing portion is in surface contact with the anode substrate 1, and the surface contact portion is formed with a large number of holes such as mesh-shaped holes. It has a similar shape.

In the process of encapsulating the fluorescent display tube, the grid support 5 is fixed between the anode substrate and the cover glass 8 by the frit sealing material 2, and at the same time the grid fixing plate 7 comes into contact with the fixing frit 3. Then, trace the furnace and anode substrate 1
, when sealing the cover glass 8, the fixing frit melts,
It soaks into the hole provided in the grid fixing plate 7, hardens when the temperature drops, and fixes the entire grid fixing plate 7 on the anode substrate 1.

FIG. 4 is a cross-sectional view showing the deformation of the grid 4 due to thermal expansion when the grid 4 is not fixed at the center of the anode substrate 1, and FIG. If not, it is a sectional view showing deformation of the grid 4. - As is clear from FIGS. 4 and 5, the floating of the grid 4 is greatly improved by fixing the grid 4 at the center of the anode substrate 1.

However, in the conventional method of fixing the grid 4, the grid fixing foot plate 7 is simply placed on the fixing hole 3 as shown in FIG. Since the side and lower surfaces of the grid fixing plate 7 are fixed onto the anode substrate 1 by the fixing frits 3, the contact force is relatively weak against upward pulling force.
Furthermore, since the elongation of the grid 4 due to thermal expansion mainly serves as a force that pulls the grid fixing plate 7 upward, the grid fixing portion has the disadvantage of being easily peeled off.

As a second method, a grid fixing plate 7 is placed on top of the frit sealing material 2 made of the first low-point glass, and a low-point glass melted in an organic solvent is used as a replacement. A method has been used in which the grid fixing plate 7 is fixed onto the anode substrate 1 by covering the grid fixing plate 7 with a frit paste from above and passing through the entire furnace. However, since there are many types of fluorescent display tubes in the method of fixing bookcase 2, it is difficult to automate the process, and the process is carried out by hand. Largely, many defects occurred due to this. In addition, when using a lot of frit paste, after enclosing a fluorescent display etc. and creating a vacuum, a large amount of residual decomposition gas such as the organic solvent contained in the 7 lit paste is generated, causing the degree of vacuum to drop completely, and the fluorescent display This had the disadvantage of deteriorating the characteristics of the tube.

(3) Purpose of the Invention In order to improve the conventional drawbacks, the invention fixes the grid fixing plate onto the anode substrate by melting 7 liter glass pellets from the top surface of the grid fixing plate and covering the grid fixing plate. The purpose is to fix the grid and fixing plate on the anode substrate in a stable state with little variation using a small area and sufficient adhesive force.

(4) Explanation of structure and operation of the invention FIGS. 6 and 7 show embodiments of the invention. FIG. 6 shows the state in which the fluorescent tube was put into a furnace during assembly and before the grid fixing plate was brought into contact with the anode substrate.

In FIG. 6, a grid fixing plate 11 is installed so as to be in contact with the anode substrate 9, and a frit glass pellet 12 made by sintering low melting point glass is placed on the grid fixing plate 11.
Further, the frit glass pellet 12 is sandwiched and fixed between the grid fixing plates 11.

FIG. 7 shows a cross section of the grid fixing portion when the fluorescent display tube assembled in the state shown in FIG. 6 is passed through a furnace and sealed.

In FIG. 7, the 7-litre glass pellets 12 melt when passed through the furnace, covering the grid fixing plate 11 and adhering to the anode substrate, thereby firmly fixing the grid fixing plate 11 onto the anode substrate 9.

(5) Explanation of Effects As is clear from FIG. 7, due to the invention, the contact strength of the grid fixing plate 11 to the anode substrate 9 in the grid lifting direction can be greatly increased, and the grid It is possible to reduce many defects related to floating.

And in non-invention, frit glass beret l"Nu
By making the sizes of the frit glass pellets uniform, the amount of frit glass can always be kept constant, and since the size of the frit glass berets is all the same, the amount of frit glass can be kept constant, and the part that is fixed by the grid fixing part is made of 7 glass pellets. It is possible to adopt a method of narrowing the beret shape and fixing it in a fixed position, and it becomes possible to manufacture products with less variation and which can be easily mass-produced.

Furthermore, since the frit glass pellet is sintered in advance, it generates far less gas than frit paste, and does not deteriorate the properties at all.

For non-inventive purposes, there is a significant increase in contact strength compared to the conventional first fixing method, and a significant increase in the accuracy of the frit glass fixing position compared to the conventional second fixing method. As a result, the area of the grid fixing portion can be reduced, and as a result, restrictions on grid fixing positions due to the influence of display patterns and the like are alleviated. Further, unlike the first conventional fixing method, it is not necessary to provide all the holes in the grid fixing plate 7 using mesh or the like, which has a great effect in reducing the number of design steps.

It goes without saying that the invention can be applied not only to fixing the grid fixing plate to the anode substrate, but also to fixing other parts to obtain the same effect.

[Brief explanation of the drawing]

Figure 1 is a structural diagram of a conventional fluorescent display tube in which the grid is fixed at the center of the anode substrate, Figure 2 is a sectional view of the grid fixing part in Figure 1, and Figure 4 is the grid fixed at the center of the anode substrate. Figure 5 shows the grid deformation when the grid is not fixed at
The figure shows grid deformation in the case of fixed fc, and FIGS. 6 and 7 show a method of adhering a small grid fixed foot plate to an anode substrate according to the invention. In the figure, 1...Anode substrate, 2...7 Rit seal material, 3...Fixing frit, 4...
Grid, 5... Grid support, 6...
...Lead terminal% 7...Glyph. fixing plate, 8...cover glass, 9...anode substrate, 10...grid support, 11...
・Grid fixing plate, 12... Fritted glass pellets are shown respectively. Figure 4 Prisoner S

Claims (1)

[Claims] (1) An anode with wiring and a display section formed on an insulating substrate. Multi-composed of grid, filament, and cover glass.
In a method for assembling a fluorescent display tube having a structure in which the entire grid or grid support is fixed on the insulating substrate, a low melting point glass pellet is placed on the fixed part of the grid or the grid support, and the insulating substrate is heated in a furnace. A method for assembling a fluorescent display tube, characterized by fixing a grid or a grid support on an insulating substrate at the same time as enclosing a substrate and a cover glass. (2. A method for assembling a fluorescent display tube, characterized by a structure in which the low melting point glass pellet as claimed in the claims is self-retained by the fixing portion of the grid or the grid support.