JPH0141154Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to improvements in control electrodes (hereinafter referred to as grids) in fluorescent display tubes, and particularly relates to a fluorescent display tube that prevents deformation of the grid caused by heat generation due to grid current. It is.

In general, in fluorescent display tubes, a support frame called a spacer frame is often used as a member for supporting and fixing grids and oxide hot cathode (hereinafter referred to as filament) supports in predetermined positions.

That is, as shown in FIG.
A spacer frame 1 is formed of a grid lead wire 3 extending from the grid frame 2 to supply an external signal to the grid 6, an anode lead wire 4, a lead wire support portion 5 for connecting and holding these lead wires, and the like. .

A grid 6 is welded and fixed to the grid frame 2 of this spacer frame 1. Further, filament supports 8, 8 are fixed to a frame portion connected to the filament lead wire 7, and a filament 9 is stretched between the filament supports 8, 8 to form an electrode assembly 10. This electrode structure 10 is
Each lead wire portion of the spacer frame 1 is sandwiched between the anode substrate 13, on which the anode portion 11 and its wiring conductor 12, etc. are formed in advance, and the container portion 14, and a sealing material such as low melting point glass is used. It is sealed and held fixed. Then, the inside of the envelope formed by the anode substrate 13 and the container part 14 is evacuated to a high vacuum state. After that, the lead wire support part 5
The unnecessary parts of the tube are cut and removed to make a fluorescent display tube.

Incidentally, in recent years, various shapes of fluorescent display tubes have been devised to meet user demands, and various shapes of spacer frames, grids, and display patterns are required, and the fluorescent display tubes themselves are also becoming larger. It is in. Therefore, due to the design of the display pattern, etc., the area of one grid becomes large.
The problem has been that the current flowing through the grid becomes large, generating heat and deforming the grid due to thermal expansion, causing it to come into contact with the anode or filament. Furthermore, even if these fatal defects do not occur, they still cause uneven brightness and the like. In particular, as the grid becomes larger, the current flowing into the grid increases accordingly, and the problem of contact between the grid and other electrodes due to heat generation frequently occurs.

Therefore, as a conventional method for preventing the grid of a fluorescent display tube from being deformed due to thermal expansion, a method as shown in FIG. 2 has been adopted. In Fig. 2a, a reinforcing frame 22' is provided on the grid frame 22 of the spacer frame to the extent that it does not affect the display, the grid frame 22 is reinforced, and the grid 21 is attached to the grid frame 22 as shown by the welding points 33 marked with an x. In addition, the deformation of the grid 21 is mechanically suppressed by welding at multiple locations.

However, with the structure described above, as shown by the dashed line in FIG. A bending moment acts on the frame 22 and the reinforcing frame 22', and since the reinforcing frame 22' is not restrained with respect to the anode substrate, it deforms and is not very effective, and also requires a lot of welding man-hours and time. There was a problem.

Further, in the structure shown in FIG. 2c, a forming claw 21' is provided on the grid 21 by pressing or the like within a range that does not affect the display, and this forming claw 21' is made to protrude toward the anode substrate side. By forming the above-mentioned forming claws 21', the grid 21 will not come into contact with the anode part, but as shown by the dashed line in FIG. 2d, there is no means for restraining the forming claws 21'. When the thermal deformation force of the grid acts on the filament side, it easily deforms and is not very effective against the lifting of the grid.
There was a problem.

The present invention was developed in view of the above-mentioned problems, and is designed to prevent thermal deformation due to grid current when electricity is applied to the grid, and in particular to prevent thermal deformation even when a single grid has a large area. It is an object of the present invention to provide a fluorescent display tube that can prevent the grid from coming into contact with other electrodes, and can eliminate uneven brightness.

In order to achieve the above object, the present invention has a structure in which a control electrode is disposed on an anode substrate on which an anode part with a phosphor layer coated on the upper surface is formed, and the electrons emitted from the cathode are controlled by the control electrode. Acceleration is controlled by electrodes,
In a fluorescent display tube that is projected onto the phosphor layer to produce a desired display, a support claw is formed integrally with the control electrode and protrudes toward the anode substrate, and an end of the support claw is connected to the anode. A fluorescent display tube is characterized in that it is fixed on a substrate.

Hereinafter, an embodiment of a fluorescent display tube according to the present invention will be described with reference to the drawings.

FIG. 3a is a plan view showing an embodiment of a fluorescent display tube according to the present invention, and FIG. 3b is a sectional view taken along the line A--A in FIG. 3a.

Here, 30, like the conventional fluorescent display tube described above and shown in FIG. It is. And this anode substrate 3
A grid 31 fixedly held by a spacer frame 34 is disposed on the spacer frame 34.

This grid 31 leaves a portion that does not affect the display without forming it into a mesh shape. Further, the stiff portion is punched out by pressing or the like to create a frame portion for claws and reinforcement, and the claw portions are bent at the same time to form supporting claws 31'. The support claw 3
1' may be formed to have a length approximately equal to the installation height of the grid 31 relative to the anode substrate 30.

The grid 31 is welded and fixed to the spacer frame 34 at welding points 33 indicated by cross marks. Further, the support claw 31' is fixed to the anode substrate 30 by a fixing material 32, for example, a sealing glass used as a sealing material 37. That is, the grid 31 of the fluorescent display tube according to the present invention has support claws 31' extending from a part of the grid 31.
is formed in a protruding manner, and one end of this support claw 31' is fixed onto the anode substrate 30.

Furthermore, a filament 40 stretched between filament supports 39 is disposed on the grid 31, similar to the conventional fluorescent display tube shown in FIG. 1 described above. Then, the container part 36 is attached to the sealing material 34 so as to cover each of these electrodes and sandwich a part of the spacer frame 34 between the anode substrate 30 and the anode substrate 30.
Seal by step 7. Thereafter, the interior is evacuated to a high vacuum state through an exhaust pipe (not shown), and the exhaust pipe is sealed to obtain the fluorescent display tube of the present invention.

In this case, if the same sealing glass as the sealing material 37 is used as the fixing material 32 used to fix one end of the support claw 31' on the anode substrate 30, the sealing of the container part 36 and the support claw ′ can be fixed at the same time. That is, the sealing material 37 is placed around the peripheral edge of the anode substrate 30 on which the anode portion 35 and the like are formed.
At the same time as applying and drying, the fixing material 32 is also applied to a desired position on the anode substrate 30 by, for example, screen printing, and dried.

Then, when the container part 36 is sealed and evacuated, the fixing material 32 is also melted and solidified at the same time, and the supporting claws 3
1' fixation may be performed. Fixing material 32
If the fixing material 37 and the fixing material 37 are different materials, the fixing of the support claw 31' by the fixing material 32 may be different from the container part 3.
It goes without saying that the sealing step 6 may be performed in a separate step.

When sealing glass is used as the fixing material 32, the material of the grid 31 is 42.6 alloy (42% Ni, 6% Cr,
The use of the remainder (Fe) has the advantage of preventing cracks from occurring due to the difference in thermal expansion coefficient with the supporting claws 31' when the fixing material is solidified, and ensuring the fixing of the supporting claws 31'.

Furthermore, as shown in FIG.
Various shapes can be adopted depending on the size of the grid 31, the height between the anode substrate 30 and the grid 31, etc.

Furthermore, if the grid 31 is relatively small,
As mentioned above, since it is not necessary to provide a frame portion to the support claws 31' to reinforce them, the support claws 31' may be formed by directly cutting and raising a part of the mesh portion of the conventional grid by pressing or the like.

Next, the operation of the fluorescent display tube according to the present invention having the above-described structure will be explained.

FIG. 4 is a diagram for explaining the operating state of the fluorescent display tube of the present invention in comparison with a conventional fluorescent display tube. In a conventional fluorescent display tube, when electricity is applied to the grid, thermal deformation occurs due to the inflowing current, and the grid 31 is raised, for example, as shown by the dashed line.

However, in the fluorescent display tube of the present invention, this thermal deformation of the grid 31 is suppressed by the support claws 31' fixed on the anode substrate 30. In this case, even if the support claw 31' is provided at only one location, the support claw 31' formed on the grid 31 is firmly fixed to the anode substrate 30 by the adhesive material 32. As shown in the figure, the amount of floating of the grid 31 is at least half that of the conventional method. The same thing can be said even if the grid 31 does not rise but sag.

Therefore, even if the grid 31 is provided with only one support claw 31', the deformation of the grid 31 is at least half that of the conventional one, and the grid 31 does not sag and come into contact with the anode section 35. Further, it will not float up and come into contact with a filament (not shown). Furthermore, since the grids 31 are held at substantially constant intervals from the anode substrate 30, it is of course possible to reduce uneven brightness.

In addition, in FIG. 4, only one support claw 31' is formed on the grid 31, but the support claw 31'
By increasing the number of 1', deformation of the grid can be further suppressed.

Furthermore, as shown in Figure 5a and b, grid 3
1 to the spacer frame 34 by welding,
By varying the welding points 33 depending on the formation position and number of the support claws 31', it becomes possible to reduce the number of welding points and effectively release the elongation due to thermal deformation of the grid. For example, Figure 5a
In this case, when the support claws 31' of the grid 31 are formed to be biased to the right side of the grid 31, the grid 31 can be firmly fixed even if the welding point 33 is not provided on the right side of the grid 31. I can do it. In addition, by providing a portion that is not welded on one side of the grid 31, the grid 3 is prevented from being welded due to thermal expansion.
1 distortion can be missed.

Furthermore, as shown in FIG. 5b, the support claw 31'
When the grid 31 is located at the lower center of the grid 31, the welding points 33 need only be provided at the upper right side and the lower left side of the grid 31, making it possible to reduce the number of welding points.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, but can be modified in various ways without changing the gist thereof.

As described above, in the present invention, the grid is provided with support claws that regulate the height from the anode substrate, and by fixing the support claws to the anode substrate with an adhesive, heat generated by the grid current during operation can be avoided. This is to prevent deformation. Therefore, lifting of the grid or drooping due to slack is prevented, and the grid does not come into contact with the filament or the anode portion. In addition, since the grid is fixed to the anode substrate via the support claws, vibration resistance and impact resistance are greatly improved, and the distance between the anode and the grid is kept almost constant, preventing uneven brightness. It is effective on

In particular, the effect obtained is extremely large when used in large-sized fluorescent display tubes in which the size of a single grid tends to increase, and in fluorescent display tubes with composite displays.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view illustrating the structure of a conventional general fluorescent display tube, FIGS. Figures a and b are a plan view and a longitudinal cross-sectional view of an embodiment of a fluorescent display tube according to the present invention, Figure 3c is a diagram showing various shapes of main parts of the embodiment, and Figure 4 is Figures 5a and 5b, which show the operating state of this embodiment in comparison with the conventional example, are plan views of main parts showing another embodiment of the present invention. 30... Anode substrate, 31... Grid, 31'... Support claw, 32... Adhesive material, 35... Anode section, 41... Phosphor layer.

Claims (1)

[Claims for Utility Model Registration] (1) A control electrode is provided on an anode substrate on which an anode portion with a phosphor layer coated on the upper surface is formed, and electrons emitted from the cathode are accelerated and controlled by the control electrode. In a fluorescent display tube that is made to strike the phosphor layer to produce a desired display, a support claw is provided which is integrally formed with the control electrode and projects toward the anode substrate, and an end portion of the support claw is provided. A fluorescent display tube characterized in that the fluorescent display tube has a structure in which: is fixed on the anode substrate. (2) The fluorescent display tube according to claim 1, wherein the support claw is integrally formed by cutting and raising a part of the control electrode.