JPS63284742A - Fluorescent character display tube - Google Patents

Abstract

PURPOSE:To stabilize the process for manufacturing the fluorescent character display tube and eliminate a projected exhaust tube by airtightly bonding a plug to an exhaust hole provided on the part of a vacuum vessel with the use of a frit glass having a softening point lower than that of a frit glass for airtightly sealing an anode substrate to a cover member. CONSTITUTION:An exhaust hole 24 having a predetermined size is provided on an anode substrate 2 and a frit glass 4-3 is applied on a plug 5 of the exhaust hole 24 in a separated process. A frit glass having a lower softening point is used as a frit glass 4-3 for bonding the plug 5 to the exhaust hole 24 so that a temperature difference between the melting point of the frit glass 4-3 and a baking temperature become smaller, and the probability with which crack on an airtightly sealed part due to the frit glasses 4-1, 4-2 of the anode substrate 2 and the cover also become smaller. Therefore, it is possible to eliminate an exhaust tube in the small sized fluorescent character display tube where a distance among the exhaust hole 24, anode substrate 2 and the airtightly sealed part formed with frit glasses 4-1, 4-2 is not efficient.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluorescent display tube that does not have an exhaust pipe for evacuating the inside of a vacuum container.

[Conventional technology]

A fluorescent display tube is a type of vacuum tube, and is generally equipped with a thin glass tube, a so-called exhaust tube, for evacuating the inside of a vacuum container.

However, this exhaust pipe protrudes from the end surface of the container by about 5 to 101111 degrees when the exhaust operation is completed, and is a complete hindrance in handling the fluorescent display tube. In addition, because it is a thin glass tube, it cracks with the slightest impact, and before the evacuation process, it protrudes from the vacuum container by about 50 to 70 I + 11, making it difficult to handle and installing it on a part of the container is very troublesome. As a result, workability was significantly reduced during the manufacturing process.

Therefore, in order to address these problems,
No. 274, JP-A-53-15749, JP-A-53-1
Fluorescent display tubes such as No. 31751 and Japanese Utility Model Application No. 55-81254 have also been proposed, but they have not been put into practical use.
Utility Model No. 60-29356.

Fluorescent display tubes such as Utility Model Application No. 61-7853 were proposed,
It has come to be put into practical use by airtightly adhering an exhaust hole plug to an exhaust hole provided in a vacuum container using a piece of frit glass.

[Problem that the invention seeks to solve]

However, in such a fluorescent display tube, the frit glass for bonding the anode substrate and the lid member and the frit glass for bonding the exhaust hole plug to the exhaust hole are made of the same frit glass. Therefore, with a large fluorescent display tube in a vacuum container, there is a sufficient distance between the exhaust hole and the frit glass part that hermetically seals the anode substrate and lid member, so this is not a particular problem, but with a small fluorescent display This is inconvenient because pipes cannot cover that distance. That is, when the frit glass that has been applied and fired in advance to the exhaust hole plug is heated and melted and adhered to the exhaust hole provided in the vacuum container, the 7-lit glass part that has been hermetically sealed between the anode substrate and the lid member is heated and melted. Cracks occur in the vacuum container.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide a fluorescent display tube with a stable manufacturing process and without a protruding exhaust pipe.

[Means for solving problems]

The fluorescent display tube according to the present invention uses frit glass, which has a lower softening point than 7-lit glass which hermetically seals the anode substrate and lid member constituting the vacuum container, to discharge crystals through an exhaust hole provided in a part of the vacuum container. It is to be attached tightly.

[Effect]

Normally, when an exhaust hole plug is hermetically bonded to an exhaust hole provided in a vacuum container, the entire vacuum container is evacuated.
Gas release baking is performed at approximately 350°C. At this time, the exhaust hole plug is heated by a heating rod to a temperature that melts the 7-litre glass coated on the exhaust hole plug, and is bonded under pressure to the exhaust hole portion of the vacuum container. Therefore, since there is a large difference between the baking temperature of the vacuum container and the melting temperature of the 7-Lit glass, if the exhaust hole is locally heated by the heating of the exhaust hole plug, the anode substrate with residual strain and the lid member's hermetic sealing by the 7-Lit glass may be damaged. This will cause cracks to form in the bonded area.

However, in the present invention, since 7-lit glass with a low softening point is used as the frit glass for adhesion of the exhaust hole plug,
The temperature difference between the melting temperature and the baking temperature of the frit glass is small, and the probability of cracks occurring in the hermetically sealed portion of the anode substrate and the lid member by the frit glass is reduced.

Therefore, even in small fluorescent display tubes where it is difficult to maintain a sufficient distance between the exhaust hole, the anode substrate, and the hermetically sealed part of the lid member made of 7-litre glass, the fluorescent display tube without an exhaust tube (also called chipless) can be used. It can be made into a light display tube, and even if it is a large fluorescent display tube with a sufficient distance, there is a greater degree of freedom regarding restrictions on the position of the exhaust hole.

〔Example〕

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a schematic perspective view showing an embodiment of a fluorescent display tube according to the present invention, and FIG. 2 is a sectional view taken along the line ■--■ in FIG. Here, an anode wiring pattern (not shown) is formed on the anode substrate 2 to take out the leads of each electrode, and a phosphor anode 21.degree. control grid 22. A filament cathode 2321- is attached. The windshield 1 and the side frame 3 are made of 7-lit glass 4-IK.
A cover glass is formed by airtightly sealing the cover glass in advance, and a 7-lit glass 4-2 is applied to the end of the side frame 3b which becomes the sealing surface with the anode substrate 2, and pre-baked in an oxidizing atmosphere to remove the binder. I'll go.

Next, the anode substrate 2 and the cover glass are hermetically sealed with a frit glass 4-2 in a non-oxidizing atmosphere such as N1 at atmospheric pressure to form a vacuum container. The steps for forming the vacuum container up to this point are similar to the steps for manufacturing conventional fluorescent display tubes. However, the anode substrate 2 is provided with an exhaust hole 24 of a predetermined size. Further, in a separate step, the exhaust hole plug 5 is coated with 7-lit glass 4-3 and fired in an oxidizing atmosphere to prepare the exhaust hole plug 5 with frit glass baked on one side.

Next, one exhaust hole stopper 5 is placed on a heating rod provided in a vacuum chamber (not shown), and the vacuum container of the fluorescent display tube is placed in the vacuum chamber with the position of the exhaust hole 24 corresponding to the position. Thereafter, the inside of the vacuum chamber is evacuated and the inside of the fluorescent display tube is evacuated. At this time, the fluorescent display tube is degassed and baked in a vacuum chamber, the filament is activated, and the exhaust hole 24 is hermetically sealed with the exhaust hole plug 5 using the frit glass 4-3. Completed fluorescent display tube.

Here, as the material of the exhaust hole plug 5, 42Nt-Fe alloy r42Nj-6Cr-Fe alloy or the like is used.

7-lit glass 4-1.4-2 is, for example, LS-0118 manufactured by Nippon Electric Glass Co., Ltd. (softening point: 390°C, sealing temperature: 43°C).
0℃), LS-0206 (softening point 410℃, sealing temperature 4
50° C.) is usually used due to the thermal expansion coefficient 9 and the working temperature.

On the other hand, for the 7-lit glass 4-3, the sealing temperature is the baking temperature of the fluorescent display tube in the vacuum chamber.
It is desirable for Z>j to be close to 50°C, but due to ease of availability and thermal expansion coefficient, for example, LS-0802 (softening point 360°C, sealing temperature 420°C) also manufactured by Nippon Electric Glass Co., Ltd.
, LS-0803 (softening point 350℃, sealing temperature 400℃
), LS-1101 (softening point 350 °C, sealing temperature 38
0℃), LS-1102 (softening point 360℃, sealing temperature 400℃), LS-2001B (softening point 380℃)
, sealing temperature 415℃), LS-2003 (softening point 370
℃, sealing temperature 430℃) KF1 manufactured by Iwaki Glass ■
316 (softening point: 356°C, sealing temperature: 440°C), etc. can be used.

In the above description, the entire fluorescent display tube is placed in a vacuum chamber and evacuated. However, the work is not limited to this, and only the exhaust hole 24 is
There is also a method of adsorbing with a ring or the like and then exposing the outer surface of the vacuum container to the atmosphere and performing the exhaust operation. In this case, in order to protect the O-ring from heat damage, it is necessary to cool the area around the O-ring, making the present invention even more effective.

〔Effect of the invention〕

As described above, the problem with the fluorescent display tube of the present invention is that the softening point of the frit glass used for adhesion of the exhaust hole plug has a small temperature difference from the vacuum baking temperature, so cracks occur in the button fluorescent display tube during exhaust work. Even if the distance between the airtight seal between the anode substrate and the lid member and the exhaust hole is not wide enough, the fluorescent display tube without an exhaust tube can be used. It can be used as a light display tube, and in the case of a large fluorescent display tube, there are advantages such as fewer restrictions on the position of providing an exhaust hole.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of a fluorescent display tube according to the present invention, and FIG. 2 is a sectional view taken along the line 1--1 in FIG. 1... Windshield, 2... Anode substrate, 3... Side frame, 4-1.4-2
・・・・・・Frit glass, 4-3・・・・・・
Fritted glass, 5...exhaust hole plug, 2
1... Fluorescent anode, 22... Control grid, 23... Filament cathode,
24...Exhaust hole.

Claims (1)

[Claims] A vacuum container is constructed by hermetically sealing an anode substrate on which each electrode of a phosphor anode, a grid, and a filament cathode is mounted, and a lid member covering the anode substrate with frit glass. In a fluorescent display tube in which an exhaust hole plug is airtightly attached to an exhaust hole provided in a vacuum with a frit glass in a vacuum, the exhaust hole is sealed with a frit glass having a softening point lower than that of the sealing frit glass of the anode substrate and the lid member. A fluorescent display tube characterized in that a hole plug is hermetically attached to an exhaust hole.