JPH0794099A - Manufacture of display tube for light source - Google Patents

Abstract

PURPOSE:To prevent the crack a front glass and a glass bulb, and improve reliability by sufficiently applying a flit glass to the glass bulb and the front glass over a wide range followed by sealing. CONSTITUTION:One opening end part 1a and peripheral part of a glass bulb 1 are coated with a flit glass 3 followed by temporary baking. The inside peripheral part of the flange part 2a of a front glass 2 is then coated with the glass 3 followed by temporary baking, and the glass 2 is set in such a manner that the part coated with the glass 3 is up, and the front surface side 2b is down, and heated and baked. Thus, the bulb 1 starts to gradually fall toward the lower direction A by its dead weight according to the softening and fusion of the glass 3. The heating and baking is successively carried out, whereby the glass 3 is molded and adhered so as to sufficiently wet over a wide range extending from the inner surface of the part 1a to the back surface side peripheral part of the glass 2, and form a spherical surface over the outer surface of the part 1a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a light source display tube, and more particularly to a sealing method for sealing a windshield and a glass bulb.

[0002]

2. Description of the Related Art FIG. 6 is a cross-sectional view of a main part showing the structure of a conventional fluorescent display tube for a light source. In the figure, 1 is a glass bulb formed in a cylindrical shape, 2 is a windshield sealed to one open end of the glass bulb 1 through a frit glass 3, and this windshield 2 is the glass bulb 1. The frit glass 3 seals the open end of the cylindrical glass bulb assembly 4 to form a cylindrical glass bulb assembly 4. 5 is a phosphor screen formed on the back side of the windshield 2, 6 is an Al metal back film formed on the phosphor screen 5, and 7 is a glass bulb 1.
Carbon film formed on the inner wall surface of the windshield 2 side of
Reference numeral 8 is a Ba getter film which is formed between the Al metal back film 6 and the carbon film 7 and electrically connects them.

Further, 10 is a stem structure sealed at the other open end of the glass bulb 1, 11 is a stem glass sealed at the other open end of the glass bulb 1 via a frit glass 12, and 13 is a stem. Exhaust pipe integrally formed on the glass 11, 14 is a lead pin 1 on the stem glass 11.
5a is a cathode structure fixedly arranged at the tip of the cathode lead 16, 17 is a cylindrical anode ring fixedly arranged at the tip of the anode lead 18 connected to the lead pin 15b, and 19 is an anode ring 17. A Ba getter 20 is attached and fixed to the tip end portion, and 20 is a valve spacer contact that is attached and fixed to the tip end portion of the anode ring 17 and is electrically connected in contact with the carbon film 7.

In such a structure, when a predetermined high voltage is supplied to the lead pin 15b from an external circuit (not shown), the path of the anode lead 18 → the anode ring 17 → the valve spacer contact 20 → the carbon film 7 → the Ba getter film 8 is formed. Are supplied to the Al metal back film 6 while being electrically connected to each other, and the lead pins 15 are similarly supplied from the external circuit.
When the control voltage is supplied via a, the cathode structure 14
An electron beam is emitted from the fluorescent substance, the fluorescent surface 5 is excited by the emitted electron beam, and the emission color corresponding to the fluorescent substance is transmitted through the windshield 2 to be emitted and displayed toward the front side.

[0005]

However, in the conventional light source display tube having such a structure, the frit glass 3 for sealing the windshield 2 and the glass bulb 1 is provided as shown in the enlarged cross section of FIG. Due to the sealing structure in which the contact angles of the windshield 2 and the glass surface of the glass bulb 1 that are in contact with each other are acute, cracks 21 are generated in the windshield 2 and the glass bulb 1 against a sudden temperature change. There has been a problem that the degree of vacuum is lowered, the life of the tube is shortened, and the reliability is lowered.

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to prevent the occurrence of cracks in the windshield and the glass bulb and to improve the reliability. It is to provide a method for manufacturing a display tube for a light source.

[0007]

In order to achieve the above object, a method of manufacturing a display tube for a light source according to the present invention comprises a step of applying frit glass to one opening end of a glass bulb, and The process of applying frit glass to the flange, the process of heating the glass bulb and the windshield and pre-baking both applied frit glasses, and the front side of the windshield facing downward on the flange of this windshield. It is formed by combining the open ends of the glass bulbs and firing.

[0008]

In the method for sealing the glass bulb and the windshield according to the present invention, since the frit glass is sufficiently applied and sealed to the glass bulb and the windshield over a wide range, the glass bulb, the windshield surface and the frit glass surface are sealed. And are not in contact with each other at an acute angle, and the strength against a sudden temperature change is improved.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 to 5 are cross-sectional views of steps for explaining an embodiment of a method of manufacturing a display tube for a light source according to the present invention, and the same parts as those in the above-mentioned drawings are designated by the same reference numerals. First, as shown in FIG. 1, a glass bulb 1 having a carbon film 7 (not shown) formed at a predetermined position on the inner wall surface is provided with an opening end portion 1a on the front side thereof and from the opening end portion 1a to the inner and outer wall surface portions. After frit glass 3 is coated on the peripheral portion by, for example, a dipping method, it is calcined. Next, as shown in FIG. 2, the windshield 2 having the fluorescent surface 5 and the Al metal back film 6 formed on the back side is attached to the flange portion 2 of the windshield 2.
Similarly, the inner peripheral edge portion of a is coated with the frit glass 3 and then calcined. Note that the calcination of the frit glass 3 coated on the glass bulb 1 and the calcination of the frit glass 3 coated on the windshield 2 may be performed at the same time or separately.

Next, as shown in FIG. 3, the windshield 2
Is installed so that the flange portion 2a coated with the frit glass 3 faces upward and the front side 2b thereof faces downward, and similarly, the opening end portions 1a coated with the frit glass 3 face each other and are combined to temporarily After the bonding, the glass bulb 1 is heated and fired at a predetermined temperature higher than the above-mentioned calcination temperature, as shown in FIG.
Along with the softening and melting of the frit glass 3, the frit glass 3 gradually begins to descend in the downward direction indicated by the arrow A due to its own weight.

Subsequently, as a result of this heating and firing, as shown in FIG. 5, the frit glass 3 is sufficiently wet and bonded in a wide range from the inner surface of the opening end 1a to the peripheral edge of the windshield 2 on the back side, and the flange 2a Is molded and adhered so as to form a spherical shape from the outer surface to the outer surface of the opening end 1a, so that the windshield 2 and the glass bulb 1 are extensively solidified and sealed by the frit glass 3.

Although the glass bulb 1 has the carbon film 7 formed on the inner wall surface thereof in the above-mentioned embodiment, it may be formed after the windshield 2 and the glass bulb 1 are sealed. . Although the case where the phosphor screen 5 and the Al metal back film 6 are formed on the back side of the windshield 2 has been described, it goes without saying that it may be formed after the windshield 2 and the glass bulb 1 are sealed. .

According to such a method, since the frit glass 3 seals the sealed portion between the windshield 2 and the glass bulb 1 over a wide range with an obtuse contact angle, a rapid temperature change due to heat conduction is prevented. Since it becomes difficult to apply a rapid thermal shock to the windshield 2 and the glass bulb 1, cracks are less likely to occur, and vacuum breakage can be reliably prevented.

Further, according to such a method, since the outer surface side sealing portion between the windshield 2 and the glass bulb 1 is overcoated with the frit glass 3, it has been conventionally performed for the purpose of protecting the sealing portion. Since it is possible to prevent the occurrence of cracks and to obtain a sealing structure with good weather resistance, it is possible to reduce the manufacturing cost because it is not necessary to attach a cap and a sealing part protection component such as a silicone resin, and the mounting work is completely unnecessary.

[0015]

As described above, according to the present invention,
Since the frit glass can seal the sealing part between the windshield and the glass bulb over a wide area, it is possible to prevent cracks on the windshield and the glass bulb against sudden temperature changes, resulting in a vacuum break. It has an extremely excellent effect that a highly reliable display tube for a light source having a long tube life can be obtained at low cost.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of a process for explaining an embodiment of a method of manufacturing a light source display tube according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of a step following FIG.

FIG. 3 is an enlarged sectional view of an essential part of a step following the step of FIG.

FIG. 4 is an enlarged sectional view of an essential part of a step following the step of FIG.

FIG. 5 is an enlarged cross-sectional view of a main part of a step following that of FIG.

FIG. 6 is a cross-sectional view showing a configuration of a conventional light source display tube.

FIG. 7 is an enlarged sectional view of an essential part for explaining a problem of the conventional light source display tube.

[Explanation of symbols]

 1 Cylindrical glass bulb 1a Open end 2 Front glass 2a Flange 2b Front side 3 Frit glass 4 Glass bulb structure 5 Fluorescent surface 6 Al metal back film 7 Carbon film 8 Ba getter film 9 Anode electrode 10 Stem structure 11 Stem glass 12 Frit glass 13 Exhaust pipe 14 Cathode structure 15a Lead pin 15b Lead pin 16 Cathode lead 17 Anode ring 18 Anode lead 19 Ba getter 20 Valve spacer contact 21 Crack

Claims (1)

[Claims] 1. A display tube for a light source, which is configured by sealing a windshield having at least a fluorescent surface formed on an inner surface thereof and a glass bulb having an electrode structure provided therein with frit glass, wherein the glass bulb A step of applying frit glass to one of the opening end portions, a step of applying frit glass to the flange portion of the windshield, a step of heating the glass bulb and the windshield, and calcination of both frit glasses. And a step of firing the front side of the windshield facing downward and combining the flange portion of the windshield with the open end of the glass bulb, and firing.