JP3245970B2 - Cathode ray tube and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cathode ray tube and a method for manufacturing the same.

[0002]

2. Description of the Related Art A flat cathode ray tube is one type of cathode ray tube.
As shown in schematic vertical and horizontal sectional views in FIGS. 1A and 1B, the main components of the flat cathode ray tube are a glass container 10, an electron gun 12, a phosphor screen 14, and a deflection yoke. Sixteen. The electron gun 12 and the deflection yoke 16
The structure is almost the same as that of a normal black-and-white picture tube or the like, except that the fluorescent screen 14 is inclined at a certain angle with respect to the axis of the electron gun 12 and is curved. ing.

[0003] The glass container 10 includes a front panel 20,
It consists of a screen panel 22 and a funnel 24, which are joined by frit fusion. In addition, the front panel 20, the screen panel 22, and the funnel 24 may be collectively referred to as a glass container component. The fluorescent screen 1 is provided on the inner surface of the screen panel 22.
4 are provided, and images and videos on the fluorescent screen 14 are observed through the front panel 20.

Usually, before assembling the glass container 10,
The front panel 20, the screen panel 22, and the funnel 24, each of which has been processed into a predetermined shape, are subjected to chamfering and polishing to each of the joints or a part thereof. By this chamfering polishing process, when the glass container components are joined with the frit, deterioration of airtightness and occurrence of leak at the joined portion are prevented.

[0005]

The chamfering and polishing process will be described below using the front panel 20 as an example. First, the flat glass is cut into a predetermined size. A partial perspective view of the cut product is shown in FIG. In this figure, specifically, the cut surface 30 is a joint portion with the funnel. Next, chamfering polishing of the ridge 32 of the cut surface 30 is performed. Conventionally, as shown in FIG. 3B, the polishing direction is perpendicular to the thickness of the front panel 20 (indicated by an arrow H in FIG. 3B), that is, parallel to the direction in which the ridge 32 extends. such a direction (indicated by arrow a in the FIG. 3 (B)). Chamfer polishing is
For example, using a lapping machine and using carborundum as an abrasive. If necessary, chamfering and polishing of the ridge at the joint between the screen panel 22 and the funnel 24 is performed in the same manner. By such chamfering polishing,
Fine grooves 36 are formed on the chamfered surface 34 in a direction perpendicular to the thickness of the glass container component, that is, in a direction parallel to the direction in which the ridge 32 extends .

[0006] The glass container components are joined with a frit,
When assembling the glass container 10, the higher the firing temperature of the frit, the more the frit becomes in a fluid state and may spread on the surface of the joint portion of the glass container component, thereby preventing leakage from the joint portion and deterioration of the airtightness of the joint portion. be able to. Generally, in order to prevent the characteristic deterioration of the phosphor screen 14,
It is necessary to set the firing temperature of the frit to 450 to 600 ° C. or less. However, at such a temperature, the viscosity of the frit is high, and it is difficult for the frit to spread sufficiently on the surface of the joint. As shown in FIG. 3B, when the fine groove 36 exists in the chamfered surface 34, the spread of the frit on the surface of the joint portion is hindered by the fine groove 36, and the frit is more difficult to spread on the surface of the joint portion. Problem.

In the case of a frit containing a solvent, it is necessary to fire the frit while expelling bubbles generated inside the frit by evaporation of the solvent during firing of the frit to the outside of the frit. This is because if such bubbles remain inside the frit, the reliability of the joint portion becomes poor. However, as shown in FIG. 3B, when the fine groove 36 is present in the chamfered surface 34, there is also a problem that the escape of the bubbles to the outside of the frit is obstructed by the groove 36.

[0008] Due to these problems, as shown in an enlarged sectional view of the joint portion in FIG. 4, a leak or poor airtightness occurs from the portion "C".

Conventionally, in order to solve these problems, various studies have been made by paying attention to the dimensions of the chamfered surface and the finish roughness of the chamfering polishing. Was difficult to achieve with a simple processing method.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cathode ray tube capable of effectively preventing the hermetic deterioration or leakage of the joint portion of the glass container components when the glass container components of the cathode ray tube are joined by frit welding. It is another object of the present invention to provide a method for manufacturing a cathode ray tube which can surely manufacture such a cathode ray tube by a simple processing method.

[0011]

A cathode ray tube according to the present invention for achieving the above object is a cathode ray tube provided with a glass container formed by joining a plurality of glass container components by frit fusion. And a leak from the joint at the ridge of the joint of the at least one glass container component.
Or, in order to suppress the deterioration of airtightness,
It is characterized in that chamfering is performed in a direction substantially perpendicular to the direction.

[0012] In a preferred embodiment of the cathode ray tube of the present invention, the glass container component can be composed of a front panel, a screen panel and a funnel.

Further, a method of manufacturing a cathode ray tube according to the present invention for achieving the above object is a method of manufacturing a cathode ray tube having a glass container formed by joining a plurality of glass container components by frit fusion. is there. And at least one
The chamfering and polishing direction of the ridge at the joint of two glass container components suppresses leakage from the joint or deterioration of airtightness
In order to achieve this, it is characterized by being substantially perpendicular to the direction in which the ridge extends .

In a preferred embodiment of the method for manufacturing a cathode ray tube according to the present invention, the glass container components can be composed of a front panel, a screen panel and a funnel.

In the cathode ray tube and the method of manufacturing the same according to the present invention, even if the edge of one joint portion of the glass container component is chamfered or polished, if necessary, two or more glass container components are joined. The edge of the portion may be chamfered and polished. Further, it is not always necessary to perform the chamfering polishing on all the ridges in one joint portion, but may be performed on only some of the ridges. Chamfer polishing direction is the direction of the ridge extension
It may not be completely parallel to the direction perpendicular to the direction . The chamfering polishing direction is preferably within 15 degrees with respect to the direction perpendicular to the direction in which the ridge extends, but is not particularly limited to this value.

The chamfering polishing method may be the same as the conventional method. For example, carborundum may be used as an abrasive to be used, and a lapping machine may be used.

[0017]

In the cathode ray tube and the method of manufacturing the same according to the present invention, the direction of chamfering and polishing of the ridge of the joint portion of the glass container component (see arrow B in FIG. 2B) is the direction in which the ridge extends.
It is almost a right angle . As shown in FIG. 2B, in the chamfering polishing, for example, the chamfered surface 3 of the front panel 20 is formed.
4, small grooves 38 are formed.
The direction of 8 is toward the outer surface of the front panel 20 (see the arrow B in FIG. 2B). Therefore, when the frit is fired, the spread of the frit on the surface of the joint portion is not hindered by the fine groove 38. In addition, the bubbles generated inside the frit when the frit containing the solvent is fired are prevented from leaking out of the frit by the fine grooves 38.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a cathode ray tube of the present invention and a method for manufacturing the same will be described based on embodiments. In this embodiment, the glass container component 10 includes a front panel 20, a screen panel 22, and a funnel 24, and the cathode ray tube is the flat cathode ray tube shown in FIG. Then, the edge 32 of the joint portion of the front panel 20 joined to the funnel 24 was chamfered and polished. Chamfer polishing direction is ridge 32
Is perpendicular to the direction in which

A flat glass sheet having a thickness of 3.0 mm is 69 × 60
mm to obtain a front panel 20. A partial perspective view of the cut front panel 20 is shown in FIG.
In this figure, specifically, the cut surface 30 is a joint portion with the funnel. Next, chamfering polishing of the ridge 32 of the cut surface 30 is performed. As shown in FIG. 2B, the polishing direction is a direction perpendicular to the direction in which the ridge 32 extends (indicated by an arrow B in FIG. 2B). The chamfering polishing is performed using a wrapping machine and using carborundum as an abrasive. In addition, if necessary, the screen panel 22
In addition, chamfering and polishing of the ridge of the joint portion of the funnel 24 can be similarly performed. By such chamfering polishing,
A fine groove 38 is formed in the chamfered surface 34 in a direction substantially perpendicular to the direction in which the ridge 32 extends .

The front panel 20 thus chamfered and polished, and the screen panel 2 manufactured by a predetermined method.
2. The funnel 24 is joined with a PbO / B ₂ O ₃ based frit. In air, the firing temperature of the frit is 450 ° C,
The firing time was 30 minutes. Thus, the glass container 10 was assembled, and a cathode ray tube was completed based on a conventional method.

As a comparative example, a method similar to that of the embodiment was adopted except that the chamfering polishing direction was perpendicular to the thickness direction of the front panel (see the arrow A in FIG. 3B) as in the conventional case. Produced a cathode ray tube.

The cathode ray tube (sample number = 5560) manufactured by the manufacturing method of the present invention described in the examples and the cathode ray tube (sample number = 4300) manufactured by the manufacturing method of the comparative example were 700
The ratio of ion current / beam current after standing for a period of time was measured to determine the gas-ratio defect ratio. As a result of the measurement, the gas-ratio defect ratio of the cathode ray tube manufactured by the manufacturing method of the present invention described in the example was 0.26%. On the other hand, the gas-ratio defect ratio of the cathode ray tube manufactured by the manufacturing method of the comparative example was 0.86%.

Although the cathode ray tube and the method for manufacturing the same according to the present invention have been described based on the preferred embodiments, the present invention is not limited to these embodiments. The size of the front panel and the like, the conditions for chamfering and polishing, the equipment to be used, etc., or the material and firing conditions and method of the frit can be changed as appropriate. As the cathode ray tube, other than the flat cathode ray tube, any cathode ray tube that requires chamfering at the ridge of the joint portion of the glass container component is included in the cathode ray tube of the present invention.

[0024]

In the cathode ray tube and the method of manufacturing the same according to the present invention, by changing the direction of chamfering and polishing of the joint portion from the conventional one, leakage from the joint portion or deterioration of airtightness can be reliably prevented, and high reliability is obtained. Can be obtained. The chamfering and polishing can be performed by simply modifying the existing apparatus, and the manufacturing cost of the cathode ray tube does not increase.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a flat cathode ray tube.

FIG. 2 is a perspective view of a glass container component taking a front panel as an example for explaining a cathode ray tube and a method of manufacturing the same according to the present invention.

FIG. 3 is a perspective view of a front panel for explaining a conventional cathode ray tube and a method of manufacturing the same.

FIG. 4 is a partial cross-sectional view of a front panel and a funnel for explaining a problem of a conventional cathode ray tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Glass container 12 Electron gun 14 Fluorescent surface 16 Deflection yoke 20 Front panel 22 Screen panel 24 Funnel 28 Frit 30 Cut surface 32 Ridge of cut surface 30 Chamfer surface 36, 38 Fine groove

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Open to the public Showa 61-87442 (JP, U) Open to the public Showa 50-98661 (JP, U) Open to the public Showa 51-77957 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) H01J 29/86 H01J 9/24

Claims (4)

(57) [Claims] 1. A cathode ray tube provided with a glass container obtained by joining a plurality of glass container components by frit fusion, wherein at least one of the glass container components is joined to a ridge of a joining portion. Leak or deterioration of airtightness
A cathode ray tube, which is chamfered and polished in a direction substantially perpendicular to a direction in which the ridge extends in order to suppress the occurrence of the ridge . 2. The glass container component comprises a front panel,
The cathode ray tube according to claim 1, comprising a screen panel and a funnel. 3. A method for manufacturing a cathode ray tube provided with a glass container obtained by joining a plurality of glass container components by frit fusion, wherein the edge of a joining portion of at least one glass container component is chamfered and polished. Direction from joint
Of the ridge in order to suppress
A method for manufacturing a cathode ray tube, which is substantially perpendicular to an extending direction . 4. The glass container component comprises a front panel,
4. The method according to claim 3, comprising a screen panel and a funnel.