JPH08111189A - Funnel for color cathode ray tube - Google Patents

Abstract

PURPOSE: To improve sealing strength and heat resistance and restrain cracking by forming an inclined part at the sealing end part side of a reference protrusion and shaping the inclined part into a gentle surface of a third order curve. CONSTITUTION: A funnel 10 has an inclined part 15 formed at the sealing end part 11 of a reference protrusion 13 thereof and shaped into a recessed third order curved surface, gradually recessed-shape toward sealing end from the center to both ends 15a. When the funnel 10 with such a protrusion 13 is sealed to a panel 20, if frit glass 14 coming out of the end 11 of the funnel 10 from the sealing end part 21 of the panel 20 drops and arrives at the protrusion 13, it is hardly cracked because of the inclined part 15 formed, even if a large angle θ and great sealing strength and heat resistance, the inclined part 15 which is shaped in a gentle third order curved surface has no angled part at both side ends 15a thereof, so that almost no stagnant liquid occurs when coating liquid is applied to the surface of the panel 20 for an antistatic film and a reflection-proof film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a funnel for a color cathode ray tube having a reference projection on an outer wall adjacent to a sealing end.

[0002]

2. Description of the Related Art A glass tube of a color cathode ray tube comprises a funnel having a neck portion for accommodating an electron gun and a panel forming an image plane. The funnel and the panel are sealed with frit glass. It is assembled by being combined.

In this case, in order to exhibit good performance as a color cathode ray tube, it is necessary that the funnel and the center of the panel are coincident with each other and are accurately sealed in a precise positional relationship.

Therefore, as shown in FIG. 4, the funnel 10 is
On the outer wall 12 close to the sealing end 11 of the
It has been practiced to provide three reference protrusions 13 having a reference surface formed at a predetermined distance from the center axis of 0, and to seal the funnel and the panel with reference to these.

FIG. 5 is a perspective view of an essential part showing the vicinity of the reference protrusion 13 of the funnel 10. The upper surface of the reference protrusion 13 is horizontal, so that the sealing end 11 side is formed at a substantially right angle. . FIG. 6 shows the sealing end portion 11 of the funnel 10 and the sealing end portion 21 of the panel 20 in the frit glass 1.
FIG. 4 is a cross-sectional view of an essential part showing a state of being sealed by using No. 4.

In the case of this funnel 10, the reference protrusion 13
There is a problem that cracks are likely to occur at the place where is provided. That is, when the frit glass 14 protruding from between the sealing ends 11 and 21 hangs and reaches the reference protrusion 13, the angle θ formed at the interface between the frit glass 14 and the upper surface of the reference protrusion 13 is small. Has a sealed shape of the reentrance having an angle of 20 to 70 °. The sealing shape of the reentrance having such a small angle is weak in terms of sealing strength and heat resistance, and cracks easily occur from here.

Under these circumstances, in recent years, a funnel for a color cathode ray tube has been developed in which an inclined portion is formed on the sealing end side of the reference protrusion.

FIG. 7 is a perspective view of an essential part showing the vicinity of a reference protrusion of such a funnel for a color cathode ray tube. In the funnel 10, the reference protrusion 1 provided on the outer wall 12 of the funnel 10.
An inclined portion 15 is formed on the side of the sealing end 11 of No. 3.
The inclined portion 15 has a flat inclined surface, and the angle of the inclined surface is set to be 30 to 60 °. FIG. 8 shows the sealing end portion 11 of the funnel 10,
FIG. 4 is a cross-sectional view of relevant parts showing a state in which the sealing end portion 21 of the panel 20 is sealed using the frit glass 14.

According to the funnel 10 having the reference protrusions 13 as described above, the frit glass 14 protruding from between the sealing end 11 and the sealing end 21 of the panel 20 hangs down and reaches the reference protrusions 13. However, the sealing end 11
Since the slanted portion 15 is formed in, the angle θ formed at the interface between the frit glass 14 and the slanted portion 15 is large.
Specifically, a sealed shape of the reentrance having an angle of 90 to 130 ° can be obtained. As a result, the sealing strength and heat resistance are strong, and cracks are less likely to occur.

[0010]

By the way, in recent years, color cathode ray tubes have been required to have antistatic and antireflection functions. Therefore, after sealing the funnel and the panel, an antistatic film is formed on the panel surface. The number of coatings with anti-reflection coatings is increasing.

There are various methods for coating such a functional film. For example, a predetermined solution is dropped on the central portion of the panel surface, and then the solution is rotated to uniformly apply the solution, followed by drying. Although there is a coating method, when such a method is adopted, the solution may reach the funnel reference protrusions.

Particularly, in the case of the funnel provided with the reference protrusion having the inclined portion as described above, the inclined portion 15 and the inclined portion 15
The solution is likely to accumulate at the corners formed at both ends 15a of the above, and when the solution is dried and solidified, cracks easily occur therein, and this crack also causes cracks in the funnel.

According to the present invention, since the angle θ formed at the interface between the frit glass and the upper surface of the reference protrusion is large, the sealing strength and heat resistance are strong, and the coating solution of the panel reaches the reference protrusion. Another object of the present invention is to provide a funnel for a color cathode ray tube, which is less likely to cause liquid pooling and therefore has less cracks.

[0014]

A funnel for a color cathode ray tube according to the present invention is a funnel for a color cathode ray tube in which a reference projection is provided on an outer wall adjacent to a sealing end, and the reference projection is inclined toward the sealing end side. Is formed, and the surface shape of the inclined part has a gentle cubic curved surface.

[0015]

In the funnel for a color cathode ray tube according to the present invention, since the inclined portion is formed at the sealing end side of the reference protrusion, the angle θ formed at the interface between the frit glass and the side end of the reference protrusion is large. It is strong in terms of sealing strength and heat resistance, and cracks hardly occur.

Further, the surface shape of the inclined portion has a gentle cubic curved surface and there is no corner portion, so that even if the solution coated on the panel reaches the reference protrusion, it is difficult for the liquid to accumulate there.

Further, in the present invention, it is preferable to form a cubic curved surface that is gradually narrowed from its central portion toward both ends.

[0018]

EXAMPLES The funnel for a color cathode ray tube of the present invention will be described in detail below with reference to examples.

FIG. 1 is a perspective view of an essential part showing the vicinity of a reference protrusion of a funnel for a color cathode ray tube according to the present invention, and FIG. 2 is a front view of the essential part. In this funnel 10, the reference protrusion 13
The inclined portion 15 is formed on the side of the sealing end portion 11, and the inclined portion 15 has a gradually curved concave third-order curved surface from the center toward both ends 15a.

FIG. 3 is a cross-sectional view of essential parts showing a state in which the sealing end portion 11 of the funnel 10 and the sealing end portion 21 of the panel 20 are sealed using the frit glass 14.

According to the funnel 10 provided with the reference protrusions 13 as described above, when the funnel 10 is sealed with the panel 20, it protrudes from between the sealing end 11 of the funnel 10 and the sealing end 21 of the panel 20. The frit glass 14 droops,
Even when reaching the reference protrusion 13, since the inclined portion 15 is formed, the angle θ formed at the interface between the frit glass 14 and the inclined portion 15 is large, and the sealing strength and heat resistance are increased, so that cracks occur. Is unlikely to occur.

Further, since the slanted portion 15 has a gentle cubic curved surface as a whole, there is no corner portion at both side ends 15a thereof, and an antistatic film or an antireflection film is formed on the surface of the panel 20. When coating the solution, the solution is the reference protrusion 13
Even if it hangs down, the inclined portion 15 and both ends 1 of the inclined portion 15
Since there is no corner in 5a, it is difficult to collect liquid.

[0023]

As described above, according to the funnel for a color cathode ray tube of the present invention, even if the frit glass hangs down to the reference protrusion, the angle θ formed at the interface between the frit glass and the inclined portion of the reference protrusion becomes large. , The sealing strength and heat resistance are stronger, and even if the solution coated on the panel surface drips down to the reference protrusion, there are no corners at both ends of the inclined part, and it is difficult for liquid to collect It is possible to suppress the occurrence.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part showing the vicinity of a reference protrusion of a funnel of the present invention.

FIG. 2 is a front view of relevant parts showing the vicinity of a reference protrusion of the funnel of the present invention.

FIG. 3 is a cross-sectional view of essential parts showing a sealed state of the funnel and the panel of the present invention.

FIG. 4 is a perspective view showing a funnel for a color cathode ray tube having a reference protrusion.

FIG. 5 is a perspective view of an essential part showing the vicinity of a reference protrusion of a conventional funnel.

FIG. 6 is a cross-sectional view of essential parts showing a sealed state of a conventional funnel and a panel.

FIG. 7 is a perspective view of an essential part showing the vicinity of a reference protrusion of a conventional funnel.

FIG. 8 is a cross-sectional view of essential parts showing a sealed state of a conventional funnel and a panel.

[Explanation of symbols]

 10 Funnels 11, 21 Sealing Ends 13 Reference Protrusions 14 Frit Glass 15 Inclined Parts 20 Panels

Claims (1)

[Claims] 1. In a funnel for a color cathode ray tube, wherein a reference protrusion is provided on an outer wall adjacent to a sealing end, an inclined portion is formed on the sealing end side of the reference protrusion, and a surface shape of the inclined portion is: A funnel for a color cathode ray tube, which is characterized by having a gentle cubic surface.