JPH11213917A - Cathode-ray tube and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cathode-ray tube together with its manufacturing method, having atmospheric strength that is not decreased though a small-diameter part of its funnel is given with a structure capable of reducing deflection power by being formed into a pyramidal shape. SOLUTION: A small-diameter part of a funnel 20 to be mounted with a deflection yoke 8 is formed into a pyramidal shape having a substantially rectangular shape corresponding to a cross-section shape of a panel 20, and the outer side of each side part 24 thereof is formed into a barrel shape with its middle part projecting outward while the inner side thereof is formed into a pin-cushion shape with its middle part projecting inward so as to colsely resemble a passage domain 25 of electron beams passing through the inside of the small-diameter part 22. In the small-diameter part 22 of the funnel 20, wall thickness of the side parts 24 is thicker than wall thickness of opposite angle parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube capable of reducing deflection power without deteriorating the atmospheric pressure intensity of a vacuum envelope and a method of manufacturing the same.

[0002]

2. Description of the Related Art At present, cathode ray tubes are widely used as display devices for television broadcasting and computer terminal equipment.

FIG. 5 shows a color picture tube as an example. The color picture tube has a funnel 1 made of glass, a substantially rectangular panel 2 made of glass joined to a large-diameter end of the funnel 1, and a funnel 1 joined to a small-diameter end of the funnel 1. And a cylindrical neck 3 made of glass. A phosphor screen 4 made of a three-color phosphor layer is provided on the inner surface of the panel 2, and a shadow mask 5 is disposed inside the panel 2 so as to face the phosphor screen 4. On the other hand, an electron gun 7 for emitting three electron beams 6B, 6G, 6R is arranged in the neck 3. The three electron beams 6B, 6G and 6R emitted from the electron gun 7 are deflected by the horizontal and vertical deflection magnetic fields generated by the deflection yoke 8 mounted from the outer surface of the small diameter portion of the funnel 1 to the outer surface of the adjacent portion of the neck 3. And
The phosphor screen 4 is leveled through the shadow mask 5,
It is formed in a structure for displaying a color image by performing vertical scanning.

[0004] One of the characteristics required for such a cathode ray tube is to reduce power consumption. The power consumed by the deflection yoke and the power consumed by the deflection yoke (deflection power) account for a large proportion of the power consumed by the cathode ray tube itself. Therefore, reducing the deflection power is extremely important for saving power of the cathode ray tube.

Conventionally, the power consumption of the deflection yoke has been reduced by reducing the diameter of the deflection yoke by reducing the diameter of the neck of the cathode ray tube, and bringing the deflection coil closer to the trajectory of the electron beam. However, in general, a cathode ray tube is
Since the focus performance is closely related to the diameter of the electron lens of the electron gun, reducing the neck diameter as described above imposes a heavy burden on the electron gun.

On the other hand, Japanese Patent Publication No. 48-34349 discloses a funnel in which a deflection yoke is mounted, in which a small diameter portion is formed in a pyramid shape. That is, FIG.
The outer shape of the vacuum envelope 10 shown in (a) in the cross section BB to FF is shown from the side of the neck 3 where the deflection yoke is mounted as shown in (b) to (f). The outer shape of the funnel 1 is changed from a circular shape to a substantially rectangular shape over the small diameter portion.

With this configuration, the deflection power is reduced by making the vicinity of the horizontal and vertical axes closer to the trajectory of the electron beam, as compared with a normal funnel in which the small diameter portion of the funnel to which the deflection yoke is mounted is conical. Can be. Therefore, the deflection power can be reduced without imposing a heavy load on the electron gun as in the case of reducing the neck diameter.

However, when the small diameter portion of the funnel 1 is formed into a pyramid shape as described above, the side portion 13 is dented by the atmospheric pressure load 12 as shown by the broken line in FIG. 14 occurs and the atmospheric pressure intensity decreases. Therefore, such a funnel 1 needs to be rounded even if the small-diameter portion has a pyramid shape, and the degree of pyramid formation is limited.

[0009]

As described above, in order to reduce the power consumption of the deflection yoke, a small diameter portion of the funnel to which the deflection yoke is mounted is conventionally made into a pyramid shape. However, when the small diameter portion of the funnel is formed into a pyramid shape, the side portion of the small diameter portion formed into a pyramid shape by the atmospheric pressure load is dented, thereby generating a tensile stress near the diagonal portion and reducing the atmospheric pressure strength. Therefore, such a funnel needs to be rounded even if the small-diameter portion has a pyramid shape, and there is a problem that the degree of pyramid formation is limited.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. Even if the diameter of the funnel to which the deflection yoke is mounted is made into a pyramid shape so that the deflection power can be reduced, the atmospheric pressure intensity is reduced. It is an object of the present invention to obtain a cathode ray tube and a method of manufacturing the same.

[0011]

(1) A funnel-shaped funnel made of glass, a substantially rectangular panel made of glass joined to the large-diameter end of the funnel, and joined to the small-diameter end of the funnel. A vacuum envelope consisting of a cylindrical neck made of glass, and an electron beam emitted from an electron gun disposed in the neck from the outer surface of the small diameter portion of the funnel to the outer surface of the adjacent portion of the neck. In a cathode ray tube in which a deflection yoke for deflecting is mounted, a small-diameter portion where a deflection yoke of a funnel is mounted is formed in a pyramid shape having a substantially rectangular cross section corresponding to a panel, and a strain stress of a side portion of the small-diameter portion is reduced. Tensile stress was averaged on the inner surface, and compressive stress was averaged on the outer surface.

(2) In the cathode ray tube of (1), the small-diameter portion to which the deflection yoke is mounted has a structure in which the center of the outer surface of the side protrudes outward and the center of the inner surface protrudes inward.

(3) In the cathode ray tube of (1), the thickness of the diagonal portion of the small diameter portion where the deflection yoke is mounted is 4 mm or less.
The thickness of the side portion was 7 mm or more.

(4) In the cathode ray tube of (1), the outer surface shape of the side of the small diameter portion to which the deflection yoke is mounted is more rounded than the shape of the corresponding portion of the molding die for press-molding the funnel. did.

(5) In a method for manufacturing a cathode ray tube in which a molten glass is supplied to a forming die and a funnel-shaped funnel in which a small-diameter portion on which a deflection yoke is mounted has a pyramidal shape is press-formed, a pyramidal shape is formed after press forming. The outer surface of the side of the small diameter portion is cooled relatively faster than the inner surface.

(6) After the press forming, the inner surface of the side of the small diameter portion of the pyramid is heated.

(7) After the press molding, the outer surface of the side of the small diameter portion of the pyramid is forcibly cooled and the inner surface is forcibly heated.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a color picture tube which is one embodiment of the present invention. This color picture tube has a funnel-shaped funnel 20 made of glass, a substantially rectangular panel 2 made of glass joined to a large-diameter portion 21 of the funnel 20, and a small-diameter portion 22 of the funnel 20. And a vacuum envelope comprising a cylindrical neck 3 made of bonded glass.
A phosphor screen 4 made of a three-color phosphor layer is provided on the inner surface of the panel 2, and a shadow mask 5 is disposed inside the panel 2 so as to face the phosphor screen 4. On the other hand, an electron gun 7 for emitting three electron beams 6B, 6G, 6R is arranged in the neck 3. And this electron gun 7
The three electron beams 6B, 6G and 6R emitted from the mirror are deflected by the horizontal and vertical deflection magnetic fields generated by the deflection yoke 8 mounted from the outer surface of the small diameter portion of the funnel 1 to the outer surface of the adjacent portion of the neck 3 so that the shadow mask 5 is moved. The phosphor screen 4 is formed to have a structure for displaying a color image by scanning the phosphor screen 4 horizontally and vertically.

In particular, in this embodiment, the small diameter portion 22 of the funnel 20 to which the deflection yoke 8 is mounted is
As shown in FIG. 2, the panel is formed in a pyramid shape having a substantially rectangular shape corresponding to the cross-sectional shape of the panel, and the outer surface side of each side portion 24 is formed in a barrel shape with a central portion protruding outward, and the inner surface is formed. The side is formed in a pincushion shape in which the central portion protrudes inward, approximating the passage area 25 of the electron beam passing inside the small diameter portion 22. Thereby, the small diameter portion 22 of the funnel 20 in this embodiment is
Is thicker than the thickness of the diagonal part.

More specifically, in a normal funnel, the thickness of the small-diameter portion 22 is about 3 to 6 mm. However, in the funnel 20, the thickness of the side portion 24 is 7 mm or more and the diagonal portion is 4 mm or less. It is thick.

Further, the side portion 24 of the small-diameter portion 22 is provided with an average tensile stress 27 on the inner surface side and an average compressive stress 28 on the outer surface side inside the center in the thickness direction of the cross section. I have.

[0023] Like the conventional funnel, such a funnel 20 is press-formed by supplying a fixed amount of molten glass to a molding die. Thereafter, the molded funnel is taken out of the molding die, and the inner wall of the side portion of the small-diameter portion 22 formed into a pyramid shape is heated to manufacture the funnel.

When the funnel 20 is configured as described above, the small-diameter portion 22 is formed in a pyramid shape, so that the deflection power is reduced and a power-saving color picture tube can be configured. Moreover, the tensile stress 27 on the inner surface side and the compressive stress 28 on the outer surface side are averaged on the inner side from the center in the thickness direction of the side portion 24 of the small-diameter portion 22, so that the diagonal portion , A compressive stress 29 indicated by an arrow is generated, so that the vacuum envelope has a sufficient atmospheric pressure strength.

That is, the small-diameter portion 22 of the funnel 20 to which the deflection yoke 8 is mounted is formed in a substantially rectangular pyramid shape corresponding to the cross-sectional shape of the panel 2, so that the deflection yoke 8 is formed of the small-diameter portion 22. The power required for deflection can be reduced by approaching the trajectory of the electron beam passing inside.

In general, since a funnel has a certain thickness, if the funnel is press-formed using a molding die, the surface cools before the inside, and after the surface solidifies, the inside cools down. Shrink. Therefore, as shown in FIG. 3, a compressive stress 31 is generated on the surface of the small-diameter portion 22, and a tensile stress 32 that opposes the compressive stress is generated inside. When the inner surface of the small-diameter portion 22 where the stresses 31 and 32 are generated is heated again after molding, as shown in FIG. 4, the outer surface has a compressive stress 31 during press molding shown in FIG. , The compressive stress shown in FIG. 3 disappears on the inner surface side, and a new tensile stress 33 is generated. Then, a tensile stress 34 is generated on the outer surface side against the tensile stress 33 on the inner surface side. As a result, the side portion 24 of the small-diameter portion 22 has a bulged central portion as shown by a broken line, and is more rounded than the shape at the time of press molding, that is, the shape of the corresponding portion of the molding die. At the same time, a compressive stress 35 indicated by an arrow accompanying the swelling is generated on the outer surface side of the diagonal portion.

As described above, the compressive stress 35 is applied to the outer surface of the diagonal portion.
When tensile stress occurs, the tensile stress at the diagonal portion caused by the depression of the side due to the atmospheric pressure shown in FIG. 7 is offset by the compressive stress, and the atmospheric pressure strength of the vacuum envelope can be improved. However, as described above, even if the inner surface of the small-diameter portion 22 is reheated to generate a compressive stress 33 on the outer surface of the diagonal portion, the normal diameter of the small-diameter portion 22 is about 3 to 6 mm. Also, the temperature difference between the inner and outer surfaces is small, and the compressive stress 35 generated on the outer surface side of the diagonal portion cannot be made sufficiently large.

However, the funnel 20 according to this embodiment
When the thickness of the second side 24 is increased, the temperature difference between the inner and outer surfaces of the side 24 can be increased during reheating, and the outer side of the diagonal is formed by the atmospheric pressure on the outer side. Compressive stress 2 that sufficiently offsets the diagonal tensile stress generated in the recess
9 can be generated and the vacuum envelope can be provided with sufficient atmospheric pressure intensity.

In the above embodiment, the inner surface of the side of the pyramid-shaped small diameter portion is heated after the funnel is removed from the mold, but the heating is performed by the side of the pyramid-shaped small diameter portion. This is a process for generating a large temperature difference between the inner and outer surfaces of the substrate to generate a tensile stress on the inner surface side. Therefore, such processing is generally achieved by cooling the outer surface side of the side of the small diameter portion after molding relatively faster than the inner surface side.

Further, the circulation of the air inside the funnel is shut off, the outer surface of the small-diameter portion is forcibly cooled, or the outer wall portion of the small-diameter portion is forcibly cooled and the inner wall portion is forcibly heated. Even in this case, a funnel similar to the funnel in the above embodiment can be formed.

In the above embodiment, a color picture tube has been described. However, the present invention can be applied to a cathode ray tube other than a color picture tube.

[0032]

As described above, the small diameter portion of the funnel to which the deflection yoke is mounted is formed in a pyramid shape, and the strain stress on the sides of the small diameter portion of the pyramid is averaged from the center of the thickness to the inside. If it is configured so that tensile stress is applied to the outside and compressive stress is applied to the outside, the small-diameter portion is made into a pyramid shape, so that the deflection yoke approaches the trajectory of the electron beam passing through the inside of the small-diameter portion. Power can be reduced, and a power-saving cathode ray tube can be configured. Moreover, the vacuum envelope is provided with sufficient atmospheric pressure strength by imparting an average tensile stress to the inner surface side and an average compressive stress to the outer surface side from the center in the thickness direction of the side portion of the small diameter portion. can do.

Also, after press molding the funnel,
By cooling the outer surface side of the side portion of the pyramid-shaped small diameter portion relatively faster than the inner surface side, it can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a color picture tube according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a shape of a small-diameter portion of a funnel of the color picture tube.

FIG. 3 is a diagram for explaining internal stress generated in a small-diameter portion of a press-formed funnel.

FIG. 4 is a view for explaining stress generated when the inner surface of the small-diameter portion of the press-formed funnel is reheated.

FIG. 5 is a diagram showing a configuration of a conventional color picture tube.

6 (a) to 6 (f) are views for explaining the shape of a vacuum envelope of a conventional color picture tube in which a small diameter portion of a funnel is formed into a pyramid shape, and FIG. FIG. 6 (b) is a cross-sectional view taken along line BB of FIG. 6 (a), FIG. 6 (c) is a cross-sectional view taken along line CC of FIG. 6 (d), and FIG.
6D is a cross-sectional view taken along line EE, and FIG. 6F is a cross-sectional view taken along line FF.

FIG. 7 is a view for explaining deformation of a small diameter portion of the conventional pyramid-shaped funnel due to an atmospheric pressure load.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 2 ... Panel 3 ... Neck 6B, 6G, 6R ... 3 Electron beam 7 ... Electron gun 8 ... Deflection yoke 20 ... Funnel 21 ... Large diameter part 22 ... Small diameter part 24 ... Side part

Claims (7)

[Claims] 1. A funnel-shaped funnel made of glass,
A substantially rectangular panel made of glass joined to the large-diameter end of the funnel, and a vacuum envelope consisting of a cylindrical neck made of glass joined to the small-diameter end of the funnel, A cathode ray tube provided with a deflection yoke for deflecting an electron beam emitted from an electron gun disposed in the neck from an outer surface of the small diameter portion of the funnel to an outer surface of an adjacent portion of the neck, wherein the funnel includes the deflection yoke. The small diameter portion to be attached is formed in a pyramid shape having a substantially rectangular cross section corresponding to the panel, and the strain stress of the side portion of the small diameter portion is an average tensile stress on the inner surface side, and an average on the outer surface side. A cathode ray tube having a compressive stress. 2. The cathode ray tube according to claim 1, wherein the small-diameter portion to which the deflection yoke is mounted has a central portion of the outer surface of the side portion protruding outward and a central portion of the inner surface protruding inward. 3. The cathode ray tube according to claim 1, wherein the small diameter portion on which the deflection yoke is mounted has a diagonal portion having a thickness of 4 mm or less and a side portion having a thickness of 7 mm or more. 4. The small-diameter portion on which the deflection yoke is mounted has an outer surface shape of a side portion which is more rounded than a corresponding portion of a molding die for press-molding a funnel. Cathode ray tube. 5. A method for producing a cathode ray tube, comprising: supplying a molten glass to a molding die to press-mold a funnel-shaped funnel having a pyramid-shaped small-diameter portion to which a deflection yoke is mounted; A method for manufacturing a cathode ray tube, wherein an outer surface of a side portion of a small-diameter portion is cooled relatively faster than an inner surface. 6. A method for manufacturing a cathode ray tube in which a molten glass is supplied to a molding die to press-mold a funnel-shaped funnel in which a small-diameter portion on which a deflection yoke is mounted has a pyramid shape. A method for manufacturing a cathode ray tube, comprising heating an inner surface of a side portion of a small diameter portion. 7. A method for manufacturing a cathode ray tube, which supplies a molten glass to a molding die and press-molds a funnel-shaped funnel in which a small-diameter portion on which a deflection yoke is mounted has a pyramid shape. A method for manufacturing a cathode ray tube, comprising: forcibly cooling an outer surface of a side portion of a small diameter portion and forcibly heating an inner surface.