JPH10241595A - Color image receiving tube and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease fallen-out particles caused by an inner shield fixed to a mask frame with an elastic clip. SOLUTION: In a manufacturing method for a color image receiving tube in which an elastic clip 38 is inserted into coaxial holes 35, 36 formed in a mask frame 25 filled to a peripheral part of a mask body 24 and a truncated cone shaped inner shield 32, and with the press contact of the elastic clip 38 the inner shield 32 is fixed on the mask frame 25, a bushing 37 to be deformed with the press contact of the elastic clip 38 is filled into the mask frame 25 and the holes 35, 36 of the mask frame 25 and inner shield 32, and the elastic clip 38 is inserted into a hole of the bushing 37, whereby the inner shield 32 is filled to the mask frame 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube and a method of manufacturing the same, and more particularly, to a color picture tube with an improved inner shield fixed to a mask frame of a shadow mask and a method of manufacturing the same.

[0002]

2. Description of the Related Art Generally, a color picture tube has an envelope composed of a substantially rectangular panel and a funnel-shaped funnel, and a phosphor screen composed of a three-color phosphor layer is provided on the inner surface of the panel. A substantially rectangular shadow mask is arranged inside the phosphor screen so as to face the phosphor screen.
The shadow mask includes a substantially rectangular mask body facing the phosphor screen and having a large number of electron beam passage holes, and a substantially rectangular mask frame attached to a peripheral portion of the mask body. On the other hand, an electron gun that emits three electron beams is arranged in the neck of the funnel. Then, the three electron beams emitted from the electron gun are deflected by a deflecting device mounted outside the funnel, and the phosphor screen is horizontally and vertically scanned through a shadow mask, so that a color image is displayed. Is formed.

In order to prevent the influence of an external magnetic field such as terrestrial magnetism on the three electron beams emitted from the electron gun, many color picture tubes are mounted on a mask frame of the shadow mask inside a large diameter portion of a funnel. A fixed truncated pyramid-shaped inner shield is arranged.

Conventionally, as a method of fixing the inner shield to the mask frame, there are a method of fixing by welding and a method of fixing by an elastic clip.
Due to problems such as workability and generation of welding splash, fixing methods using elastic clips are often used.

As shown in FIG. 6, the outer clip 2 and the mask frame 3 are provided on the large diameter side of the inner shield 1 having a truncated pyramid shape.
A plurality of openings 5 and 6 are provided coaxially in the inner projecting portion 4 provided at the electron gun side end, and an elastic clip 7 is inserted into these openings 5 and 6. The elastic clip 7 is formed by bending a single elastic metal wire into a barbed shape having a constricted portion 9 at an intermediate portion.
Both ends of the elastic metal wire are formed in a side-by-side structure, and an intermediate constricted portion 9 is pressed against the inner walls of the openings 5 and 6 to form a distal end 11.
The large diameter portion 12 and the base end portion 10 of the inner frame 1 and the outer projection 2 of the inner shield 1 are
Are pressed into contact with the outer surface of each of them to hold them.

As shown in FIG. 7, when the inner shield 1 is attached by the elastic clip 7, both ends of the base end 10 of the elastic clip 7 are compressed in directions approaching each other as shown by arrows 14 and 15, and the distal end is compressed. The diameter of the large-diameter portion 12 and the intermediate constriction 9 is reduced and inserted into the openings 5 and 6 of the outer protruding portion 2 of the inner shield and the inner protruding portion 4 of the mask frame, and then the base end 10 is compressed. This is done by canceling.

[0007]

As described above, at present,
Many color picture tubes are provided with an inner shield located inside the large diameter part of the funnel to prevent the influence of an external magnetic field such as terrestrial magnetism on the three electron beams emitted from the electron gun. A plurality of openings are provided coaxially in the outer projections provided and the inner projections provided in the mask frame, and are fixed to the mask frame by press-fitting of elastic clips inserted into these openings. Conventionally, the elastic clip is formed of a single elastic metal wire formed in a torsion shape having a middle constricted portion, and has a structure in which both ends of the elastic metal wire are arranged in parallel at a base end portion. Is pressed against the inner wall of the opening provided in the outer projection of the inner shield and the inner projection of the mask frame, and the large-diameter portion of the distal end and the base end are in contact with the inner projection of the mask frame and the outer side of the inner shield. It has a structure in which it is pressed against the outer surface of the overhang portion and sandwiches them.

However, when the inner shield is attached by the elastic clip, both ends of the base end of the elastic clip are compressed in a direction approaching each other, and the large-diameter portion at the distal end and the intermediate constriction are reduced in diameter. This is done by inserting into the opening of the inner extension of the frame and the outer extension of the inner shield, so when compressing both ends of the base end in a direction approaching each other, the elastic metal wires of this base end are arranged in parallel. Both ends rub together, generating burrs and shavings.
Also, even if both ends of the base end are compressed in a direction approaching each other,
If not sufficiently compressed, the large-diameter portion at the distal end portion rubs against the opening edge or the inner wall of the mask frame and the inner shield, and burrs formed at the opening edge by press punching are scraped off. Such burrs and shavings do not fall off when the elastic clip is inserted, but may fall off due to impact or vibration applied to the color picture tube.

As a result, there is a problem that the fallen particles adhere to the shadow mask and block the electron beam passage hole, or adhere to the electrode of the electron gun, causing electrode touch and withstand voltage failure.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to reduce particles that fall off due to fixing an inner shield to a mask frame of a shadow mask by an elastic clip. .

[0011]

An opening is formed coaxially in a mask frame and an inner shield in the shape of a truncated pyramid attached to the periphery of a mask body in which a number of electron beam passage holes are formed. In a method of manufacturing a color picture tube in which an elastic clip is inserted into a hole and an inner shield is attached to a mask frame by pressure contact of the elastic clip, a bushing deformed by pressure contact of the elastic clip is fitted into an opening of the mask frame and the inner shield,
An elastic clip was inserted into the opening of the bushing, and the inner shield was attached to the mask frame via the bushing.

An elastic clip is inserted into an opening coaxially provided in a mask frame and a frustum-shaped pyramid-shaped inner shield which are attached to a peripheral portion of a mask body in which a large number of electron beam passage holes are formed, In a color picture tube in which the inner shield is fixed to the mask frame by pressing the elastic clip, a bushing that is deformed by pressing the elastic clip into the opening of the mask frame and the inner shield is inserted into the opening of the mask frame and the inner shield, and inserted into the opening of the bushing. The inner shield was fixed to the mask frame via the bushing by pressing the elastic clip.

In the above color picture tube, the bushing is made of a metal material having a Vickers hardness of 30 to 70 kg / mm ² and a thickness of 10 to 50 μm.

[0014]

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

FIG. 1 shows the structure of a color picture tube as one embodiment. This color picture tube has a substantially rectangular panel 2.
It has an envelope composed of 0 and a funnel 21 having a funnel shape. On the inner surface of the panel 20, there is provided a phosphor screen 22 made of a three-color phosphor layer that emits blue, green, and red light, and a substantially rectangular shadow mask is provided inside and opposed to the phosphor screen 22. 23 are arranged. The shadow mask 23 has a plurality of electron beam passage holes formed therein, a substantially rectangular mask body 24 facing the phosphor screen 22, and a substantially rectangular mask frame attached to the periphery of the mask body 24. 25. One end of the mask frame 25 is provided with an inner protruding portion 26, which is formed in an L-shaped cross section. on the other hand,
In the neck 28 of the funnel 21, three electron beams 29B,
An electron gun 30 for emitting 29G and 29R is provided.

Further, in order to prevent the three electron beams 29B, 29G, and 29R emitted from the electron gun 30 from being affected by an external magnetic field such as terrestrial magnetism, a truncated pyramid is formed inside the large diameter portion 31 of the funnel 21. Inner shield 3
2 are arranged. An outer extension 33 for attaching the inner shield 32 to the inner extension 26 of the mask frame 25 is provided on the large diameter side of the inner shield 32.

The fixing of the inner shield 32 to the inner protruding portion 26 of the mask frame 25 is performed by using a plurality of holes coaxially provided on the outer protruding portion 33 of the inner shield 32 and the inner protruding portion 26 of the mask frame 25. 3
A bushing 37 is fitted into the bushing 5, 36, and is fixed by pressing an elastic clip 38 inserted into an opening of the bushing 37.

The bushing 37 corresponds to the shape of the openings 35 and 36 of the outer projecting portion 34 of the inner shield 32 and the inner projecting portion 26 of the mask frame 25. For example, if the openings 35 and 36 are circular, As shown in FIG. 2A, when the openings 35 and 36 are formed in a cylindrical shape with a flange portion 40 formed at one end portion, and the opening portions 35 and 36 are rectangular, the flange portion 40 is formed at one end portion as shown in FIG. Is used. Any of the bushings 37,
In order to facilitate deformation of the elastic clip 38 by pressing,
Vickers hardness 30-70 kg / mm ² , film thickness 10-50
It is formed of an aluminum foil or a nickel foil having a thickness of μm, and a plurality of cut grooves 41 are provided in the cylindrical portion.

As shown in FIG. 3, the elastic clip 38 is formed by bending a single elastic metal wire such as stainless steel.
It is formed into a crimped shape with an intermediate constriction 43, and the base end 4
Reference numeral 4 denotes both ends of the elastic metal wire extending in opposite directions, and both ends of the elastic metal wire are inclined as shown by an angle α in a direction approaching the distal end portion 45, and the outer protrusion of the inner shield and the mask are provided. When inserted into the opening of the inner projecting portion of the frame, the constricted portion 43 presses against the inner wall of each opening via the bushing, and the large-diameter portion 46 of the distal end portion 45 and the base end portion 4
4 are pressed against the outer surfaces of the inner protruding portion of the mask frame and the outer protruding portion of the inner shield, and are formed in a structure for sandwiching them.

As shown in FIG. 4 (a), the outer clip 33 of the inner shield is positioned on the inner clip 26 of the mask frame and coaxially arranged. A bushing 37 is fitted into the openings 35 and 36 of the inner shield and the mask frame. Next, as shown in FIG. 2B, both ends of the base end portion 44 of the elastic clip 38 are
Compressed in the direction approaching each other as indicated by 49
And the constricted portion 43 is reduced in diameter and inserted into the opening of the bushing 37 fitted into the opening 35, 36 of the inner shield and the mask frame. Thereafter, the compression is performed by releasing the compression of the base end portion 44. By releasing the compression of the base end portion 44, as shown in FIG.
The constricted portion 43 is expanded in diameter, and each opening 3 is formed via a bushing 37.
5 and 36, and the base end 44 (see FIG. 3), which is inclined at an angle α, is elastically deformed.
The large-diameter portion 46 and the base end portion 44 deform the cylindrical portion of the bushing 37, and the deformed bushing 37 allows the outer surface of the inner protruding portion 26 of the mask frame and the outer surface of the outer protruding portion 34 of the inner shield. Pressing and holding the inner shield on the mask frame.

In the manufacture of the color picture tube, a phosphor screen was formed on the inner surface of the panel by a photographic printing method using a shadow mask as a photomask, and the shadow mask was mounted on the panel on which the phosphor screen was formed. Then, the inner shield is attached to the mask frame of the shadow mask by the above method. Then, the panel with the inner shield attached to this mask frame is combined with a funnel whose inner surface is coated with a conductive film, joined and joined, the electron gun is sealed in the neck of the funnel, and the vacuum exhaust is performed. Manufactured.

As described above, the easily deformable bushings 37 are fitted into the openings 35, 36 of the outer projection 34 of the inner shield 32 and the inner projection 26 of the mask frame 25, and the elastic clip having the structure shown in FIG. Using 38,
When the inner shield 32 is attached to the mask frame 25, even if the elastic clip 38 compresses both ends of the base end portion 44 in a direction approaching each other, the elastic clip 38 has few portions that rub against each other. As compared to c)), generation of burrs and shavings due to rubbing can be reduced. Further, the elastic clips 38 are provided with the openings 35 and 36 of the inner shield 32 and the mask frame 25.
The inner shield 32 and the opening 35 of the mask frame 25 are inserted into the opening of the bushing 37 fitted in the opening.
Since there is no friction due to direct contact with the vicinity of 36, burrs and the like formed at the edges of the openings 35 and 36 are not scraped off by press punching. Therefore, the falling particles can be significantly reduced.

Table 1 shows that a 17-inch color picture tube panel on which a phosphor screen is formed and on which a shadow mask is mounted is coated with a 10 μm-thick aluminum foil as shown in FIGS. 5 (a) and 5 (b). A bushing 3 which has been cut into a shape and bent by inserting a notch 51 with an X mark in the center.
7 and a panel assembly according to this embodiment in which an inner shield is mounted using an elastic clip 38 obtained by modifying a conventional elastic clip into the structure shown in FIG. 3, and a panel assembly in which an inner shield is mounted by a conventional method. The results of a comparative test, in which 10 pieces were assembled each, are shown.

In this comparative test, the panel of each of the above-mentioned panel assemblies was turned upside down at a frequency of 5 by a vibrator.
At 0 Hz, the number of particles having a size of 10 μm or more is counted out of the particles falling off when a vibration of 15 G acceleration is applied.
Of the fallen particles, metal particles were replaced with EPMA (Electron Probe
Micro Analizer).

[0025]

[Table 1] In the panel assembly described above, in addition to the elastic clips for fixing the inner shield, the stud pins provided on the panel for mounting the shadow mask and the frame holder attached to the mask frame and locked to the stud pins are each made of stainless steel. Therefore, in Table 1, the dropped stainless steel particles are classified based on the Cr-Ni ratio analyzed by the EPMA, and in the case of the stainless steel particles other than the stainless steel particles from the elastic clip, Other metal particles were included. The values in parentheses in the method according to the embodiment of the present invention are ratios to the conventional method.

As shown in Table 1 above, when the inner shield is fixed by the method of this embodiment, particles falling off from the elastic clip, the mask frame and the inner shield are fixed by the conventional elastic clip. It is shown that each of them is reduced to about 1/4 as compared with the method, and the amount of the dropped metal particles is reduced to less than 1/2 as compared with the conventional method.

Therefore, when the inner shield is fixed as in this embodiment, conventionally, when the inner shield is attached to the mask frame by the elastic clip, the dropout particles generated when the inner shield is attached to the mask frame cause the electron beam passage hole of the shadow mask to be clogged. Electrode touch and withstand voltage failure can be greatly reduced.

[0028]

According to the present invention, an elastic clip is inserted into an opening provided coaxially with a mask frame and an inner shield having a truncated pyramid shape attached to a peripheral portion of a mask body having a large number of electron beam passage holes. In the color picture tube having the inner shield fixed to the mask frame by the pressing of the elastic clip and the method of manufacturing the same, a bushing deformed by the pressing of the elastic clip is fitted into the opening of the mask frame and the inner shield. By pressure contact of the elastic clip inserted in the opening,
If the inner shield is fixed to the mask frame via a bushing, and the bushing is made of a metal material having a Vickers hardness of 30 to 70 kg / mm ² and a thickness of 10 to 50 μm, the inner shield is conventionally provided by an elastic clip. Clogging of the electron beam passage holes in the shadow mask due to particles that have fallen off when the
Electrode touch and withstand voltage failure of the electron gun can be greatly reduced.

[Brief description of the drawings]

FIG. 1A is a diagram showing a configuration of a color picture tube according to an embodiment of the present invention, and FIG. 1B is a diagram showing a fixing structure of an inner shield to a mask frame.

FIG. 2A is a view of a cylindrical bushing fitted into a circular opening of the inner shield and the mask frame of the color picture tube, and FIG. 2B is a rectangular shape fitted into a rectangular opening; It is a figure of a bushing.

FIG. 3 is a view showing a structure of an elastic clip used for fixing an inner shield of the color picture tube.

FIGS. 4A and 4B are diagrams for explaining a method of attaching an inner shield to a mask frame.

FIG. 5A is a plan view of a bushing used for comparing an inner shield mounting method according to an embodiment of the present invention with a conventional inner shield mounting method, and FIG. 5B is a cross-sectional view thereof. FIG.

6 (a) to 6 (c) are views showing the shape of a conventional inner shield and a structure for fixing the inner shield to a mask frame, respectively.

FIG. 7 is a view for explaining a method of attaching a conventional inner shield to a mask frame.

[Explanation of symbols]

 23 ... Shadow mask 24 ... Mask body 25 ... Mask frame 26 ... Inner projection 32 ... Inner shield 33 ... Outside projection 35 ... Opening 36 ... Opening 37 ... Bushing

Claims (3)

[Claims] An opening is formed coaxially in a mask frame and a frustum-shaped pyramid-shaped inner shield attached to a peripheral portion of a mask body in which a large number of electron beam passage holes are formed, and elastic clips are formed in these openings. In a method for manufacturing a color picture tube for attaching the inner shield to the mask frame by pressing the elastic clip and pressing the elastic clip, a bushing deformed by pressing the elastic clip into the opening of the mask frame and the inner shield is fitted. A method for manufacturing a color picture tube, comprising: inserting the elastic clip into an opening of the bushing; and attaching the inner shield to the mask frame via the bushing. 2. An elastic clip is inserted into an opening provided coaxially with a mask frame and an inner shield having a truncated pyramid shape attached to a periphery of a mask main body having a plurality of electron beam passage holes formed therein. In the color picture tube in which the inner shield is fixed to the mask frame by pressing the elastic clip, a bushing deformed by pressing the elastic clip into the opening of the mask frame and the inner shield is fitted. A color picture tube, wherein the inner shield is fixed to the mask frame via the bushing by pressure contact of the elastic clip inserted into the opening. 3. The bushing has a Vickers hardness of 30 to 7.
3. A color picture tube according to claim 2, wherein said color picture tube is made of a metal material having a thickness of 0 kg / mm < ² > and a thickness of 10 to 50 [mu] m.