JP2701686B2 - Manufacturing method of grid device for color picture tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grid device for a color picture tube, and more particularly to a method for manufacturing a grid device for a color picture tube, wherein a color selection grid is formed by slit holes.

[0002]

2. Description of the Related Art In a grid device for a color picture tube, since an electron beam is irradiated on a grid portion of a color selection mechanism to select a color, most of the energy of the electron beam collides with the grid portion and is transmitted as heat, so that the grid is transmitted. The part expands and deforms,
As a result, the electron beam cannot strike a predetermined phosphor. In order to solve this problem, a grid device is manufactured in a state where tension is previously applied to the grid portion in each of up, down, left, and right directions, and a flat tension system or an aperture grill system in which the tension is canceled against thermal expansion of the grid unit. Grid devices have been proposed.

A flat tension type manufacturing method is disclosed in, for example, Japanese Patent Application Laid-Open No. 63-298936. As shown in FIGS. 2 and 3, this flat tension system employs a frame 22 having an L-shaped cross section on a substrate 21 of a welding apparatus.
Is placed, and is deflected inward by a predetermined amount by a spring 23 via a push rod 24. Push rod 24, as such uniform stress on each side of the frame 22, for example, two on each side, a total of eight were arranged, arrows A _1, A ₂ in FIG. _{3, B 1, B 2,} C 1 , C ₂ , D
_1, the portion indicated by D ₂ so as to deflect in the direction of the arrow.

Next, a shadow mask 25 having a large number of electron beam passage holes 25a formed in a thin metal plate is mounted on a frame 22. In this case, since the shadow mask 25 has a small thickness and is easily flexed up and down, the shadow mask 25
The tension is applied to the outer side by the spring 26 from eight directions, that is, vertical, horizontal and diagonal, with such a tension that the horizontal becomes horizontal.

Then, the shadow mask 25 is moved from the upper surface of the shadow mask
Heat to 0 ° C. In this case, since the heat capacity of the frame 22 is large, the temperature rise is negligible. In some cases, a shielding plate 29 may be placed to shield infrared rays. With the shadow mask 25 heated in this manner, the shadow mask 25 is continuously welded to the substantially center of the upper end 11a of the frame 22 over the entire circumference by a welding machine.

In FIG. 3, a two-dot chain line indicates a welding point. After welding, take out the shadow mask structure,
The temperature of the shadow mask 25 drops, and the shadow mask 2
5 is under tension. After that, an extra portion around the shadow mask 25 is removed. Since the shadow mask 25 that has been heated and expanded is fixed to the frame 22 with the inward stress applied thereto, the frame 22 has a tension that tends to spread outward. The tension of the frame 22 cancels the tension of the shadow mask 25 that cools and deflects inward. As a result, there is no problem that the frame is bent and deformed by the tension of the shadow mask after the fixation, and a predetermined tension is not applied to the shadow mask, and a uniform tension can be applied.

A method of manufacturing the aperture grill system is disclosed, for example, in Japanese Patent Application Laid-Open No. 62-252131. This will be described with reference to FIGS. In FIG. 5, a grid element 42 having a slit serving as an electron beam passage hole extending in the vertical direction is formed by a pair of support members 43,
44, and U-shaped elastic members 45, 4 supporting both ends thereof
6 on a metal support frame 47 made of

In this case, a pair of support members 43 and 44 of the support frame 47 are attached to the support frame 47 so that the grid body 42 is stretched with a required tension.
Are applied to each other so as to bend toward each other, and the grid element 42 is fixed by electric welding or laser welding in this state. Thereafter, the external force is removed and the grid element 42 is restored with the restoring force of the support frame 47. There is a method of giving tension to the element body 42.

In the case of a large pipe, in particular, the above-described method causes a rotational moment acting on the support members 43 and 44 about the longitudinal direction thereof when the support frame 47 is bent.
Since the rotational moment varies depending on the position of the support members 43 and 44 in the longitudinal direction, the support members 43 and 44 are twisted, thereby deteriorating the reliability of welding and generating wrinkles or pitch unevenness of slits. Manufacturing methods have been proposed.

As shown in FIG. 4, in a state where the grid element 42 and the support frame 47 are separated, the grid element 42 is heated by a heater 51 and thermally expanded.
In a state of thermal expansion, that is, by elongating mechanically the elongation due to the thermal expansion and absorbing the slack, the grid element 42 in a state without slack.
When the temperature is returned to room temperature, the grid element 42 is given a required tension. Therefore, since the support frame 47 is not bent, the rotational moment does not act on the support members 43 and 44, and the reliability of welding is improved. Variation is reduced.

[0011]

In a conventional method for manufacturing a color picture tube grid device, when a color selection electrode is fixed to a support frame and tension is applied, the support frame is deformed inward in advance and the grid element is welded. Since the grid element was preheated, expanded and welded to the support frame, and the grid element returned to room temperature and contracted, tension was applied to the grid element. After the element body and the support frame are welded and integrated as a grid device, tension is applied by the reaction force of the support frame or the contraction of the grid element body, so that the grid device is greatly deformed, and the slits have unevenness and wrinkles. This is problematic in that the dimensional accuracy is not sufficient due to the large change in the outer diameter. Also, it was difficult to obtain a desired tension distribution.

An object of the present invention is to provide a method of manufacturing a grid device for a color picture tube in which the deformation of the grid device is small and unevenness and wrinkles of the slit are prevented.

[0013]

In order to achieve the above object, a method of manufacturing a grid device for a color picture tube according to the present invention comprises the steps of performing a tension process and a joining process.
A method for manufacturing a grid device for a color picture tube, in which a grid element having an opening for controlling an electron beam reaching a phosphor screen is integrally assembled to a frame, wherein the tensioning treatment applies tension in a longitudinal direction of the grid element. While applying a compressive force in the inward direction to the frame side of the frame, and applying a reactive force between the tension and the compressive force by a link mechanism that maintains a correlation therebetween. This is a process in which the grid element body after the tension processing is welded to the frame and assembled integrally.

[0014]

[0015] Further, the tension processing is performed by using the grid
A process is provided to expand the body by heating it, and after cooling,
The same compression force as the tension applied to the lid body
Is to be granted.

[0016]

The equal amount of reaction force generated by the pressure applied to the frame and the equal amount of reaction force generated by the tension applied to the grid element are used to release the applied pressure and tension after welding.
The displacement caused by the pressurization of the frame and the displacement applied to the grid element always keep a constant ratio within the elastic limit so that they are always equal. For this reason, generation of wrinkles and unevenness of the slit is prevented.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. 1A and 1B are diagrams showing a method of manufacturing a grid device for a color picture tube according to an embodiment of the present invention in the order of steps. The grid device according to the present invention includes: a grid element body 11 having a large number of slits serving as electron beam passage holes;
A pair of frame sides 12 and 13 arranged at predetermined intervals to finally weld and support the grid body 11
And a pair of arms 14, 15 for supporting the frame sides 12 and 13.
Consists of

Further, the manufacturing apparatus according to the present invention includes a pretension portion 16 and 17 for pulling the grid element body 11 to apply sufficient tension to the slit, a heating apparatus 10 for heating the grid element body and thermally expanding the grid element, The pressure acting as a reaction force having the same magnitude as the tension applied to the element body 11 is applied to the frame sides 12 and 1.
Pressurizing portions 18 and 19 for acting in a compression direction on a frame in which portions 14 and 15 are integrated by 3 or the like;
And a welding device 20 for welding the frame sides 12 and 13 after pressing.

In the manufacturing process, first, a predetermined tension or tension distribution is applied to the grid body 11 by the pretension portions 16 and 17. This tension distribution is very close to the tension distribution after the completion of the grid device.

Next, the frame sides 12 and 13 and the arms 14 and 15
Is applied to the frame in which the tension is applied to the grid element body 11 by the pressurizing portions 18 and 19 or a reaction force having the same magnitude as the tension distribution. In FIG. 1B, the pretension unit and the pressurizing unit are linked while maintaining a fixed ratio, but may be independent as long as the mechanism can maintain the correlation therebetween. Then, both are welded and fixed by the welding device 20 in a state where the above-mentioned forces are applied. Finally, when the force of the pretension portion and the pressing portion is released to remove unnecessary portions of the grid body, FIG. 1 (C)
A grid device as shown in FIG.

Since the above-described tension and pressure are applied to the grid element and the frame in this manner, the two are fixed by welding.
Even when the applied force is released, the force to contract due to the tension of the grid element and the force to expand to the outside of the reaction force due to the pressurization of the frame balance, and the frame bends and deforms. There is no problem that no tension is applied to the element body, and a predetermined tension can be applied. Further, the operation of the tension distribution is easy, the dimensional accuracy after assembly is improved, and the productivity can be increased.

In the above-described method, the grid element is given a tension or a tension distribution at the pretension portion.
A similar effect can be obtained by heating the grid element. That is, the grid element is connected to the heating device 10.
When heated, it expands and expands thermally. It can be seen that the amount of elongation should be approximately the same as the amount of elongation when the pretension portion of the above embodiment is used.

The dimensions of the heating device are due to heat irradiation.
Since the grid element can be stretched relatively uniformly,
Easy to set and work. For example, the amount of elongation of the grid body by the pretension portion is 0.1 to 0.9.
mm, when the grid element is to be extended by 0.5 mm, the length of the grid element is 1 = 360 mm and the thermal expansion coefficient α is 140 × 10 ⁻⁶ / ° C., so that the strain ε = Δl / l =
0.5 / 360 = 1.39 × 10 ⁻³ , the heating temperature Δ
T = ε / α = 1.39 × 10 ⁻³ / 14 × 10 ⁻⁶ ≒ 100
It can be seen that it is sufficient to heat from 0 ° C., that is, normal temperature to + 100 ° C. When an actual experiment was performed, even when the grid body was heated to about + 80 ° C., there was no problem that tension was not applied to the grid body as compared with the case where the grid body was not heated, and a predetermined tension could be applied. . In addition, it can be seen that, in addition to this method, applying tension at the pretension portion may be used together.

[0024]

As described above, according to the present invention, a grid element having a very elongated opening for controlling an electron beam reaching the phosphor screen is preliminarily tensioned in the longitudinal direction of the hole, and After applying a pressure with a certain correlation with the tension in the compression direction in advance to the frame supporting the element body, the grid element and the frame are welded together. Smaller,
Slit wrinkles and unevenness are prevented, and the outer diameter change is small, so dimensional accuracy is improved. Also when mounting the grid device to the picture tube via a spring, the mounting position accuracy is improved, and product yield is improved. There is an effect that can be improved.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention, in which (A) is a process diagram before pressing, (B) is after pressing, and (C) is a process diagram after completion.

FIG. 2 is a cross-sectional view showing a manufacturing method disclosed in Japanese Patent Application Laid-Open No. 63-298936.

FIG. 3 is a perspective view of a shadow mask structure disclosed in JP-A-63-298936.

FIG. 4 is a process chart disclosed in JP-A-62-252031.

FIG. 5 is a perspective view showing a grid device disclosed in Japanese Patent Application Laid-Open No. 62-252031.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Heating device 11 Grid element body 12, 13 Frame side 14, 15 Arm part 16, 17 Pretension part 18, 19 Pressurization part 20 Welding device

Claims (2)

(57) [Claims] 1. A method for manufacturing a grid device for a color picture tube, wherein a grid element having an aperture for controlling an electron beam reaching a phosphor screen is integrally assembled with a frame by performing a tension process and a joining process. The tension treatment is to apply an inward compressive force to the frame side of the frame while applying a tension in the longitudinal direction of the grid element body, and to correlate a reaction force between the tension and the compressive force.
The joining process is a process of welding the grid element body after the tension processing to the frame and assembling the frame element integrally with the frame, and the joining process is performed by a link mechanism generated while maintaining the engagement. Production method. 2. The tensioning treatment includes a treatment for heating and expanding the grid element, and applying a compressive force of a reaction force substantially equal to a tension applied to the grid element after cooling. The method for manufacturing a grid device for a color picture tube according to claim 1.