JP2004047201A - Method and device for manufacture of cathode-ray tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for manufacture of a cathode-ray tube capable of preventing wrinkles of a shadow mask by reducing the tension unevenness of the shadow mask. <P>SOLUTION: In the method for manufacture of the cathode-ray tube, the shadow mask is fixed to a mask frame by welding in a state of applying a first pressing force in a direction narrowing an interval of at least one pair of sides of the mask frame and applying a second pressing force to the shadow mask in a direction opposite to the first pressing force. The first pressing force is applied from the center of the mask frame at equal intervals of ≤100mm. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a cathode ray tube used for a television or a display of a computer, and more particularly, to a method and an apparatus for manufacturing a cathode ray tube to be fixed to a frame while applying a tensile force to a shadow mask. About.
[0002]
[Prior art]
In recent years, with the flattening of the front panel of the color cathode ray tube, the shadow mask has also been flattened. When the shadow mask is planarized, it is difficult to maintain the plane of the shadow mask only by supporting the shadow mask body with a frame as in the related art. Further, if the frame is simply supported by the frame, the shadow mask is easily vibrated by an external vibration, which adversely affects the display screen of the color cathode ray tube. For this reason, a technique of applying a certain tension to a shadow mask and supporting the shadow mask on a frame is being developed.
[0003]
On the other hand, even in a doming phenomenon in which the surface of the shadow mask is deformed due to thermal expansion due to the collision of the electron beam with the shadow mask, the surface of the shadow mask is flattened, particularly due to the doming phenomenon near both ends of the screen. The displacement of the electron beam will be large. Therefore, in order to absorb the thermal expansion due to the collision of the electron beam in the above-described suspension of the shadow mask, a technique of applying a tension at a practical maximum level close to the elastic limit is applied to the shadow mask. .
[0004]
According to such a stretch holding, even when the temperature of the shadow mask rises, the vibration of the shadow mask due to the external vibration and the mutual interaction between the electron beam passage holes of the shadow mask and the phosphor dots on the phosphor screen surface. It is said that the displacement can be prevented.
[0005]
In general, a stretched and held shadow mask is called a tension type shadow mask. The tension type shadow mask has an aperture grill type in which a number of strips are stretched on a mask frame, and a substantially rectangular electron beam passage hole in a flat plate. There are a slot type in which many holes are formed and a dot type in which many round electron beam passage holes are formed in a flat plate.
[0006]
In addition, there are a one-dimensional tension method and a two-dimensional tension method for stretching and holding. The one-dimensional tension method is a method of applying tension only in the vertical direction (up-down direction) of the shadow mask, and the two-dimensional tension method is a method of applying tension in both the vertical direction and the horizontal direction. A one-dimensional tension system is used for the aperture grill type, and a one-dimensional tension system or a two-dimensional tension system is used for the slot type or dot type.
[0007]
Further, in order to apply a predetermined tension to the shadow mask, a method of manufacturing a color cathode ray tube in which the shadow mask and the mask frame are fixed by welding while applying a tensile force to the shadow mask and pressurizing the mask frame, Various proposals have been made. For example, the invention described in JP-A-63-298936, JP-A-8-55577, and JP-A-9-7508 relates to a method of fixing a shadow mask and a mask frame by using the welding described above. There is disclosure. Furthermore, in the invention disclosed in Japanese Patent Application Laid-Open No. 2000-67747, a method of pressing the upper end of the mask frame has also been proposed.
[0008]
[Problems to be solved by the invention]
However, the above-described prior art has the following problems.
[0009]
(1) When pressurizing at several locations, even if pressure is applied through a Duracon, local deformation occurs in the mask frame at the pressurized portion and other locations. Therefore, after the compression force is released, the possibility of unevenness in the mask tension increases.
[0010]
(2) Wrinkles are generated in the shadow mask due to unevenness of the squatting. Also, even if wrinkles do not occur after the shadow mask is welded to the frame, there is a high possibility that wrinkles will occur due to the subsequent heat treatment.
[0011]
The present invention solves the above-mentioned conventional problems, and a method for manufacturing a cathode ray tube capable of reducing tension unevenness of a shadow mask by a pressing method and preventing wrinkles of the shadow mask from occurring. It is intended to provide a device.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a method of manufacturing a cathode ray tube according to the present invention according to claim 1 includes applying a first pressing force to at least a pair of sides of a mask frame in a direction in which a distance between the pair of sides is reduced. Is a method for manufacturing a cathode ray tube in which the shadow mask is fixed by welding to the mask frame in a state where a second pressing force is applied in a direction opposite to the first pressing force. Is performed at equal intervals of 100 mm or less and from the center of the mask frame.
[0013]
Further, the apparatus for manufacturing a cathode ray tube according to claim 2 is a compression unit for applying a first pressing force in a direction in which a distance between at least a pair of sides of the mask frame is reduced, and the first pressing force is applied to the shadow mask. Is a cathode ray tube manufacturing apparatus comprising: a pulling means for applying a second pressing force in an opposite direction; and a fixing means for welding the shadow mask to the mask frame. The pressing jig is arranged at equal intervals of 100 mm or less, and is arranged from the center of the mask frame.
[0014]
According to a third aspect of the present invention, there is provided a cathode ray tube manufacturing apparatus according to the second aspect, wherein a distance between centers of the pressing jigs is 100 mm or less.
[0015]
According to a fourth aspect of the present invention, there is provided a cathode ray tube manufacturing apparatus according to the second or third aspect, wherein the pressing jig has a width which is a half of an arrangement interval of the pressing jig. It is characterized by having.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a method and an apparatus for manufacturing a cathode ray tube according to an embodiment of the present invention will be described in detail with reference to the drawings to provide an understanding of the present invention. The embodiments described below are specific examples of the present invention and do not limit the technical scope of the present invention.
[0017]
Hereinafter, description will be made in the order of manufacturing steps with reference to FIGS. The specific operation procedure related to the method of manufacturing a cathode ray tube includes: (1) a shadow mask setting step (FIG. 1 (a)), (2) a shadow mask chucking step (FIG. 1 (b)), and (3) a shadow mask. Stretching process (FIG. 1 (c)), (4) mask frame pressurizing process (FIG. 2 (a)), (5) welding process (FIG. 2 (b)), (6) completed state (FIG. 2 (c) )).
[0018]
First, the shadow mask setting step will be described with reference to FIG. In the figure, the shadow mask 1 shows an example of a slot type one-dimensional tension system. The mask frame 2 is a rectangular frame formed by fixing left and right short side frames 2c and 2d to upper and lower long side frames 2a and 2b having an L-shaped cross section opposed to each other.
[0019]
In this step, as shown in FIG. 3, the shadow mask 1 is held using a shadow mask holding device (hereinafter, referred to as “holding device 3”), and the shadow mask 1 is positioned with respect to the mask frame 2. This positioning is performed by, for example, fitting a hole or notch provided in the shadow mask 1 with a projection provided in the holding device 3.
[0020]
At this time, the upper surface 3a of the holding device 3 has a predetermined surface shape, for example, a cylindrical surface, and the suction portion 4 is formed on the upper surface 3a. For this reason, the shadow mask 1 is held by the suction unit 4, so that a predetermined aspect shape is maintained. For example, a magnet, evacuation, or the like is used for suction by the suction unit 4. In the case of a magnet, a magnet in which the magnet is embedded in the upper surface 3a of the holding device 3 may be used. In the case of vacuuming, an air suction port may be provided in the upper surface 3a of the holding device 3.
[0021]
Further, while the shadow mask 1 is held in the shape of the surface by the holding device 3, the shadow mask 1 is sufficiently stretched by being pulled outward with respect to the center thereof to remove wrinkles or slack of the shadow mask 1. . At this time, the direction in which the shadow mask 1 is stretched may be only in the direction in which the shadow mask 1 is stretched, or only in the diagonal direction of the shadow mask 1, and may be in both directions. By stretching the shadow mask 1 in this manner, the holding device 3 is moved in the direction in which the shadow mask 1 is stretched, or the magnet pieces placed at the four corners of the shadow mask 1 are slid radially.
[0022]
By such a method, the shadow mask 1 can be held in a state of being stretched on the mask frame 2. As a result, a tensile force can be applied in the next step without wrinkles of the shadow mask 1, so that unevenness of stress occurs in the shadow mask 1 after welding and wrinkles are generated after the heat treatment step. It is possible to do.
[0023]
Next, the step of shadow mask chucking will be described with reference to FIG. In this step, a shadow mask chucking device (hereinafter referred to as “chucking device 5”) shown in FIG. 3 is used. The shadow mask 1 is sandwiched between the upper chucking jig 6 and the lower chucking jig 7.
[0024]
The lower surface 6a of the upper chucking jig 6 has a surface shape (concave shape), and the lower chucking jig 7 has an upper surface 7a having a surface shape (convex shape). Therefore, when the shadow mask 1 is sandwiched between upper and lower chucking jigs, the shadow mask 1 is held in the same predetermined shape as the upper surface 3 a of the holding device 3.
[0025]
Subsequently, the shadow mask spanning step will be described with reference to FIG. In this step, the shadow mask 1 sandwiched by the chucking devices 5 is pulled in the direction of arrow a to apply tension.
[0026]
Further, the mask frame pressing step will be described with reference to FIG.
[0027]
In this step, a compressive force is applied to the side surfaces of the rising portions of the outer side surfaces of the long side frames 2a and 2b of the mask frame 1. FIG. 4 is a perspective view of a mask frame pressing device (hereinafter, referred to as “pressing device 8”) used in this step. Although only the frame 2a side is shown in FIG. 4, a similar device is disposed on the frame 2b side.
[0028]
The pressing device 8 includes a plurality of pressing jigs. The pressing jigs are arranged at equal intervals of 100 mm or less. Further, the width of the pressing jig is set to の of the interval at which the jig is arranged. In such a state, the compressive force is applied to the mask frame 1 by applying a force in the direction b by the pressing jig 9.
[0029]
FIG. 5A shows a state before and after the mask frame deformation when a compressive force is applied to the side surface of the rising portion. The two-dot chain line indicates the state of application of the compressive force. At the upper end of the side surface of the rising portion 15, the compression force and the repulsive force of the rising portion 15 trying to return to the original thrust direction by the spring action are balanced. Further, a tensile force (arrow a) is applied to the shadow mask 1. As described later, in this state, the upper surface of the rising portion 15 and the shadow mask are welded, and then the compressive force is released. When the compression force is released, the tension force of the shadow mask 1 and the repulsion force of the rising portion 15 are balanced.
[0030]
FIG. 5B shows a state before and after deformation when the same compressive force is applied through a conventional Duracon. In the conventional pressing method, since the pressing positions are not equally spaced, local deformation occurs at a position where the pressing block exists. Therefore, unevenness in the mask tension occurs. FIG. 6 shows a comparison between a conventional pressing method using a Duracon and a mask stress when pressing jigs are arranged at equal intervals.
[0031]
As described above, by setting the pressing positions at equal intervals, local deformation can be reduced and unevenness in mask tension can be reduced.
[0032]
FIG. 2B shows a welding step. In this step, the upper surface of the rising portion of the long side frames 2a and 2b of the mask frame 2 and the shadow mask 1 are welded. A specific welding method is performed by, for example, the roller electrode 11 as shown in FIG. After the welding is completed, the compressive force on the mask frame 2 is released.
[0033]
Finally, FIG. 2C shows a state in which unnecessary portions outside the mask frame 2 of the shadow mask 1 after the welding is completed are cut. Through the above steps, the spanning of the shadow mask is completed.
[0034]
In this embodiment, the case of the one-dimensional tension system in which tension is applied only in the vertical direction of the shadow mask has been described. However, the same effect can be obtained by the two-dimensional tension system in which tension is applied in both the vertical direction and the horizontal direction. .
[0035]
Further, although the example in which the shadow mask is of the slot type has been described, a dot type or an aperture grill type may be used. Although the embodiment in which the shadow mask is fixed on the mask frame on the surface has been described, a case in which the shadow mask is fixed in a plane shape may be used.
[0036]
【The invention's effect】
According to the method and apparatus for manufacturing a cathode ray tube of the present invention, the positions of the pressing jigs are arranged at equal intervals of 100 mm or less, and the width of the pressing jigs is reduced to half of the arrangement interval. The distortion of the upper end of the frame at the time of pressurization can be reduced as compared with the technology. As a result, tension unevenness of the shadow mask can be reduced. Also, wrinkles generated in the mask can be prevented.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a series of flows from a shadow mask setting step to a mask frame stretching step according to an embodiment of the present invention. FIG. FIG. 3 is a perspective view showing a series of flows up to a process. FIG. 3 is an arrangement diagram of a pressing device, a chucking device, and a holding device according to an embodiment of the present invention. FIG. 5A is a top view showing before and after the deformation of the mask frame according to the embodiment of the present invention. FIG. 5B is a top view showing before and after the deformation of the mask frame. FIG. It is a diagram showing a comparison of stress when pressed,
(A) is a transverse stress diagram on the center line. (B) is a diagram showing longitudinal stress on the center line.
Reference Signs List 1 shadow mask 2 mask frame 2a, 2b long side frame 2c, 2d short side frame 3 holding device 3a holding device upper surface 4 suction unit 5 chucking device 6 upper chucking jig 6a upper chucking jig lower surface 7 lower chucking Jig 7a Upper surface of lower chucking jig 8 Pressing device 9 Pressing block 10 Rising section 11 Roller electrode

Claims (4)

In the mask frame, a first pressing force is applied in a direction in which at least the interval between the pair of sides becomes smaller, and a second pressing force is applied to the shadow mask in a direction opposite to the first pressing force. A method for manufacturing a cathode ray tube, wherein the shadow mask is fixed by welding to the mask frame,
The method of manufacturing a cathode ray tube, wherein the first pressing force is performed at equal intervals of 100 mm or less and from the center of the mask frame. Compression means for applying a first pressing force in a direction in which a distance between at least a pair of sides of the mask frame is reduced; and tension means for applying a second pressing force to the shadow mask in a direction opposite to the first pressing force. And a fixing device for welding the shadow mask to the mask frame, the device for manufacturing a cathode ray tube,
The apparatus for manufacturing a cathode ray tube, wherein the compression means is constituted by a plurality of pressing jigs, and the pressing jigs are arranged at equal intervals of 100 mm or less, and are arranged from the center of the mask frame. . 3. The apparatus according to claim 2, wherein a distance between centers of the pressing jigs is 100 mm or less. The cathode ray tube manufacturing apparatus according to claim 2, wherein the pressing jig has a width that is の of an arrangement interval of the pressing jig.

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