JPH0554794A - Assembling device of shadow mask for cathode-ray tube - Google Patents

Abstract

PURPOSE:To facilitate and ensure positioning and improve producing yield by providing a mechanism supporting a shadow mask on the curvature central side and expanding/contracting from the inner part to four corners. CONSTITUTION:A shadow mask is assembled by the lining method of welding a shadow mask 2 to the inside of a support frame 1. A shadow mask curved surface receiving jig 5 for supporting the mask 2 on the curvature central side has an expanding/contracting mechanism 6 having top end parts 6a expansible and contractible from the inner part of the jig to the inside surface of the frame 1. The frame 1 is installed to a precise position of the jig 5 by the engagement between a leaf spring 3 and a stud 4 in the state where the mechanism 6 is contracted, and the mechanism 6 is then expanded to situate the four corners of the mask 2 in precise relative positions to the frame 1, followed by welding and fixing. After the work is completed, the mechanism 6 is contracted again, whereby the assembled product can be easily taken out from the device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shadow mask assembling apparatus for a color cathode ray tube capable of easily producing an inner lined shadow mask which is assembled by welding a shadow mask inside a support frame with a high yield.

[0002]

2. Description of the Related Art Conventional shadow masks are
It is made of thin mild steel plate with a plate thickness of 0.25 mm or less, and three electron beams for each specific color that are incident at different angles are formed at different predetermined positions on the inner surface of the panel that are separated by a predetermined distance. A large number of round holes or elongated slits for passing an electron beam are formed in order to properly hit the dots or stripes of the specific color phosphor. Therefore, the shadow mask is poor in rigidity and is still easily deformed even when the periphery is bent to form a so-called skirt portion. Therefore, the end portion of the skirt portion is surrounded by an L-shaped steel material in which the side far from the screen is bent inward. The support frame is frame-shaped, and is welded and fixed to a portion of the inner surface of the side of the L-shaped steel material, which is orthogonal to the screen, near the bent portion.

FIG. 2A shows a conventional cathode ray tube tube.
Shadow mask 2 is supported using a shadow mask assembly device.
Side cut to explain the work to attach to the port frame 1
It is a side view. First, support frame 1
It is placed on the boom receiving jig 8. Shadow mask assembly
The correct relative to the color cathode ray tube bulb panel
Position (As can be seen from the explanation above, the shadow mask panel
The relative position of the inner surface with respect to the fluorescent surface must be extremely accurate.
Each of the inner surface of the panel skirt for mounting
Engage with the end of a stud planted in the
Leaf springs 3 for holding the shadows (shadow mask panel
The relative position of the inner surface to the fluorescent surface is extremely accurate
It is necessary to actually install a particular panel valve fan
Dew in combination with a specific shadow mask before bonding to the flannel.
Fluorescent surface by illuminating and fixing the photosensitive fluorescent film to the inner surface of the panel
Is formed, but during this work, it is not attached to the desired places.
Of the shadow mask to remove the specific color
It is necessary to repeat attachment and detachment, and leaf spring 3 is used for attachment and detachment.)
However, the positions corresponding to the above studs on each side of the support frame 1
Is stuck to. As shown in Fig. 2 (a), the support frame
The leaf springs 3 fixed to each side of the frame 1 are attached to the collar shade.
In the same way as when mounting on the inner surface of the cathode ray tube panel,
And engage the stud 4 of the shadow mask assembling device.
For example, the support frame 1 should be installed in the shadow mask assembly device.
Installed properly. If you do this, support
The frame 1 is for the shadow mask curved surface receiving jig 5
The vertical and horizontal position, the correct relative
Can take position. Then shadow mass
Place the shadow 2 on the shadow mask curved surface receiving jig 5
Each side of the skirt around the mask 2 is
Support frame 1 mounted on the mask assembly device
Make sure that the correct relative position is taken for each side of
Place. Figure showing the shadow mask 2 placed in this way
Press the shadow mask curved surface pressing jig 7 as shown.
The shadow mask 2 and fix the end of the skirt of the shadow mask 2.
On the side of the port frame 1 in the direction perpendicular to the L-shaped steel screen
Attach by welding and fixing to a place near the bent part of the inner surface.
Note that this type of shadow mask assembling apparatus is related
Examples of the materials include Japanese Patent Publication No. 62-17819.
Be done.

[0004]

As described above, the support frame 1 is first mounted on the shadow mask assembling apparatus,
Since the shadow mask 2 must be removed from the shadow mask assembling apparatus when the shadow mask 2 is welded and fixed to the support frame and the assembling work is completed, the shadow mask curved surface receiving jig 5 is made of the L-shaped steel material forming the periphery of the support frame 1. The side away from the screen that bends inward (commonly called flange)
It must be able to freely pass through the rectangular part (flange inner diameter part) surrounded by the inside of the. Therefore, the periphery of the shadow mask 1 inevitably protrudes outside the curved surface receiving jig 5 as can be seen from FIG. Therefore, in FIG.
When the conventional shadow mask assembling apparatus shown in (a) is used, each side of the skirt portion of the shadow mask 2 is correct relative to each side of the support frame 1 previously attached to the shadow mask assembling apparatus. The shadow mask curved surface receiving jig 5 must be mounted on the shadow mask curved surface receiving jig 5 by visual observation so that the support frame and the shadow mask skirt are evenly spaced. It is very difficult to judge whether the shadow mask mounting place is correct or not. Therefore, as shown in FIG. 2B, the position of the shadow mask is biased to one side (upper left in the case shown) with respect to the support frame, or
As shown in (c), a defective product that has been welded and assembled occurs in a state where it is rotated from the normal position (to the left in the case of the drawing). For products with a small deviation from the correct relative position,
It can be remedied by adjusting the deflection yoke of the electron beam when it is attached, but if the deviation is large, the screen display will be immediately affected and cannot be used. In addition, if the inner diameter of the support frame and the outer dimension of the shadow mask are made close to each other in order to prevent the occurrence of such defective products, it becomes difficult to insert the shadow mask into the support frame, and a long time is required for the operation. New defects such as defective deformation of the shadow mask curved surface occur. As already mentioned, the shadow mask has low rigidity and is easily deformed.Therefore, the shadow mask must be inserted and combined into the support frame in a loosely fitted state, and the shadow mask must be positioned reliably and accurately with respect to the support frame. It had to be a challenge.

The present invention solves the above-mentioned conventional problems, and at the time of assembling a shadow mask, it is necessary to visually judge whether the shadow mask mounting position is correct or not in the step of inserting and mounting the shadow mask into the support frame. It is an object of the present invention to provide a shadow mask assembling apparatus for a color cathode ray tube which is free from the above problems.

[0006]

In order to solve the above problems, the present invention provides a shadow mask assembling apparatus for a color cathode ray tube of a liner type shadow mask in which a shadow mask is attached by welding to a support frame to assemble the shadow mask. When extended to the four corners of the shadow mask curved jig that supports the shadow mask on the side of the center of curvature, the tips are suitable for attaching the shadow mask to the support frame by welding by positioning the four corners of the shadow mask correctly. When held in the correct relative position and contracted, the above-mentioned tip is also stored inside the curved surface receiving jig, and the support frame is attached to the predetermined position of this assembling device at the beginning of the assembling work. Stretchable to prevent the shadow mask from being removed together with the support frame from the assembly device later It was to be provided with a structure.

[0007]

If the shadow mask assembling apparatus having the above structure is used, the support frame is retracted to the predetermined position of this assembling apparatus while the expansion / contraction mechanism is contracted and the tip portion is housed inside the shadow mask curved surface receiving jig. , And the holes of the leaf springs attached to the respective sides are engaged with the stud ends of the assembling apparatus so that the correct relative position can be obtained with respect to the shadow mask curved surface receiving jig. Next, with the telescopic mechanism extended, position the four corners of the shadow mask with the tip of the telescopic mechanism as a reference and place them in the correct relative positions with respect to the support frame, without relying on visual inspection as before. It can be fixed and the shadow mask can be assembled correctly. After the assembly work is completed, the shadow mask supported by the support frame can be removed from the shadow mask assembly apparatus together with the support frame by contracting the expansion mechanism again.

[0008]

1 is a view for explaining an assembling work for welding and fixing a shadow mask 2 to a support frame 1 using a shadow mask assembling apparatus according to an embodiment of the present invention.
FIG. 1 (a) shows an expanding / contracting driving air cylinder 6b attached to a shadow mask curved surface receiving jig 5 and a supporting frame 1 already mounted on the shadow mask assembling apparatus for a color cathode ray tube according to the present invention. The distal end portion 6a of the expansion / contraction mechanism 6 including the distal end portion 6a is extended,
It is a top view which shows the state which the four corners of the shadow mask 2 mounted on the shadow mask curved surface receiving jig 5 are correctly positioned on the basis of it. 1 (b) is shown in FIG. 1 (a).
It is the XX sectional view shown inside. In FIG. 1C, the shadow mask assembly work is completed by welding and fixing the vicinity of the end of the skirt portion of the shadow mask 2 to the inside of the side of the support frame 1 perpendicular to the screen, and the shadow mask assembly is supported. FIG. 6 is a cross-sectional view taken along the diagonal line of the support frame showing a state in which the tip end portion 6a of the expansion and contraction mechanism 6 is contracted until it is housed inside the shadow mask curved surface receiving jig 5 in order to remove the frame together with the assembly device.

According to the above-described embodiment of the present invention, the position of the shadow mask is biased to one side with respect to the support frame,
Alternatively, since they are not assembled by welding in a rotated state, the effective surface of the shadow mask (electron beam passage hole drilling region) does not deviate from the panel of the color cathode ray tube.
In addition, since the shadow mask can be inserted and combined into the support frame in a loosely fitted state (the clearance between the skirt portion of the shadow mask and the side surface of the support frame can be increased), the shadow mask can be inserted into the support frame. The work is easy and the deformation potential of the shadow mask curved surface can be reduced.

[0010]

As described above, according to the present invention, the shadow mask can be easily and surely positioned with respect to the support frame, and the shadow mask is eccentric with respect to the support frame or rotated from the normal position. It is possible to obtain the effect of preventing the generation of defective products that have been attached by the method, and it is possible to prevent the appearance of the screen effective surface (fluorescent body forming region) of the color cathode ray tube from being impaired.

[Brief description of drawings]

FIG. 1 is a view for explaining an assembling work for welding and fixing a shadow mask to a support frame by using a shadow mask assembling apparatus according to an embodiment of the present invention. FIG. 1 is a top view showing a state in which the shadow mask 2 is inserted at a position, FIG. 1 (b) is a cross-sectional view in a diagonal direction showing the same state, and FIG. 1 (c) is for removing the shadow mask assembly together with the support frame from this assembly device. FIG. 9 is a cross-sectional view in a diagonal direction showing a state in which the distal end portion of the expansion mechanism is contracted.

FIG. 2A is a side sectional view for explaining an assembling work for welding and fixing a shadow mask to a support frame by a conventional shadow mask assembling apparatus for a color cathode ray tube;
FIG. 2B is a top view of a defect example in which the shadow mask is fixed to the support frame by shifting it from the correct relative position to the upper left, and FIG. 2C shows the shadow mask from the correct relative position to the support frame. FIG. 7 is a top view of a defective example in which it is fixed by rotating counterclockwise.

[Explanation of Codes] 1 ... Support frame, 2 ... Shadow mask, 3 ...
Leaf spring, 4 ... Stud, 5 ... Shadow mask curved surface receiving jig, 6 ... Expansion / contraction mechanism, 6a ... Tip of expansion / contraction mechanism,
6b ... Air cylinder of expansion / contraction mechanism, 7 ... Shadow mask curved surface holding jig, 8 ... Support frame receiving jig.

Claims (1)

[Claims] 1. A shadow mask assembling apparatus for a color cathode ray tube for a liner type shadow mask assembly, wherein a shadow mask is attached by welding inside a support frame to assemble the shadow mask, the shadow mask being supported on the side of the center of curvature and having an outer diameter of the shadow mask. At the four corners of the shadow mask curved surface receiving jig that is smaller than the inner diameter of the flange of the support frame,
A shadow mask assembling apparatus for a color cathode ray tube, wherein a tip end portion is provided with an expanding / contracting mechanism capable of expanding and contracting from an inside of the curved surface receiving jig to an inside surface of the support frame.