JP2001043794A - Shadow mask welding machine for color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shadow mask welding machine for a color cathode-ray tube, that can keep an interval between the inner surface of a glass panel and a shadow mask at its four outermost peripheral corners as a prescribed value similarly to its central part, and prevent degradation of display quality due to multiple color hitting near the four outermost peripheral corners of the shadow mask, by improving a structure of a movable die of the shadow mask welding machine. SOLUTION: Shape error data for the inner surface size of a glass panel 11 corresponding to the four outermost peripheral corners of a shadow mask 14 is measured previously, the parts corresponding the four outermost peripheral corners of the shadow mask 14 of a movable die 25 are provided with divided movable portions 26 which is independent of the main body, and the divided movable portions 26 are controlled, based on the measured shape error data of the inner surface size of the glass panel 11, corresponding to the four outermost peripheral corners of the shadow mask 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a color cathode ray tube, and more particularly, to manufacturing a color cathode ray tube by welding and fixing a mask frame and a shadow mask when assembling a mask assembly disposed inside a glass panel. Related to the device.

[0002]

2. Description of the Related Art A color CRT is generally provided with a shadow mask 41 inside a glass panel 45 as shown in FIG.
And a mask frame 42.

The mask frame 42 of the mask assembly is a rectangular frame made of metal as shown in FIGS. 5 and 6, and has elastic metal strips at three or four locations on its outer wall. Are fixed by welding. At the tip of the hook spring 43, a mounting hole 44 is formed. On the other hand, as shown in FIG. 4, the shadow mask 41 has a curved surface portion corresponding to the curved surface shape of the glass panel 45, and a large number of beam transmission holes (not shown) are formed in the curved surface portion. Has a skirt 46 extended by bending the periphery of the skirt. As described later, the skirt 46 of the shadow mask 41 is fitted into the mask frame 42 and fixed by welding, so that the shadow mask 41 and the mask frame 42 are integrated.

When assembling a mask assembly in which the above-mentioned mask frame 42 and shadow mask 41 are integrated into a glass panel 45, as shown in FIG. A stud pin 47 provided on the inner surface of the panel 45 is inserted into the mounting hole 44 of the hook spring 43 of the mask frame 42, and the fitting is carried out.
5 holds the mask assembly. At this time, it is necessary to position the gap between the shadow mask 41 and the inner surface of the glass panel 45 to a predetermined value with high accuracy. It should be noted here that the curved shape of the glass panel 45 has a large error with respect to the design value. Therefore, the dimensional error of the inner surface of each glass panel 45 is measured, and the position of the shadow mask 41 is individually adjusted accordingly. Need to decide.

Since the mounting position of the mask frame 42 on the glass panel 45 is fixed, the shadow mask 4
Position adjustment 1 is performed on the mask frame 4 of the shadow mask 41.
This is done by adjusting the position of attachment to 2. Therefore, in order to position the relative position between the shadow mask 41 and the glass panel 45 with high accuracy, the shadow mask 41 must be attached to the mask frame 42 with high accuracy. Therefore, the attachment of the shadow mask 41 to the mask frame 42 has been performed as follows.

First, the shape error data of the inner surface of the glass panel 45 shown in FIG. 4 is measured for the center point 48 and the eight peripheral points 49 within the range of the shadow mask 41 shown in FIG. Next, as shown in FIG. 8, the shadow mask 41 and the mask frame 42 are temporarily fixed and the shadow mask welding machine 8 is
0, and the vertical position of the mask frame 42 is adjusted using the fixed mold 81 of the shadow mask welding machine 80 as a reference position based on the shape error data of the inner surface of the glass panel 45. (Using the fixed mold 81 as the reference position is equivalent to setting the shadow mask 41 as the reference position.) This is achieved by setting the vertical position of the guide pin 82 inserted in the mounting hole 44 of the hook spring 43 to a pulse motor (not shown). This is done by making fine adjustments such as

Next, as shown in FIG. 9, the shadow mask 41 is pressed downward by a movable mold 83 from above. Here, portions of the fixed mold 81 and the movable mold 83 that are in contact with the shadow mask 41 coincide with the curved surfaces of the shadow mask 41. The shadow mask 41 is pressed by the movable mold 83 so that the skirt 46 of the shadow mask 41
Is pushed in while being fitted on the inner wall surface of the. This pushing operation is completed when the shadow mask 41 is clamped at a predetermined pressure in the gap between the fixed mold 81 and the movable mold 83. In this state, although not shown, electrodes are arranged outside the mask frame 42 and inside the skirt 46 of the shadow mask 41 and both are welded. Thus, a mask assembly in which the shadow mask 41 is mounted on the mask frame 42 is obtained.

[0008]

When the above-described mask assembly is assembled inside the glass panel 45 as shown in FIG. 4, the distance between the shadow mask 41 and the inner surface of the glass panel 45 at the center of the glass panel 45 is equal to a predetermined value. However, in the vicinity of the outermost four corners of the shadow mask 41, the intervals do not always become the predetermined intervals. The cause is that the dimensional error of the glass panel 45 is near the outermost four corners of the shadow mask 41, and the central point 48 and the eight peripheral points of the inner surface of the glass panel 45 shown in FIG.
This is because the shape of the shadow mask 41 was not corrected in accordance with the shape, though it was larger than expected from the measurement in FIG.

The shadow mask 41 and the glass panel 4 are located at the outermost four corners of the shadow mask 41.
If the distance from the electron beam 5 does not reach a predetermined value, the position where the electron beam hits is shifted from the hole of the black matrix and multi-colored (for example, the color to be originally struck so that the electron beam to strike the red phosphor strikes the blue phosphor) (Electron beams hit phosphors of different colors), and display quality is degraded. However, this problem cannot be avoided in the conventional shadow mask welding machine 80.

An object of the present invention is to improve the structure of the movable mold of the shadow mask welding machine so that the distance between the shadow mask and the inner surface of the glass panel at the outermost four corners of the shadow mask is the same as the predetermined value as in the central part. It is an object of the present invention to provide a shadow mask welding apparatus for a color cathode-ray tube, which can maintain display quality and prevent deterioration of display quality due to multicoloring near the outermost four corners of the shadow mask.

[0011]

In order to achieve the above object, a shadow mask welding apparatus for a color cathode-ray tube according to the present invention measures shape error data of the inner surface dimensions of a glass panel corresponding to the outermost four corners of a shadow mask in advance. A movable mold having a divided movable portion independent of the central portion at a portion corresponding to the outermost four corners of the shadow mask; and a glass corresponding to the outermost four corners of the shadow mask having a height of the divided movable portion. The control is performed based on the shape error data of the inner surface size of the panel.

That is, according to the first aspect of the present invention, the vertical position of the mask frame is adjusted based on the shape error data of the inner surface dimensions of the glass panel measured in advance, and then the shadow mask is moved to the fixed mold and the movable mold. In the shadow mask welding machine for a color cathode-ray tube in which the mask frame and the shadow mask are welded and fixed, the shape of the inner surface dimensions of the glass panel corresponding to the outermost four corners of the shadow mask Error data is measured in advance, and a portion corresponding to the outermost four corners of the shadow mask of the movable mold is provided with a divided movable portion independent of a central portion, and glass corresponding to the outermost four corners of the shadow mask is provided. The height of the divided movable portion is controlled based on shape error data of panel inner surface dimensions. To.

According to a second aspect of the present invention, the shape error data of the inner surface dimensions of the glass panel corresponding to the four outermost corners of the shadow mask is taken into the arithmetic unit, and the arithmetic error data generated by the arithmetic unit is used. The height of the divided movable portion of the movable mold is automatically controlled.

According to a third aspect of the present invention, the height of the divided movable portion of the movable mold is controlled by a servomotor or a pulse motor.

According to a fourth aspect of the present invention, the height of the divided movable portion of the movable mold is ± 20 with respect to a center value.
It is characterized by being controlled within an accuracy of 2 μm within a range of 0 μm.

[0016]

According to the first aspect of the present invention, the shape error data of the inner surface dimensions of the glass panel corresponding to the four outermost corners of the shadow mask are measured in advance, and the shape error data near the outermost four corners of the shadow mask are measured based on the shape error data. The height of the divided movable portion at the outermost four corners of the movable mold shadow mask is controlled so that the distance between the shadow mask and the glass panel becomes the predetermined value, and the shadow mask is pushed into the mask frame, whereby the shadow mask can be moved to the minimum position. The shape of the outer four corners is corrected according to the shape of the corresponding portion of the glass panel, and the distance between the shadow mask and the inner surface of the glass panel can be set to a predetermined value over the entire screen. This eliminates the occurrence of the conventional multi-color hitting of the electron beam.

Further, as in the second invention, the shape error data of the inner surface of the glass panel corresponding to the four outermost corners of the shadow mask is fetched into an arithmetic unit, and the movable mold is automatically generated by the arithmetic data created by the arithmetic unit. By controlling the height of the divided movable part, the welding of the shadow mask and the mask frame according to the present invention can be realized without requiring extra processing steps and processing time as compared with the related art.

Further, as in the third invention, the height of the divided movable portion of the movable mold is controlled by a servo motor or a pulse motor, so that the height of the divided movable portion can be easily, inexpensively and accurately adjusted by a known control mechanism. Control can be realized.

Further, as in the fourth invention, the control range of the height of the divided movable portion of the movable mold is set to ± 200 μm with respect to the center value.
m, the shape error of the outermost four corners of the shadow mask of a normal glass panel is almost 100%.
It is possible to cope with it and to make the correction accuracy of the shadow mask within the necessary and sufficient 2 μm or less.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below.
This will be described in detail with reference to the drawings.

First, as shown in FIG.
The shape error data of the inner surface of the glass panel 11 at four points corresponding to the outermost four corners 15 of the shadow mask 14 in addition to the center point 12 and the eight peripheral points 13 are measured. The data is automatically measured by an automatic measuring machine (not shown), and the result is sent to an arithmetic unit (not shown). Next, as shown in FIG. 2, the shadow mask 14 and the mask frame 16 are inserted into the shadow mask welding machine 20 in a temporarily fixed state, and based on the shape error data of the center point 12 and the eight peripheral points 13 described above, the mask frame 16 is The vertical position is adjusted using the fixed mold 21 of the shadow mask welding machine 20 as a reference position.
This is performed by finely adjusting the vertical position of the guide pin 24 inserted into the mounting hole 23 of the hook spring 22 using a pulse motor (not shown) or the like.

The shadow mask welding machine 20 of the present invention differs from the conventional one in that the outermost four corners corresponding to the shadow mask 14 of the movable mold 25 are divided to form a divided movable portion 26 as shown in FIG. The divided movable part 26 can move independently ± 200 μm with respect to the movable mold 25 main body.

Before the shadow mask 14 is pressed downward by the movable mold 25 and pressed into the mask frame 16, four points of the inner surface of the glass panel 11 corresponding to the outermost four corners 15 of the shadow mask 14 measured previously are measured. Based on the shape error data, the height of the divided movable portion 26 (movable mold) is adjusted so that the distance between the outermost four corners of the shadow mask 14 and the inner surface of the glass panel 11 is as specified when the pushing of the shadow mask 14 is completed. 25 The amount of protrusion or retraction from the main body) is adjusted. Since the amount of adjustment of the divided movable portion 26 is automatically performed according to a command from the arithmetic unit, no special man-hour is required for adjustment. In the normal case, the adjustment amount of the divided movable part 26 is about 100 μm, and the accuracy is within 2 μm.

The height of the divided movable portion 26 is adjusted by a servo motor or a pulse motor (not shown).
Servomotors are expensive, but they are accurate and require a short adjustment time. Pulse motors may have low accuracy and require relatively long adjustment times, but are inexpensive. Which one to use may be selected depending on the situation.

Next, as shown in FIG. 3, the shadow mask 14 is pressed downward from above by a movable mold 25 including a divided movable portion 26 and is pushed into the mask frame 16. Here, the portion of the fixed mold 21 and the movable mold 25 other than the divided movable portion 26 in contact with the shadow mask 14 is the shadow mask 1.
4 coincides with the curved surface. However, since the outermost four corners of the shadow mask 14 follow the surface position of the divided movable part 26, the extension of the curved surface at the center of the shadow mask 14
It is pushed in a state shifted upward or downward by about 0 μm. This is a feature of the shadow mask welding machine 20 of the present invention which is not included in the conventional shadow mask welding machine 80. The shadow mask 14 is pushed by the movable mold 26.
Is pushed in a state where the skirt 17 is fitted on the inner wall surface of the mask frame 16. This pushing operation is completed when the shadow mask 14 is clamped at a predetermined pressure in the gap between the fixed mold 21 and the movable mold 25. In this state, although not shown, electrodes are arranged outside the mask frame 16 and inside the skirt 17 of the shadow mask 14 and both are welded. Thus, the mask frame 16
A mask assembly having the shadow mask 14 attached thereto.

Here, the shadow mask 14 is fixed to the fixed mold 21.
When the pressing operation is completed by being sandwiched between the movable mold 25 and the movable mold 25 at a predetermined pressure, the shadow mask 1 is moved as described above.
The outermost four corners of the movable member 4 are divided in advance so that the distance from the inner surface of the glass panel 11 becomes a predetermined value.
When the obtained mask assembly is assembled to the glass panel 11 in the next step as shown in FIG. 4, not only the central portion of the shadow mask 14 but also the outermost periphery of the shadow mask 14 is different from the conventional case. Even at the four corners, the distance from the inner surface of the glass panel 11 always becomes the predetermined value.

[0027]

As described above, according to the present invention, the distance between the shadow mask at the outermost four corners of the shadow mask and the inner surface of the glass panel can be set to a predetermined value in the same manner as the center part, and the outermost four corners of the shadow mask can be set. A shadow mask welding device for a color cathode-ray tube capable of preventing a deterioration in display quality due to multicoloring can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing measurement points of glass panel shape error data in an embodiment of a shadow mask welding machine for a color cathode ray tube according to the present invention.

FIG. 2 is a plan view and a sectional view of an embodiment of a shadow mask welding machine for a color CRT according to the present invention before welding.

FIG. 3 is a plan view and a cross-sectional view of one embodiment of a shadow mask welding machine for a color CRT according to the present invention at the time of welding.

FIG. 4 is a cross-sectional view in which a shadow mask and a mask frame are assembled on a glass panel.

FIG. 5 is a plan view of a mask frame.

FIG. 6 is a sectional view showing the relationship between a shadow mask and a mask frame.

FIG. 7: Measurement points of glass panel shape error data in a conventional shadow mask welding machine for a color cathode ray tube

FIG. 8 is a cross-sectional view of a conventional shadow mask welding machine for a color CRT before welding.

FIG. 9 is a sectional view of a conventional shadow mask welding machine for a color cathode ray tube at the time of welding.

[Explanation of symbols]

 Reference Signs List 11 glass panel 12 center point 13 peripheral 8 points 14 shadow mask 15 outermost 4 corners 16 mask frame 17 skirt 20 shadow mask welding machine 21 fixed mold 22 hook spring 23 mounting hole 24 guide pin 25 movable mold 26 divided movable section 41 Shadow mask 42 Mask frame 43 Hook spring 44 Mounting hole 45 Glass panel 46 Skirt 47 Stud pin 48 Center point 49 8 peripheral points 80 Shadow mask welding machine 81 Fixed mold 82 Guide pin 83 Movable mold

Claims (4)

[Claims] 1. A vertical position of a mask frame is adjusted based on shape error data of a glass panel inner surface dimension measured in advance, and then a shadow mask is positioned by being sandwiched in a gap between a fixed mold and a movable mold. Next, in a shadow mask welding machine for a color cathode ray tube in which the mask frame and the shadow mask are welded and fixed, shape error data of the inner surface dimensions of the glass panel corresponding to the four outermost corners of the shadow mask are measured in advance, and the movable metal A portion corresponding to the outermost four corners of the shadow mask of the mold is provided with a divided movable portion independent of a central portion, and the shape is based on shape error data of the inner surface dimensions of the glass panel corresponding to the outermost four corners of the shadow mask. A shadow mass for a color cathode ray tube, wherein the height of the divided movable part is controlled. Welding machine. 2. The apparatus according to claim 1, wherein the shape error data of the inner surface dimensions of the glass panel corresponding to the four outermost corners of the shadow mask is taken into an arithmetic unit, and the movable data is automatically generated by the arithmetic data created by the arithmetic unit. A shadow mask welding machine for a color cathode ray tube, wherein the height of the movable part of the mold is controlled. 3. The shadow mask welding machine for a color cathode ray tube according to claim 2, wherein the height of said divided movable part of said movable mold is controlled by a servomotor or a pulse motor. 4. The shadow for a color cathode ray tube according to claim 1, wherein the height of said divided movable portion of said movable mold is controlled within a range of ± 200 μm with respect to a center value and within an accuracy of 2 μm. Mask welding machine.