JPH0799671B2 - Shade mask structure manufacturing equipment - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a manufacturing apparatus for a sheer mask structure, and more particularly, to a sheer mask surface on a sheer mask surface for improving the color purity reproduction characteristics of the sheer mask type color picture tube. The present invention relates to an apparatus for manufacturing a shed mask structure which is stretched around a mask frame while being applied with a uniform tension in all directions (hereinafter, simply referred to as a uniform tension).

[Technical background of the invention and its problems] Generally, in a shadow mask type color picture tube, red,
After the three electron beams corresponding to green and blue pass through one electron beam passage hole of the shed mask, the three red, green and blue phosphor layers are formed on the inner surface of the panel facing the shed mask. The phosphor layers are made to strike and emit light from each of the fluorescent layers.

Therefore, in order to perform good color reproduction, the relative positional relationship between the large number of electron beam passage holes of the shear mask and the corresponding three-color phosphor layers is in a predetermined matching relation, and the electron beam passage holes are The electron beam that has passed through must land exactly on a given phosphor layer.

However, the transmittance of the shadow mask of an electron beam is usually 15 to 20%, and most of the other electron beams collide with the shadow mask to heat and expand the shadow mask. This heating and expansion increase remarkably when the anode voltage and the beam current of the color picture tube are increased in order to obtain a particularly bright screen, and as a result, the beam landing position is largely changed and the color purity is deteriorated. Become.

Next, an example of an ordinary shadow mask type color picture tube will be described with reference to FIGS.

That is, a panel (1) having a fluorescent surface (2) made up of fluorescent material dots emitting red, green and blue light on its inner surface.
And a sheer dough mask structure (5) consisting of a sheer dough mask (3) arranged at a predetermined distance from the fluorescent surface (2) and a mask frame (4) to which the sheer dough mask (3) is fixed, It is composed of a mask support structure (6) for supporting the mask frame (4) on the panel pins (6) and an electron gun (9) provided in the neck (8) of the picture tube.

In such a color picture tube, the shadow mask (3) is made by press-molding a thin iron plate of 0.1 to 0.2 mm, which is provided with a large number of electron beam passage holes by etching or the like, into a dome shape and has a thickness of 0.5 to 1.5 mm. It is welded and fixed to the mask frame (4) at a plurality of points to form a shed mask structure (5).

As described above, a part of the electron beam (10) emitted from the electron gun (9) passes through the electron beam passage hole portion of the shadow mask (3) and strikes the fluorescent surface (2) to be a predetermined area. The phosphor dots are made to emit light, but most of the rest hits the sheer dough mask (3) and heats the sheer dough mask (3). The heating causes the shear mask (3) to rise in temperature and expand, and the heat causes the mask frame (4) to expand.
Since the light is transmitted from the mask support structure (6) to the panel (1), a temperature difference is generated at each part and the parts are deformed, so that the electron beam (10) passes through the electron beam passage hole portion and the fluorescent surface (2). )
A so-called landing error occurs in which the landing position moves upward from a predetermined position.

This landing error changes with time, and immediately after the operation or when a bright part is locally generated on the screen, the shadow mask (3) undergoes a rapid thermal expansion. However, since the mask frame (4) having a relatively large heat capacity does not immediately rise in temperature, the shadow mask (3) is located at the position (3 '),
That is, it bulges toward the fluorescent surface (2). As a result, the electron beam (11) passing through the same electron beam passage hole is (1
1 ′), and the landing position from (12) to (1
2 '), causing a beam landing error.
When the color picture tube is further operated, the mask frame (4) also thermally expands after a sufficiently long time elapses, so that the beam landing position shifts in the opposite direction to that immediately after the above operation.

The amount of displacement of the landing position is about several tens of μm to 100 μm, which causes deterioration of color purity. Further, as the anode voltage of the color picture tube is increased and the beam current is increased in order to obtain a bright screen, the energy that collides with the shadow mask (3) also increases, so that the landing error also becomes large and the deterioration of the color purity is remarkable. Become.

On the other hand, in order to realize a high-definition image, it is necessary to reduce the mutual interval between the electron beam passage holes of the shadow mask (3) to increase the number of picture elements. This reduces the spacing between the three color phosphor dots deposited on the phosphor surface (2) and the landing margin of each phosphor dot. Therefore, a higher definition color picture tube requires more accurate beam landing.

Various proposals have heretofore been made to reduce the above-mentioned beam landing error. For example, the thermal capacity can be improved by blackening the shadow mask or by black coating to improve heat dissipation to reduce the temperature rise, and by adjusting the thickness and length of the shadow mask side wall, or by providing holes and cutouts. There are structures that reduce the size of the material to achieve uniform heating, and structures that use low thermal expansion materials such as amber. However, these measures have not been sufficient for applications requiring high brightness, such as those used in bright external light such as in aircrafts and vehicles.

As a structure for solving this problem, R.I. C. "A High-Brightness Shadow-Mask Color CR Fore Cockpit Death Place. Digest of Paper of 1983 Symposium of Society For Information Desplay 9,5" by RC Robinder
(“A High-Brightness Shadow-Mask Color CRT for
Cockpit Displays.Digest of Paper of 1983 Symposium
In the Society of Information Display 9,5), a color picture tube equipped with an improved sheer mask structure was announced. As shown in FIG. 7, this color picture tube has a flat sheer dough mask (3) which is fixed to the mask frame (4) by applying tension, and the thermal expansion of the sheer dough mask (3) is absorbed by tension relaxation. However, the shear mask structure (5) which is not deformed even at high brightness is realized. It has been reported that this color picture tube has a significantly improved landing error as compared with a color picture tube having a conventional dome-shaped shadow mask.

However, in a color picture tube having this kind of shadow mask structure (5), it is sufficient to simply apply tension to the shadow mask (3) and fix it to the mask frame (4) to form the shadow mask structure (5). It is not possible to expect an effect, and it is necessary that the tension strength is constant at any position of the shear mask and that uniform tension is applied in all directions parallel to the shear mask surface. That is, the unevenness of the strength and direction of the tension may cause a place where sufficient tension is not locally applied to absorb the thermal expansion, or cause an undesired deformation such as a twist in the shadow mask structure (5) to cause a landing error. Cause to occur.

However, there is currently no simple method or device for applying uniform tension and uniform tension to a thin plate having a large number of electron beam passage holes, such as a shear mask, and therefore, there is no beam landing error. It has been a hindrance to manufacture a color picture tube having the above-mentioned shed mask.

[Object of the Invention] The present invention has been made in view of the above circumstances, and a shadow mask is applied to a mask frame in a state in which a constant and uniform tension is applied for a high-luminance color picture tube without deterioration of color purity. It is an object of the present invention to provide a manufacturing apparatus for a shed mask structure that can be stretched.

SUMMARY OF THE INVENTION That is, according to the present invention, a pair of presser plates having an opening at the center for holding the peripheral edge of a shadow mask material having electron beam passage holes regularly, and an opening of the presser plate. A supporting plate that supports a cylindrical frame having a smaller outer diameter and a pressing pin that supports a mask frame provided inside the cylindrical frame, and the pressing plate and the supporting plate are relatively close to each other. And a moving mechanism for separating the mask frame and the ribbon while the pressing plate and the tubular frame are applied with a uniform tension to the shear mask material at least in the tubular frame by the pressing plate and the tubular frame. An apparatus for manufacturing a shed mask structure, characterized in that it can be held and fixed by a frame.

[Embodiment of the Invention] That is, as shown in FIGS. 1 to 4, circular openings (22) and (23) are provided in the center, and rubber plates (17) and (18) are attached to the facing surface. Pair of holding plates (15), (1
According to 6), the peripheral portion of the shadow mask material (13 ₁ ) having electron beam passage holes regularly provided on the entire surface is clamped and fixed. These rubber plates (17) and (18) are applied to the shadow mask material (13 ₁ ) when tension is applied to the shadow mask material (13 ₁ ).
Is provided to prevent movement of the.

On the other hand, a cylindrical frame (25) is provided on the support plate (24), and a holding pin (28) is provided inside the cylindrical body (25). The outer diameter of the cylindrical frame (25) is the holding plate (15),
If selected so as to be smaller than the inner diameters of the circular openings (22) and (23) of (16), when the support plate (24) is moved in the axial direction, the inside of the circular openings (22) and (23) The cylindrical frame body (25) is designed to fit in with a predetermined gap. The height of the cylindrical frame body (25) is the same as that of the pressing pin (28) on the cylindrical frame body (25).
The height of the welded part (14 ₁ ) of the mask frame (14) fixed by is set to be slightly lower than the height.

Further, a support rod (29) is fixed to the base (31), and the support rod (29) can move the support plate (24) in the axial direction and clamp and fix the shadow mask material (13 ₁ ). Holding plates (15) and (16) are arranged. Further, the support plate (24) is moved up and down between the base (31) and the support plate (24) to move the support plates (15), (16) and the support plate close to and away from each other by using hydraulic pressure and air pressure. A feeding device (30) is provided.

Next, a process of forming a shed mask structure with this shed mask manufacturing apparatus will be described with reference to the same drawings.

First, Shiyadoumasuku material as shown in FIG. 2 (13 ₁₎ arranged on the support rod (29) the holding plate (15) is sandwiched and fixed between (16). At this point, the support plate (24) has a cylindrical frame (2
5) and the upper surface of the welded part (14 ₁ ) of the mask frame (14),
The shadow mask material (13 ₁ ) is brought into contact with or slightly lowered.

Next, as shown in FIG. 3, when the vertical feed device (30) is operated, the support plate (24) moves in the direction close to the holding plates (15) and (16), and the shadow mask material (13 ₁ ) does not move. Presser plate (1
Due to the relationship between 5) and (16) and the cylindrical frame (25), uniform tension is applied in the entire circumferential direction while being bent by the cylindrical frame.

Next, the shadow mask material (13
_{When a} predetermined tension is applied to ₁ ), a mask frame (14) and a ribbon-shaped frame (26) corresponding to the welded part (14 ₁ ) are attached to the welded part from above the shadow mask (13 ₁ ) as shown in FIG. (14 ₁ ), and then the ribbon mask (26) is densely welded at the welding point (27) and clamped and fixed to complete the shadow mask structure.

Although the vertical feed device is used in the above-mentioned embodiment, a press machine or the like may be used, the openings (22) and (23) are circular, and the cylindrical frame (25) is used. It is needless to say that the tension is not limited and uniform tension may be applied to the shadow mask material depending on the shape of the mask frame (14) and the like.

[Effects of the Invention] As described above, according to the present invention, there is provided a device for manufacturing a shadow mask structure which can easily manufacture a good quality shadow mask structure in which uniform tension is applied in advance so as to prevent a landing error due to thermal expansion of the shadow mask. Can be provided.

[Brief description of drawings]

1 to 3 are views showing an embodiment of a manufacturing apparatus for a shed mask structure of the present invention, and FIG. 1 is a perspective view of a main part,
FIG. 2 is a cross-sectional view showing a state before applying a uniform tension to the sheer dough mask material, and FIG. 3 is a cross-sectional view showing a state in which a uniform tension is applied to the sheer dough mask material and sandwiched and fixed between the mask frame and the ribbon frame. FIG. 4 is a perspective view of a completed sheer mask structure, FIG. 5 is a sectional view for explaining a conventional sheer mask type color picture tube, and FIG. 6 is a sectional view for explaining an essential part showing a beam landing state, FIG. FIG. 7 is a cross-sectional view for explaining a main part of another example of the conventional shade mask type color picture tube. 3,13 …… Shadow mask 13 ₁ …… Shadow mask material, 15,16 …… Holder plate 24 …… Support plate, 25 …… Cylinder frame 26 …… Ribbon frame, 27 …… Welding point 28 …… Holder pin, 29 …… Support rod 30 …… Vertical feed device, 31 …… Base

Claims (1)

[Claims] 1. A pair of presser plates having an opening at the center for holding the peripheral edge of a sheer mask material having electron beam passage holes regularly, and an outer member having a diameter smaller than that of the presser plate. A supporting plate that supports a cylindrical frame body having a diameter and a pressing pin that supports a mask frame provided inside the cylindrical frame body, and a moving mechanism that relatively moves the pressing plate and the supporting plate close to and away from each other. And a mask frame in a state in which a uniform tension is applied to at least a portion of the shear mask material in the cylindrical frame body by the pressing plate and the cylindrical frame body when the pressing plate and the support plate are close to each other. A device for manufacturing a shadow mask structure, characterized in that it can be held and fixed by a ribbon-shaped frame.