JPH0773027B2 - Manufacturing method of color selection mechanism of cathode ray tube - Google Patents

Description

The present invention relates to a method for manufacturing a color selecting mechanism for a cathode ray tube such as a color television picture tube or a color display device.

[Outline of Invention]

In the present invention, in forming a color selection mechanism by forming a color selection electrode in which a metal thin plate is provided with an electron beam transmission opening on a curved surface by simple bending and supporting it on a support frame,
Place a support frame around the pedestal that determines the curved surface,
By selecting the welding position of the electrode metal thin plate with respect to the support frame in the specified order, the color selecting mechanism with high accuracy can be reliably manufactured.

[Conventional technology]

In the color cathode ray tube, as shown in the schematic cross-sectional view of the main part of FIG. 1, the cathode ray tube body (1) includes a panel portion (1P), a funnel portion (1F), and a neck portion (1N). ) And. The panel part (1P) has a color fluorescent surface (3) on the inner surface.
The panel (2a) on which the and are formed is integrally molded with the skirt portion (2b) extending from the periphery toward the funnel portion and the end surface of which is fritted to the open end surface of the funnel portion (1F). . Then, in the panel portion (1P), a color selection electrode (an electron beam transmitting opening (4a) is formed so as to face the color fluorescent surface (3) formed on the inner surface of the panel portion (2a) ( 4) For example, a shadow mask is arranged, and three electron beams R, G, B corresponding to respective colors, for example, red, green and blue, are applied onto the corresponding fluorescent patterns of the respective colors on the color fluorescent surface (3). It is designed to land.
(7) shows horizontal / vertical deflection means for the electron beams R, G, B.

This color selection electrode (4), for example, a shadow mask, is usually formed on a cold-rolled steel plate material having a thickness of 0.08 to 0.35 mm by a photochemical method, that is, a photolithography technique, and is provided with a large number of horizontal and vertical directions, respectively. A color selection electrode is formed by forming an opening such as a circular hole or an elongated hole, and press processing, that is, drawing processing of this, a required surface shape, that is, a shape corresponding to the curved surface shape of the panel of the cathode ray tube body, Generally, it is formed in a spherical shape. Then, the periphery thereof is welded to the support frame (5) to form the color selection mechanism (6).

However, in order to obtain a color selection electrode by pressing a metal plate material in this way, an elongation of 1 to 3% is added during the pressing work. In a reducing atmosphere prior to pressing to prevent breakage
Annealing work by 850 to 950 ℃ processing is required, and it is necessary to remove the yield point elongation caused by this annealing by passing the plate material through the roller leveler, and press work is performed after these operations. , Its manufacturing work is remarkably complicated (Magazine: Iron and Steel, 67 (1981) No. 2, pp. 65-70).

Further, according to this method, the homogeneity of the material of the metal plate material itself becomes a problem. That is, if a component segregation portion is present in this metal plate material, the amount of elongation is not uniform during press working, resulting in a non-uniform shape change in the opening and non-uniform electron beam transmittance. Since the nonuniformity of the material of the metal plate material is found after the press working, that is, after undergoing many steps such as the annealing and leveler steps, the work loss is large. Further, if the crystal grains after annealing are too large, uneven electron beam transmittance due to stretcher strain will occur, so careful examination of the material lot is required.

Furthermore, in the case of this method, it is necessary to design in advance in consideration of changes in the size of the openings and the pitch due to the elongation of the material that occurs during press molding, which is a major instability factor. Further, in designing this opening, it is necessary to consider in order to avoid occurrence of moire due to interference between a so-called bridge portion between the openings and the scanning line, and therefore, in designing the opening, Considering the shape change is also complicated.

Further, in designing the spherical surface of the color selection electrode, it is necessary to consider the spring back. In other words, when a metal plate material is formed into a spherical shape by press working, the metal plate material is deformed in a plastic region that exceeds its elastic limit. However, after this plastic deformation, elastic restoration, that is, spring back is performed. Occurs.
Therefore, for example, considering the case where press working is performed with a die having a radius of curvature R, the finally obtained radius of curvature of the electrode is R + ΔR which is larger by ΔR. Therefore, in order to finally obtain an electrode having a curved surface with a radius of curvature R, it is necessary to correct the radius of curvature of the press die in advance in consideration of the above-mentioned spring back. In general, several modifications of the mold are performed to press-mold an electrode having a surface with a desired curvature. Modification of this mold is extremely troublesome,
Further, since the springback amount also fluctuates due to the compositional variation of the metal plate material, it is extremely difficult and complicated to obtain a highly accurate color selection mechanism having a desired size and shape.

On the other hand, the dot-shaped or stripe-shaped phosphor patterns of each color forming the color fluorescent surface in the color cathode ray tube are required to be arranged as evenly as possible on the inner surface of the panel (2a) of the cathode ray tube. Accordingly, each of the beams R, G, B is required to be selected and landed by the color selecting mechanism on the phosphor of the corresponding color. As is well known, the fluorescent pattern of each color is separately applied to the inner surface of the panel (2a) by applying a fluorescent substance slurry containing a photosensitive binder to the inner surface of the panel, while the color selection mechanism is applied. Is opposed to a predetermined position, the electron beam path is replaced with light, and the fluorescent slurry of each color is sequentially optically baked using the actual color selection mechanism as an exposure mask.

As described above, in order to obtain the proper state in which the phosphors of the respective colors are landed in the uniform arrangement relationship, and thus the respective electron beams R, G, B are arranged in the uniform arrangement relationship, the color selection electrode (4) and the panel ( 2a) needs to be set in a predetermined relationship.

In general, a panel of a color cathode ray tube tube has a basic surface shape of a spherical surface and a cylindrical surface, and as described above, the arrangement of the phosphor patterns of each color is made uniform. Therefore, in order to set the color selection electrode (4) and the panel (2a) in an appropriate relationship, when the color selection electrode (4) is spherical, the panel (2a) is also used in combination with a spherical shape, Further, when the color selection electrode (4) has a cylindrical surface, it is desirable to use the panel (2a) having a cylindrical surface in combination.

As the cylindrical surface-shaped color selection electrode (4), there is one in which an opening for transmitting an electron beam is formed by a slit extending over the entire area in the vertical direction of the effective screen, and the slits are arranged in parallel. In this case, the color selection electrodes in which the slits are arranged are welded to the pair of frame sides that bend along the cylindrical surface of the support frame at both ends of the extension of the slits without using the above-described drawing process. The color selection electrode is tensioned and bent to form a cylindrical surface, and with such a configuration, the above-described annealing process and leveling process associated with the drawing process can be avoided. However, since it is held in a tensioned state, the radius of curvature is completely infinite, that is, a linear shape, in the tensioning direction, and there is no design freedom. Therefore, in this case, the size and shape of the panel portion (1P) of the tubular body used in combination with this is restricted. This will be described next. As described above, the phosphor patterns of the respective colors, in other words, the panel of the electron beams R, G, B corresponding to the respective colors set by the color selection mechanism (2
The electrode (4) and the panel (2a) are arranged so that the landing position on a) has a proper layout relationship in the panel section (2a).
The proper distance L _SG between each part is It is known to be given by. Where S _D is the three electron beams R, R corresponding to red, green and blue.
As shown in Fig. 1 by G and B, when viewed from the panel (2a) side,
When arranged linearly on a horizontal line, the distance between the deflection centers P _C and P _{S of} the beam located at the center and the beams located on both sides of it, P _G is the aperture pitch, and L _S is the deflection center It is the distance between P _C and the fluorescent surface (3), and L _S and S _D are values that change depending on the deflection of the electron beam. That is, if the above expression (1) is satisfied in the entire area of the fluorescent surface (3),
The landing positions of the three beams R, G and B are properly arranged in the entire area of the fluorescent surface.

Now, as shown in FIG. 11A, each beam R, G, regulated by the aperture (4a) of the color selection electrode (4) on the fluorescent surface (3),
If the spacing between the panel (2a) and the electrode (4) when the landing positions LpR, LpG, LpB of B have the proper arrangement is as shown in FIG. 11B, it is shown in FIG. 12B. As shown in FIG. 12A, when the radius of curvature of the panel (2a) is large, the landing positions LpR, LpG, LpB become degroupings that spread at the corners, and as shown in FIG. When the radius of curvature is small, excessive grouping occurs at the corners as shown in FIG. 13A. Actually, there are some differences depending on the aperture of the color selection electrode (4), that is, the pitch P _G of the slit (4a), the deflection angle, the beam space of the electron gun, the specifications of the deflection means (7), etc. When an attempt is made to obtain a stripe-shaped phosphor pattern of proper alignment by using the color selection electrode of, the shape of the panel (2a) is, for example, the horizontal direction on the surface along the panel surface (2a) is the x-axis. Direction, the vertical direction is the y-axis direction, and the central axis is the z-axis direction, the radius of curvature Rpyo in the y-direction passing through the z-axis and the radiuses of curvature Rpys on both outer sides parallel to this are Rpys < Rpyo ...... (2) The radius of curvature Rpxo in the x direction passing through the z axis and the radii of curvature Rpxs on both outer sides parallel to this are Rpxs <Rpxo (3).

[Problems to be solved by the invention]

As described above, in the conventional method for obtaining the color selection mechanism, when the color selection electrode has a spherical shape, a complicated manufacturing process is required, and when the color selection electrode has a perfect cylindrical surface, the phosphor pattern is used. There is a problem that in order to make the arrangement of (1) appropriate, complicated adjustment or selection of the inner surface shape of the panel is required.

The present invention intends to solve such problems or to reduce them and to realize a color selecting mechanism with higher accuracy.

[Means for solving problems]

As described with reference to FIG. 1, the present invention first obtains a rectangular color selecting mechanism for selecting landing positions on the fluorescent surface of an electron beam, that is, a rectangular color selecting mechanism.
A 35 mm thin cold-rolled metal sheet is provided with a plurality of electron beam transmission openings in a predetermined pattern in both horizontal and vertical directions by a well-known high-precision technique such as photolithography (photo etching) to form a color selection electrode ( 4) is produced. On the other hand, as shown in FIG. 2, for example, the front end surface is used as an electrode supporting surface (5a), and the supporting surface (5a) has a cylindrical surface as a basic shape. ) Is provided, and the thin plate-like electrode (4) is provided on the supporting surface (5a) along the electrode supporting surface (5a) of the frame (5) by a simple bending process within the elastic limit that does not produce the drawing effect. I bend it and put it. That is,
The thin plate-shaped color selection electrode (4) is curved so that its basic surface shape is a substantially cylindrical surface. Then, the electrode (4) is welded to the supporting surface (5a) of the frame (5) at its abutting portion.

Thus, as shown in its perspective view in FIG. 3, and its front view and its sectional view taken along line AA in FIGS. 4 and 5, respectively, it is supported by the frame (5) and its basic A color selection mechanism (6) including a color selection electrode (4) having a substantially cylindrical surface is obtained. Here, the basic surface shape is a shape having a required radius of curvature in one direction, for example, the horizontal direction, but the radius of curvature is infinitely long in another direction, for example, the vertical direction, which is orthogonal to this. It refers to a shape that approximates a cylindrical surface as a whole, such as making it considerably larger than that in the horizontal direction or bending only at the corners.

The opening (4a) of the color selection electrode (4) is a plurality of elongated holes or circular holes in both the horizontal and vertical directions, and it is possible to avoid forming a slit shape over the entire area in one direction of the effective screen.

The present invention basically manufactures the color selection mechanism of the cathode ray tube by the above-mentioned method. Further, in the present invention, a special method is used for welding the electrode (4) to the support frame (5). Take. That is, in the present invention, the pedestal (9) for determining the curved surface of the rectangular color selection electrode is provided, and the support frame (5) is provided on the outer periphery thereof. The cradle (9) is the third
A curved surface having respective radii of curvature Rxo and Ryo with respect to the horizontal direction X and the vertical direction Y across the central axis Z in the finally obtained color selection electrode (4) shown in the figure is determined, but the electrode (4 ) Has a receiving surface (9a) for which the curved surface is not set. On the other hand, the supporting surface (5a) of the supporting frame (5) is at least the above-mentioned receiving surface (9a) of the pedestal (9).
And exist on the same curved surface required to extend in the X and Y directions passing through the above-mentioned central axis Z, that is, on the surface forming the radii of curvature Rxo and Ryo to be finally obtained. Then, in this state, the receiving surface (9
a) and the supporting surface (5a) of the supporting frame (5) across the supporting surface (5a) as described above. The electrode material is bent and placed along the curved surface of the receiving surface (9a) and the supporting surface (5a) by the extension surface thereof by bending within the elastic limit of the electrode material so as to prevent occurrence of. Then, in this state, first, the center of each of the four side edges of the long side and the short side of the color selection electrode (4) is attached to the electrode support surface (5) of the support frame (5).
Spot weld to a). Then, after that, welding is performed on the support surface (5a) from these welding points toward the corner of the support frame (5).

[Action]

As described above, in the present invention, the surface shape of the color selection electrode is processed by simple bending, not by drawing, so that it is possible to solve all the problems associated with the drawing described at the beginning.

Further, in particular, according to the present invention, when mounting the color selection electrode (4) on the support frame (5), a pedestal (9) is provided in the support frame (5) to set the curved surface of the electrode (4). If there is some wetting in the frame (5) due to what was done, and in this case, it was made free in the corner portion without setting it, so that if the electrode support surface (5a ) Generally maintains a predetermined shape in the X direction and the Y direction passing through the central axis Z, but as it goes away from these, that is, in the corner portion, a small displacement is performed forward or backward from the predetermined surface. Even if such a slight twist exists, the electrode (4) is lifted from the supporting surface (5a) of the frame (5) by the pedestal (9), for example, even if such a slight twist exists. Up It is avoided that the welding of the electrode (4) to the supporting surface (5a) is hindered or impossible. In addition, since the welding of the electrode (4) to the supporting surface (5a) is carried out from the center of each side to the corner, even if the above-mentioned slight twist exists, the electrode (4) Since the slack generated in the thin metal plate of 4) can be released to the corners, the electrode (4) can be attached to the frame (5) without generating wrinkles.

Further, according to the manufacturing method of the present invention, the basic shape of the color selection electrode is a cylindrical surface, but the shape is not limited to a perfect cylindrical surface, so that it has a proper relationship with the panel (2a). The degree of freedom in design for setting to, therefore, the degree of freedom in adjusting and selecting the shape of the panel portion (1P) is increased.

〔Example〕

A metal thin plate such as a cold rolled steel plate, for example, a rimmed steel plate, a killed steel plate, or an amber (36% Ni-remainder Fe) plate is subjected to a known photolithography technique, for example, as shown in FIG. the elongated shape of the electron beam penetrating apertures having a major axis in the direction) (4a), in the vertical direction with a plurality required interval W _B with sequences with a predetermined pitch Py, the horizontal direction (X with a predetermined pitch Px Direction)).

In this case, the openings (4a) in the adjacent rows are arranged so as to be different from each other, and the bridge portion (8) between the openings (4a) in each row is arranged.
Are not arranged in the horizontal scanning line direction for all columns.

Meanwhile, a support frame (5) is prepared. As shown in FIG. 7, the support frame (5) may be formed in a ring shape with four sides integrated by press-molding a metal steel plate. In this case, in order to increase strength, the electrode support surface (5a ) Is integrally molded with a flange portion (5b) that is bent and protrudes inward on the opposite side.

And the flange part (5b) in this support frame (5)
In the center part surrounded by, as shown in FIG.
The pedestal (9) having the receiving surface (9a) described in the figure is inserted and arranged.

As shown in FIG. 9, this pedestal (9) has radii of curvature Rxo and Rxy described above in the X and Y directions passing through the central axis Z, respectively.
And a receiving surface (9a) having a narrow cross pattern that does not reach the corner portion.

Then, the color selection electrode (4) is placed across the receiving surface (9a) of the pedestal (9) so as to straddle the electrode supporting surface (5a) of the supporting frame (5). In this way, the electrode (4) is bent by its own weight from above to follow the curved surfaces of the receiving surface (9a) of the pedestal (9) and the end surface (5a) of the frame (5), or By pressing a holding jig (11) having a concave curved surface (10a) matching this curved surface toward the pedestal (9), the electrode (4) is supported on the supporting surface (5a) of the frame (5).
Bend within its elastic limit so that

In that state, the electrode (4) is attached to the support frame (5),
Weld at the abutting portion against the electrode supporting surface (5a). As shown in FIG. 8 for the position of this welding, first, the center point P ₁ of each of the four sides on the support frame (5) and the support surface (5a) is set.
~ P _{4 is} spot welded, then the weld points are moved outward to points P ₅ ~ P ₁₂ outside these points P ₁ ~ P ₄ , respectively, and finally, at the corners of each corner part. The welding is finished at the points P _{C1 to} P _C4 .

The curved surface of the color selection electrode (4) by bending, that is, the surface shape of the end surface (5a) of the support frame (5) can be a perfect cylindrical surface, but as shown in FIG. A cross section (Z-Y plane) including Z and a vertical direction (Y direction)
Is larger than the radius of curvature (hereinafter referred to as the radius of curvature in the X direction) in the (Z-X plane) including the central axis Z and the horizontal direction (the direction of X), and Let Ryo and Rys, Rxo and Rxs be the radii of curvature of the central part and the peripheral part, respectively.
, Then Ryo>Rys>Rxo> Rxs.

That is, when considering the panel (2a) of the cathode ray tube, this panel (2a) is vertical (y direction) in order to avoid the influence of external light on the screen, especially the illumination of the ceiling in the room.
It is desirable that the radius of curvature Rpy of R is larger than the radius of curvature Rpx in the horizontal direction (x direction) and the basic shape is a cylindrical surface, for example, a perfect cylindrical surface. Considering now a cylindrical surface-shaped panel (2a), when the panel (2a) is a perfect cylindrical surface, the arc height in the xz plane of the panel (2a) shown in FIG. 10 is considered. h is the length of each arc in the x and y directions and is l _x and l _y , Can be expressed as Also, a shape close to a cylindrical surface Can be considered. However, in both cases, Rpy> Rpx. The above equations (6), (7), and (8) are so-called barrel-shaped surface shapes. Generally, as the surface shape of the panel (2a), the shapes of the expressions (5) to (8) are used. For large cathode ray tubes, the panel (2
Considering that a) is deformed by the atmospheric pressure, an appropriate radius of curvature Rpy is given so that the outer surface shape does not become convex toward the inside of the cathode ray tube after exhausting. Regarding the inner surface of the panel (2a), the glass thickness of the panel (2a) is molded from the center to the periphery in consideration of the strength of the pipe after exhaust, The radius of curvature in the direction is chosen to be slightly smaller than that on the outer surface. The surface shape of the inner surface of the panel (2a) may be a high-order bilobal hyperboloid, depending on the characteristics of the deflecting means (7).

As described above, the panel (2a) of the actual panel portion (1P) often does not have a perfect cylindrical surface shape due to various circumstances, and therefore, the arrangement of the fluorescent material patterns of each color is made uniform in each portion. In addition, the surface shape of the color selection electrode (4) is also selected according to the surface shape of the panel (2a), and it is appropriate to bring about a change in each curvature in the X and Y directions without taking a perfect cylindrical surface. May be.

Actually, in the manufacturing process of the cathode ray tube, for example, in the process of blackening the color selection mechanism, or in the frit sealing process of joining the panel part (1P) and the funnel part (1F), etc. When heat of about 480 ℃ is applied,
Recrystallization occurs in the thin metal plate of the color selection electrode, which may cause deformation of the color selection electrode in the finally completed cathode ray tube. Therefore, it is desirable to heat the thin metal plate in advance before manufacturing and processing the color selection electrode, at a highest heating temperature of about 480 ° C. or a temperature significantly higher than this. However, even in this case, since the heating temperature is different from the high temperature heating of 850 to 950 ° C. for annealing described at the beginning, the leveler treatment required after this high temperature heating is not necessary.

〔The invention's effect〕

As described above, according to the manufacturing method of the present invention, since the surface shape of the electrode (4) of the color selecting mechanism (6) is formed by simply bending within the elastic limit, various cases in the case of the conventional press working described at the beginning Can solve all problems. In other words, for example, high-temperature heat treatment for annealing, leveler treatment, etc. are not required, so the manufacturing process is simplified, and the occurrence of defective products due to component segregation accompanying this press work, the problem of reliability, etc. is avoided. To be done. Further, by avoiding the drawing by a press, i.e., by the elongation is not applied to the electrode material, the spacing between openings described (4a) in Figure 6, i.e. the width W _B of the bridge portion prior 1 It can be made as small as about / 2, so that it is possible to avoid the shadow on the screen caused by the bridge portion depending on the distance between the color selection electrode and the panel. Also, since the pitch Py can be made larger than that of the conventional one, the problem of moiré with the scanning line is also improved.By this, due to the difference in each broadcasting system such as NTSC, PAL, SECAM etc. to avoid the conventional moiré, it is possible to adapt to the destination. It is possible to avoid the inconvenience of incorporating different color selection mechanisms by enabling the application of a common color selection mechanism, and it is possible to achieve mass production and thus cost reduction.

Furthermore, as a color cathode ray tube, the total area of the color selection electrode opening is about 20%, and most of the electron beam that has passed through the opening due to scanning of the electron beam is converted into light that has collided with the phosphor. The remaining 80% of the electron beam collides with the color selection electrode, and most of it is converted into heat. At this time, thermal expansion occurs in the electrode and elongation occurs (doming). In this case, misalignment of the electron beam trajectory occurs. This is an unavoidable phenomenon in a color selection electrode in which a steel plate or a metal thin plate that has been heat-treated at a high temperature, that is, an annealing process, is press-formed into a spherical shape. However, the cold-rolled metal sheet is in a work-hardened state as it is, that is, since residual stress exists and deformation resistance is high, a color selection made by applying a bending moment to the cold-rolled metal sheet as in the present invention. In the case of the mechanism, even if the temperature of the color selection electrode rises during the operation of the cathode ray tube, the amount of deformation is smaller than that of the conventional annealed and press-molded product, so that a cathode ray tube with less mislanding can be provided. You can do it.

Further, according to the present invention, when the electrode (4) is attached to the support frame (5), the pedestal (9) is used, and further the limitation of the curved surface setting position, the welding procedure, etc. are specified, so that the support frame is obtained. Even if there is a slight twist in (5), the electrode (4) can be securely attached to the electrode (4) without causing wrinkles, etc., so that a more accurate color selection mechanism can be obtained and a higher quality color can be obtained. A cathode ray tube can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of a cathode ray tube used for explaining the present invention, and FIG.
The drawing is a cross-sectional view in one step of the manufacturing method of the present invention, FIG. 3 is a perspective view of an example of a color selecting mechanism according to the manufacturing method of the present invention, FIG. 4 is a front view thereof, and FIG. 5 is on line AA of FIG. A sectional view, FIG. 6 is a pattern diagram of an example of a color selection electrode in the manufacturing method of the present invention,
FIG. 7 is a perspective view of an example of a support frame, FIG. 8 is a perspective view of the support frame fitted with a pedestal, FIG. 9 is a perspective view of the pedestal, and FIG. 10 is an explanatory view of a panel. , Fig. 11, Fig. 12
13A and 13B are front views showing the beam landing of the cathode ray tube, and FIG. 13B is a schematic side view showing the relationship between the panel portion of the cathode ray tube and the color selecting mechanism. (1P) is the panel part, (2a) is the panel, (3) is the fluorescent surface,
(6) is a color selection mechanism, (4) is the color selection electrode, (4a)
Is the opening, (5) is the supporting frame, (5a) is the electrode supporting surface, (9) is the pedestal, and (9a) is the receiving surface.

Claims (1)

[Claims] 1. A support frame for supporting the color selection electrode is arranged on the outer periphery of a pedestal that determines a curved surface of the rectangular color selection electrode, and the support frame of the color selection electrode on the support frame and on the pedestal. A color selection electrode consisting of a cold-rolled thin metal plate with an electron beam transmission opening formed along the curved surface by bending within the elastic limit of the electrode material so that the drawing effect does not occur. , Curved, and in this state, spot weld the center of each of the four side edges of the long side and the short side of the color selection electrode to the support surface of the support frame, and then from these welding points to the corners of the support frame. A method of manufacturing a color selection mechanism for a cathode ray tube, wherein the welding of the color selection electrode to the support surface of the support frame is advanced toward.