JPH0773026B2 - 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 the Invention] The present invention configures a color selection mechanism by forming a color selection electrode having an electron beam transmission opening formed in a thin metal plate on a curved surface by simple bending and supporting the color selection electrode on a support frame,
When attaching the color selection electrode to the support frame, a reinforcing film is attached to the color selection electrode, and the film is eliminated after attachment to the support frame. Increase the aperture ratio of the transmission aperture.

[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 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 (4) having an electron beam transmitting opening (4a) formed so as to face the color fluorescent surface (3) formed on the inner surface of the panel (2a). ), For example, a shadow mask is arranged, and three electron beams R, G, and B corresponding to respective colors, for example, red, green, and blue are landed on the fluorescent pattern of the respective corresponding colors on the color fluorescent surface (3). It is designed to do.
(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 large number of circles in the horizontal and vertical directions by a photochemical method, that is, a photolinography technique. A color selection electrode with a hole or an opening such as a long hole is formed, and this is pressed, that is, drawn, to have a desired surface shape, that is, a shape corresponding to the curved surface shape of the panel of the cathode ray tube body, generally. Is formed to have a spherical shape. Then, by welding the periphery thereof onto the support frame (5), the color selection mechanism (6)
Is configured.

However, in order to obtain the color selection electrode by pressing the metal plate material in this way, an elongation of 1 to 3% is added during the pressing work, and this elongation causes the metal plate material, especially the space between the electron beam transmitting openings, to expand. In order to prevent breakage in the bridge part, annealing work by heat treatment at 850 to 950 ° C in a reducing atmosphere is required prior to pressing, and the yield point elongation caused by this annealing is applied to the roller leveler by the plate material. It is necessary to remove them by passing them through, and press work is performed after these operations, so that the manufacturing work is extremely complicated (Magazine: Iron and Steel, 67th (1981) No. 2, p. 65- See page 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 and place in advance the size of the electron beam transmission aperture and the change in pitch due to the elongation of the material that occurs during press molding,
Instability is large. Further, in designing the electron beam transmission aperture, it is necessary to consider in order to avoid occurrence of moire due to interference between a so-called bridge portion between the apertures and the scanning line. It is complicated to consider the change in pitch and shape.

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 appropriate distance L _SG between each part of the electrode (4) and the panel (2a) so that the landing position on a) has a proper positional relationship in the panel (2a) 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. 10A, each of the beams 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, and LpB of B are in the proper arrangement is as shown in FIG. 10B, it is shown in FIG. 11B. As shown in FIG. 11A, when the radius of curvature of the panel (2a) is large, the landing positions LpR, LpG, LpB become degroupings that spread at the corners, as shown in FIG. 12B. When the radius of curvature is small, excessive grouping occurs at the corners as shown in FIG. 12A. 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 aims to solve or reduce such problems and further improve the aperture ratio of the color selection electrode.

[Means for solving problems]

As described with reference to FIG. 1, the present invention first obtains a color selection mechanism for selecting a landing position on the fluorescent surface of an electron beam, by first forming a thin cold-rolled metal having a thickness of 0.08 mm to 0.35 mm. A well-known high-precision technology in which a plurality of electron beam transmission apertures are formed in a predetermined pattern on a thin plate in both horizontal and vertical directions,
For example, the color selection electrode (4) is formed by making holes by photolithography (photo etching), and as shown in FIG. 2, for example, the front end face (5a) has a cylindrical surface shape as a whole. The thin plate electrode (4) is placed on the supporting frame (5) formed as a basic shape, and the thin plate electrode (4) is simply bent within the elastic limit without producing a drawing effect, and is attached to the front end face (5a) of the frame (5). Make it bend along the way.
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 attached to the frame (5) and its front end face (5a)
Weld at the part that is in contact with the top.

Thus, as shown in FIGS. 3 to 5, the color selection mechanism (6) is supported by the frame (5) and has a color selection electrode (4) whose basic surface shape is substantially a cylindrical surface. ) Get.

Here, the basic surface shape means a shape having a required radius of curvature in one direction, for example, in the horizontal direction,
In the other direction orthogonal to this, for example, in the vertical direction, the radius of curvature is set to be infinitely long or significantly larger than that in the horizontal direction, or it is curved only at the corners, and is approximated to a cylindrical surface as a whole. Refers to the shape.

As shown in FIG. 6, the opening (4a) of the color selection electrode (4) has a plurality of long holes in both horizontal and vertical directions.
Alternatively, it is possible to avoid forming a circular hole and forming a slit shape over the entire area in one direction of the effective screen.

In the present invention, as described above, the color selection electrode (4)
Is simply attached to the support frame (5) so as to form a required curved surface, and is supported. However, prior to the attachment to the frame (5), that is, the electron beam is applied to the thin metal plate. After forming the permeation opening (4a), or before the formation of the permeation opening (4a), a reinforcing film (10) is included on one surface of the metal thin film as shown in FIG. Then, for example, the entire surface is bonded. This film (10) has flexibility and is tough enough to obtain the reinforcing effect of the electrode (4), and at the same time, the electrode (4)
After being attached to the frame (5), a structure that can be easily removed is adopted.

[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 the present invention, since the reinforcing film (10) is attached before attaching the electrode (4) to the supporting frame (5), the electron beam transmission aperture ratio can be sufficiently increased. That is, according to the manufacturing method of the present invention, since the color selection electrode (4) is mounted on the support frame (5) with a required curved surface by simple bending, the thickness of the metal thin plate of this color selection electrode (4) is increased. That is, a sufficiently thin one can be used, and the upper limit of the aperture ratio of the electron beam transmitting aperture (4a), that is, the lower limit of the aperture interval, can be obtained by a technique for forming the aperture (4a), for example, a photoetching technique. It can be made sufficiently small within the range, and the thickness of the thin metal plate is
Assuming 0.1 mm, the electron beam transmission aperture (4
The width W _B of the bridge part (8) between a) can be up to 0.03 mm in principle. However, when the electrode (4) made of a thin metal plate having such a narrow bridge width W _B is handled alone, it is necessary to further attach the electrode (4) to the support frame (5). Accidents such as bending or breaking will occur, more careful handling is required, and defective products are likely to occur.
However, in the present invention, since the handling work is performed in the state where the reinforcing film (10) is bonded, it is possible to avoid inadvertently refracting or breaking the electrode (4). Further, since the thin metal plate of the electrode (4) can be made sufficiently thin, there is a benefit that the accuracy of photoetching, and eventually the accuracy of the arrangement and shape of the electron beam transmission aperture (4a) can be improved.

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 cold-rolled steel plate, for example, a rimmed steel plate, a killed steel plate, or an amber (36% Ni-remaining Fe) plate, or the like, is formed on a thin metal plate by a known photolithography (photoetching) technique, as shown in FIG. 6, for example. Vertical direction (y direction)
Long hole-like electron beam transmission aperture (4a)
Are arrayed in the vertical direction at a predetermined pitch Py with a required spacing W _{B, and} are arrayed in a plurality of rows in the horizontal direction (X direction) at a predetermined pitch Px In this case, the openings (4a) in the adjacent rows are The bridges (8) between the openings (4a) in each row are arranged so as to be inconsistent with each other.
Are not arranged in the horizontal scanning line direction for all columns.

Next, the reinforcing film (10) is attached to one surface of the color selection electrode (4) formed of the metal thin film in this manner as described with reference to FIG. This Reinforcement Film (10)
Has flexibility and is sufficiently thin within a range where a reinforcing effect can be obtained. The film (10) may be formed by coating a film-like base material having a thickness of 50 to 150 μm, such as polyethylene or polyester, with a pressure-sensitive adhesive, that is, a pressure-sensitive adhesive, which is as thin as possible, for example, a thickness of several μm.
Then, on this adhesive side, a film (1
Paste 0).

After that, the electrode (4) having the reinforcing film (10) attached thereto is placed on the front end face (5a) of the support frame (5) on the side opposite to the film (10) as described in FIG. Place it in contact with. In this case, a pedestal (9) having a receiving surface (9a) formed on the same curved surface as the front end surface (5a) of the supporting frame (5) is arranged in the supporting frame (5), and a color selection electrode ( 4) is laid on the receiving surface (9a) of the pedestal (9) and the supporting frame (5) around the receiving surface (9a). 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 the holding jig (11) having the concave curved surface (10a) matching this curved surface toward the pedestal (9), the electrode (4) can be aligned with the supporting surface (5a) of the frame (5). Bend within its elastic limits.

In this state, the electrode (4) is welded in a line or spot shape along the end surface (5a) of the support frame (5) at the abutting portion of the end surface (5a) of the support frame (5).

Then, after that, the reinforcing film (10) is peeled off, or the adhesive is dissolved in a solvent to remove it.

The curved surface of the color selection electrode (4) formed by bending, that is, the surface shape of the end surface (5a) of the support frame (5) is the seventh shape.
As shown in the figure, it may be a perfect cylindrical surface.
As shown in the figure, the radii of curvature (hereinafter referred to as the radii of curvature in the Y direction) in the cross section (Z-Y plane) including the central axis Z and the vertical direction (Y direction) are the central axis Z and the horizontal direction (X direction). Ryo and Rys, and Rxo and Rxs are the radiuses of curvature of the central part and the peripheral part, respectively, which are larger than the radius of curvature in the (Z-X plane) (hereinafter referred to as the radius of curvature in the X direction). ＞ Rys ＞ Rxo ＞ Rx
can be s.

That is, now, when considering the panel (2a) of the cathode ray tube, this panel (2a) has a vertical (y direction) radius of curvature Rpy in order to avoid the influence of external light on the screen, especially the illumination of the ceiling in the room. Is preferably as large as possible than the radius of curvature Rpx in the horizontal direction (x direction) and has a basic shape of a cylindrical surface, for example, a perfect cylindrical surface. Now the cylindrical surface panel (2a)
Now, if this panel (2a) is a perfectly cylindrical surface, the arc height h in the xz plane of the panel (2a) shown in FIG. When the length is lx and ly, 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. The surface shape of each selection electrode (4) is also selected in accordance with 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. In this case, a color selecting mechanism having a basic shape of a cylindrical surface and having a desired surface shape of the color selecting electrode (4) can be configured.

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 portion (1P) and the funnel portion (1F), the color selection mechanism also has a temperature of about 430 to 480 ° C. When the above-mentioned heat 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. The ratio also by avoiding the drawing by a press, i.e., by the elongation is not given to the electrode material, the spacing between openings described (4a) in Figure 6, i.e. the width W _B of the bridge portion in the conventional The width W _{B of the} bridge can be further reduced by using the reinforcing film (10) as described above, and the aperture of the electron beam transmission aperture (4a) can be reduced. You can increase the rate. Further, by this, it is possible to avoid the shadow caused by the bridge portion from being generated on the screen 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.
Due to the difference in each broadcasting system such as L, SECAM, etc., the inconvenience of incorporating a different color selection mechanism depending on the destination can be avoided by making it possible to apply a common color selection mechanism, and mass production, therefore The cost can be reduced.

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 rise of the color selection electrode during the operation of the cathode ray tube occurs, 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.

[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 front view of an example of a color selecting mechanism according to the manufacturing method of the present invention, and FIGS. 4 and 5 are lines AA and BB in FIG. 3, respectively. Sectional view on the line,
FIG. 6 is a pattern diagram of an example of a color selection electrode in the manufacturing method of the present invention, FIGS. 7 and 8 are explanatory views of bending processing in the manufacturing method of the present invention, FIG. 9 is an explanatory view of a panel, FIGS. FIGS. 12A and 12B are front views showing the beam landing of the cathode ray tube, and FIGS. 12A and 12B are schematic side views 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 its opening, and (5) is a support frame.

Claims (1)

[Claims] 1. A color-selecting electrode is formed by forming a plurality of electron beam transmitting openings in a horizontal and vertical direction in a cold-rolled metal thin plate, and a reinforcing film is attached to the color-selecting electrode. The color selection electrode to which is adhered is bent and held on the frame by a simple bending process within the elastic limit of the electrode material so that the basic surface shape becomes a substantially cylindrical surface shape so that the drawing effect does not occur. A method of manufacturing a color selection mechanism for a cathode ray tube, characterized in that the reinforcing film is removed thereafter.