JPS6276243A - Color selection mechanism for cathode-ray tube - Google Patents

Abstract

PURPOSE:To simplify formation of face shape by fixing springs between the opposite end sections of facing frame sides formed on a curved face to form a frame then securing a color selection electrode curved to provide a tubular face. CONSTITUTION:A color selection electrode 4 for cathode-ray tube having a plurality of electron beam transmission openings 4a is curved through simple bending work without causing the restriction effect such that the basic face shape will be tubular. While a frame 5 having curved frame sides 5A, 5B facing each other where forwardly inflated springs 25A, 25B are fixed between the opposite end sections is prepared. Then the color selection electrode 4 is secured through the springs 25A, 25B to the frame 5 with such face shape as having different curvature from that in the central section. Consequently, the restriction work is eliminated to simplify the manufacturing resulting in the improvement of freedom for setting the face shape and the quality.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a color selection mechanism for a cathode ray tube such as a color television picture tube or a color display device.

[Summary of the invention]

The present invention constructs a color sorting mechanism in which a color sorting electrode in which an electron beam transmission aperture is formed in a thin metal plate is formed into a curved surface by simple bending and supported on a support frame with a special structure, thereby simplifying manufacturing. , improve yield, improve precision, etc.

[Conventional technology]

As shown in FIG. 20, which shows a cross section of the main parts of the tube body of a color cathode ray tube, the cathode ray tube tube body (1) is connected to the panel section (
IP), funnel part (IF), and neck part (IN)
It consists of The panel part (IP) consists of a panel (2a) on which a color fluorescent surface (3) is adhered and formed on the inner surface, and a panel (2a) that extends from the periphery toward the funnel part (
The skirt portion (2) is fritted on the open end surface of the IF).
b) are integrally molded. In this panel part (IP), there is an electron beam transmission aperture (4a) facing the color fluorescent surface (3) formed on the inner surface of the panel (2a).
) perforated with color-selective electrodes (4), for example shadow masks, are arranged, and three corresponding to each color, for example red, green and blue.
The electron beams R, G, and B of the book are made to land on the corresponding color phosphor patterns of the color phosphor surface (3). (7) shows horizontal and vertical deflection means for electron beams R, G, and B.

This color selection electrode (4), for example a shadow mask, is usually formed on a cold-rolled steel plate with a thickness of 0.08 to 0.035+sm by a photochemical method, that is, a photolithography technique, in a large number in the horizontal and vertical directions. A color-selecting electrode with an opening such as a circular hole or a long hole is formed, and this is pressed, or drawn, into a desired surface shape, that is, a shape that corresponds to the curved surface shape of the panel of the cathode ray tube body. , generally formed in a spherical shape. A color sorting mechanism (6) is constructed by explosively contacting its periphery onto a support frame (5).

However, in order to obtain color-selecting electrodes by pressing a metal plate in this way, an elongation of 1 to 3% is added during the press process, and this elongation causes damage to the metal plate, especially in the bridge portions between the openings. In order to prevent breakage, it is necessary to perform annealing at 850 to 950°C in a reducing atmosphere prior to press working, and the yield point elongation caused by this annealing is passed through the plate material using a roller leveler. The manufacturing process is extremely complicated because it requires removal work and press processing is performed after these works (Magazine: Tetsu to Hagane No. 67 (1981) No. 2, pp. 65 to 70). (see page)
.

Moreover, when using this method, the homogeneity of the material of the metal plate material itself becomes a problem. That is, if a component segregation part exists in this metal plate material, the amount of elongation will not be uniform during press working, causing a non-uniform shape change in the opening, and the transmittance of the electron beam will become non-uniform. The non-uniformity of the material of the metal plate material becomes apparent after the press working, that is, after many processes such as annealing and a leveling process have been carried out, resulting in a large loss of work. Furthermore, if the crystal grains are too large after annealing, electron beam transmittance unevenness will occur due to stretcher strain, so careful examination of the material loft is required.

Furthermore, in the case of this method, it is necessary to take into account in advance changes in the size of the opening and the pinch due to the elongation of the material that occurs during press molding, and therefore there is a large instability factor. In addition, when designing this aperture, it is necessary to consider how to avoid moiré caused by interference between the so-called bridge part between the apertures and the scanning line. Taking shape changes into consideration also becomes complicated.

Furthermore, when designing the spherical surface of this color selection electrode, consideration must be given to its springback.

In other words, when a metal plate is drawn into a spherical shape by press working, the metal plate is deformed in a plastic region that exceeds its elastic limit, but after this plastic deformation, it undergoes elastic recovery, that is, a spring bank. arise. Therefore, for example, if we consider the case where press working is performed using a mold with a radius of curvature R, the radius of curvature of the electrode finally obtained will be 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 mold in advance in anticipation of the above-mentioned spring bank. Generally, the mold is modified several times to press-mold an electrode having a surface with the desired curvature.

Modifying this mold is extremely troublesome, and the amount of spring bank changes depending on changes in the composition of the metal plate material, so it is extremely difficult and complicated to obtain a highly accurate color sorting mechanism with the desired dimensions and shape. be.

On the other hand, the dot-like or stripe-like phosphor patterns of each color forming the color phosphor surface in a 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, and B is required to be sorted and landed on a phosphor of a corresponding color by a color sorting mechanism. As is well known, in order to coat the inner surface of the panel (2a) with a fluorescent pattern of each color, a phosphor slurry containing a photosensitive binder is applied to the inner surface of the panel, and a color sorting mechanism A method is adopted in which the electron beam path is replaced by light, and the phosphor slurry of each color is sequentially optically printed using the actual color selection mechanism as an exposure mask.

As mentioned above, in order to obtain a proper state in which the phosphors of each color are arranged in an equal arrangement relationship, and therefore each electron beam R, G, and B is landed in an equal arrangement relation, the color selection electrode (4) is required.
and panel (2a) need to be set in a predetermined relationship.

In general, color cathode ray tube panels have either spherical or cylindrical surface shapes, and as mentioned above, the phosphor patterns of each color are arranged evenly. Therefore, in order to set the color selection electrode (4) and the panel (2a) in a proper relationship, if the color selection electrode (4) is spherical, the panel (2a) is also spherical. Further, when the color selection electrode (4) has a cylindrical surface, it is desirable to use a panel (2a) having a cylindrical surface in combination.

As the cylindrical color selection electrode (4), there is one in which the electron beam transmission aperture consists of slits extending over the entire area in the vertical direction of the effective screen, and the slits are arranged in parallel. In this case, instead of using the drawing process described above, the color selection electrodes having slits arranged therein are welded to the pair of frame sides curved along the cylindrical surface of the support frame at both ends of the extension of the slits. The color selection electrode is stretched under tension and curved into a cylindrical shape. With this configuration, the above-mentioned annealing process and leveling process associated with the drawing process can be avoided. However, since this is to maintain tension, the direction of tension is completely limited to an infinite radius of curvature, that is, a linear shape, and there is no degree of freedom in design.

Therefore, in this case, there are restrictions on the size and shape of the panel portion (IP) of the tube used in combination with this.

Next, to explain this, as mentioned above, the phosphor patterns of each color, in other words, the panels of electron beams R2G and B corresponding to each color set by the color selection mechanism (
2a) The electrode (4) and the panel (2a) are arranged in such a way that the landing position on the panel (2a) is in a proper positional relationship.
It is known that the appropriate distance Lsa between each part and a) is given by: However, here in the SO, three electron beams R, G, and B corresponding to red, green, and blue are arranged linearly on the horizontal line when viewed from the panel (2a) side, as shown in Figure 20. In the case of Ls and SO are values that change depending on the deflection of the electron beam. In other words, if the above formula (1) is satisfied over the entire area of the fluorescent surface (3), the landing positions of the three beams R, G, and B will be properly arranged over the entire area of the fluorescent surface.

Now, as shown in FIG. 21A, the landing positions LpR, LpG, L of each beam R, G, B regulated by the aperture (4a) of the color selection electrode (4) on the fluorescent surface (3) are determined.
If pB shows a proper arrangement, and if the spacing between panel (2a) and electrode (4) is in the relationship shown in Figure 21B, then the curvature of panel (2a) is as shown in Figure 22B. When the radius is large, the landing positions LpR, LpG, and LpB are degrooved to widen at a part of the corner, as shown in Figure 22A, and when the radius of curvature of the panel is small, as shown in Figure 23B. , excessive grouping occurs at some corners as shown in FIG. 23A. Actually, the pitch PG of the aperture (4a) of the color selection electrode (4), the deflection angle, the beam space of the electron gun, the deflection means (7
) There are some differences depending on the specifications, etc., but when trying to obtain a properly aligned striped phosphor pattern using the completely cylindrical color selection electrode described above, the shape of the panel (2a) is, for example, as follows. 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 2
When the axis is the radius of curvature Rpy in the y direction passing through the z axis
.

and the radius of curvature Rpys of both outer sides located in parallel is R
pys< Rpyo...(2)
The radius of curvature Rpxo in the X direction passing through the z-axis is
The radius of curvature Rpxs of both outer sides located in parallel is Rpx
s< Rpxo °---(31 relationships).

In addition, in practice, the dimensional error of the color selection electrode is small, the error of the pitch PG is small, and the distance Ls between the beam deflection center Pc and the fluorescent surface (3), the center beam deflection center Distance S between PC and deflection center Ps of both beams
The error in D is small, and the problem is the curvature variation error of the glass. However, the panel part (IP) is obtained by molding glass melted at high temperature.
In this case, depending on various conditions such as the temperature of the glass and the cooling time in the mold, for example, each loft may have its own panel (2a).
Since the curvature and shape of the panel part (IP) changes,
After the formation, size selection is required, which reduces work efficiency.

[Problem that the invention seeks to solve]

As mentioned above, in the conventional method of obtaining a color selection mechanism, if the color selection electrode has a spherical shape, a complicated manufacturing process is required, and if the color selection electrode has a completely cylindrical surface, a phosphor pattern is required. In order to make the arrangement appropriate, there are problems such as the need for complicated adjustment or selection of the inner surface shape of the panel.

In order to solve these problems, the present applicant previously published Japanese Patent Application No. 140918/1988 titled ``Method for manufacturing color selection mechanism for cathode ray tube''. This manufacturing method involves preparing a color-selecting electrode with electron beam transmission apertures in a cold-rolled thin metal plate, and simply bending the electrode within its elastic limit.
It is supported by being brought into contact with the electrode support surface of a frame whose basic surface shape is approximately cylindrical.

In the present invention, in the color selection mechanism obtained by such a method, the degree of freedom in setting the surface shape is increased, thereby further increasing the latitude in panel design, and further improving the cathode ray tube having an appropriate phosphor pattern arrangement. The present invention provides a color selection mechanism for cathode ray tubes that can be manufactured reliably, easily, and in mass production.

[Means for solving problems]

The present invention was filed by the applicant, patent application No. 1409/1986.
Similar to the invention described in No. 18, in order to obtain a color selection mechanism for selecting the landing position of an electron beam on a fluorescent surface, first, a thin cold-rolled metal with a thickness of 0.08 mm to 0.20 m is used. A color selection electrode (4) is produced by drilling a plurality of electron beam transmission apertures in a predetermined pattern in a thin plate in both horizontal and vertical directions using a well-known high-precision technique such as photoetching.

As shown in FIG. 13, for example, the front end surface (5a)
However, it is placed on a support frame (5) whose overall surface shape is basically a cylindrical surface, and the thin plate electrode (4) is simply bent within the elastic limit without causing a squeezing effect. , and curved along the front end surface (5a) of the frame (5). In other words, a thin plate-shaped color selection electrode (
4) is curved so that its basic surface shape becomes approximately a cylindrical surface. Then, this electrode (4) is welded to the frame (5) at a portion where it abuts on its front end surface (5a).

In this way, as shown in FIGS. 14 to 16, the color selection mechanism (4) is supported by the frame (5) and has a color selection electrode (4) whose basic surface shape is roughly cylindrical. 6) is obtained.

Here, the basic cylindrical surface shape is defined as a shape having a required radius of curvature in one direction, for example, the horizontal direction.
In other directions orthogonal to this, for example, the vertical direction, the radius of curvature is infinite or extremely large compared to that in the horizontal direction, or it is curved only at some corners, so that the surface approximates a cylindrical surface as a whole. Name the shape.

The apertures (4a) of the color selection electrodes (4) are formed into a plurality of long holes or circular holes in both the horizontal and vertical directions, thereby avoiding a slit shape that covers the entire area of the effective screen in one direction.

In particular, in the present invention, as shown in FIG.
) and (25B). Frame side (5A)
The front end surface on which the electrodes (4) of (5B) and (5B) are arranged is formed to form the basic cylindrical surface described above, and both ends of the front end face are formed by an external force in a direction that brings each frame side (5A) and (5B) closer to each other. By being plastically deformed into a bent state, the springs (25A) and (25B) are bent so as to bulge forward, that is, toward the panel side of the tube body. ) and the frame edge (5
In cooperation with A) and (5B), the electrode (4) basically has a cylindrical surface shape, and the springs (25
A) and (25B''), the surface shape is set to have a curvature different from that of the central portion.

[Effect]

As described above, in the present invention, the surface shape of the color selection electrode is processed by simple bending without drawing, so that all the problems associated with the drawing described at the beginning can be solved.

Further, according to the manufacturing method of the present invention, the basic shape of the surface of the color selection electrode is a cylindrical surface, but it is limited to a completely cylindrical surface by selecting the degree of curvature of (25A) and (25B) using a spring. This increases the degree of freedom in design for establishing an appropriate relationship with the panel (2a), and therefore increases the degree of freedom in adjusting and selecting the shape of the panel portion (IP).

〔Example〕

Cold rolled steel plates, such as rimmed steel plates and killed steel plates.

Alternatively, as shown in FIG. 17, elongated holes with long axes in the vertical direction (y direction) are formed on a metal thin plate such as an amber (36% Ni-balance Fe) plate using a well-known photolithography technique. The electron beam transmission aperture (4a) of
A plurality of electrodes (4) made of a thin metal plate are formed by arranging a plurality of electrodes in the vertical direction with a required interval WB and a predetermined pitch py, and by forming a plurality of rows in the horizontal direction (X direction) with a predetermined pitch Pχ.

The openings (4a) in each adjacent row are arranged to be spaced apart from each other, and the bridge portion (4a) between the openings (4a) in each row is
8) should not be arranged in the horizontal scanning line direction for all columns.

The support frame (5) is made of, for example, chrome steel, stainless steel, mild steel, etc., and as shown in FIG. The configuration is supported by (5C) and (5D). The front end surfaces (5a) of the frame sides (5^) and (5B) are a common cylindrical surface, for example, a cylindrical surface whose radius of curvature decreases toward both ends. Then, springs (25^) and (25B) are stretched between both ends of both frame sides (5A) and (5B), respectively, while maintaining a somewhat tensioned state, for example, linearly. These springs (25A) and (25B), as shown in FIG. Frame side (
Weld both ends of 5A) and (5B) by spot welding or the like. Both frame sides (
5A) and (5B), on each front end surface (5a), the 17th
The color selection electrode (
4) is placed as explained in FIG. In this case, the support frame (5) has a receiving surface (9a) formed in the same curved surface as each front end surface (5a) of the frame sides (5A) and (5B) (not shown) of the support frame (5). ) with a pedestal (9), and the color selection electrode (4) is placed on this pedestal (9).
straddle the receiving surface (9a) of the receiver and the surrounding support frame (5).

In this way, the electrode (4) is bent from above by its own weight along the curved surface of the receiving surface (9a) of the pedestal (9) and the end surface (5a) of the frame (5), or Furthermore, by pressing the holding jig (11) having a concave curved surface (10a) that matches this curved surface toward the pedestal (9), the electrode (4) is made to align with the end surface (5a) of the frame (5). bend within its elastic limits.

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

In this way, as shown in FIG. 3, the electrode (4) is mounted on the frame (5) with a curved surface along the cylindrical surface formed by the front end surface (5a) of the frame sides (5A) and (5B).
is stretched. Both ends of the frame sides (5A) and (5B) of the frame (5) to which the electrode (4) is attached in this way are
As shown by the arrow C%f in the figure, an external force is applied from the upper and lower outer sides so that the opposing ends are drawn together. When these external forces are removed, the frame edge (5A
) and (5B) are selected to have a size and distribution such that both ends thereof are maintained in the required curved shape, that is, the required plastic deformation is imparted. The left and right edges of the springs (25A) and (25B) and the electrode (4) in contact with the springs (25A) and (25B) bulge due to the plastic deformation of both ends of the frame sides (5A) and (5B) in the direction of mutual attraction. be curved. The curvature of this curve can be arbitrarily selected depending on the amount of deformation of the frame sides (5A) and (5B).

In this configuration, the surface shape formed by the front end surface (5a) of the frame sides (5A) and (5B) can be a perfect cylinder, but the cylindrical surface shape is preliminarily formed with different curvatures at the center and both ends. In this case, as shown in FIG. 18, the radius of curvature (hereinafter referred to as the radius of curvature in the Y direction) in the cross section (Z-X plane) including the central axis Z and the perpendicular direction (Y direction) is the central axis Z.
and the radius of curvature in the (Z-Y plane) including the horizontal direction (X direction) (hereinafter referred to as the radius of curvature in the
.

and Rxs, Ryo>Rys>Rxo>
It can be Rxs.

In this way, the color selection mechanism (6) is constructed. On the other hand, if we consider the panel (2a) of the cathode ray tube, this panel (2a) is designed to absorb external light onto the screen, especially indoor ceiling lighting. In order to avoid the influence of
It is desirable that the basic shape is a cylindrical surface, for example, a complete cylindrical surface, which is as large as possible than pχ. Now, considering the cylindrical panel (2a), this panel (2a)
is a perfect cylindrical surface, the panel shown in FIG. 19 (2a
) in the x-z plane is the length of each part in the X and X directions as l× and 2. When h = Rpx - px" ItΣ ... (5
) can be expressed as Also, the shape h = close to a cylindrical surface
Rpx+ Rpy-/“i Roamer f Lower Door 7A...”
・(6) ...(7) ...(8) are possible. However, in both cases, Rpy>Rpx.

The above formulas (6), (71, and (81) have a so-called barrel-shaped surface shape. Generally, the shapes of formulas (5) to (8) are used as the surface shape of the panel (2a). In large cathode ray tubes, in consideration of the fact that the panel (2a) will be deformed by external pressure when the inside of the tube is evacuated, the panel (2a) should be designed so that its outer surface does not become convex toward the inside of the cathode ray tube after the tube is evacuated. The radius of curvature Rpy is given.In addition, regarding the inner surface of the panel (2a), the glass thickness of the panel (2a) is molded so that it becomes thicker from the center to the periphery, taking into consideration the strength of the pipe body after evacuation. The radius of curvature in each direction on the inner surface of the panel is selected to be slightly smaller than that on the outer surface.The shape of the inner surface of the panel (2a) is determined by the characteristics of the deflection means (7), etc. It is sometimes considered to be a bilobal hyperboloid.

In this way, the panel (2a) of the actual panel part (IP) often does not have a perfect cylindrical shape due to various circumstances, and for this reason, the phosphor patterns of each color are arranged evenly in each part. In this case, the surface shape of the color selection electrode (4) is selected according to the surface shape of the panel (2a), and it is appropriate to change the curvature in each of the X and Y directions without taking a completely cylindrical surface. According to the color sorting mechanism according to the present invention, although its basic shape is a cylindrical surface, as described above, on both the left and right sides, there is a surface with a curvature that is different from the other part with respect to X and Y, that is, the central part. The shape allows for uniform phosphor arrangement.

Incidentally, in the configuration shown in FIG. 1, each length L of the frame sides (5A) and (5B) of the frame (5) in the state shown in FIG.
In the case where P is 390 baking soda and the distance FAN D p between the upper and lower outer surfaces of both frame sides (5A) and (5B) is 290 dragons,
Set Lp to 289.8 on both end faces of frame sides (5A) and (5B).
When applying plastic deformation to +u, the spring (25A
) and (25B) were curved with a radius of curvature of 5000 mm.

It goes without saying that the support frame (5) is not limited to the above-mentioned structure, and can have various structures. For example, as shown in Figure 6, the support frame (
5) and the frame sides (5A) and (5B) facing each other, and the arm parts (5C) and (5
D) is integrally constructed in the shape of a picture frame by, for example, 1 chrome steel plate, 1 mild steel, stainless steel, or other material, and the frame side (5
Springs (25A) and (25B) made of, for example, leaf springs are stretched between both ends of frames (5A) and (5B), and the springs (25A) and (25B) of these frame sides (5A) and (5B)
5^) and (25B) are cut grooves (26A1) from the edge of the frame sides (5A) and (5B) toward the center.
(26A2) and (26B1) (26B2) can be formed and placed. In this state, the electrode (4) is placed on the front end surface (5a) of the frame sides (5A) and (5B), which has a predetermined surface shape, as described above, and a cylindrical surface is formed along this surface (5a). After attaching the electrode (4), as shown in Fig. 7, the ends of the frame sides (58) and (5B) are cut into grooves (26A, > (261+t)) provided respectively.
(26A2) From (26B2), spring (
An external force of arrow C%f is applied from the outside to the mounting portions of 25A) and 25B> to deform these ends, causing the electrodes 4 to deform together with the springs 25Δ and 25B.
) to the required curvature. If you do this, the kerf (2681) (2682) (26B1
) (26B2), the frame edge (5
The ends of ^) and (5B) can be easily modified.

Furthermore, other examples of the frame (5) are shown in FIGS. 8 to 10.
As shown in the figure, the frame structure may be similar to that explained in Figs. 6 and 7, or the kerf (261h) (2
6A2 ) (2681> (26B2 ) As shown in FIG. 8, the arm part (5C) and (
5D), each having a required recess (29) in the center thereof, and the arms (5C) and (5D) are inserted and pressed toward each recess (29). By means of a press means (28) having a press body (28B), bent portions (30) are formed in each arm portion (5C) and (5D), respectively, and each frame side is formed as shown in FIGS. 8 and 9. (
58) and (5B), and apply an external force as shown by arrows c w f to both ends of the frame sides (5A) and (5B) from the outside to bend them. By strengthening the bending at the portion (30) and giving plastic deformation to the ends of the frame sides (58) and (5B), as shown in FIG. and (25B
) and both side edges of the electrode (4) may be given a required curved shape.

In addition, the springs (25A) and (25B) are not limited to band-shaped leaf springs, but include rod-shaped springs,
Coil springs and other types of springs can also be used. In addition, when using a band-shaped leaf spring,
By making each part a strip-shaped leaf spring with a uniform width, each part can be curved with a more or less uniform curvature, but by making some parts have different widths, or as shown in Fig. 11. Various structures can be used depending on the final shape, such as forming U-shaped bent parts (27) on both sides of the central part so that there is almost no curvature in this part. .

The electrode (4) made of a metal thin film is attached to the frame (5) by welding to the end faces (5a) of the frame sides (5A) and (5B), and if necessary, a spring ( 25A) and (25B) can also be welded point-wise or linearly.

Then, welding of the electrode (4) to the upper and lower frame sides (5^) and (5B) is performed as shown in Fig. 12A.
5B), the end surface on which the electrode (4) is attached is made a surface corresponding to the final curvature of the electrode (4) in the Y direction shown in FIG. It is possible to weld the two sides together. Or, Figure 12B
As shown in , the end faces of the frame sides (5A) and (5B) are the first
When forming a curved surface that forms a required curved surface only in the left-right direction X shown in FIG.
Welding only at each outer shoulder (40) of 5A) and (5B) is advantageous in achieving the desired surface shape of the electrode (4).

〔Effect of the invention〕

As described above, according to the structure of the present invention, the surface shape of the electrode (4) of the color sorting mechanism (6) is formed by a small bending process within the elastic limit. It can solve all problems. In other words, for example, high-temperature heat treatment for annealing, rehering treatment, etc. are not required, which simplifies the manufacturing process, and also avoids the occurrence of defective products and reliability problems due to component segregation associated with this press processing. be done. In addition, by avoiding the drawing process by pressing, that is, by not giving elongation to the electrode material, the distance between the openings (4a) explained in FIG. Depending on the distance between the color selection electrode and the panel, it is possible to avoid a shadow caused by this bridge portion on the screen. In addition, since the pitch py can be made larger than the conventional one, the problem of moiré with the scanning line is also improved.
Due to the differences in broadcasting systems such as C and PALSECAM, the inconvenience of having different color sorting mechanisms built in depending on the destination can be avoided by making it possible to apply a common color sorting mechanism, making mass production easier. Cost reduction can be achieved.

Furthermore, in a color cathode ray tube, the total area of the color selection electrode aperture is around 20%, and most of the electron beam that passes through the aperture during electron beam scanning is converted into light that collides with the phosphor. , the remaining 80% or so 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, causing elongation (doming). In this case, a deviation in the trajectory of the electron beam (mislanding) occurs.

This is an unavoidable phenomenon in color-selecting electrodes made by press-molding a heat-treated, ie, annealed, steel plate or metal thin plate into a spherical shape. However, cold-rolled thin metal sheets are in a work-hardened state as they are, that is, they have residual stress and have high deformation resistance. In the case of the color selection mechanism, even if the temperature of the color selection electrode increases during operation of the cathode ray tube, the amount of deformation is smaller than that of conventional annealed and press-formed electrodes, thus providing a cathode ray tube with less mislanding. It is possible.

In addition, panels are formed from glass melted at high temperatures in a mold, but bulges (generally called sagging) that differ from the standard dimension (curvature) occur around the inner surface, especially in the case of square corners, at diagonal corners. . In such a case, it is necessary to curve the equidistant distance Mlf L sa between the electrode (4) and the panel (2a) by the amount of the bulge.

In the case of the present invention, although the basic shape is a cylindrical surface, an appropriate distance LSG can be obtained by curving only a part of the corner. In this way, it is possible to eliminate or reduce the problem of panel curvature variation, and it is possible to provide a cathode ray tube in which phosphors of each color are evenly arranged.

Further, in particular, in the present invention, springs (25A) and (25B) are arranged on both the left and right sides of the frame, and are curved and bulged to regulate the shape of the electrode (4). 4) The degree of freedom in selecting the overall surface shape is increased, which increases the latitude in selecting the panel shape, making it possible to manufacture high-quality cathode ray tubes at a high yield, and improving mass productivity. You will be able to do that.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an example of a color selection mechanism for a cathode ray tube according to the present invention, FIG. 2 is a perspective view of its frame, and FIG. 3 is a perspective view of the frame with electrodes made of thin metal plates attached thereto. 4 is a process diagram of the frame in which the electrodes shown in FIG. 3 are arranged, FIG. 5 and FIG. 7
The figure is a perspective view of another example of the color sorting mechanism according to the present invention obtained using the frame of FIG. 6, FIG. 10 is a perspective view of still another example of the color sorting mechanism according to the present invention, and FIGS. 9 is a manufacturing process diagram of the color sorting mechanism shown in FIG. 10, FIGS. 12A and 12B are diagrams showing how the electrodes are attached to the frame, respectively, and FIG. 13 is a diagram showing the manufacturing method of the color sorting mechanism according to the present invention. 14 is a front view of an example of a color sorting mechanism according to the manufacturing method of the present invention, and FIGS. 15 and 16 are A-A in FIG. 14, respectively.
17 is a pattern diagram of an example of the color selection electrode in the manufacturing method of the present invention, FIG. 18 is an explanatory diagram of the color selection mechanism according to the present invention, FIG. 19 is an explanatory diagram of the panel, Figure 20 is a configuration diagram of a cathode ray tube, Figures A in Figures 21, 22, and 23 are front views showing the beam landing of the cathode ray tube, and Figures B in the same figures are the panel section and color selection mechanism of the cathode ray tube. It is a route side view showing the relationship. (IP) is the panel part, (2a) is the panel, (3) is the fluorescent surface, (6) is the color selection mechanism, (4) is the color selection electrode, (
4a) is the opening, (5) is the frame, (5^) and (
5B) is its frame, (5C) and (5D) are its arms,
(25A) and (25B) are springs.

Claims (1)

[Claims] A color-selecting electrode consisting of a plurality of electron beam transmission apertures drilled in a cold-rolled thin metal plate in both the horizontal and vertical directions is placed on a frame by simple bending within the elastic limit of the electrode material, so that its basic surface shape is approximately the same. The frame is curved and held in a cylindrical surface shape, and the end surface on which the color selection electrode is arranged has opposing frame sides formed in a curved surface regulating the basic surface shape. At the same time, a spring is attached between both ends of these opposing frame sides, and the spring is curved into a predetermined shape depending on the amount of deflection of the ends of these frame sides, and the color selection electrode is arranged along the curve. A color selection mechanism for a cathode ray tube, characterized in that it is abutted and supported.