JPH0456037A - Manufacture of color image receiving tube - Google Patents

Abstract

PURPOSE:To eliminate the stabilization process as required on a panel/mask assembly according to the conventional techniques, by heat treating only frame/ holder assemblies followed by welding of a mask body to these frame/holder assemblies, or otherwise heat treating only the shadow mask and installing it on a panel. CONSTITUTION:A plurality of frame/holder assemblies 32 are supported by a supporting tool 33 and subjected to a stabilization process consisting of 10min heating at 400-450 deg.C followed by cooling. A spherical mask body is formed equipped with a skirt at the periphery. This mask body 36 is welded to the frame/holder assemblies 32 having undergone stabilization process, and a shadow mask 37 is yielded. This shadow mask is installed on a panel to yield a panel/ mask assembly. Then a fluorescent screen is formed on the inner surface of this panel, wherein no stabilization process must necessarily be applied to this panel/mask assembly which is necessary according to the conventional techniques.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method of manufacturing a color cathode ray tube, and more particularly to a method of manufacturing a color cathode ray tube with improved shadow mask stabilization processing.

(Prior Art) Generally, a color cathode ray tube consists of a spherical panel (1) with a skirt formed on the periphery and a funnel-shaped funnel integrally joined to this panel (1), as shown in FIG. (2), and on the inner surface of the panel (1) is formed a phosphor screen (3) consisting of a three-color phosphor layer in the form of dots or stripes that emit light in blue, green, and red. A shadow mask (4) is mounted inside the phosphor screen (3), facing the phosphor screen (3). Also,
3 electron beams (6) in the neck (5) of the funnel (2)
B).

An electron gun (7) that emits (ec) and (61?) is provided. The three electron beams (6B), (6G), (OR) emitted from the electron gun (7) are then directed to a deflection yoke (8) attached to the outside of the funnel (2).
The phosphor screen (3) is deflected by horizontal and vertical deflection magnetic fields generated by the phosphor screen (3) to horizontally and vertically scan it, thereby displaying a color image.

As shown in FIG. 8, the shadow mask (4) consists of a spherical mask body (10) in which a large number of electron beam passage holes are formed and a skirt portion formed around the periphery, and the skirt portion is welded together. It consists of a mask frame (11) with a rectangular cross section that supports the mask body (JO), and a plurality of holders (12) made of elastic bodies are welded to the sides of this mask frame (11), and each of the holders (12) is attached to the inside of the panel (1) by fitting and locking the fitting hole formed at the free end to the stud pin (13) fixed to the inner surface of the skirt portion of the panel (1). There is. As shown in FIG. 9(a), the holder (12) supporting this shadow mask (4) is usually a bent strip-shaped holder (12) that is welded to the mask frame via a bimetal clip. In addition to holders 1 and 2a), there is also a wedge-shaped holder (12b), as shown in holder 1 and 2a).

By the way, conventional color picture tubes are manufactured by the process shown in FIG. 1D.

That is, a shadow mask is assembled by welding a mask body and a holder to a mask frame, and the assembled shadow mask is assembled into a panel to assemble a panel-mass 2 assembly. Then, this panel mask assembly was
The stabilized panel/mask assembly is heated and cooled according to the processing conditions indicated by the broken line (16) in the figure, and a phosphor screen is formed on the inner surface of the panel by photoengraving. It is manufactured by joining (arriving) a panel on which a phosphor screen is formed and a funnel together, sealing an electron gun in the neck of the funnel, and then evacuating it.

The reason why the panel/mask assembly is stabilized before forming the phosphor screen on the inner surface of the panel as described above is that the mask body is formed by press molding from low carbon steel or stainless steel, and the mask frame is Since it is formed by press forming using carbon steel as a material, processing distortion remains. In addition, distortion due to welding between the mask frame and the mask body or holder remains. Therefore, if a phosphor screen is formed with such machining and welding distortions remaining, the sealing process between the panel and the funnel, which requires high-temperature heating of 400 to 500°C, will cause damage to the phosphor screen. The processing distortions and welding distortions are removed, and the shadow mask components become sag due to high-temperature heating, and the position of the shadow mask relative to the inner surface of the panel changes after manufacturing the color picture tube compared to when the phosphor screen is formed, and the phosphor screen The landing of the electron beam on the three-color phosphor layer is shifted, leading to deterioration of color purity. Therefore, in order to eliminate a change in the position of the shadow mask between when the phosphor screen is formed and after the tube is manufactured, a stabilization process is performed on the panel/mask assembly before the phosphor screen is formed.

However, as shown in Figure 4, this stabilizing treatment requires a maximum temperature of 440 to 455°C to be maintained for 35 minutes or more, and the temperature must be gradually raised and lowered to avoid damaging the glass panel. Therefore, it takes about 3 hours to process.

FIG. 11 shows a processing furnace used for the stabilizing process. This stabilization processing furnace includes a furnace body (17), a mesh belt (18) running inside the furnace body (17), and a drive device (19) for driving the mesh belt (18). A frame (21) on which panel mask assemblies (20) are mounted, for example, in three stages and four rows, is placed on the frame (2I) while passing through the furnace body (I7). The structure is such that the mounted panel/mask assembly (20) is stabilized. The size of this furnace depends on the production volume of color picture tubes and the size of the panel, but the panel/mask assembly (20) mounted on the frame (21) is heated and cooled according to the above processing conditions. Therefore, the length is 30 to 40 m and the width is 4 to 5 m.
m, and in order to operate the furnace efficiently and continuously, a return conveyor (
22) is also required, resulting in a very large size.

(Problems to be Solved by the Invention) As described above, in the conventional method of manufacturing color picture tubes, a shadow mask is incorporated into the panel to assemble a panel/mask assembly, and a phosphor screen is formed on the inner surface of the panel. Previously, stabilization processing is performed to remove processing distortions and welding distortions remaining in the shadow mask, and to prevent the shadow mask constituent members from becoming sagging due to high-temperature heating. However, this stabilization process is
The process takes about 3 hours, as it is necessary to maintain the maximum temperature of ~455°C for more than 35 minutes and gradually raise and lower the temperature to avoid damaging the glass panel. A processing furnace is required.

As a result, equipment costs and furnace installation space have increased, and energy consumption has also increased. Furthermore, on the loading side of the furnace, a considerable amount of labor is required to load the panel/mask assembly onto the frame, and on the unloading side, not only to unload it, but also to return the frame to the loading side.

This invention was made in view of the above problems, and
It is an object of the present invention to provide a manufacturing method capable of constructing a required color picture tube without performing stabilization processing on a panel/mask assembly.

[Structure of the Invention] (Means for Solving the Problems) In a method of manufacturing a color picture tube, a shadow mask is mounted as a panel on a mask frame that supports a mask body formed with a large number of electron beam passage holes and formed into a predetermined shape. A frame holder assembly is assembled by welding a holder to be attached to the inside, and only this frame holder assembly is heat-treated to 400 to 500 degrees Celsius, and then the mask body is attached to the heat-treated frame holder assembly. or by welding the mask body and holder to the above mask frame to assemble a shadow mask, heat-treating only this shadow mask to 400 to 500 degrees Celsius, and then assembling it into a panel to form a panel/mask assembly. I decided to produce it.

(Function) As described above, when a color picture tube is manufactured by assembling and processing shadow masks, processing distortions and welding distortions remaining in the frame/holder assembly or shadow mask are removed by heat treatment at 400 to 500°C. , and the shadow mask components can be stabilized at high temperatures before forming the phosphor screen, and heating after forming the phosphor screen can be done without performing the conventional stabilization process of the panel/mask assembly. It is possible to prevent the positional change of the shadow mask due to

(Example) Hereinafter, the present invention will be described based on an example with reference to the drawings.

Example 1 As shown in Fig. 1, a mask frame with an angled cross section was formed by press molding, and as shown in Fig. 2, a plurality of holders (31) were welded to this mask frame (30). Assemble the frame holder assembly (32). Then, as shown in FIG. 3, the plurality of frame holder assemblies (32) are supported on the support (33),
Depending on the processing conditions shown by the solid line (34) in FIG.
Stabilization treatment is performed by heating at 450°C for 10 minutes and cooling.

On the other hand, a spherical mask body having a skirt around the periphery is formed by press molding a flat mask in which a large number of electron beam passage holes are formed by photoetching. Then, as shown in FIG. 5, this mask body (36) is attached to the stabilized frame.
Welded to the holder assembly (32), the shadow mask (
37) Assemble.

Next, this shadow mask is assembled into a panel to assemble a panel/mask assembly. After that, a phosphor screen is formed on the inner surface of the panel without stabilizing the panel/mask assembly as in conventional color picture tube manufacturing methods, and the panel with the phosphor screen formed thereon is integrated with the funnel. After bonding (sealing) and sealing the electron gun, the electron gun is evacuated to produce a color picture tube.

By the way, if only the frame/holder assembly (32), which is formed by welding the holder (31) to the mask frame (30), is stabilized as described above before forming the phosphor screen, then the panel/mask can be stabilized as before. Even if a phosphor screen is formed without stabilizing the assembly, the position of a shadow mask (37) can be prevented from changing due to sealing between a panel and a funnel after the phosphor screen is formed or heating due to exhaust, etc. As a result, a color picture tube with good color purity can be obtained.

In other words, as mentioned above, the causes of the change in the position of the shadow mask due to heating after forming the phosphor screen are the molding distortion of the mask frame and mask body formed by press molding, the distortion between the mask frame and the holder, and between the mask frame and the mask body. This includes welding distortion and sagging of shadow mask components due to high-temperature heating.The purpose of stabilizing treatment is to remove molding distortion and welding distortion before forming the phosphor screen, and to prevent sagging under high temperatures. It is to keep it. In such stabilization processing,
The difference between the stabilization processing in this example and the conventional stabilization processing is that in the conventional stabilization processing, a shadow mask is attached to the panel, and the holder is heated while being pressurized and elastically deformed, whereas in the stabilization processing in this example, The differences are that only the frame-holder assembly (32) is treated and the holder is heated in an open state without pressurizing it, and that only the frame-holder assembly (32) is stabilized without welding the mask body.

Regarding this difference, the mask body usually has a plate thickness of 0.15r.
Since the molding is as thin as n and sufficiently annealed, the molding distortion is small, and the welding distortion between the mask body and the mask frame is also small, so only the frame/holder assembly (32) that is not welded to the mask body is stabilized. , the stabilized frame ◆ Even if a shadow mask is assembled by welding the mask body to the holder assembly (32) and the shadow mask is assembled into a panel to form a phosphor screen, the The change in the position of the shadow mask due to heating is small and is rarely a problem.

In addition, regarding the point of heating the holder in an open state without applying pressure, when stabilizing a conventional panel/mask assembly, even if the holder is heated in a state where it is elastically deformed by applying pressure, the stabilization The expansion and contraction of the panel during processing is approximately 10 to 20 μm, and the deformation of the holder due to the expansion and contraction of the panel is always constant and consistent, and quantitatively small, so it is caused by the deformation of the holder. Changes in the position of the shadow mask can be corrected by adjusting the distance from the inner surface of the panel to the light source when forming the phosphor screen.

Therefore, other things that require stabilizing treatment include molding distortion of the mask frame, welding distortion between the mask frame and holder, and fatigue of the mask frame under high temperature. 32
) can be sufficiently removed by heating at 400 to 450°C for 10 minutes as described above, and as a result, even if only the frame holder assembly (32) is stabilized,
It is possible to prevent the position of the shadow mask from changing due to heating after forming the phosphor screen, eliminate the need for a large stabilization processing furnace that consumes a lot of energy, and create a color picture tube with good color purity. can. In particular, this manufacturing method can be applied to a color picture tube in which the landing margin of the electron beam on the three-color phosphor layer is relatively large, and sufficiently satisfactory results can be obtained.

Example 2 As shown in FIG. 6, a mask body is formed from a mask frame by press molding and a flat mask in which a large number of electron beam passage holes are formed by photoetching, and a holder and a holder are attached to the mask frame. The mask bodies are welded together to assemble a shadow mask. Then, this shadow mask is heated at 400 to 450 DEG C. for 10 minutes and cooled to undergo a stabilization treatment under the processing conditions of Example 1 shown in FIG. Thereafter, this stabilized shadow mask is assembled into a panel to assemble a panel/mask assembly. Hereinafter, the above Example 1
Similarly, a phosphor screen is formed on the inner surface of the panel using this panel/mask assembly, the panel on which the phosphor screen is formed and the funnel are joined together, and the electron gun is further sealed. , exhaust.

With this manufacturing method, as in the above embodiment, it is possible to prevent the position of the shadow mask from changing due to heating after forming the phosphor screen, and it eliminates the need for a large stabilizing furnace that consumes a large amount of energy. , a color picture tube with good color purity can be obtained. In particular, this manufacturing method can be applied to a color picture tube in which the landing margin of the electron beam with respect to the three-color phosphor layer is relatively small, and good results can be obtained.

[Effects of the invention] A frame holder assembly is assembled by welding a holder for attaching a shadow mask to the inside of the panel to a mask frame, and this frame holder assembly alone is manufactured at 400 yen.
After heat treatment at ~500°C, the mask body is welded to this heat-treated frame/holder assembly, or the mask body and holder are welded to the mask frame to assemble a shadow mask, and this shadow mask alone is assembled. After heat treatment at 400 to 500°C, it is assembled into a panel to assemble a panel/mask assembly. It is possible to eliminate the need for a stabilizing process, to prevent the position of the shadow mask from changing due to heating after forming the phosphor screen, and to obtain a color picture tube with good color purity.

[Brief explanation of drawings]

ff Figures 11 to 6 are detailed explanatory diagrams of the present invention. Figure 1 is a block diagram showing the manufacturing process of a color picture tube, which is the first embodiment, and Figure 2 is a diagram showing the manufacturing process of a color picture tube that is a first embodiment of the invention. A diagram showing the structure of the assembled frame holder assembly, Figure 3 is a diagram showing the supporting method when the frame holder assembly is stabilized, and Figure 4 is a diagram showing the process when the frame holder assembly is stabilized. A diagram showing the conditions in comparison with the processing conditions when stabilizing a conventional panel mask assembly. FIG. 5 is a diagram showing the configuration of the assembled shadow mask. FIG.
FIG. 7 is a block diagram showing the manufacturing process of a color picture tube as an example; FIG. 7 is a diagram showing the configuration of the color picture tube; FIG. 8 is a partially cutaway diagram showing the configuration of the panel/mask assembly; FIG. 9 (a) and (b) are diagrams showing different shapes of holders for supporting shadow masks, respectively; FIG. 10 is a block diagram showing the manufacturing process of a conventional color picture tube; and FIG.
Figures (a) and (b) are a front view and a plan view, respectively, showing the configuration of a stabilizing processing furnace used for stabilizing a conventional panel/mask assembly. 30...Mask frame, 31...Holder 32...Frame φ holder assembly, 36...Mask body, 37...Shadow mask. Figure 4 ゛''f Figure 5 Agent Patent Attorney Oko Nen Huo Figure 6 Figure 10 Figure 1

Claims (1)

[Claims] A frame/holder assembly is assembled by welding a holder for attaching the shadow mask to the inside of the panel to a mask frame supporting a mask body formed into a predetermined shape and having a large number of electron beam passage holes formed therein.
After heat treating only the holder assembly to 400 to 500°C, the mask body is welded to the heat-treated frame/holder assembly, or the mask body and holder are welded to the mask frame to form a shadow. Assemble the mask and make only this shadow mask 400-50
A method for manufacturing a color picture tube, which comprises heating it to 0°C and then incorporating it into a panel to produce a panel/mask assembly.