JPH05190087A - Manufacture of color picture tube - Google Patents

Abstract

PURPOSE:To provide a good color purity color picture tube with no working distortion in assembling a shadow mask. CONSTITUTION:In a manufacture of a color picture tube, a formed mask for which a flat mask with a number of electron beam transition holes formed is molded is blackened to manufacture a shadow mask mainframe, and a frame holder assembly for which a holder is welded to a molded mask frame is blackened at 500-580 deg.C. Next, the blackened shadow mask mainframe is welded to the blackened frame holder assembly to assemble a shadow mask. After the shadow mask is given heat treatment for three minutes or longer at 200 deg.C or higher, it is assembled into a panel to form a panel mask assembly and form a fluorescent screen inside the panel of the panel mask assembly by photographic printing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a color fluff tube, and more particularly to an improved method of assembling a shadow mask to manufacture a color flounce tube which does not require a stabilizing process of a panel / mask assembly. Regarding the method.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 3, a color frown tube is composed of a spherical panel 1 having a skirt portion formed on the periphery and a funnel-shaped funnel 2 integrally joined to the panel 1. It has an envelope and on the inner surface of its panel 1,
Dots or stripes that emit blue, green, and red 3
A phosphor screen 3 composed of a color phosphor layer is formed, and a shadow mask 4 is mounted inside the phosphor screen 3 so as to face the phosphor screen 3. Also funnel 2 neck
An electron gun 7 that emits three electron beams 6B, 6G, and 6R is arranged in the chamber 5. And 3 emitted from this electron gun 7
A color image is displayed by horizontally and vertically scanning the phosphor screen 3 by deflecting the electron beams 6B, 6G and 6R by the horizontal and vertical deflection magnetic fields generated by the deflection yoke 8 mounted outside the funnel 2. It is formed in the structure.

As shown in FIG. 4, the shadow mask 4 has a spherical shadow mask body 12 in which a large number of electron beam passage holes 10 are formed in a predetermined arrangement and a skirt portion 11 is formed in the peripheral portion. A mask frame having an L-shaped cross section, which is welded to the skirt portion and supports the shadow mask body 12
It consists of 13. Then, a plurality of holders 14 made of an elastic body are welded to the outer surface of the mask frame 11, and a fitting hole formed at the free end portion of each holder 14 is provided with a stud provided on the inner surface of the skirt portion of the panel 1. Pin 16 (see Figure 3)
It is mounted inside the panel 1 by being fitted and locked to. As shown in FIG. 4, the holder 14 for supporting the shadow mask 4 is usually a bimetal clip.
In addition to the substantially Z-shaped bent plate-shaped holder 14 welded to the mask frame 13 via 17, there is also a wedge-shaped holder 14 as shown in FIG.

The shadow mask 4 is manufactured by the following method in the conventional method for manufacturing a color cathode ray tube. That is, as shown in FIG. 6, (a) a flat mask in which a large number of electron beam passage holes are formed by a photoetching method is formed into a spherical formed mask having a skirt portion in the peripheral portion by press forming. After cleaning this foamed mask,
A shadow mask body is manufactured by blackening in a steam or gas atmosphere. (B) A mask frame molded into a predetermined shape by press molding is cleaned or washed and then Ni-plated in a steam or gas atmosphere. Blackening treatment (c) Weld a holder that has been previously heat-treated (cured) at a temperature of 450 to 520 ° C to the mask frame that has been blackened by (b) to assemble the frame / holder assembly (d) The shadow mask (mask / frame assembly) is assembled by welding the shadow mask main body blackened in (a) to the frame / holder assembly assembled in (c). Assembling the panel mask assembly by incorporating the shadow mask into a panel.
At this time, the positioning is adjusted so that the distance between the inner surface of the panel and the shadow mask body becomes a predetermined value (q value).

The panel / mask assembly assembled as described above is heat-treated (stabilize) at a temperature of about 450 ° C. to remove the distortion of each portion generated during the assembly of the shadow mask. Then, with respect to this panel / mask assembly, a phosphor screen is formed on the inner surface of the panel by a photo printing method using a shadow mask as a photo mask. After that, the panel on which the phosphor screen is formed and the funnel are joined (sealed), and then the electron gun is sealed in the neck of the funnel and exhausted to complete the color CRT.

In the method for manufacturing a color cathode ray tube, after the panel / mask assembly is assembled, the panel / mask assembly is heat-treated before the phosphor screen is formed, because the processing distortion remaining in the assembled shadow mask is eliminated. This is to remove it. That is, in the shadow mask assembled as described above, the shadow mask main body and the mask frame, which are the constituent members of the shadow mask, have the processing distortions removed by the blackening treatment, respectively. The processing strain caused by the welding of the above and the welding of the shadow mask body remains.
If this processing distortion is not removed, even if a phosphor screen is formed on the inner surface of the panel using the shadow mask as a photomask, the panel / mask assembly will not be heated when the panel and funnel are subsequently joined or when exhausting. As a result, the residual processing strain is released, and the position of the shadow mask with respect to the phosphor screen formed on the inner surface of the panel changes.
The landing of the electron beam on the color phosphor layer is displaced,
This is to cause deterioration of color purity.

However, the stabilization process performed on the panel / mask assembly must be performed according to a predetermined temperature schedule in which the temperature rising / lowering speed is strictly controlled in order to prevent damage to the glass panel. A large and expensive processing furnace is required. In addition, the productivity of the color cathode ray tube is deteriorated due to an increase in the space factor of the processing equipment, the processing time, and the number of processing steps.

[0008]

As described above, according to the conventional method for manufacturing a color cathode ray tube, a flat mask manufactured by a photoetching method is molded into a spherical formed mask by press molding, and this formed mask is formed. The mask is blackened to produce the shadow mask body.
On the other hand, the mask frame formed by press forming is blackened, and a holder is welded to the blackened mask frame to assemble a frame / holder assembly. After that, the shadow mask main body subjected to the blackening treatment is welded to the frame holder assembly to assemble the shadow mask.

Therefore, according to this manufacturing method, the distortion of the shadow mask main body and the mask frame, which are the constituent members of the shadow mask, is removed by the blackening treatment. The processing strain caused by the welding of the main body remains. Therefore, if this processing strain is not removed before the phosphor screen is formed, the processing strain will be released by the bonding between the panel and the funnel after the phosphor screen is formed, and the heat generated during exhausting will be released on the inner surface of the panel. The position of the shadow mask with respect to the phosphor screen changed to 3
The landing of the electron beam on the color phosphor layer is displaced,
Color purity deteriorates. Therefore, in the conventional color cathode ray tube manufacturing method, before the phosphor screen is formed, the panel
The mask assembly is subjected to a heat treatment for removing the processing strain remaining in the shadow mask.

However, this heat treatment requires a large and expensive treatment furnace, which deteriorates the productivity of the color cathode ray tube due to the increase in the space factor of the manufacturing equipment, the treatment time, the treatment steps, and the like. Also, due to the adhesion of dust from the furnace atmosphere,
There is a problem in that the shadow mask is clogged and the quality of the phosphor screen is deteriorated.

The present invention has been made in order to solve the above-mentioned problems, and the panel after the phosphor screen is formed is not required to heat the panel / mask assembly before the phosphor screen is formed, which is conventionally required. It is an object of the present invention to obtain a method for manufacturing a color cathode ray tube in which the position of the shadow mask does not change due to heating at the time of joining with the funnel and heating during exhaust.

[0012]

In a method for manufacturing a color cathode ray tube, a flat mask having a large number of electron beam passage holes is formed into a formed mask having a predetermined shape, and the formed mask is blackened. A shadow mask body is manufactured, and a holder that locks to a stud pin provided on a panel is welded to a mask frame formed into a predetermined shape to assemble a frame holder assembly. ~ 580
Blackened at a temperature of ℃, this blackened frame
The blackened shadow mask body is welded to the holder assembly to assemble the shadow mask, and the shadow mask is heat-treated at a temperature of 200 ° C. or higher for 3 minutes or more, and then the heat-treated shadow mask is incorporated into a panel. The panel / mask assembly was assembled, and the phosphor screen was formed on the inner surface of the panel of the panel / mask assembly by the photo printing method.

[0013]

As described above, when the frame holder assembly is assembled by welding the holder to the mask frame and the frame holder assembly is blackened at a temperature of 500 to 580 ° C., the mask frame before the blackening treatment is performed. By welding the holder to the, it is possible to prevent the splash and peeling of the blackening film, which have been apt to occur in the past, and it is possible to remove the processing strain caused by the welding between the mask frame and the holder. The shadow mask body is welded to the blackened frame / holder assembly to assemble the shadow mask, and the shadow mask is heat-treated at a temperature of 200 ° C. or higher for 3 minutes or longer. It is possible to eliminate the processing distortion caused by welding of the shadow mask body to the shadow mask body, and to omit the stabilization process that has been conventionally performed before forming the phosphor screen after assembling the panel / mask assembly.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

FIG. 1 shows the manufacturing process of the shadow mask of the color cathode ray tube manufacturing method. In this manufacturing method, the shadow mask has a thickness of 0.15 mm by the photo-etching method.
A flat mask is manufactured by forming a large number of electron beam passage holes in a predetermined arrangement on a low carbon steel plate or low thermal expansion material plate such as amber, and this flat mask is press-formed into a spherical surface with a skirt portion in the peripheral portion. Shaped mask. Then, the formed mask is washed and blackened at a temperature of 580 to 650 ° C. in a water vapor or gas atmosphere to manufacture a shadow mask body.

(B) A mask frame having an L-shaped cross section is formed from a carbon steel plate having a predetermined thickness by press forming,
This mask frame is washed or Ni-plated after washing. Next, add 450-
The frame-holder assembly is assembled by welding the holder that has been heat-treated (cured) at a temperature of 520 ° C. Thereafter, the frame / holder assembly is blackened at a temperature of 500 to 580 ° C. in a steam or gas atmosphere.

(C) A shadow mask (mask / frame assembly) is assembled by welding the shadow mask main body blackened in (a) to the frame holder assembly blackened in (b). Then, the mask / frame assembly is heat-treated at a low temperature of 200 ° C. or more for 3 minutes or more (low-temperature heat treatment).

In the manufacture of the color cathode ray tube, the above-described shadow mask is then incorporated into a panel to assemble a panel / mask assembly. At this time, the positioning between the inner surface of the panel and the shadow mask body is adjusted to a predetermined value (q value).

Thereafter, with respect to the panel / mask assembly, a phosphor screen is formed on the inner surface of the panel by using a shadow mask as a photomask by a photo printing method. After that, the panel on which the phosphor screen is formed and the funnel are joined, and then the electron gun is sealed in the neck of the funnel and exhausted.

By the way, in the production of the shadow mask as described above, after the holder is welded to the mask frame to assemble the frame holder assembly, the frame
When the holder assembly is blackened, the blackened frame / holder assembly is welded to the blackened shadow mask body to make a shadow mask, and then this shadow mask is heat treated at a low temperature. (200 ℃ or more, 3 minutes or more), the splash and black film peeling is prevented by welding the mask frame and holder before the blackening process, which was most likely to cause splash or black film peeling. In addition, processing distortion caused by welding the holder to the mask frame can be eliminated. The shadow mask body is welded to the blackened frame / holder assembly to assemble the shadow mask, and the shadow mask is assembled at a temperature of 200 ° C. or higher for 3 minutes.
By heat-treating for more than a minute, the processing strain caused by welding the frame holder and the shadow mask body can be removed. Moreover, this heat treatment does not depend on the temperature rising / falling speed, and only needs to control the maximum temperature and the holding time, and the heat treatment (stabilization treatment) performed after the conventional panel / mask assembly and before the phosphor screen formation is omitted. Thus, it is possible to prevent the shadow mask from being displaced due to heating when the panel and the funnel are joined together after the phosphor screen is formed or when exhausting.

In FIG. 2A, the shadow mask main body is made of amber material, the mask frame is made of low carbon steel, and the horizontal axis based on the holder before and after the final low temperature heat treatment of the shadow mask manufactured by the above method. (H
Axis), vertical axis (V axis), diagonal axis (D axis), intermediate axis (F20), (F20) inclined by 20 ° and 60 ° with respect to the horizontal axis.
The mask deformation on 60) is shown by lines 20a-20e, respectively. As shown in this figure, the shadow mask manufactured by the above method has a horizontal axis of 80 to 100 μm,
It varies by 40 to 50 μm on the diagonal axis. However, even if the shadow mask that has been subjected to the low temperature heat treatment is further subjected to the conventional stabilization process, as shown in FIG. 7B, the corresponding horizontal axis, vertical axis, diagonal axis and intermediate The mask deformation on the axes (F20, F60) is almost zero as shown by lines 21a-21e, respectively. This means that the distortion of the shadow mask is almost removed and does not remain by the above-mentioned low temperature heat treatment.

Therefore, when a color cathode ray tube is manufactured using the shadow mask manufactured by the above method,
After assembling the mask and frame, which was conventionally required, without performing the stabilization process before forming the phosphor screen,
A color CRT having good color purity can be obtained.

[0023]

EFFECT OF THE INVENTION A shadow mask main body is manufactured by blackening a formed mask having a predetermined shape formed by molding a flat mask having a large number of electron beam passage holes, and a mask frame having a predetermined shape. Frame-holder assembly with the holder welded to 500-580
Blackening is performed at a temperature of ℃, and the blackened shadow mask body is welded to the blackened frame / holder assembly to assemble a shadow mask, and the shadow mask is heated at a temperature of 200 ° C or higher for 3 minutes. After the above heat treatment, when assembled into a panel to assemble a panel / mask assembly, by welding the holder to the mask frame before the blackening treatment, which was liable to cause splashing or peeling of the blackening film, the splash and Peeling of the blackening film is prevented,
In addition, it is possible to remove processing strain caused by welding the mask frame and the holder. The shadow mask body is welded to the blackened frame / holder assembly to assemble the shadow mask.
By heat-treating at a temperature of 00 ° C or higher for 3 minutes, the processing distortion caused by the welding of the frame holder and the formed mask can be removed. Conventionally, the stabilization was performed after the panel / mask assembly and before the phosphor screen formation. A color CRT having good color purity can be obtained without any treatment.

[Brief description of drawings]

FIG. 1 is a flow chart for explaining a method of assembling a shadow mask in a method of manufacturing a color CRT according to an embodiment of the present invention.

FIG. 2 (a) is a view showing a modification of the shadow mask assembled by the above-mentioned assembling method, and FIG. 2 (b) is a still-stabilized shadow mask assembled by the above-mentioned assembling method. It is a figure which shows the deformation | transformation of the shadow mask in the case.

FIG. 3 is a diagram showing a configuration of a color CRT.

FIG. 4 is a diagram showing a configuration of the shadow mask.

5 is a view of a holder different from the holder attached to the shadow mask shown in FIG. 4. FIG.

FIG. 6 is a flow chart for explaining a shadow mask assembling method in a conventional color cathode ray tube manufacturing method.

Claims (1)

[Claims] 1. A step of forming a flat mask having a large number of electron beam passage holes into a formed mask having a predetermined shape, and a step of blackening the formed mask to produce a shadow mask body. The step of assembling the frame / holder assembly by welding the holder that locks to the stud pin provided on the panel to the mask frame formed in a predetermined shape, and the frame / holder assembly at a temperature of 500 to 580 ° C. A step of blackening, a step of assembling a shadow mask by welding the blackened shadow mask body to the blackened frame / holder assembly, and a step of assembling the shadow mask at a temperature of 200 ° C. or higher. Heat treatment for more than a minute, and the heat-treated shadow mask is incorporated into a panel to assemble a panel / mask assembly. Method of manufacturing a color cathode-ray tube, characterized in that a step of forming a phosphor screen by a photographic printing method panel inner surface of Le mask assembly.