JPH065606B2 - Method for manufacturing color picture tube member - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an improvement in a method for manufacturing a member used in a color picture tube.

[Technical Background of the Invention and Problems Thereof] In general, a color image receiving structure has a configuration shown in the figure. That is, 1 in the figure is a glass envelope. The neck 2 at one end of the envelope 1 is provided with, for example, an electron gun 3 in an in-line arrangement, and the face 4 at the other end facing the electron gun 3 is provided with a large number of red, blue, and green. Divided fluorescent surface 5
Is provided. A shadow mask 6 having a large number of beam apertures is arranged close to the fluorescent surface 5.
The shadow mask 6 is attached to a frame 7 via a locking tool 8, and the frame 7 is attached with an inner shield 9 for blocking the geomagnetism on the electron gun 3 side. In the color picture tube having such a structure, the electron beam 11 emitted from the electron gun 3 is focused and accelerated, deflected by the deflecting device 10, passes through the aperture of the shadow mask 6 and strikes the fluorescent surface 5, Reproduce the image.

By the way, the members of the shadow mask, frame and inner shield used for the color picture tube have better etching properties and moldability than conventional ones, and rimmed steel or Al killed steel which can easily form an oxide film that contributes to reduction of electron beam reflection. It was made of steel. However, with the recent practical use of personal computer displays, character multiplex broadcasting, hygiene broadcasting, and captain systems, etc., "easiness to see" and "detailedness" of TV screens have become important, It was difficult to use a member such as a shadow mask made of the rimmed steel or Al killed steel for the following reasons.

That is, generally, when a color picture tube is operated, the temperature of each member rises to 30 to 60 ° C., and so-called doming occurs, for example, in the shadow mask, the molding shape is distorted due to thermal expansion. As a result, the relative positional relationship between the aperture of the shadow mask to be on the electron beam orbit and the fluorescent layer on the fluorescent surface is deviated, and a color misregistration phenomenon called purity drift (PD) occurs. In the detailed and easy-to-see color picture tube described above, the aperture pitch and hole diameter of the shadow mask are very small.Therefore, the amount of color misalignment with respect to the relative displacement between the shadow mask aperture and the fluorescent surface of the fluorescent surface due to doming. Is significantly larger than that for consumer use, and conventional shadow masks made of rimmed steel or aluminum-killed steel having a large coefficient of thermal expansion cannot be used practically.

Under such circumstances, a member for a color picture tube such as a shadow mask formed of an Fe-Ni alloy having a small coefficient of thermal expansion, for example, amber (36Ni-Fe) has been proposed (Japanese Patent Publication No. 42-25446 and Japanese Patent Laid-Open No. 50446). -58977,
JP-A-50-68650). However, Fe-Ni alloys such as Amber have low thermal conductivity and easily store heat, so that there is a limit in obtaining a color picture tube with less color shift.

[Object of the Invention] An object of the present invention is to provide a method for manufacturing a member such as a shadow mask capable of realizing a fine and easy-to-see color picture tube with extremely little color shift.

[Summary of the Invention] In manufacturing at least one member of a shadow mask, a frame and an inner shield used for a color picture tube, the present invention contains Fe and Ni as main components,
After forming a base material through a vacuum annealing step, heat treating the base material in O ₂ gas or an oxidizing gas obtained by diluting O ₂ gas with N ₂ gas to form a black film on the surface of the base material. It is characterized by. According to such a method, a member for a color picture tube, which has a property of having a small coefficient of thermal expansion due to a base material containing Fe and Ni as main components, and has excellent heat dissipation due to a black film formed on the surface of the base material, For example, a shadow mask can be manufactured. That is, while making use of the excellent low thermal expansion property of the base material, the base material produced through the vacuum annealing step has a property of low thermal conductivity (a property of easily storing heat) and O ₂ gas or O ₂ gas It is possible to obtain a shadow mask that is compensated by the excellent heat dissipation of the black coating formed by heat treatment in an oxidizing gas diluted with ₂ gases. As a result, when this shadow mask is incorporated into a color picture tube used for personal computer displays, etc., doming due to temperature rise during use is remarkably improved, and fine apertures of the shadow mask and a fluorescent layer on the fluorescent surface are formed. It is possible to remarkably suppress the color shift due to the relative positional shift of the color picture tube, and it is possible to realize a color picture tube in which "fineness" and "viewability" are effectively achieved by miniaturizing the openings of the shadow mask.

To produce the base material containing Fe and Ni as the main components,
For example, an ingot of an alloy composed of 30 to 40% Ni, Fe and ancillary components, or 0.1 to 7% Co, 31 to 3
A method may be employed in which an alloy ingot composed of 5.9% Ni, Fe and ancillary components is annealed and cold-worked repeatedly to form a plate, and then pressed. The annealing temperature is Fe
The conditions may be set to be suitable for the -Ni system.

As the oxidizing gas, O ₂ gas and O ₂ gas are N ₂ gas.
What was diluted with gas can be used.

The heat treatment temperature is usually in the range of 200 to 1000 ° C. and is selected in relation to, for example, the O ₂ concentration in the oxidizing gas. When the oxygen concentration in the oxidizing gas is low, it is desirable to perform the heat treatment on the high temperature side, and when the oxygen concentration is high, it is desirable to perform the heat treatment on the low temperature side. The reason for limiting the heat treatment temperature to the above range is that if the temperature is set to less than 200 ° C., the surface of the base material changes to a purple color, making it difficult to form a black film with excellent heat dissipation. If it exceeds, it is brittle because a black film (oxide film) grows rapidly on the surface of the substrate, and it becomes difficult to form a film having excellent adhesion to the substrate. The black film thus formed has an emissivity of 0.4 or more when the emissivity of a perfect black body is 1.

[Examples of the Invention] Next, the present invention is applied to a member for a color picture tube (shadow mask,
An example applied to the production of the shadow mask of the frame and the inner shield) will be described.

Example 1 First, an alloy (amber) ingot containing 36% Ni and Fe as main components and C, Si, Mn, P, and S as auxiliary components in an amount of 1% or less by weight, respectively, was prepared. Was repeatedly annealed and cold worked to obtain a plate material having a thickness of 0.15 mm. Subsequently, this plate material was applied with a photosensitizer, exposed, developed and etched by burning to prepare a flat mask material having a large number of holes. After that, the flat mask material is washed and sheared, then 1150
Vacuum annealing was performed at 0 ° C. and press working was performed to produce a mask substrate. Then, a heat treatment was performed in an O ₂ gas atmosphere at 200 ° C. for 1 hour to form an oxide film (black film) on the surface of the base material made of amber to manufacture a shadow mask.

Example 2 A mask substrate similar to that in Example 1 was placed in air at 600 ° C. for 1 hour.
After heat treatment for a period of time, an oxide film (black film) was formed on the surface of the base material to manufacture a shadow mask.

Example 3 A mask base material similar to that in Example 1 was applied with 10% O ₂ at 1000 ° C.
Was heat-treated for 10 seconds at -N ₂ gas atmosphere to form an oxide film (black coating) in the substrate surface, to produce a shadow mask.

Then, when an image was transferred to the illustrated color picture tube in which the shadow masks 1 to 3 of this embodiment were incorporated, a stable image was obtained in each case. Further, when the PD value of the color picture tube (conventional example) in which the shadow mask composed of these color picture tube and amber without a black film was incorporated was measured, the PD value was about 120 μm in the conventional example, but this example 1 The color picture tubes incorporating the shadow masks Nos. 3 to 3 all showed extremely low values of 90 μm or less. Furthermore, in all of the color picture tubes incorporating the shadow masks of Examples 1 to 3, the time from the occurrence of PD to the normal return was reduced to half. In addition, the present embodiment 1
After the 90 ° bending test of the shadow masks Nos. 3 to 3, a cellophane tape was attached to the bent portion and peeled off to examine the adhesion of the black film. No black film peeled at all.

[Effects of the Invention] As described in detail above, according to the present invention, a base material containing Fe and Ni as main components, which has a small thermal expansion coefficient and a small thermal conductivity and easily stores heat, is prepared, and the base material is oxidized. A black film with excellent heat dissipation is formed on the surface of the base material by heat-treating it in an inert gas, and the color shift is extremely small, and "fineness" and "readability" for personal computers, sanitary broadcasting, etc. are important. It is possible to provide a method for manufacturing a member for a color picture tube that can realize the color picture tube described above.

[Brief description of drawings]

The drawing is a sectional view showing a color picture tube. 1 ... Envelope, 3 ... Electron gun, 5 ... Fluorescent surface, 6 ... Shadow mask, 7 ... Frame, 9 ... Inner shield, 10 ...
Deflection device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shoji Kanto Kanto, Himeji City, Himeji City, Hyogo Prefecture, 50 No. 50 Kamimayu, Tokyo Shibaura Electric Co., Ltd. No. 2 in Fukaya CRT factory, Shibaura Electric Co., Ltd. (56) Reference JP-A-50-58977 (JP, A) JP-A-50-68650 (JP, A) JP-B-42-25446 (JP, B1)

Claims (3)

[Claims] 1. In manufacturing at least one member of a shadow mask, a frame and an inner shield used for a color picture tube, Fe and Ni are used as main components, and after a base material is manufactured through a vacuum annealing step, manufacturing a color picture tube member, characterized in that allowed to form a black film on the substrate surface by Hodokosuru heat treatment of the substrate with O ₂ gas or O ₂ gas an oxidizing gas diluted with N ₂ gas Method. 2. A base material mainly composed of Fe and Ni, and C
The method for producing a member for a color picture tube according to claim 1, which is produced from a composition containing o. 3. The oxidizing gas is O ₂ gas 15 to 25%, N ₂
The method for producing a member for a color picture tube according to claim 1, characterized in that the heat treatment temperature of the oxidizing gas is in the range of 500 to 700 ° C.