JPS59211932A - Manufacture of member for color picture tube - Google Patents

Abstract

PURPOSE:To obtain the member of a shadow mask and such that can achieve a fine color picture tube easy to observe with exceedingly small color shift by creating a substrate whose primary components are Fe and Ni, formation-processing the surface of the member, and foring a black coat. CONSTITUTION:When at least either one of a shadow mask 6, a frame 7, and an inner shield 9 is manufactured, a substrate whose primary components are Fe and Ni is created and then a black coat is formed on the surface of the substrate by formation-processing the substrate. As a result, the member for a color picture tube that is provided with the property of small coefficient of thermal expansion owing to the substrate whose primary components are Fe and Ni and the excellent heat dissipation owing to the black coat formed on the surface of the substrate, for example, the shadow mask can be manufactured and doming by the temperature rise in operation can be improved sharply.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a method of manufacturing a member used in a color picture tube.

[Technical background of the invention and its problems]

Generally, a color picture tube has the configuration shown in the figure. That is, 1 in the figure is a glass envelope.

A neck portion 2 at one end of the envelope 1 is provided with, for example, an in-line electron gun 3, and a face portion 4 at the other end facing the electron gun 3 is provided with a large number of red, blue, and green colors. A segmented fluorescent surface 5 is provided. A shadow mask 6 having a large number of beam apertures is disposed adjacent to the fluorescent surface 5 of the light source. This shadow mask 6 is attached to a frame 7 via a fastener 8, and an inner shield 9 is attached to the frame 1 on the electron gun 3 side for blocking earth's magnetic field. In the color picture tube having such a configuration, the electron beam 11 emitted from the electron gun 3 is focused, accelerated, deflected by the deflection device 10, and impinges on the fluorescent surface 5 through the aperture of the shadow mask 6. Reproduce the image.

Incidentally, the members of the shadow mask, frame, and inner shield used in the color picture tube are conventionally made of rimmed steel, which has good etching properties and formability, and which makes it easy to form an oxide film that contributes to reducing electron beam reflection. It was made of At-killed steel. However, recently, with the practical use of motherboard displays, teletext broadcasting, satellite broadcasting, captain systems, etc., one part of the television screen
As more and more emphasis has been placed on visibility and fine detail, it has become difficult to use components such as shadow masks made of rimmed steel, At-kill steel, and solid steel for the following reasons: That is, in general, when a color picture tube is operated, the temperature of each member increases to 30 to 60 DEG C., and for example, in the case of a shadow mask, the molded shape is distorted due to thermal expansion, which is so-called doming. As a result, the relative positional relationship between the aperture of the shadow mask, which should be located on the trajectory of the electron beam, and the phosphor layer on the phosphor surface is shifted, and a color shift phenomenon called purity drift (PD) occurs. In the detailed and easy-to-see color picture tube described above, the pitch and diameter of the apertures in the shadow mask are very small, so the degree of color shift is dependent on the amount of relative positional shift between the apertures in the shadow mask and the phosphor layer on the phosphor surface due to doming. is significantly larger than that for consumer use, and conventional shadow masks made of rimmed steel or aluminum-killed steel with large coefficients of thermal expansion cannot withstand practical use.

For this reason, members for color picture tubes such as shadow masks formed of Fe-N1 alloys with a small coefficient of thermal expansion, such as 36Ni-Fe, have been proposed (Japanese Patent Publication No. 42-25446, 50-58977
, Japanese Unexamined Patent Publication No. 5O-68650).

However, since Pa-Ni alloys such as amber have low thermal conductivity and easily accumulate heat, there is a limit to the ability to obtain a color picture tube with little color shift.

[Purpose of the invention]

An object of the present invention is to provide a method for manufacturing members such as a shadow mask, which can realize a color picture tube with very little color shift and fine detail and easy viewing.

[Summary of the invention]

The present invention is directed to manufacturing at least one member of a shadow mask, a frame, and an inner shield used in a color picture tube, after producing a base material containing F and Nl as main components, It is characterized by forming a black film on the surface of the base material by subjecting it to a chemical conversion treatment. According to this method, a member for a color picture tube has a low coefficient of thermal expansion due to the base material mainly containing Fe and N1, and has excellent heat dissipation due to the black film formed on the surface of the base material, For example, shadow masks can be manufactured. One! , C. While taking advantage of the excellent low thermal expansion of the base material, the low thermal conductivity property (property of easily accumulating heat) can be improved by chemical conversion treatment of the base material. A shadow mask with better heat dissipation performance can be obtained. As a result, when this shadow mask is incorporated into a color picture tube used in a computer display, etc., it significantly improves doming caused by temperature rise during use, and the phosphor layer on the fine aperture of the shadow mask and the phosphor layer on the phosphor surface. 5- A color picture tube that can significantly suppress color misalignment caused by relative positional deviation between realizable.

In order to produce a base material containing the above-mentioned re and Ni as main components, an alloy consisting of, for example, 30 to 40% Ni, Fs and incidental components, and c) 0.1 to 7% Co, 31 to 7% 35
．． After the alloy input consisting of 9% Nl, Fa and incidental components was repeatedly annealed and cold-worked into a plate material,
A method such as pressing may be adopted.

The black film formed on the surface of the substrate by the above chemical conversion treatment has an emissivity of 0.4 or more, assuming that the emissivity of a perfect black body is 1.

[Embodiments of the invention]

Next, the present invention is applied to color picture tube members (shadow masks,
An example in which the present invention is applied to manufacturing a shadow mask of a frame and an inner shield will be described.

6- Example 1 First, an ingot of an alloy (amber) containing 36% Ni and Fe as main components and 1 inch or less of C, Si, Mn + P, and S as incidental components by weight was prepared, This ingot was repeatedly annealed and cold worked to a thickness of 0.
It was made into a 15m5 board. Subsequently, this plate material was coated with a photosensitizer, exposed, developed, and etched by burning to produce a flat mask material having a large number of holes. Subsequently, this flat mask material was washed, sheared, vacuum annealed at 1150° C., and pressed to produce a mask base material. Next, this mask base material was degreased, pickled, and washed with water, and then subjected to chemical conversion treatment under the conditions shown in the table below to produce seven types of shadow masks in which a black film was formed on the surface of the mask base material made of amber.

When images were transferred to the illustrated color picture tube incorporating the shadow masks of Examples 1 to 7, stable images were obtained in all cases.

In addition, when we measured the PD value of these color picture tubes and a color picture tube (conventional example) incorporating an amber color shadow mask without a black film, we found that the PD value of the conventional example was 12.
On the other hand, the color picture tubes incorporating the shadow masks of Examples 1 to 7 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 7, the time from occurrence of PD to return to normality was reduced by half. In addition, 906 regarding the shadow masks of Examples 1 to 7.
After the bending test, cellophane tape was attached to the bent portion and peeled off to examine the adhesion of the black film, and no peeling of the black film occurred in any case.

Although the coating formed by the above chemical conversion treatment may become amorphous, heating can convert it into a sufficiently dense black coating with excellent heat dissipation.

〔Effect of the invention〕

As described in detail above, according to the present invention, a base material whose main components are Fe and N1, which have a small thermal expansion coefficient but a low thermal conductivity and which easily accumulate heat, is prepared, and this base material is subjected to a chemical conversion treatment. By forming a black film with excellent heat dissipation on the material surface,
It is possible to provide a method for manufacturing a member for a color picture tube, which can realize color picture tubes in which color shift is extremely small and where 1. fineness and 6. ease of viewing are important for personal computers, satellite broadcasting, etc.

[Brief explanation of the drawing]

The figure 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.

Claims (2)

[Claims] (1) Shadow mask used in color picture tubes,
At least one of a frame and an inner shield
1. A method for producing a color picture tube member, which comprises producing a base material containing F and N1 as main components, and then chemically treating the surface of the member to form a black film. (2) The base material mainly contains Fe and Ni, and C. 2. The method for manufacturing a color picture tube member according to claim 1, wherein the color picture tube member is manufactured from a composition containing the following.