JPH0727760B2 - Color picture tube - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a display image quality that is formed by using in-tube parts such as a shadow mask, a frame, an inner shield, and a bimetal, which have good moldability and excellent thermal characteristics. Regarding high color picture tubes.

[Technical Background of the Invention and Problems Thereof] A color picture tube generally has a structure shown in FIG.
That is, a neck portion 2 forming one end of the glass envelope 1 is provided with, for example, an electron gun 3 in an in-line arrangement, and a face portion 4 at the other end of the glass envelope 1 facing the electron gun 3 is provided. In addition, a fluorescent surface 5 in which red, blue, and green fluorescent bodies are arranged and arranged is provided. A shadow mask 6 having a large number of beam apertures is arranged to face the fluorescent surface 5 so as to face it.
The shadow mask 6 is attached to a frame 7 via a system stopper 8, and an inner shield 9 is attached to the frame 7 so as to block the influence of geomagnetism.

In the color picture tube thus constructed, the electron beam 11 emitted from the electron gun 3 is deflected by the deflection control by the deflecting device 10 provided at the base of the neck 2. Then, the light passes through the aperture of the shadow mask 6 and strikes the fluorescent surface 5 to generate fluorescent light, thereby forming a color image.

By the way, the shadow mask 6, the plane 7, and the inner shield 9 are better in etching property and formability than conventional ones, and are easy to form an oxide film which contributes to reduction of reflection of electron beams on the surface thereof. It is made of steel or the like. However, in order to cope with various new media in recent years, it is required that the quality of the color picture tube be improved, that is, the so-called legibility of the displayed image be extremely fine, and it be composed of the rimmed steel or Al killed steel described above. Problems have occurred in using the shadow mask 6, the frame 7, and the inner shield 9.

That is, during operation of the color picture tube, the temperature of each member rises to 30 to 100 ° C., and so-called doming occurs due to distortion in the molded shape of the shadow mask due to its thermal expansion, for example. As a result, the relative positional relationship between the shadow mask and the fluorescent surface is deviated, and a color misregistration referred to as "purity drift (PD)" is generated. Especially in a high-quality color picture tube, the aperture diameter and the aperture pitch of the shadow mask are very small, so the relative deviation amount becomes large, and the inside of the tube made of the rimmed steel or Al-killed steel described above becomes large. Parts cannot be used practically. In particular, in a high-curvature type color picture tube in which distortion of an image and reflection of external light are reduced, the above-mentioned problem remarkably occurs.

Therefore, conventionally, as a material for forming this kind of in-pipe component,
Ni-Fe alloys with a small coefficient of thermal expansion, such as amber (36Ni
The use of --Fe) has been proposed, for example, in Japanese Examined Patent Publication No. 42-25446, Japanese Patent Laid-Open No. 50-58977, Japanese Patent Laid-Open No. 50-68650 and the like. However, this type of Ni—Fe alloy has poor thermal conductivity and is not only susceptible to heat storage, but is also likely to cause a recess from the normal shadow mask spherical surface to the electron gun side, a so-called spring pack. For this reason, it has conventionally been necessary to perform vacuum annealing at 1000 ° C or higher. However, when this treatment is performed, the crystal grains become coarse, and there is a drawback that unevenness is likely to occur when molding into an ordinary curved surface.

[Object of the Invention] The present invention has been made in consideration of such circumstances, and an object of the present invention is to provide a high-quality image that has a screen that is nearly flat, has little color misregistration, and is extremely fine and bright. It is to provide a color picture tube that can be obtained.

SUMMARY OF THE INVENTION The present invention provides at least one of internal components such as a shadow mask, an inner shield, a frame, and a bimetal in a color picture tube with 25 to 45 wt% Ni, 0.03 to 10 wt% Cr, 0.
Is a blackened film made of a spinel-type oxide film of NixCryFe _3-xy O ₄ (where 0 <x, y <3) formed on an alloy consisting of 002 to 0.01 wt% N and the balance substantially Fe? , Or 25〜
45 wt% Ni, 0.03 to 10 wt% Cr, Mn substituting up to 40% of Cr, 0.002 to 0.01 wt% N, and an alloy consisting of Fe at the balance substantial point, and NixCryMnzFe _3-xyz O on the surface ₄ (however 0
By providing a blackened film made of a spinel type oxide film of <x, y, z <3), its formability and heat dissipation property are improved. As a result, a color picture tube having a low PD value, a bright, flat, and easily viewable image is realized.

Here, the reason why the composition amount of Ni is 25 to 45 wt% is that the coefficient of thermal expansion thereof is 90 × 10 ⁻⁷ / ° C. or less, and if the addition amount of Ni is out of the above range, the present invention However, it becomes impossible to obtain the material for the in-pipe parts having a low coefficient of thermal expansion. That is, PD
Images with low values cannot be obtained. Further, if the amount of addition of Ni exceeds 45 wt%, it is a measure of the quality of the formability.
An increase in 0.2% proof stress occurs, and the formability thereof is significantly deteriorated. Then, for example, in a shadow mask, springback occurs, which makes it difficult to obtain a clear image.
At the same time, the improvement in the oxidation resistance makes the blackening treatment, which is usually performed on the surface, extremely difficult.

Regarding the etching property, if the amount of Ni becomes large, it becomes difficult to perform fine etching, the inner wall of the etching hole becomes a so-called dry hole, and a large amount of Ni dissolved in the etching solution causes a decrease in the etching rate. Problem arises.

Further, Gr increases the coefficient of thermal expansion of the Fe-Ni alloy, but on the other hand, it reduces the 0.2% proof stress and greatly contributes to the improvement of its formability. Therefore, the addition of Cr does not make the PD value worse than the conventional amber. This plays an important role in improving the formability of the shadow mask, especially when obtaining a shadow mask having a high curvature.

That is, generally, Cr is added to 36Ni-Fe alloy, and when not annealed at a recrystallization temperature or higher, since the crystal grains are fine, 0.2% proof stress at room temperature is increased, and for example, the curvature as a shadow mask is maintained. However, the addition of Cr only increases the strength of the material. However, when a specific annealing treatment is applied to the 36Ni-Fe alloy containing Cr as in the present invention, the 0.2% proof stress reduction amount is significantly larger than that of the 36Ni-Fe alloy containing no Cr (amber). Become. In other words, Cr contained in the material has an important effect in greatly reducing the 0.2% proof stress of the material in the annealing process.

FIG. 2 is a material according to the present invention, in which 6 wt% of Cr is added 3
The change in the 0.2% proof stress with respect to the annealing temperature of the 6Ni-Fe alloy is shown as the characteristic A, and the property B is the change of the 0.2% proof stress with respect to the annealing temperature in the Cr-free 36Ni-Fe alloy shown for comparison. As shown in this figure, the 0.2% proof stress is higher in the material for pipe parts according to the present invention at room temperature, but when it is annealed at 500 ° C. or higher, its 0.2% proof stress is sufficiently higher than the conventional one. Get lower. For example 1000-1200 ℃
When vacuum-annealed in 0, the material for pipe parts according to the present invention 0.
The 2% proof stress is 12 kg / mm ² , but the 0.2% proof stress of the conventional one without Cr is as large as about 22 kg / mm ² . Therefore, also from this, it can be seen that the addition of Cr greatly contributes to the reduction of the 0.2% proof stress during annealing. Mn has the same function as Cr. Therefore, it is possible to replace part of Cr with Mn. In this case, it is up to about 40% of Cr.

By the way, if the addition amount of Cr is less than 0.03 wt%, even if the annealing temperature is increased to 1200 ° C as in the case of the Cr-free 36Ni-Fe alloy, its 0.2% proof stress will be 22 kg / mm ² or less. There is no.
Also, if the addition amount exceeds 10 wt% or if the Mn substitution amount exceeds 40%, the thermal expansion coefficient becomes 90 × 10 ^-7 / ° C or more, which causes color misregistration. Not suitable for use in pipes. Further, when the amount of Cr added exceeds 10 wt%, a Cr ₂ O ₃ protective film is easily formed on the surface,
This causes inconvenience in the blackening process such as a decrease in the surface blackening speed.

Conventionally, 36Ni was used for the purpose of increasing the strength of the material for pipe parts.
An example of adding Cr to a Fe alloy is disclosed in JP-A-59-59861. However, no measures have been taken to achieve low yield strength, the material is simply high strength, and 0.2% yield strength has not been reduced. Further, as described below, a blackening film is not formed on the surface, and in consideration of such a point, it can be said that the material for pipe parts according to the present invention is completely different.

N is an important element that prevents the crystal grains from coarsening and reduces the unevenness when forming parts. That is, unavoidable components contained in the alloy, Al, Si, V, Ti, Zr, Ca, Nb, Ta, B, or Cr, Mn added as a component to reduce the yield strength, to form a fluoride, the crystal during annealing. Prevents grain coarsening. The lower limit is set to 0.002 wt% because the effect is thin at a content below this, and the upper limit is set to 0.01 wt% at a content above this because the crystal grains become too fine and the yield strength increases and This is because the elongation at the time of molding is reduced. With the addition of N, the crystal grain size is JIS JIS even when annealed at 1000 ° C.
The particle size numbers 6 to 10 indicated by −0551 are set.

In the present invention, Co may be further contained.
Co has the effect of improving the etching property and the effect of lowering the thermal expansion coefficient. When the Cr concentration increases, etching is difficult unless the grain size is specified in Nos. 8 to 12 shown in JIS G0551, but when Co is added, etching is possible even if the grain size regulation is not always met. Furthermore, etching is possible even if the crystal orientation of the rolled surface is not necessarily set to {100}. The coefficient of thermal expansion is Co
It becomes smaller with the increase of, and becomes the minimum value with the addition of 5 wt%.
The upper limit of the Co content is 10 wt%, preferably 0.2
~ 10wt%. This is because if it deviates from this range, the above effects cannot be obtained. The inclusion of O is also effective. Like N, O forms an oxide with an unavoidable metal element to prevent coarsening of crystal grains, and also gives an oxide film having good adhesion when forming a black oxide film. The upper limit is 0.008 wt%, and a content higher than this not only leads to an increase in yield strength,
This is because the oxide as an intercalation material during etching significantly damages the etching property. Preferably 0.001-0.008
wt%.

The inclusion of C is also effective. Like N, C forms carbides and prevents coarsening of crystal grains. This is because the upper limit is 0.038 wt%, and if it is more than this, carbides become large, roughening the etching property and increasing the yield strength, and springback is likely to occur during molding. It is preferably 0.01 to 0.038 wt%.

Now, the blackening film formed on the surface of the material plays an important role in improving the heat dissipation property thereof, and plays a great role in lowering the PD value of the color picture tube. It is the degree of blackness and surface roughness that determine the heat dissipation property, and the blackened film according to the present invention is excellent in the following points.

That is, the roughness of the blackened film on the surface depends on the crystal grain size inside the alloy. The cross section of the black film is shown in Fig. 4, and as is clear from the figure, the oxide film is raised at the grain boundaries (14) of the alloy. That is, the larger the area of this raised portion, the larger the surface area of the blackened film. In the present invention, the crystal grains of the alloy are made fine by adding N, C and O, and finally the heat dissipation of the blackened film is improved. The spinel type oxide film (0 <x, y <3) of NixCryFe _3-xy O ₄ which is the blackening film according to the present invention is, for example, 550 to 900 ° C.
Obtained by oxidation in steam, air or carbon dioxide. In the present invention, the addition of N, and further C and O, causes the blackened film to grow rapidly, the blackened film thickness increases, and the heat dissipation property improves. A small amount of α-Fe ₃ O ₄ layer (11) is formed on the surface, but most of it is NixCryFe _3-xy O ₄ spinel type layer (1).
2) This film is bonded to the Ni-Fe alloy layer (15) with good adhesion through the Cr concentrated layer (13).

Further, when the material is one in which a part of Cr is replaced with Mn, the blackening film has a spinel structure of NixCryNnzFe _3-xyz O ₄ , and even in such a case, the same action is exhibited. When air oxidation, steam oxidation, or carbon dioxide oxidation is adopted for forming this blackened film, α-
Fe ₂ O ₃ is formed, but it is not a problem because the film thickness is small.

By the way, N 0.006wt%, O 0.005wt%, C 0.015wt%
A shadow mask of the above-mentioned material in which a blackened film having the above composition is formed on the added 36Ni-Fe, and 0.001% of N and 0.0 of O are added.
Comparing the PD values of each color picture tube assembled using a shadow mask in which a blackening film was formed on 36Ni-Fe with 0.004wt% of 007wt% and C added, the PD values were found to be low. Although the PD value was 90 μm for 3 minutes, C,
It was confirmed that the PD value of a large amount of N and O was as small as 75 μm. In other words, the surface area of the blackening film is increased, the heat dissipation effect is enhanced, and a great effect is exerted in suppressing PD. Especially, the effect of this blackening film is that the curvature is 900 mm.
This is remarkable when the above-described flattened shadow mask is formed.

[Effects of the Invention] Thus, according to the present invention, Cr of a predetermined Ni-Fe alloy or Mn is added as necessary to reduce its 0.2 yield strength, and N is added to suppress coarsening of crystal grains. The color picture tube is formed by using in-tube parts such as a shadow mask with a predetermined black oxide film formed on the surface to prevent uneven spread and improve its formability, so the image is brightened and extra fine. It can be of high quality. Moreover, because of its good moldability, it is possible to effectively obtain an image with little color shift even at the four corners of the screen, and it is possible to suppress color change even for a white image for a long time. Since it is possible to form a particularly flat screen, it is possible to suppress the bending of a straight line image,
It is effective for displaying bright and high-contrast images. On the other hand, since the crystal grains are small and the strength is high, vibrations due to low frequency from speakers placed close to each other are not caused, and a so-called fluctuation-free image that sufficiently withstands mechanical shock and the like is obtained. The effect of being obtained is exhibited.

Embodiments of the Invention Next, embodiments of the present invention will be described.

[Example-1] First, 36 Ni and Fe as main components, containing 3 wt% of Cr and N of 0.0
Prepare an alloy ingot containing 05wt%, 0.004wt% of O, 0.012wt% of C, and 0.05wt% of P and S, respectively, and manufacture a sheet material with a thickness of 0.13mm by repeatedly annealing and cold working this ingot. did. Thereafter, a photoresist was applied to the plate material, dried, and then a film having a slot or dot-shaped reference pattern formed on both surfaces thereof was brought into close contact with the plate material to expose and develop the photoresist. By this development, the photoresist in the unexposed portion is dissolved and removed.
Thereafter, the remaining photoresist was burned and cured, and then ferric chloride solution etching treatment was performed. Then, the remaining resist was removed with hot alkali to prepare a flat mask which is a master plate of the shadow mask.

Then, this flat mask was washed and sheared, then vacuum annealed at 10 ⁻⁴ torr and 1000 ° C., and pressed to obtain a formed mask having a radius of curvature of 1000 mm. After subjecting this foamed mask to acid treatment, trichlene washing, and water washing treatment,
30% O ₂ -N ₂ Heat oxidization for 30 minutes at 670 ℃ in a wet atmosphere.
A blackened film made of a -Cr-Fe-O-based spinel oxide film was formed.

The shadow mask thus produced was attached by spot welding to a frame produced by a similar method, and this was attached to the panel via a bimetal.
After that, according to the hole of the shadow mask, red, blue, green phosphor is applied, Al vapor deposition, after Doug application, the inner shield is attached and the funnel of the envelope part with the electron gun,
A color picture tube was manufactured by connecting this panel and evacuating the inside. The inner shield was also made of the same material.

[Example 2-7] Using an ingot containing N shown in Table 1 containing 36 wt% Ni and Fe as main components and containing 2 to 4 wt% of Cr (some cases may include some Mn or Co). A flat mask was prepared in the same manner as in Example-1. And this flat mask is 1100 ℃
Vacuum annealing was carried out at 680 ° C for 30 minutes to obtain a shadow mask, which was used to complete a color picture tube.

In accordance with the table, the grain size number shown in JIS-G0551 is shown as the thermal emissivity of the blackened film (1.0 for a perfect black body).

As a result of examining the PD values at the four corners of each of the color picture tubes of Examples 1 to 7 obtained in this way, the conventional values were about 90 μm, but a small value of about 75 μm was shown. It was In addition, the time from the occurrence of PD to the return to the original normal state was about 3/4 (about 2 minutes and 30 seconds) compared to the conventional method. In addition, since the molding could be performed without unevenness, an extremely fine and high-quality image with no color shift was obtained over the entire screen.

Although the formation of the shadow mask has been described as an example here,
A color picture tube can be obtained by similarly manufacturing an inner shield frame, a bimetal, and the like. In addition, the present invention can be variously modified and implemented without departing from the scope of the invention such as a lead frame and a glass sealing material.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic structure of a color picture tube, FIG. 2 is a diagram showing changes in 0.2% proof stress with respect to annealing temperature, and FIG. 3 is Cr.
FIG. 4 is a diagram showing changes in the thermal expansion coefficient and 0.2% proof stress with respect to the addition amount of, and FIG. 1 ... Envelope, 3 ... Electron gun, 6 ... Shadow mask, 7 ... Frame, 9 ... Inner shield, 11 ... α-Fe ₂ O ₃ layer, 12
… NixCryFe _3-xy O ₄ layer, 13… Cr concentrated layer, 14… Alloy grain boundary, 1
5 ... Fe-Ni alloy.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mio Mitsuji 8 Shinsugita-cho, Isogo-ku, Yokohama, Kanagawa Pref., Yokohama Metal Works, Ltd. (56) References JP-A-61-201758 (JP, A)

Claims (2)

[Claims] Claims: 1.25 to 45 wt% Ni, 0.03 to 10 wt% Cr, 0.002
A blackened film made of a spinel type oxide film having a surface of NixCryFe _3-xy O ₄ (where 0 <x, y <3), which is formed of an alloy of ˜0.01 wt% N and the balance substantially Fe, was provided. A color picture tube characterized by using parts inside the tube. 2. Ni of 25 to 45 wt%, Cr of 0.03 to 10 wt%,
NixCryMnzFe is formed on the surface by an alloy consisting of Mn up to 40%, 0.002 to 0.01 wt% N and the balance substantially Fe.
A color picture tube characterized by using an in-tube component provided with a blackening film made of a spinel type oxide film of _3-xyz O ₄ (where 0 <x, y, z <3).