JP3228989B2 - Color picture tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube,
In particular, the present invention relates to a color picture tube in which at least one of a frame, a shadow mask, and an inner shield is improved.

[0002]

2. Description of the Related Art Generally, a color picture tube is provided with a plurality of electron guns 3 arranged in an in-line arrangement on a neck portion 2 of a glass envelope 1 as shown in FIG. It has a structure in which a fluorescent screen 5 divided into red, blue, and green is provided in the section 4. A shadow mask 6 having a large number of beam apertures is fixedly arranged on a frame 7 of the frame 7 by using a locking member 8 in proximity to the fluorescent screen 5. In the frame 7,
An inner shield 9 for blocking adverse effects of geomagnetism is attached. In the figure, reference numeral 10 denotes a deflector.

In the color picture tube having the above-described configuration, the electron beam 11 emitted from the electron gun 3 is focused, accelerated, and polarized and scanned by the polarizer 10 with respect to the face portion 4. Then, the electron beam 11 collides with the phosphor screen 5 via the shadow mask 6, and exhibits a predetermined color.

However, the shadow mask 6, the frame 7, the inner shield 9, and the like in the conventional color picture tube are made of a metal containing Fe as a main component, and have a structure in which a black oxide film is formed on the surface. The oxide film has an effect of preventing rusting after producing the member such as the shadow mask, increasing heat radiation during operation, and reducing electron beam reflection.

When the color picture tube is operated, the temperature of the above-mentioned members rises to about 30 to 100.degree. For this reason,
For example, in the shadow mask 6, purity drift (PD) occurs due to doming due to thermal expansion. The purity drift greatly hinders the realization of “extra fineness” and “easiness of viewing” of a color image.

For this reason, as a member of the shadow mask 6 or the like, amber (Fe-36) is used instead of Fe.
Attempts have been made to use Fe-Ni alloys having a small coefficient of thermal expansion, such as Ni). However, the amber has a problem that it is difficult to form fine holes by etching, it is difficult to form the alloy due to its high proof stress, and it is also difficult to form a black oxide film at a relatively low temperature. Was. Attempts have been made to remedy this problem, but not all.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has an improved etching property, a reduced yield strength of a material, an improved press formability, and an improved adhesion. It is an object of the present invention to provide a color picture tube having a member such as a shadow mask on which a high-quality black oxide film is formed and capable of obtaining a fine image.

[0008]

According to the present invention, there is provided an electron gun provided at one end in an envelope, a fluorescent screen provided at the other end facing the electron gun, and a fluorescent screen provided near the fluorescent screen. A color picture tube comprising: a shadow mask having a large number of apertures attached to a frame provided as described above; and an inner shield attached to the shadow mask, wherein at least one of the frame, the shadow mask and the inner shield is provided. The two in-pipe parts are 25-45 wt% Ni, 0.005-0.2 wt% Si, 0.001-
2 wt% Co, 0.001-2 wt% Cr, 0.2
A balance of Cr and Si formed at the interface between the alloy and the oxide film at the interface between the alloy and the oxide film; The oxide film has an α-F located on the outermost surface.
a first layer of e ₂ O ₃ and a position between the first layer and the enrichment layer
And a second layer made of an oxide containing Ni and Fe
That it is configured in which the features. (1) Ni

[0009] Ni is blended to adjust the coefficient of thermal expansion of the alloy. When the amount of Ni is in the above range (25)
４５45%), the coefficient of thermal expansion of the alloy increases. A more preferred amount of Ni is 30 to 40%. (2) Si

[0010] Si is concentrated between the alloy and the oxide film formed on the surface of the alloy, to increase the formation speed of the oxide film,
Formulated to reduce oxidation temperature. If the amount of the Si is less than 0.001%, it cannot be sufficiently concentrated between the oxide film and the alloy, while if the amount of the Si exceeds 0.2%, the yield strength of the alloy increases. I do. A more preferable compounding amount of Si is 0.01 to 0.05%. (3) Co

[0011] Co is blended to improve the etching property. If the amount of Co is less than 0.001%, the effect of adding Co cannot be exhibited.
If the amount of o exceeds 2%, the moldability deteriorates and the cost of the material increases. A more preferable blending amount of Co is 0.05 to 1%. (4) Cr

[0012] Cr is blended for improving the adhesion of the oxide film and for reducing the proof stress and improving the formability. In particular, it has an effect of suppressing peeling of the oxide film which is concentrated between the oxide film and the alloy and formed thick by the addition of Si. If the amount of the Cr is less than 0.001%, it cannot be sufficiently concentrated between the oxide film and the alloy,
On the other hand, if the content of Cr exceeds 2%, the oxidation rate is reduced, and the thermal expansion coefficient of the alloy material is increased to cause color shift. (5) C C is added in an amount of 0.2% or less to increase the proof stress.

The oxide film formed on the alloy surface is preferably Ni _x Fe _3-x O ₄ . At the interface between the oxide film and the alloy, C is set due to the heat dissipation and adhesion of the oxide film.
An enriched layer of r and Si is formed.

That is, annealing is performed to such an extent that an alloy having the above composition can be formed (with a yield strength of 8.720 kg / mm ^2). )
The crystal grains are coarsened and the Ni _x Fe
_3-x O _{4 is} also coarsened. As a result, heat dissipation is reduced. Therefore, α-Fe ₂ O ₃ is formed on the surface of the oxide film, and the surface of the oxide film is made uneven to increase the surface area. Such α-
It is desirable that Fe ₂ O ₃ has a thickness of 2 to 30% of the entire oxide film.

In order to form the α-Fe ₂ O ₃ , it is effective to increase the dislocation density on the alloy surface before forming an oxide film than that inside the alloy. When the precipitates are formed by concentrating Si on the alloy surface, the dislocation density can be increased. The dislocation density is usually 10 ¹² dl / c
m ² It is preferable that the dislocation density is not more than 10 μm, and it is desirable that the dislocation density is not more than twice as large as the inside of the surface layer.
The reason is that even if the dislocation density is twice or more, the growth rate of the oxide film cannot be further increased. Further, it is desirable that the concentration of Si be twice or more the inside. The thickness of the concentrated layer is desirably 5 μm or less.

In order to form the Si enriched layer, it is desirable to anneal in a hydrogen atmosphere (wet atmosphere) having a dew point of 10 ° C. or more. N ₂ may be mixed in the atmosphere,
It is desirable that the hydrogen concentration be 10% or more. The annealing temperature is a temperature at which secondary recrystallization does not occur, for example, 650 to 900.
It is desirable to set the temperature to ° C.

If the α-Fe ₂ O ₃ is rapidly grown, the oxide film is liable to peel off, so that Cr is concentrated at the interface between the alloy and the oxide film. While the Si acts on the formation of the α-Fe ₂ O ₃ , the Cr has a function of concentrating at the interface between the alloy and the oxide film to improve the adhesion. Therefore, it is desirable that the oxide film has the following structure from the outer layer (surface). First layer: α-Fe ₂ O ₃ (2 to 30% of oxide film) Second layer: Ni _x Fe _3-x O ₄ (0 <x <3) Third layer: Cr is concentrated to form an oxide film solid solution was Ni _x Cr _y
Fe _3-xy O ₄ (0 <x + y <3) 4th layer; Si concentration layer

For the specific formation of such an oxide film, a method of annealing in a vacuum atmosphere after the above-described hydrogen annealing is preferable. It is desirable that the degree of vacuum be 10 ⁻¹ torr or less and the temperature be 750 ° C. or more. Other than the vacuum annealing, the annealing may be performed by lowering the initial oxygen partial pressure at the time of oxidation as compared with the latter oxygen partial pressure. The temperature in this case is 550-800
It is desirable that the initial oxygen partial pressure is less than or equal to 1/2 of the late oxygen partial pressure. Further, a small amount of nitrogen may be added during the hydrogen annealing as described above. The slight blackening of the surface by the residual oxygen in the nitrogen is due to the concentration of Cr. The nitrogen concentration is acceptable up to 90%, and it is particularly desirable to set the concentration to 20 to 60%. The oxygen concentration at this time is 0.0
It is desirable to make it about 5 to 5%.

The alloy may have an M content of 2% or less, if necessary.
It is allowed to contain n and 0.05% or less of P and S. In addition, Al, Ti, Ta, Zr, Nb, Y
Etc. are allowed.

[0020]

According to the invention, from 25 to 45% by weight of Ni,
0.005-0.2 wt% Si, 0.001-2 wt% Co, 0.001-2 wt% Cr, 0.2 wt%
By forming an enriched layer of Cr and Si at the interface between the alloy and the oxide film while covering the surface with an oxide film and forming an enriched layer of Cr and Si, Has good heat dissipation by the membrane,
It is possible to provide a color picture tube including an in-tube part such as a shadow mask in which the adhesion of the oxide film to the alloy is improved and holes with high precision are formed by fine etching.

Further, since the color picture tube of the present invention is provided with an in-tube part such as a shadow mask having an oxide film formed on the surface, a bright, ultra-fine, high-quality image can be displayed.
Moreover, because of its good formability, images with little color shift can be obtained even at the four corners of the screen, and color changes can be suppressed even for long-time white images. In particular, since a flat screen can be formed, the straight image can be prevented from being bent, which is effective for displaying a bright and high-contrast image.

Further, since the in-pipe component has a high strength, it does not generate vibration due to low-frequency sound waves from a speaker arranged in the vicinity, and sufficiently withstands a mechanical shock or the like. No images can be displayed.

[0023]

Embodiments of the present invention will be described below in detail. Examples 1 to 10 and Comparative Examples 1 and 2

First, the compositions shown in Table 1 below (Examples 1 to 3)
6, Ingots of Examples 9 and 10 and Comparative Examples 1 and 2) were produced by vacuum melting. However, in Example 8 in Table 1 below,
9 used the molten metal quenching method. This method takes a molten metal in a tundish, and rotates the twin rolls at 100 ° C./s.
It cools at a speed of ec or more.

[0025]

[Table 1]

Next, each of the ingots except for Examples 8 and 9 was repeatedly hot-rolled and then pickled to obtain primary and secondary ingots.
Next, cold rolling was performed. The rolling ratio in this process is 60 ~
90%. Then, in a box type annealing furnace, 10 ^-2
After annealing the alloy material subjected to the above-mentioned rolling treatment at 700 to 1000 ° C. torr, adjusted rolling was performed at a rolling reduction of 20% or less. By this adjustment rolling, 12 kinds of in-pipe component materials having an austenite structure having a crystal grain size of 9 to 13 specified in JIS-G0551 were produced. A shadow mask was manufactured by the following method using each of the in-pipe component materials manufactured in this manner.

First, a photoresist is applied to both sides of the material, and after drying, a film (mask material) having a slot or dot-shaped reference pattern is brought into close contact with both sides, and the photoresist is exposed. Was removed and development processing was performed. By this development, the unexposed portion of the photoresist was selectively dissolved and removed to form a resist pattern. Subsequently, after the resist pattern is cured, the exposed material is selectively etched using a ferric chloride solution (etching solution) using the resist pattern as a mask, and then the resist pattern is removed by hot alkali. As a result, a flat mask serving as an original plate of the shadow mask was manufactured.

Next, each of the flat masks was used in Table 2 below.
The treatment was carried out under the annealing and oxidizing conditions as shown in Table 2 to produce 12 types of shadow masks having an oxide film on the surface. In addition,
Table 2 below also shows the concentration ratios of Si and Cr to the inside of the alloy. The measurement of the concentration ratio of Si is performed by secondary ion mass spectrometry, calibrated by molybdenum blue absorption spectrometry, the measurement of the concentration ratio of Cr is performed by rainbow ion mass spectrometry,
It was calibrated by plasma emission spectroscopy and determined.

For each of the obtained shadow masks, the etching property, the blackening property, and the adhesion of the oxide film to the alloy were measured. Table 2 also shows the results. The etching property was evaluated by ○ when the appearance was checked and there was no unevenness. The blackening property is measured by measuring the film thickness, and the thickness is 0.5
〜3 μm was evaluated as ○. The surface of the shadow mask was cut with a cutter knife like a grid and a peeling test was performed with scotch tape. The case where 80% or more remained was evaluated as ○. In such a measurement, a case where all the tests were satisfied was evaluated as ○, and a case where any of the tests was bad was evaluated as ×.

[0030]

[Table 2]

Also, after fitting the shadow masks of Examples 1 to 10 into a panel connected to a frame, the shadow mask is connected to a funnel to which a phosphor-coated electron gun is attached, and a polarizing device is further fitted. Were assembled. Purity drift (PD) values at the four corners of each color picture tube

Was measured. As a result, a color picture tube using a conventional iron-made shadow mask has a size of 120 to 130 μm.
m, whereas the color picture tube of the present invention is about 6
The value was as small as about 0 μm. Further, the time required for the color picture tube of the present invention to return to the original state after the occurrence of PD is about 30% (about 2 minutes) compared to the conventional color picture tube.
Met. Further, with the color picture tube of the present invention, a fine high-quality image was obtained without color shift along the entire screen.

In the above embodiment, the formation of the shadow mask has been described as an example. However, it is also possible to obtain other color tube parts such as an inner shield, a frame, and a bimetal in the same manner as in the embodiment. It is.

[0034]

As described above in detail, according to the present invention, the etching ability is improved, the yield strength of the material is reduced, the press formability is improved, and the shadow formed with a black oxide film having high adhesion is formed. It is possible to provide a color picture tube including a tube part such as a mask and capable of obtaining a fine image.

[Brief description of the drawings]

FIG. 1 is a cutaway sectional view showing a schematic configuration of a color picture tube.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Envelope, 3 ... Electron gun, 5 ... Phosphor screen, 6 ... Shadow mask, 7 ... Mask frame, 9 ... Inner shield.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yasuhisa Otake 1-9-2 Hara-cho, Fukaya-shi, Saitama In-house Toshiba Fukaya Electronics Factory (56) References JP-A-3-202446 (JP, A) JP-A-61-201763 (JP, A) JP-A-61-218051 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 29/07 H01J 29/02

Claims (1)

(57) [Claims] 1. An electron gun provided at one end in an envelope, a phosphor screen provided at the other end facing the electron gun, and a frame provided near the phosphor screen. A color picture tube comprising: a shadow mask having a large number of apertures provided therein; and an inner shield attached to the shadow mask, wherein at least one of the frame, the shadow mask, and the inner shield has a pipe part of 25 to 45. weight%
Ni, 0.005 to 0.2% by weight of Si, 0.001%
２2% by weight of Co, 0.001-2% by weight of Cr,
An alloy containing 2% by weight or less of C and the balance substantially consisting of Fe is coated with an oxide film, and a concentrated layer of Cr and Si is formed at an interface between the alloy and the oxide film. and wherein the oxide film is located on the outermost surface
a first layer of α-Fe ₂ O ₃ , between the first layer and the enriched layer
Layer composed of an oxide containing Ni and Fe located at
And a color picture tube.