JPH07122202A - Image receiving tube - Google Patents

Abstract

PURPOSE:To prevent the degradation of color pureness such as chromatic misconvergence, unevenness, etc., for a long period of time from the initial stage of operation. CONSTITUTION:A control electrode 3b, shadow mask 7, frame 8, supporting spring 9, magnetic shield 11, and/or contact spring 12 contain chiefly Fe including 25-45wt.% Ni. A striped surface unevenness is formed at the surface of a material consisting of an alloy containing 0.3-5wt.% through such element(s) solely or compositely as Cr, Ti, V, Mn, Al, Si, Ca, Mg which have a stronger bonding force with O than Fe with an ambient temperature of 0-600 deg.C. The surface roughness Ra of this surface unevenness part is put in a range between 0.2-0.4mum in the direction along the stripe and also within a range between 0.6-0.8mum in the direction right across the stripe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a picture tube used in monochrome and color televisions.

[0002]

2. Description of the Related Art Conventionally, in a color picture tube, internal members such as a cathode, a control electrode and a shadow mask are provided inside the tube, and an electron beam is passed through a beam opening hole of the shadow mask so as to be projected onto a fluorescent surface. , To form a color image.

However, during operation, the temperature of the tube inner member rises to 30 to 100 ° C. As a result, CO emitted from the tube inner member adheres to the cathode and the number of electrons decreases, and in the shadow mask, heat is generated. Due to the occurrence of doming due to the distortion, the relative positional relationship between the beam opening hole of the shadow mask and the fluorescent surface is deviated, and a color misregistration called “purity drift” (hereinafter referred to as PD) is generated. Further, since the shadow mask is attached and detached several times before the completion of the picture tube, the color shift of the PD occurs due to mechanical deformation.

Therefore, conventionally, for example, in a shadow mask which is one of the members in the tube, in order to reduce doming,
In order to improve mechanical strength by using an amber alloy having a small coefficient of thermal expansion made of a Ni alloy containing Fe as a main component,
The amber alloy contains Cr, Ti and the like. Further, as shown in FIG. 5, the surface of the shadow mask 15 is isotropic (for example, satin finish) in order to reduce the etching rate and improve the accuracy of the beam opening hole shape by etching.
The surface roughness Ra is finished in the range of 0.4 to 0.6 μm.

[0005]

However, in such a conventional picture tube, since the material inside the tube contains Ni, which has a weaker binding force to O than Fe, the oxidation resistance is improved and the thermal radiation is improved. The rate becomes low and the amount of CO gas released from the pipe inner member increases. As a result, there is a problem that the life of the picture tube is shortened.

The present invention provides a picture tube which takes advantage of Ni, which has a small coefficient of thermal expansion, enhances the thermal emissivity, and reduces the amount of CO gas released, and can obtain a high quality image with a long life. To do.

[0007]

The picture tube of the present invention is made of Ni
Is contained in an amount of 25 to 45% by weight of Fe as a main component, and the surface of a material made of an alloy containing 0.3 to 5% by weight of an element having a stronger bonding force with O than Fe at an atmospheric temperature of 0 to 600 ° C. It is provided with a pipe inner member having a concave and convex portion.

[0008]

With this structure, the emission of CO gas from the pipe inner member is reduced, and the thermal emissivity of the pipe inner member is increased.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 to 3 show a color picture tube which is an embodiment of the present invention. As shown in FIGS. 1 and 2, an electron gun 3 having a cathode 3a in an in-line arrangement and a control electrode 3b for adjusting the number of electrons from the cathode 3a is provided on a neck portion 2 which constitutes one end of a glass bulb 1. The face 5 facing the electron gun 3 is provided with a fluorescent surface 6 in which red, blue, and green fluorescent bodies are arranged in sections, and a shadow having a large number of beam apertures close to the fluorescent surface 6. A mask 7 is arranged so as to face the fluorescent surface 6.
The shadow mask 7 includes a panel pin 1 fixed to the glass bulb 1 via a frame 8 and a support spring 9.
It is attached to 0. A magnetic shield 11 and a contact spring 12 are attached to the frame 8.

In this color picture tube, the electron beam 13 adjusted by the control electrode 3b is deflected by the deflector 1.
The shadow mask 7 is deflected by the deflection control
The light beam passes through the beam aperture of the above and strikes the fluorescent surface 6 to form a color image.

As the shadow mask 7 in the color picture tube shown in FIG. 1, Cr containing 25 to 45% by weight of Ni as a main component and Cr having a stronger bonding force with O than Fe at an ambient temperature of 0 to 600 ° C., Ti, V, Mn, Al, S
As shown in FIG. 3, streak-shaped uneven portions are formed on the surface of a material made of an alloy containing 0.3 to 5% by weight of elements consisting of i, Ca, and Mg alone or in combination, and the surface of the uneven portions is formed. The roughness Ra is 0.2 to 0.4 μm in the muscle direction Y.
In the range of 0.6 to 0.8 in the direction X perpendicular to the muscle.
Those in the range of μm were used.

Here, the Ni composition is 25 to 45% by weight.
By setting the above, the thermal expansion coefficient can be reduced to 9 × 10 ⁻⁶ / ° C. or less, and a high quality image with a low PD value can be obtained.
The reason for setting the range is that if it is less than 25% by weight, the thermal expansion coefficient becomes 1 × 10 ⁻⁵ / ° C. or more, the shadow mask 7 is largely deformed, and the image quality is deteriorated. Further, the composition amount of Ni is 45
When the content exceeds the weight%, the etching rate and the shape of the etching hole of the beam opening hole are remarkably lowered during the production of the shadow mask 7, and the cathode 3
There is a problem that the amount of CO attached to a increases.

Fe at an ambient temperature of 0 to 600 ° C.
Cr, Ti, V, Mn, A, which has a stronger bond with O than
By containing 0.3 to 5% by weight of the element consisting of 1, Si, Ca and Mg alone or in combination, the increase of CO due to the addition of Ni is prevented, and as a result,
In particular, the number of electrons from the cathode 3a is stabilized for a long time, and a stable image without a decrease in brightness can be obtained. The reason for setting the content range of the above elements is that if the amount is less than 0.3% by weight, the amount of CO released is about 3/4, and the amount of CO adhering to the cathode 3a is large, so that a stable image cannot be obtained for a long time. Further, when it exceeds 5% by weight, in the shadow mask 7,
During operation, the amount of thermal expansion becomes large, and a high quality image with a low PD value cannot be obtained. For example, the element is Cr,
When 3 wt% was added, a stable oxide film was formed by heating the heat treatment temperature to 580 ° C, and it was possible to lower the temperature by 40 ° C while it was necessary to heat to 620 ° C conventionally. Time costs can be reduced.

A streaky uneven portion is formed on the surface of the material, and the surface roughness Ra thereof is set in the range of 0.2 to 0.4 μm in the streak direction Y, and 0.6 to 0 in the direction X perpendicular to the streak. By setting the thickness in the range of 0.8 μm, the thermal emissivity can be increased and a high quality image with a low PD value can be obtained. The reason for setting the range is
If the surface roughness Ra is less than 0.2 μm in the streak direction Y and exceeds 0.8 μm in the direction X at right angles to the streak, for example, in the production of the shadow mask 7, the productivity is lowered or the beam aperture shape is distorted. I have a problem Further, when the surface roughness Ra exceeds 0.4 μm in the muscle direction Y and is less than 0.6 μm in the direction X perpendicular to the muscle, the surface condition becomes almost the same as the conventional matte finish (isotropic), There is a problem that the emissivity ε decreases and color shift occurs during operation.

By the way, when the surface condition of the shadow mask 7 is, for example, a conventional satin finish and the surface roughness Ra is in the range of 0.4 to 0.6 μm, the thermal emissivity ε is 0.
2 to 0.4, and the amount of color misregistration during operation (the amount of beam movement is 100% in the prior art) is as shown by the curve A in FIG. On the other hand, under the above conditions of the present invention, the thermal emissivity ε is 0.8 to 0.9, the amount of color misregistration is significantly improved as shown by the curve B in FIG. 4, and the image quality with a low PD value is high. You can get a statue. Further, the etching rate of the beam opening hole of the shadow mask 7 and the shape of the etching hole are not adversely affected.

In the above embodiment, an example in which the above alloy is applied to the shadow mask 7 has been described, but instead of this, the control electrode 3b, the frame 8, the support spring 9, the magnetic shield 11 or the contact spring 1 is used.
2 can be used.

[0018]

As described above, the present invention is mainly composed of Fe containing 25 to 45% by weight of Ni and is an improving element having a stronger bonding force with O than Fe at an atmospheric temperature of 0 to 600 ° C. By including the pipe inner member in which streaky irregularities are formed on the surface of the material made of the alloy containing 0.3 to 5 wt% of CO, the emission of CO gas from the pipe inner member is reduced, and the heat radiation of the pipe inner member is reduced. As a result, it is possible to provide a high-quality picture tube having a high rate and a long life.

[Brief description of drawings]

FIG. 1 is a sectional view of a color picture tube according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view showing an electron gun section of the color picture tube.

FIG. 3 is an enlarged perspective view showing a surface state of a shadow mask of the color picture tube.

FIG. 4 is a diagram showing a comparison of color shift amounts between the same color picture tube and a conventional color picture tube.

FIG. 5 is an enlarged perspective view showing a surface state of a shadow mask of a conventional color picture tube.

[Explanation of symbols]

 3b Control electrode 7 Shadow mask 8 Frame 9 Support spring 11 Magnetic shield 12 Contact spring

Claims (5)

[Claims] 1. An alloy containing, as a main component, Fe containing 25 to 45% by weight of Ni and containing 0.3 to 5% by weight of an element having a stronger bonding force with O than Fe at an atmospheric temperature of 0 to 600 ° C. A picture tube comprising an inner tube member in which streaky irregularities are formed on the surface of the material. 2. The surface roughness Ra of the streaky uneven portion is 0.2.
2. The picture tube according to claim 1, wherein the picture tube is in the range of .about.0.8 .mu.m. 3. The surface roughness Ra of the streaky uneven portion is in the range of 0.2 to 0.4 μm in the streak direction and in the range of 0.6 to 0.8 μm in the direction perpendicular to the streak. The picture tube according to claim 1, characterized in that 4. A shadow mask, a frame,
The picture tube according to claim 1, comprising a support spring, a magnetic shield, a contact spring or a control electrode. 5. The element is Cr, Ti, V, Mn, Al, S.
The picture tube according to claim 1, wherein the picture tube comprises at least one of i, Ca and Mg.