JP2003059419A - Color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cathode-ray tube capable of preventing generation of wrinkles of a color selecting electrode in heat treatment by regulating the Ni content of the color selecting electrode and a frame. SOLUTION: The color selecting electrode 6 forms a large number of opening holes 15 between a pair of supports 11a and 11b, and has a color selecting electrode body structure tensioned and held in a state of impressing tensile force in the Y direction. A material of the supports 11a and 11b and the color selecting electrode 6 is an Ni-Fe alloy. When the Ni content (%) of the supports 11a and 11b is X and the Ni content (%) of the color selecting electrode 6 is Y, the relationship of Y>(6X+34)/7 is satisfied. Thus, tension at tensioning time can be reduced, weight of the color selecting electrode body structure can be reduced, and generation of the wrinkles of the color selecting electrode by high temperature heat treatment can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube used for a display device such as a computer monitor and a television set.

[0002]

2. Description of the Related Art In recent years, in a color cathode ray tube, flattening of a panel has been promoted because it has the advantages that the range of reflected external light can be reduced and image distortion can be prevented. Along with this, the color selection electrode (shadow mask) that plays a role of color selection for the three electron beams emitted from the electron gun also needs to be held in a state close to a plane.

In this case, during the operation of the cathode ray tube, the aperture of the color selection electrode is displaced by thermal expansion due to the bombardment of the electron beam, and the electron beam passing through the aperture does not hit the predetermined phosphor correctly. However, a doming phenomenon occurs in which color unevenness occurs. For this reason, a tensile force capable of absorbing thermal expansion due to a temperature rise of the color selection electrode is applied in advance to stretch and hold the color selection electrode on the support. According to such stretching and holding, even if the temperature of the color selection electrode rises, it is possible to reduce the misalignment between the aperture of the color selection electrode and the phosphor stripe on the phosphor screen surface.

For the stretching and holding, a one-dimensional stretching method in which a plate-shaped color selection electrode having a plurality of apertures is applied and held in tension in one direction, or a two-dimensional stretching method in which tension is applied and held in two directions. There is a dimension extension system. There is also an aperture grill system in which a color selection electrode formed of a plurality of metal strips is applied with tension in one direction along the longitudinal direction of the metal strips and held. In either method, an iron material is generally used as a material for the color selection electrode, but if a material containing nickel (Ni) and having a small thermal expansion coefficient is used, a shadow mask during operation of the cathode ray tube is used. The thermal expansion of can be suppressed.

Among the above-mentioned stretching methods, the one-dimensional stretching method has the advantages that the tension distribution of the color selection electrodes is easy to manage, the color selection electrodes are easy to handle, and they are resistant to vibrations due to impacts. is doing. As an example of the technique of such a one-dimensional extension system, Japanese Patent Laid-Open No. 8-77936 discloses
A technique has been proposed in which a color selection electrode having slot-shaped openings is welded to a frame in a state where tension is applied in the vertical direction (the vertical direction of the screen).

[0006]

However, the above-described conventional tension holding has the following problems. Until the completion of the color picture tube, as a high temperature manufacturing step after the color selection electrodes are stretched and held, for example, a frit sealing step (44) for sealing the panel and the funnel.
0-470 ° C).

In such a high temperature heat treatment process, due to thermal expansion of the frame to which the color selection electrode is attached,
The color selection electrode is stretched excessively, causing plastic deformation,
A thermal creep phenomenon in which plastic deformation progresses also occurs. Due to such plastic deformation, the initial tensile force decreases,
During operation of the cathode ray tube, there is a problem that the effect of reducing the mutual positional deviation between the aperture of the color selection electrode and the phosphor stripe on the phosphor screen surface cannot be sufficiently exerted.

Further, as described above, when a material containing Ni and having a small coefficient of thermal expansion is used for the color selection electrode and the frame for fixing the same, wrinkles are generated in the color selection electrode when the temperature is returned to room temperature. It will be easier. When wrinkles occur on the color selection electrode, the positions of the apertures of the color selection electrode are also displaced, which causes mislanding of the electron beam, which causes color misregistration, color unevenness, and brightness reduction. There was a problem.

The above-mentioned problem of reduction in tensile force can be solved by applying a sufficient tensile force in advance, but it is not possible to reduce wrinkles, and wrinkles of Ni-containing material are used. The occurrence was one of the causes of the decrease in the yield of the color selection electrode structure.

The present invention is to solve the above-mentioned conventional problems, and by defining the Ni content of the color selection electrode and the frame for fixing the same, the wrinkles of the color selection electrode in the heat treatment are eliminated. It is an object of the present invention to provide a cathode ray tube which is prevented from occurring.

[0011]

In order to achieve the above object, the first color cathode ray tube of the present invention comprises a color selection electrode having a large number of openings between a pair of opposing supports. A color selection electrode assembly is stretched and held in a state in which a tensile force is applied in at least one direction, and the material of the support and the color selection electrode is a Ni-Fe alloy, and the N of the support is N.
When the i content (%) is X and the Ni content (%) of the color selection electrode is Y, the relationship of Y> (6X + 34) / 7 is satisfied.

Next, the second color cathode ray tube of the present invention is
A color selection electrode having a large number of apertures formed between a pair of opposing supports is provided with a color selection electrode structure that is stretched and held in a state in which a tensile force is applied in at least one direction. And the material of the color selection electrode is a Ni-Fe alloy,
When the Ni content (%) of the support is X and the Ni content (%) of the color selection electrode is Y, the relationship of 35.6 ≦ X ≦ 36.2 35.9 ≦ Y ≦ 36.5 is satisfied. Characterized by satisfaction.

According to the first and second cathode ray tubes, by using the Ni--Fe alloy having a small coefficient of thermal expansion,
The tension at the time of stretching can be reduced and the weight of the color selection electrode structure can be reduced, and by setting the Ni content within the range satisfying the above relational expression, the wrinkle of the color selection electrode due to the high temperature heat treatment can be reduced. Occurrence can be prevented.

[0014]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a sectional view of a color cathode ray tube according to an embodiment of the present invention. The color cathode-ray tube 1 shown in this figure has a substantially rectangular face panel 2 having a phosphor screen surface 2b formed on the inner surface thereof, and a funnel 3 connected to the rear of the face panel 2 to form an envelope. Has been formed. An electron gun 4 that emits three electron beams is built in the neck portion 3 a of the funnel 3, and the electron beam emitted from the electron gun 4 is generated by a deflection yoke 5 arranged on the outer peripheral surface of the funnel 3. , Is deflected and reaches the screen surface 2b.

Inside the face panel 2, a color selection electrode (shadow mask) 6 provided so as to face the phosphor screen surface 2b is arranged. The color selection electrode 6 plays a role of color selection for the three electron beams emitted from the electron gun 4. A indicates the electron beam trajectory. In the color selection electrode 6 according to this embodiment, a large number of substantially slot-shaped apertures, which are electron beam passage apertures, are formed in a flat plate by etching. Further, the color selection electrode 6 is fixed to the frame 7 which is a support, and the color selection electrode 6 and the frame 7 form a color selection electrode structure. The color selection electrode structure is hooked on panel pins 9 of the face panel 2 by spring members 8 provided on the frame 7.

In a color cathode ray tube, due to thermal expansion caused by electron beam bombardment, the aperture is displaced, and the electron beam passing through the aperture does not correctly strike a predetermined phosphor, resulting in color unevenness, which is a doming phenomenon. Occurs. For this reason, a tensile force capable of absorbing thermal expansion due to a temperature rise of the color selection electrode 6 is applied in advance to stretch and hold the color selection electrode 6 on the frame 7. According to such stretching and holding, even if the temperature of the color selection electrode 6 rises, it is possible to reduce the misalignment between the aperture of the color selection electrode 6 and the phosphor stripe on the phosphor screen surface 2b. You can

FIG. 2 shows a perspective view of a color selection electrode assembly according to an embodiment of the present invention. Between the pair of opposing long side frames 11a and 11b which are the supports of the color selection electrode 6, the short side frames 12a and 12 which are a pair of elastic members.
b is fixed. The color selection electrode 6 is the long side frame 1
It is joined to the upper surfaces of 1a and 11b by welding. An opening 15 which is an electron beam passage hole is formed in the color selection electrode 6 by etching. In the present embodiment, in order to prevent the above-mentioned doming phenomenon, a one-dimensional stretching method is used, and the color selection electrode 6 is mainly applied with a tensile force in the arrow Y direction (vertical direction of the screen). In this state, it is stretched and held between the supports 11a and 11b.

FIG. 3 shows a perspective view of the long side frame 11a. The state shown in this figure corresponds to the state after the press molding step and the degreasing step of the frame shown in FIG. The long side frame 11a is formed by bending a press-punched material having a plate thickness of 1.4 to 1.8 mm. In this embodiment, a 36% Ni—Fe alloy (hereinafter referred to as “36Ni”) is used as the material. In addition, the number before the element symbol indicates the weight% of the component. In addition, in order to increase rigidity and ensure a predetermined strength, it has a bent portion whose cross-sectional shape is triangular, and as shown by 11c, the end portion of the bent portion extends in the longitudinal direction. Are welded along.

FIG. 4 shows a perspective view of the short side frame 12a. The state shown in this figure corresponds to the state after the press molding step and the degreasing step of the frame shown in FIG. The short-side frame 12a is formed by bending a press-punched material having a plate thickness of 1.4 to 1.8 mm, similarly to the long-side frame 11a. Reference numeral 13 is a mounting plate for the spring member 8 shown in FIG. In this embodiment, 42% Ni-Fe alloy is used as the material of the short side frame 12a. In addition, the number before the element symbol indicates the weight% of the component. In this embodiment, since the Ni-Fe alloy having a small thermal expansion coefficient is used for the material of the color selection electrode and the frame, the thermal expansion of the shadow mask during the operation of the cathode ray tube can be suppressed. Therefore, the tension at the time of stretching can also be reduced, and the weight of the color selection electrode structure can be reduced.

FIG. 5 is a perspective view showing the long side frames 11a and 11b joined to the short side frames 12a and 12b. The state shown in this figure corresponds to the state after the assembly and welding process of the frame shown in FIG. On the upper surfaces of the short side frames 12a and 12b, which are a pair of elastic members,
The pair of long side frames 11a and 11b facing each other are joined and integrated by welding.

The integrated frame-shaped structure is heat-treated at a temperature of 550 ° C. or higher for 15 minutes in order to remove work strain during welding. This heat treatment corresponds to the blackening heat treatment step of the frame in FIG. This heat treatment may be performed by a method in which the atmosphere gas dew point of CO or CO ₂ is around 40 ° C. Also, the color selection electrode before being integrated with the frame is 36 Ni
In order to prevent the shrinkage due to the heat of heat and to increase the thermal emissivity, CO, CO
Heat treatment is performed in advance in the atmosphere gas dew point of about ₂ ° C. of 40 ° C. This step corresponds to the blackening heat treatment step of the flat plate in FIG.

After passing through such a pre-stage treatment, the process proceeds to the stretching step shown in FIG. 6 and the color selection electrodes are stretched and held on the frame. In this case, if the tension of the color selection electrodes is set to be uniform, when a color cathode ray tube is installed in a television set, for example, a phenomenon in which vibration from a speaker vibrates the color selection electrodes causes There is a case where the color shift phenomenon occurs as a result of selecting another color without hitting the regular position.

Therefore, the tension applied to the color selection electrode is 100% at the central tension and 90% to 6% at the peripheral tension.
It is preferably in the range of 5%. In this case, by attaching a damper for preventing vibration to the non-hole portion of the color selection electrode (damper mounting step in FIG. 6), vibration of the color selection electrode can be suppressed and color misregistration can be prevented.

As an example of the damper, a frame-shaped body obtained by bending a rod-shaped body can be used. By inserting the frame-shaped body into a hole formed in the color selection electrode and attaching it, the frame-shaped body and the color selection electrode can be attached. Vibration between the color selection electrodes can be absorbed by sliding between the color selection electrodes.

Next, as shown in FIG. 6, the spring member 8 is attached to the four-corner mounting plate 13 (FIG. 2) of the color selection electrode.
After the step of welding (SP welding step), the heat treatment step is performed. This heat treatment step includes a glass frit step and a heat treatment step before the glass frit step. In the glass frit process, the panel and the funnel are heat-treated and bonded under the conditions of 450 ° C. and about 20 minutes.

During this heat treatment, a tensile force is further applied to the color selection electrodes due to the thermal expansion of the frame. Therefore, the initially set tensile force is reduced to about 50% due to the plastic deformation of the color selection electrode due to the thermal creep phenomenon. When the tensile force is reduced in this way, the position of the aperture of the color selection electrode and the position of the phosphor are displaced, the electron beam does not hit the proper position, and this causes color unevenness.

In order to prevent such a decrease in tensile force, there is a method of applying a sufficient tensile force in advance, but in this case, in order to secure the strength of the frame, the weight of the frame increases. . As another method, there is a method in which after mounting the damper, heat treatment is performed in advance under the same conditions as the frit conditions. This is the heat treatment process before the glass frit process. According to the experiment, the thermal creep phenomenon was reduced in the second heat treatment (glass frit process), and it was possible to secure a tensile force at a level where there was no practical problem.

On the other hand, since the coefficient of thermal expansion differs depending on the Ni content, the heat treatment is performed on the color selection electrode and the color selection electrode assembly in which the Ni content of the long side frame connecting the color selection electrode is changed. An experiment (heat treatment temperature 450 ° C., time 40 minutes) was performed. As a result of repeating such an experiment, it was found that there is a difference in the generation of wrinkles depending on the combination of the Ni content of the color selection electrode and the frame. The following Table 1 shows samples of the color selection electrode and a plurality of color selection electrodes (Sample N in which the Ni content of the long side frame is changed).
o. 1-18) was produced and the wrinkle generation state was confirmed. The coefficient of thermal expansion in the table is at 450 ° C.

[0029]

[Table 1]

FIG. 7 shows the distribution state of each sample in Table 1. FIG. 7 shows the data of each sample with the horizontal axis as X in Table 1 (Ni content (%) in the long side frame) and the vertical axis as Y in Table 1 (Ni content (%) in the color selection electrode). It is a plot. In FIG. 7, black circles indicate samples whose wrinkle evaluation in Table 1 was ◯, and x indicates wrinkle evaluation in Table 1.
Shows a sample that was. In addition, when the wrinkle evaluation is ◯, the unevenness of the surface of the color selection electrode is within 10 μm, and when the wrinkle evaluation is x, the unevenness exceeds 10 μm.

Considering that the distribution shown in FIG. 7 is divided into a range where wrinkles are generated and a range where wrinkles are not generated, the distribution shown in FIG. It can be divided. That is, the range above the straight line 20 is a range in which no wrinkles are generated, and the range below the straight line 20 is a range in which wrinkles are generated. Straight line 20
In the (X, Y) coordinates are (35.4, 35.
2), and a straight line passing through (36.8, 36.4),
It is represented by the following formula (1).

Equation (1) Y = (6X + 34) / 7 Therefore, when the Ni content (%) of the long side frame is X and the Ni content (%) of the color selection electrode is Y, the following equation (2) If (X, Y) is selected so as to satisfy (1), wrinkles can be prevented.

Formula (2) Y> (6X + 34) / 7 Further, the samples indicated by black circles with a wrinkle evaluation of ◯ are:
In particular, it is distributed within the quadrangle 21 of FIG. 7, and (X, Y) may be selected within the quadrangle 21 in order to prevent the occurrence of wrinkles. In the quadrangle 21, seven samples (Sample No. 4-7
9-11) are included. Specifically, assuming that the Ni content (%) of the long side frame is X and the Ni content (%) of the color selection electrode is Y, the ranges satisfy the following formulas (3) and (4). Formula (3) 35.6 ≦ X ≦ 36.2 Formula (4) 35.9 ≦ Y ≦ 36.5 That is, according to the present embodiment, the color selection electrode and the frame material are made of Ni having a small thermal expansion coefficient. By using the —Fe alloy, the tension at the time of stretching can be reduced, the weight of the color selection electrode assembly can be reduced, and the Ni content can be in the range satisfying the relationship of the formula (1) or the formula (2). By setting the range to satisfy the relationship of (3) and (3), it is possible to prevent the generation of wrinkles of the color selection electrode due to the high temperature heat treatment.

As described above, in the present embodiment, the Ni content in the long-side frame, not in the short-side frame, is defined as follows.
This is because the color selection electrode is stretched over the long side frame, and the long side frame greatly contributes to the generation of wrinkles in the color selection electrode.

[0035]

As described above, according to the present invention, a cathode ray tube having no wrinkles in the color selection electrode can be obtained by defining the Ni content of the color selection electrode and the support for joining the same. .

[Brief description of drawings]

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

FIG. 2 is a perspective view of a color selection electrode assembly according to an embodiment of the present invention.

FIG. 3 is a perspective view of a long side frame according to an embodiment of the present invention.

FIG. 4 is a perspective view of a short side frame according to an embodiment of the present invention.

FIG. 5 is a perspective view of a frame assembly according to an embodiment of the present invention.

FIG. 6 is a flowchart of an example of a method of manufacturing a color cathode ray tube according to an embodiment of the present invention.

FIG. 7 is a diagram showing a distribution of samples in which the Ni content of the color selection electrode and the long side frame is changed.

[Explanation of symbols]

1 color cathode ray tube 2 face panel 3 funnel 6-color selection electrode 7 frames 8 Spring material 11a, 11b long side frame 12a, 12b Short side frame 13 Mounting plate

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Claims (2)

[Claims] 1. A color selection electrode structure in which a color selection electrode having a large number of apertures formed between a pair of opposing supports is stretched and held in a state in which a tensile force is applied in at least one direction. The material of the support and the color selection electrode is Ni-F.
and an Ni content (%) of the support is Y and a Ni content (%) of the color selection electrode is Y, the relationship of Y> (6X + 34) / 7 is satisfied. Color cathode ray tube. 2. A color selection electrode structure in which a color selection electrode having a large number of openings formed between a pair of opposing supports is stretched and held in a state in which a tensile force is applied in at least one direction. The material of the support and the color selection electrode is Ni-F.
35.6 ≦ X ≦ 36.2 35.9 ≦ Y ≦ 36, where X is the Ni content (%) of the support and Y is the Ni content (%) of the color selection electrode. A color cathode ray tube characterized by satisfying the relationship of 0.5.