JP3420128B2 - 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.

[0002]

2. Description of the Related Art In a shadow mask type color picture tube, a shadow mask having a large number of pores through which an electron beam passes is arranged to face a fluorescent screen formed on an inner surface of a panel with a predetermined gap. . A mask frame is fixed to the outer periphery of the shadow mask. A frame holder is arranged between the mask frame and the panel.

The electron beam passing through the aperture of the shadow mask is usually about 20% of the electron beam emitted from the electron gun. The remaining 80% of the electron beam collides with the shadow mask and mask frame and is absorbed. When the shadow mask or the mask frame thermally expands due to the collision of the electron beam, the relative positions of the pores of the shadow mask and the dots formed on the fluorescent screen are displaced, and the color purity deteriorates.

Therefore, the shadow mask is generally made of a low thermal expansion alloy such as Fe-Ni alloy. On the other hand, the normal mask frame is made of a general Fe-based material because of its strength and the like. Therefore, an elastically deformable spring material is used in a part of the frame holder so as to absorb the thermal expansion of the mask frame.

In such a structure, since the shadow mask and the mask frame have different thermal expansions when the electron beam collides, the color purity is deteriorated simply by absorbing the thermal expansion of the mask frame by the spring material. . Therefore,
In addition to the spring material, a thermal deformation member that deforms in the direction opposite to the thermal expansion direction of the mask frame is used for a part of the frame holder. A so-called bimetal, in which a high thermal expansion member made of an Fe—Ni—Cr alloy and a low thermal expansion member made of an Fe—Ni alloy are laminated, is usually used as a thermal deformation member that is a part of such a frame holder. It is used.

In a bimetal using a high thermal expansion member made of an Fe-Ni-Cr alloy and a low thermal expansion member made of an Fe-Ni alloy, a high thermal expansion member and a low thermal expansion member are used in accordance with a required thermal deformation rate. The plate thickness ratio of the expansion member is set. In addition, the total plate thickness that can secure the material strength and long-term reliability is set. In bimetals used for color picture tubes, etc., to ensure material strength and long-term reliability,
For example, a total plate thickness of 0.7 mm or more is required.

[0007]

However, the conventional bimetal is an alloy having a high Ni content in both the high thermal expansion member and the low thermal expansion member, that is, Fe-Ni-C.
Since the r-based alloy and the Fe-Ni-based alloy are used, there is a problem that the manufacturing cost is high. In order to reduce the manufacturing cost of such a bimetal, it is conceivable to reduce the plate thickness of both the high thermal expansion member and the low thermal expansion member. However, if the total plate thickness of the bimetal is reduced, the strength and long-term reliability as a heat deformable member for a color picture tube will be impaired. Furthermore, Fe-Ni-C
Both r-based alloys and Fe-Ni-based alloys have a problem that they are inferior in workability to general Fe-based materials such as steel materials.

[0008] Incidentally, in Japanese Patent Laid-Open No. 7-234292, Fe-
A bimetal using a high thermal expansion member made of a Ni-Cr alloy and a low thermal expansion member made of an Fe-Ni alloy, Ni, Ni alloy, Zr-C for the purpose of adjusting electric resistance.
It is described that an u alloy is interposed as an intermediate layer. Further, Japanese Patent Application Laid-Open No. 3-13889 describes a clad material having an intermediate member made of Cu, Ni or an alloy thereof, which is different in high thermal expansion member. Further, Japanese Patent Application Laid-Open No. 47-13209 discloses a laminated thermostatic oven material using a Mo-Cu-Ni-based alloy for the high thermal expansion member because it has a different application from the bimetal used for the color picture tube described above. ing. According to this publication, in an assembled thermostatic chamber material having a bimetal structure, various iron alloys can be used as an intermediate layer within a range that the cost is lower than that of the outer layer and resistance and flexibility of the assembled material are not inappropriate. Is described.

As described above, a bimetal structure having a middle layer for the purpose of adjusting electric resistance and a bimetal structure thermostatic oven material having a low-cost iron alloy as a middle layer have already been proposed. However, a heat-deformable member used for a color picture tube has not yet been found that has an appropriate curvature coefficient required for them and enables cost reduction.

The present invention has been made in order to address such a problem, and it does not impair strength and long-term reliability.
It is an object of the present invention to provide a color picture tube in which the manufacturing cost is reduced and the workability is improved by using a heat-deformable member for an electron tube, thereby improving color purity and reliability and reducing the manufacturing cost.

[0011]

[0012]

As described in claim 1, a color picture tube of the present invention comprises an electron gun for irradiating an electron beam and a fluorescent screen on which the electron beam emitted from the electron gun collides. It is made of an Fe-Ni-based alloy having a panel and a large number of pores or slits which are arranged to face the fluorescent screen with a predetermined gap and allow an electron beam to pass therethrough.
A shadow mask, a mask frame fixed to the shadow mask, a heat deformation part and an elastic part, and one end fixed to the panel and the other end fixed to the mask frame. In the color picture tube including, the thermal deformation portion of the frame holder,
A high thermal expansion member made of an Fe-Ni-Cr alloy, and Fe
-A low thermal expansion member made of a Ni-based alloy, and Fe and A interposed between the high thermal expansion member and the low thermal expansion member.
an intermediate member made of one kind of metal selected from 1 or an alloy based on the metal, the high thermal expansion member, the intermediate member and the low thermal expansion member are laminated,
And the plate thickness ratio of the high thermal expansion member and the low thermal expansion member is
Within the range of 55:45 to 45:55, the plate thickness of the intermediate member is within 80% (excluding 30% or less) of the total plate thickness of the high thermal expansion member, the intermediate member and the low thermal expansion member. It is characterized by comprising a heat deformable member for an electron tube.

In the heat deformable member for an electron tube used in the heat deformable portion of the frame holder according to the present invention, the intermediate member has a coefficient of thermal expansion intermediate between that of the high thermal expansion member and that of the low thermal expansion member.
The amount of thermal deformation as the thermal deformation member can be determined by the thermal expansion coefficient of the high thermal expansion member and the low thermal expansion member and the plate thickness ratio thereof. Therefore, by adopting a material that is low in cost and excellent in workability as the intermediate member, it is possible to obtain a desired degree of thermal deformation and to secure a total plate thickness that affects strength and long-term reliability. In addition, the plate thicknesses of the high thermal expansion member and the low thermal expansion member can be reduced by the plate thickness of the intermediate member. As a result, the manufacturing cost of the heat deformable member for an electron tube as a whole can be reduced, and the workability can be further improved.

In the color picture tube of the present invention, the heat-deformable portion of the frame holder is constituted by the heat-deformable member for an electron tube as described above. Therefore, even when thermal expansion occurs in the shadow mask or the mask frame, after preventing the deterioration of the color purity due to the displacement of the relative positions of the phosphor screen formed in the panel and the pores or slits of the shadow mask, It is possible to reduce the manufacturing cost.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Modes for carrying out the present invention will be described below.

FIG. 1 is a perspective view showing an embodiment of a heat deformable member for an electron tube used in a frame holder of a color picture tube of the present invention. The electron tube thermal deformation member 1 shown in FIG. 1 has a first member and a second member, that is, a high thermal expansion member 2 and a low thermal expansion member 3, which contribute to basic performance of thermal deformation such as thermal bending. is doing. Here, the high thermal expansion member 2 and the low thermal expansion member 3 may have different thermal expansion coefficients,
It is not limited to these absolute values of the coefficient of thermal expansion.

For the high thermal expansion member 2 and the low thermal expansion member 3 ,
, Since the large Kinanetsu curvature (curvature factor) is obtained,
The high thermal expansion member 2 with use of the Fe-Ni-Cr alloy, the low thermal expansion member 3 Ru with Fe-Ni based alloy. The thickness ratio of the high thermal expansion member 2 (thickness t ₁₎ and the low thermal expansion member 3 (plate thickness _{t 2) (t 1: t} 2) is set according to the thermal bending rate of interest. For example, in the thermal deformation member (bimetal) 1 for a color picture tube using the alloy as described above, the plate thickness ratio t
_1: t ₂ is 55: 45-45: set in the range of 55.

Fe-Ni- used as the high thermal expansion member 2
As a Cr-based alloy, 15 to 30 wt% Ni and 2 to 10 wt%
Examples of the alloy include Cr, and the balance is substantially Fe. If the added amounts of Ni and Cr are out of the above range, the coefficient of thermal expansion will decrease in any case.
The Fe-Ni alloy used as the low thermal expansion member 3 contains 30 to 50% by weight of Ni, and the balance is substantially F.
An example is an alloy composed of e. Even if the Ni content is less than 30% by weight or more than 50% by weight, the coefficient of thermal expansion increases in both cases. In other words, the Ni content is 30
In the range of up to 50% by weight, good low thermal expansion can be obtained.

The high thermal expansion member 2 and the low thermal expansion member 3 described above
Is between the coefficient of thermal expansion α ₁ of the high thermal expansion member ₂ and the coefficient of thermal expansion α ₂ of the low thermal expansion member 3 α ₃ (α ₁ >).
The intermediate member 4 having α ₃ > α ₂ ) is interposed. The thermal deformation member 1 for an electron tube is configured by laminating and pasting these layers 2, 3 and 4. Thermal deformation member 1 for electron tube is a clad material with a three-layer structure (three-layer laminated material)
Can be called a bimetal. A general clad method can be applied to the bonding between the layers 2, 3, and 4. Specifically, the layers 2, 3, and 4 are bonded together by, for example, hot rolling.

The plate thickness t ₃ of the intermediate member 4 can be appropriately set basically within the range of the total plate thickness T required for strength and long-term reliability of the electron tube thermal deformation member 1. However, in practical use, the thermal deformation of the high thermal expansion member 2 and the low thermal expansion member 3, especially the thermal deformation of the high thermal expansion member 2, may be constrained by the intermediate member 4 and the thermal curvature may decrease, so that The plate thickness t ₃ is within 80% of the total plate thickness T (including 30% or less
No)) . This also depends on the constituent materials of the layers 2, 3, and 4. Further, when the coefficient of thermal expansion α ₃ of the intermediate member 4 is closer to either of the coefficients of thermal expansion α ₁ and α ₂ of the high thermal expansion member 2 and the low thermal expansion member 3, the member (2
Alternatively, the plate thickness of 3) may be reduced to set the thermal bending rate of the electron tube thermal deformation member 1 to a desired value.

The specific material of the intermediate member 4 may be appropriately selected depending on the materials of the high thermal expansion member 2 and the low thermal expansion member 3. For example, as the high thermal expansion member 2, Fe-Ni-C
Fe-Ni is used as the low thermal expansion member 3 using an r-based alloy.
When using a system alloy, with less expensive than these alloys excellent in workability, it is preferable to use one kind of metal selected either et Fe and Al, or an alloy containing these metals as the intermediate member 4. In the present invention , Fe, Al, or an alloy based on these metals is used as the constituent material of the intermediate member 4 from the viewpoints of thermal bending characteristics and workability. In particular,
Steel materials that are effective in reducing manufacturing costs can be said to be desirable materials. As the steel material used for the intermediate member 4,
A steel material SS 400 (SS 400 defined in JIS G 3101) in which C is 0.3% by weight or less, P is 0.05% by weight or less, S is 0.05% by weight or less, and the balance is Fe and inevitable impurities is mentioned.

Here, the intermediate member 4 is the high thermal expansion member 2 (α
₁ ) and the low thermal expansion member 3 (α ₂ ) have an intermediate thermal expansion coefficient α ₃ , the thermal bending coefficient of the electron tube thermal deformation member 1 is the same as that of the high thermal expansion member 2 and the low thermal expansion member 3. α ₁ , α
₂ and their plate thickness ratio (t ₁ : t ₂ ). Therefore, for example, the conventional bimetal 5 shown in FIG.
Of the high thermal expansion member 2 and the low thermal expansion member 3 (t ₁ ′:
t ₂ ′) and the heat deformable member 1 for an electron tube according to this embodiment.
Of the high thermal expansion member 2 and the low thermal expansion member 3 of the plate thickness ratio (t ₁ : t
_{If 2} ) are equal, almost the same thermal curvature can be obtained.

[0023] At this time, in the conventional bimetal 5 shown in FIG. 2, it is necessary to secure 'the thickness t ₁ of the high thermal expansion member 2' SoitaAtsu T sheet thickness t ₂ 'of the low thermal expansion member 3. On the other hand, in the heat deformable member 1 for an electron tube of the present invention shown in FIG. 1, the plate thicknesses t ₁ and t ₂ of the high thermal expansion member 2 and the low thermal expansion member 3 can be reduced by the plate thickness t ₃ of the intermediate member 4. . Even if these plate thicknesses are reduced, as described above, the heat deformable member 1 for an electron tube used in the present invention has a thermal bending rate substantially equal to that of the conventional bimetal 5. In other words, the plate thicknesses t ₁ and t ₂ of the high thermal expansion member 2 and the low thermal expansion member 3 are reduced, and a thermal bending rate almost equal to that of the conventional bimetal 5 is obtained, which is necessary for strength and long-term reliability. Total plate thickness T
Can be secured.

Table 1 shows the bending coefficients of some specific examples of the heat deformable member 1 for an electron tube described above. Each of these specific examples
High thermal expansion member 2 Fe-22 wt% Ni-4.5 wt%
A Cr alloy is used and Fe- is used as the low thermal expansion member 3.
36 wt% Ni alloy was used. As the intermediate member 4, a steel material SS 400 having various plate thicknesses was used. The plate thickness ratio between the high thermal expansion member 2 and the low thermal expansion member 3 was 1: 1 and the total plate thickness T of the electron tube thermal deformation member 1 was 2.5 mm. The comparative example of Table 1 is shown in FIG.
It is the conventional bimetal 5 (bimetal for color picture tube) shown in FIG. High thermal expansion member 2 and low thermal expansion member 3 of Comparative Example
The constituent materials, the plate thickness ratios thereof, and the total plate thickness T ′ were the same as those in the above-mentioned embodiment.

[0025]

[Table 1]

As is clear from Table 1, in each of the examples, the larger the composition ratio of the intermediate member 4 made of the steel material SS 400, the lower the bending coefficient. However, in the electron-tube heat-deformable member 1 having the above structure, it can be seen that the intermediate member 4 having a plate thickness composition ratio of about 60% can be sufficiently used as a bimetal for a color picture tube. Fe-22 wt% Ni-4.
Compared to 5 wt% Cr alloy and Fe-36 wt% Ni alloy,
The cost of steel is about 1/4. Therefore, as compared with the conventional bimetal 5, the thermal deformation member 1 for an electron tube of each embodiment can reduce the manufacturing cost by about 30 to 40% as a whole. Further, the steel material is excellent in workability as compared with the Fe-22 wt% Ni-4.5 wt% Cr alloy and the Fe-36 wt% Ni alloy. Therefore, according to the heat deformable member 1 for an electron tube of each embodiment, it is possible to improve the workability as compared with the conventional bimetal 5.

As described above, in the heat deformable member 1 for an electron tube of this embodiment, the total plate thickness T that affects the desired thermal curvature and strength and long-term reliability is set to the high thermal expansion member 2 and the low thermal expansion. It can be obtained after reducing the plate thicknesses t ₁ and t ₂ of the member 3. Therefore, as the high thermal expansion member 2 and the low thermal expansion member 3, the manufacturing cost is high and the workability is inferior.
When using an e-Ni-Cr-based alloy or an Fe-Ni-based alloy, by arranging the intermediate member 4 which is lower in cost and excellent in workability, the desired thermal bending rate is obtained, and then the electron It is possible to reduce the manufacturing cost of the thermal deformation member for a pipe 1 as a whole and improve the workability.

Next, an embodiment of the color picture tube of the present invention will be described with reference to FIGS. 3 and 4.

FIG. 3 is a sectional view showing the structure of the main part of a color picture tube according to an embodiment of the present invention. In the figure,
Reference numeral 11 denotes a panel having a phosphor screen (not shown) formed on the inner surface. Panel pins 12 are installed on the inner peripheral surface of the panel 11 near the opening. A shadow mask 13 is arranged inside the panel 11 so as to face the fluorescent screen formed on the inner surface of the panel 11 with a predetermined gap.

A large number of pores or slits (not shown) are formed in the shadow mask 13, and the electron beam passing through these pores or slits is configured to collide with the phosphor screen. The electron beam is emitted from an electron gun (not shown). The electron gun is placed in a neck (not shown) connected to the panel 11 via a funnel (not shown).

The shadow mask 13 is formed of a low thermal expansion alloy such as Fe-Ni alloy. A mask frame 14 made of an Fe-based material such as steel is fixed to the outer peripheral edge of the shadow mask 13. Mask frame 14
The frame holder 15 has one end fixed thereto, and the other end of the frame holder 15 is engaged and fixed to the panel pin 12. In this way, the shadow mask 13 is elastically held by the panel 11 via the frame holder 15.

The frame holder 15 described above has an elastic portion 15a made of, for example, a stainless spring material, and a thermal deformation portion 15b made of the thermal deformation member 1 for an electron tube described in the above embodiment. The elastic portion 15a is arranged on the panel 11 side and has a spring property (elasticity) that absorbs the shadow mask 13 and the mask frame 14 when they are thermally expanded. On the other hand, the thermal deformation portion 15b is shown in FIG.
As shown in the enlarged view of FIG. 2, the low thermal expansion member 3 of the electron tube thermal deformation member 1 is located on the mask frame 14 side, and the intermediate member 4
The thermal deformation member 1 for an electron tube is arranged such that the high thermal expansion member 2 is located on the panel 11 side via the.
That is, when the shadow mask 13 and the mask frame 14 are thermally expanded, the thermal deformation portion 15b is deformed in the direction opposite to the thermal expansion direction.

Shadow mask 13 and mask frame 14
Even if they have different thermal expansion coefficients due to the collision of electron beams when they have different thermal expansion coefficients, the frame holder 15 having the elastic portion 15a and the heat deformable portion 15b described above can prevent the fluorescent surface formed on the inner surface of the panel 11 from changing. It is possible to prevent the relative positions of the dots and the pores or slits of the shadow mask 13 from being displaced.

As described in the above-mentioned embodiment, this displacement prevention is cheaper than the conventional bimetal, has excellent workability, and secures the total plate thickness that affects the strength and long-term reliability. This is realized by the heat deformable member 1 for an electron tube of the invention. Therefore, the manufacturing cost of the color picture tube can be reduced, and the reliability of the color picture tube can be improved as the workability is improved.

[0035]

[0036]

As described above, according to the color picture tube of the present invention, the heat-deformable member for an electron tube, which is low in cost, excellent in workability, and excellent in strength and long-term reliability, is thermally deformed in the frame holder. Since it is used for a part, it is possible to obtain good color reproduction characteristics and reliability while achieving cost reduction.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of an embodiment of a heat deformable member for an electron tube used for a frame holder of a color picture tube of the present invention.

FIG. 2 is a perspective view showing a configuration of a conventional bimetal.

FIG. 3 is a cross-sectional view showing a main configuration of a color picture tube according to an embodiment of the present invention.

FIG. 4 is an enlarged view of a main part of the color picture tube shown in FIG.

[Explanation of symbols]

1 ... Thermal deformation member for electron tube 2 ... High thermal expansion member (first member) 3 ... Low thermal expansion member (second member) 4 ... Intermediate member 11 ... Panel 13 ... Shadow mask 14 ... Mask frame 15: Frame holder 15a ... Elastic part 15b ... Thermal deformation part

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-234292 (JP, A) JP-A-47-13209 (JP, A) Practical application Sho-64-5353 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) H01J 29/02

Claims (5)

(57) [Claims] 1. An electron gun for irradiating an electron beam, a panel having a fluorescent screen on which the electron beam emitted from the electron gun collides, and a fluorescent lamp screen facing the fluorescent screen and passing through the electron beam. A shadow mask made of an Fe—Ni alloy having a large number of pores or slits, a mask frame fixed to the shadow mask, a thermal deformation part and an elastic part, and one end of which is fixed to the panel. In addition, in the color picture tube, the other end of which is provided with a frame holder fixed to the mask frame, wherein the thermal deformation portion of the frame holder is made of Fe-Ni-C.
A high thermal expansion member made of an r-based alloy, a low thermal expansion member made of an Fe-Ni alloy, and a high thermal expansion member interposed between the high thermal expansion member and the low thermal expansion member, and selected from Fe and Al.
An intermediate member made of one kind of metal or an alloy based on the metal, the high thermal expansion member, the intermediate member and the low thermal expansion member are laminated, and the high thermal expansion member and the low thermal expansion member With a plate thickness ratio of 55:45 to 45:55, the plate thickness of the intermediate member is the total plate thickness of the high thermal expansion member, the intermediate member and the low thermal expansion member.
A color picture tube comprising a heat-deformable member for an electron tube, which is within 80% (excluding 30% or less). 2. The color picture tube according to claim 1, wherein a plate thickness of the intermediate member of the heat deformable member for an electron tube is 30 to 30 which is a total plate thickness of the high thermal expansion member, the intermediate member and the low thermal expansion member. Color picture tube characterized by being 60% (but not including 30%). 3. The color picture tube according to claim 1, wherein when the coefficient of thermal expansion of the high thermal expansion member is α ₁ and the coefficient of thermal expansion of the low thermal expansion member is α ₂ , the intermediate member is α ₁ ＞ α ₃
A color picture tube having a coefficient of thermal expansion α ₃ satisfying> α ₂ . 4. The color picture tube according to claim 1, wherein the intermediate member of the heat deformable member for an electron tube has C of 0.3% by weight or less and P of 0.05% by weight or less, A color picture tube characterized in that S is 0.05% by weight or less and the balance is Fe and inevitable impurities. 5. The color picture tube according to any one of claims 1 to 4, wherein the Fe—Ni—Cr alloy of the heat deformable member for an electron tube is 15 to 30% by weight of Ni and 2 ~ 10 wt% Cr,
The balance consists essentially of Fe, and the Fe-Ni alloy contains 30 to 50% by weight of Ni, and the balance consists essentially of Fe.
A color picture tube characterized by consisting of.