JPH1092330A - Cathode body structure for cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the cathode body structure of a cathode-ray tube, wherein no separation is caused in the insulating layer of a heater even heat following heat treatment at high temperature is applied at the time of a manufacturing process for a cathode-ray tube. SOLUTION: In the cathode body structure of a cathode-ray tube composed of at least a metallic sleeve 13, a cap-like metallic base body 14 fitted to one end of the metallic sleeve 13, having an electron emitting material layer 15 coated on the surface, heaters 16 insertedly retained by the sleeve 13, heater supports 19 joined to the end parts of the heaters 16, and heater support supporting members 22 joined to insulating supports 21 in a fixed condition, for supporting the heater supports 19 by the insulating supports 21, the supporting members 22 are constituted of an inverted L-shaped member, and the heaters 16 are arranged so as to recede from the metallic base body 14 when the temperature of the heater supports 19 and the supporting members 22 is increased to thermally expand them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode structure of a cathode ray tube, and more particularly, to a method in which a heater abuts on a cap-shaped metal base due to thermal expansion of a heater during a high temperature heat treatment in a cathode ray tube manufacturing process. The present invention relates to a cathode structure of a cathode ray tube, which prevents the insulating layer from peeling off due to stress applied to an insulating layer covering the insulating layer.

[0002]

2. Description of the Related Art Generally, in a cathode ray tube such as a color picture tube used for a television receiver or a monitor color picture tube used for a display, a metal sleeve containing a heater is fitted to one end of the metal sleeve, and the surface of the metal sleeve is attached to the surface. An indirectly heated cathode structure including a cap-shaped metal substrate on which an electron emitting material layer is adhered, a heater support for fixing an end of the heater to an insulating support, a heater support support member, and the like is used.

FIG. 3 is a sectional view showing an example of the configuration of such a known indirectly heated cathode structure.

As shown in FIG. 3, an indirectly heated cathode 30 includes at least a cylindrical metal sleeve 31 made of a high melting point metal such as molybdenum, a cap-shaped metal base 32 made of the same high melting point metal, and an electron emitting material. A layer 33, a heater 34, an insulating layer 35 of alumina or the like, a dark coat covering layer 36 of tungsten fine powder or the like, a pair of heater supports 37 having one end enlarged in the width direction, and an insulating support described later. A metal sleeve holder 38 held by a body 39, an insulating support 39 such as a bead glass fixedly arranged on an electron gun of a cathode ray tube, and a rectangular shape fixed to the insulating support 39 and supporting the heater support 37 by welding. And a heater support member 40.

The cylindrical metal sleeve 31 has a cap-shaped metal base 32 fitted at one end and a metal sleeve receiver 38 at the other end. Cap-shaped metal base 32
Has an electron-emitting material layer 33 on the surface. The heater 34 has a surface coated with an insulating layer 35, a dark coat coating layer 36 for improving the heat radiation efficiency, and a central portion inserted into the metal sleeve 31.
The pair of heater supports 37 is provided with a heater 3 at a narrow end.
4 are welded to each other, and the wide end and the protruding end of the heater support member 40 are spot welded.

In this case, when heating power is supplied to the heater 34 through the pair of heater supports 37 during operation of the cathode ray tube, the heater 34 generates heat, and after the heat is transmitted to the metal sleeve 31 and the metal base 32, the heat is transmitted to the electron source. Emissive material layer 33
To emit thermal electrons from the electron emitting material layer 33.

During operation of the cathode ray tube, the heater 34
Generates heat, the heater 34 thermally expands, and a portion of the heater 34 facing the cap-shaped metal base 32 slightly extends toward the cap-shaped metal base 32. At this time, the heat generated by the heater 34 causes the metal sleeve 31 to be heated. Also become hot and thermally expand in the longitudinal direction. For this reason, the heater 34 is
Does not strongly contact the insulating layer 35, the insulating layers 35, 36 covering the heater 34 are not subjected to a large stress, and cracks occur in the insulating layers 35, 36, and the insulating layer 3
5 and 36 do not peel off.

[0008]

In the known cathode ray tube manufacturing process, high-temperature heat treatment is performed in several steps. For example, in the step of inserting the cathode assembly into the neck of a glass vacuum envelope (bulb),
A high temperature is applied to the cathode assembly, the neck of the cathode assembly is melted and inserted and adhered to the neck of the bulb.Also, in the bulb sealing process, a part of the bulb is melted and welded. doing.

In these heat treatment steps, the heater 3
4, the heater 34 is not directly heated, but the heat associated with the heat treatment is applied to the heater support 37 and the heater support support member 40 near the heat source, and the heater support 37 and the heater support The support member 40 is thermally expanded, and in particular, due to the thermal expansion of the heater support 37, the heater 34 is entirely shifted to the cap-shaped metal base 32 side. It comes into strong contact with the metal base 32. At this time, the heater 3
A large stress is applied to the insulating layer 35 of alumina or the like covering the insulating layer 4, and the stress causes a crack in the insulating layer 35 to cause the insulating layer 35 to peel off. If the strip of the insulating layer 35 that has peeled off falls on the shadow mask, the electron beam passage hole of the shadow mask may be blocked, and the mask may be clogged in the cathode ray tube. Even when the cathode ray tube falls, it may float in the cathode ray tube and cause a withstand voltage failure in the cathode ray tube.

As described above, in the cathode structure of the known cathode ray tube, the insulating layer 35 may be peeled off due to the high temperature heat applied during the manufacturing process of the cathode ray tube, thereby causing a mask clogging of the cathode ray tube. And / or a withstand voltage failure occurs in the cathode ray tube.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and an object of the present invention is to remove the insulating layer of a heater even when heat accompanying a high-temperature heat treatment is applied during a manufacturing process of a cathode ray tube. There is no need to provide a cathode ray tube cathode assembly.

[0012]

In order to achieve the above object, a cathode structure of a cathode ray tube according to the present invention comprises a heater support supporting member having an inverted L-shape, wherein the heater support supporting member has an inverted L-shape. Fix one end of the short side of the mold to the insulating support,
By spot-welding the heater support to the other end of the long side of the inverted L-shape, heat is applied to the heater support and the heater support support member, so that when they thermally expand, the heater separates from the cap-shaped metal base. Means.

According to the above means, at the time of manufacturing the cathode ray tube,
Even if the heat from the high-temperature heat treatment is applied to the heater support and the heater support member, and they expand thermally,
Since the heater acts to separate from the cap-shaped metal base, the heater does not come into contact with the cap-shaped metal base, no stress is applied to the insulating layer covering the heater, and the insulating layer does not peel off.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention, a cathode structure of a cathode ray tube has at least a metal sleeve and a cap-shaped metal fitted on one end of the metal sleeve and having an electron emitting material layer adhered to the surface. A base, a heater inserted into and held by a metal sleeve, a heater support coupled to an end of the heater, and a heater support coupled to the fixed insulating support for supporting the heater support with the insulating support. In the cathode structure of the cathode ray tube comprising the support member, the heater support support member is formed in an inverted L-shape, and the temperature of the heater support and the heater support support member rises when the cathode ray tube is manufactured, so that they are thermally expanded. Then, the heater is arranged so as to be separated from the cap-shaped metal base.

According to the embodiment of the present invention, the heater support supporting member is formed in an inverted L-shape, and one end of the short side of the inverted L-shape is fixed to the insulating support, and the inverted L-shape is fixed. Since the heater support is spot-welded to the other end of the long side of the mold, during the manufacture of the cathode ray tube, the heat associated with the high-temperature heat treatment is applied to the heater support and the heater support supporting member, causing them to expand. Even if the heating occurs, the thermal expansion of the heater support member acts to separate the heater from the cap-shaped metal base.

As described above, according to the embodiment of the present invention, even if the heater support member thermally expands, the heater does not come into contact with the cap-shaped metal base, and the insulating layer covering the heater does not come into contact. Since no stress is applied to the cathode ray tube, peeling of the insulating layer does not occur, and mask clogging and withstand voltage failure do not occur in the cathode ray tube.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing the configuration of one embodiment of a cathode ray tube having a cathode structure according to the present invention, and shows an example in which the cathode ray tube constitutes a color cathode ray tube.

In FIG. 1, 1 is a panel portion, 2 is a neck portion, 3 is a funnel portion, 4 is a fluorescent film, 5 is a shadow mask, 6 is an internal magnetic shield, 7 is a deflection yoke, and 8 is a magnet for purity adjustment. , 9 is a center beam static convergence adjustment magnet, 10 is a side beam static convergence adjustment magnet, 1
1 is an electron gun and 12 is an electron beam.

The glass vacuum envelope (bulb) constituting the color cathode ray tube is disposed on the front side, and has a panel section 1 having a fluorescent film 4 formed on the inner surface of the front panel.
And an elongated neck portion 2 disposed on the rear side and accommodating the electron gun 11, and a funnel portion 3 having a substantially funnel shape connecting the panel portion 1 and the neck portion 2. The shadow mask 5 is fixedly arranged inside the panel unit 1,
It is held in a state facing the fluorescent film 4. The substantially trapezoidal internal magnetic shield 6 is disposed inside the tube at the connection portion between the panel unit 1 and the funnel unit 3. The deflection yoke 7 is attached to the outside of the tube at the connection portion between the funnel 3 and the neck 2. Magnet for adjusting purity 8, Magnet for adjusting center beam static convergence 9,
The side beam static convergence adjusting magnets 10 are arranged side by side outside the neck portion 2, and the three electron beams 12 radiated from the electron gun 11.
(Only one is shown in FIG. 1)
Are deflected in a predetermined direction by the magnetic field generated, and reach a pixel of a corresponding color in the fluorescent film 4 through many electron beam transmission holes (not shown) provided in the shadow mask 5. .

The operation of the color cathode ray tube having the above-described structure, that is, the image display operation is exactly the same as the image display operation of the known color cathode ray tube, and therefore the description of the image display operation of the color cathode ray tube is omitted. I do.

FIG. 2 is a sectional view showing an example of the configuration of the indirectly heated cathode structure of the color cathode ray tube shown in FIG.

In FIG. 2, 13 is a cylindrical metal sleeve made of a high melting point metal such as nichrome, 14 is a cap-shaped metal base also made of a high melting point metal such as nickel, 15 is an electron emitting material layer, 16 is a heater, 17 Is an insulating layer made of alumina or the like, 18 is a dark coat covering layer made of tungsten fine powder or the like, 19 is a pair of heater supports whose one end is wider in the width direction than the other end, and 20 is a metal. A sleeve receiver 21 is an insulating support made of bead glass or the like, and 22 is a pair of inverted L-shaped heater support supporting members.

The cylindrical metal sleeve 13 has a cap-shaped metal base 14 fitted at one end and a sleeve receiver 2 at the other end.
It is held by 0. The sleeve receiver 20 is fixed to an insulating support 21 fixed to the electron gun 11 (see FIG. 1), and the cap-shaped metal base 14 has an electron emitting material layer 15 on the surface. The heater 16 has an insulating layer 1 on the surface.
7 is coated thereon, and a dark coat coating layer 18 for increasing the heat radiation efficiency is coated thereon, and the central portion is inserted into the metal sleeve 13. In the pair of inverted L-shaped heater support members 22, one end of the short side of the inverted L shape is fixed to the insulating support body 21, and the other end of the long side of the inverted L shape is connected to the heater support 19. Spot welded. The pair of heater supports 19 are formed by welding the ends of the heaters 16 to the narrow ends, respectively, and the wide ends are the other ends of the inverted L-shaped long sides of the heater support support member 22. Each is spot welded near the tip.

The indirectly heated cathode structure having the above structure operates as follows.

When the heating power is supplied to the heater 16 through the pair of heater supports 19 when the color cathode ray tube operates, the heater 16 generates heat. At this time, heater 1
6 is transferred to the electron emitting material layer 15 via the metal sleeve 13 and the cap-shaped metal base 14,
Is raised to a predetermined temperature, and thermoelectrons are emitted from the electron emitting material layer 33.

In this case, when the heater 16 generates heat, the heater 16 thermally expands, and the portion of the heater 16 facing the cap-shaped metal base 14 slightly extends (approaches) to the cap-shaped metal base 14 side. However, the heat generated by the heater 16 also causes the metal sleeve 13 to be heated to a high temperature and thermally expanded in the length direction. Therefore, the heater 16 does not come into strong contact with the cap-shaped metal base 14 and the insulation covering the heater 16 Since a large stress is not applied to the layer (alumina) 17, cracks do not occur in the insulating layer 17 and the insulating layer 17 does not peel off.

Also, during the high temperature heat treatment in the process of manufacturing the color cathode ray tube, for example, when the electron gun 11 is welded to the bulb, the heat generated by the heat treatment causes the heat generated by the heat support 19 and the heater support support member 22.
When the temperature reaches a high level, the heater support 19
And the heater support member 22 thermally expands. At this time, when the heater support 19 thermally expands, the entire heater 16 moves so as to be close to the cap-shaped metal base 14, while when the heater support support member 22 thermally expands, the entire heater 16 moves from the cap-shaped metal base 14. The heater support 19 and the heater support support member 22 are selected so as to have a predominant influence of the thermal expansion of the heater support support member 22. When the support 19 and the heater support member 22 are thermally expanded, the heater 16
Are separated from the cap-shaped metal base 14.

As described above, according to the cathode structure of the color cathode ray tube according to the present embodiment, it is assumed that the heat accompanying the high temperature heat treatment is applied to the heater support 19 and the heater support supporting member 22 during the manufacturing process of the color cathode ray tube. Also, since the heater 16 does not move in the direction of the cap-shaped metal base 14 or strongly contacts the cap-shaped metal base 14, a large stress is not applied to the insulating layer (alumina) 17 covering the heater 16. The insulating layer 17 does not crack or the insulating layer 17 does not peel off, and the color cathode ray tube does not cause mask clogging or withstand voltage failure.

In the above embodiment, the cathode ray tube is described as an example of a color cathode ray tube. However, the cathode ray tube according to the present invention is not limited to a color cathode ray tube.
It may be a monochrome type cathode ray tube.

[0031]

As described above, according to the present invention, during the manufacturing process of the cathode ray tube, heat accompanying the high-temperature heat treatment is applied to the heater support and the heater support supporting member, and the heater support and the heater support supporting member are heated. When expanded, the heater does not strongly contact the cap-shaped metal base,
Since a large stress is not applied to the insulating layer covering the heater, the insulating layer does not crack, the insulating layer does not peel off, and the cathode ray tube causes mask clogging or withstand voltage failure. There is an effect that it does not do.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of an embodiment of a cathode ray tube having a cathode structure according to the present invention.

FIG. 2 is a cross-sectional view showing an example of a configuration of an indirectly heated cathode structure of the color cathode ray tube shown in FIG.

FIG. 3 is a cross-sectional view showing an example of a configuration of a known indirectly heated cathode structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Panel part 2 Neck part 3 Funnel part 4 Fluorescent film 5 Shadow mask 6 Internal magnetic shield 7 Deflection yoke 8 Purity adjustment magnet 9 Center beam static convergence adjustment magnet 10 Side beam static convergence adjustment magnet 11 Electron gun 12 Electron beam DESCRIPTION OF SYMBOLS 13 Metal sleeve 14 Cap-shaped metal base 15 Electron emitting material layer 16 Heater 17 Insulating layer (alumina) 18 Dark coat covering layer 19 Heater support 20 Metal sleeve receiver 21 Insulating support 22 Inverted L-shaped heater support supporting member

Claims (1)

[Claims] At least a metal sleeve, a cap-shaped metal base fitted to one end of the metal sleeve, and having an electron emitting material layer adhered to a surface thereof; a heater inserted and held in the metal sleeve; In a cathode assembly of a cathode ray tube comprising a heater support coupled to an end of a heater, and a heater support supporting member coupled to a fixed insulating support and supporting the heater support with the insulating support, The heater support supporting member is formed in an inverted L-shape, and at the time of manufacturing the cathode ray tube, when the temperature of the heater support or the heater support supporting member rises and they thermally expand, the heater is set to the cap. A cathode structure of a cathode ray tube, wherein the cathode structure is arranged so as to be separated from a metal substrate.