JPH11185660A - Electron gun structural body for color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily dispose a shield cup part without enlarging a total neck length and without loosing strength in a neck part of a power saving type cathode-ray tube bulb having a smaller diameter neck part to place a deflection yoke and a larger diameter neck part to store an electron gun. SOLUTION: An electron gun 8 composed of a control electrode 4, an acceleration electrode 5, a convergence electrode 6 and a final acceleration electrode 7 is sealed in a larger diameter neck part 2b fixed through a smaller neck part 2a, and a shield cup part 9 is attached to the final acceleration electrode 7. Since a side wall part 9a of the shield cup part 9 is formed slantwise in a turncated cone shape in parallel with a slant part 2c in a boundary area of the smaller diameter neck part 2a and the larger diameter neck part 2b, the shield cup part 9 is easily stored in the neck part 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun assembly for a power-saving color cathode ray tube, and more particularly, to an outer diameter of a neck portion at which a deflection yoke is disposed, which is smaller than an outer diameter of a neck portion for accommodating an electron gun. The present invention relates to a shield cup shape of an electron gun assembly corresponding to a cathode ray tube bulb.

[0002]

2. Description of the Related Art FIG. 10 is a sectional view of a main part of a general color cathode ray tube device. Generally, the color cathode ray tube 21
A fluorescent film 23a formed on an inner surface of a panel 23 constituting a front surface of the bulb 22 and a shadow mask 27 are sequentially arranged, and an electron beam 31a emitted from an electron gun 31 disposed on a neck 25 is used as a deflection yoke. The image is displayed by deflecting by the magnetic field by 28 and scanning the fluorescent film 23a through the shadow mask 27. The neck portion 25 has the same outer diameter from the vicinity of the welded portion with the funnel portion 24 to the electron gun 31 side.

FIG. 11 is an enlarged sectional view of the neck portion of FIG. As shown in FIG. 11, an electron gun 31 includes a cathode (not shown) for emitting electrons, a control electrode 32 for controlling an electron beam, an accelerating electrode 33, a converging electrode, and a final accelerating electrode 3.
5 and the like, which are stacked with high precision by an assembling jig, and are formed by implanting respective ends on a pair of insulating supports 37 called BO glass. . A contact element (bulb spacer) 36a is fixed to the cathode ray tube fluorescent film side of the shield cup portion 36 attached to the final accelerating electrode 35, and its tip end is connected to a graphite film 38 electrically connected to the anode electrode. It is pressed.

The detailed structure of the shield cup is shown in FIG. As shown in this figure, a plurality of connection elements 36 are provided on the outer peripheral surface of the cylindrical shield cup portion 36.
a is welded. The contact elements 36a are arranged at predetermined intervals in the circumferential direction, and have their tips protruding in the direction in which the electron beam is emitted and bulging radially outward. The plurality of contact elements 36a are connected to the axis of the electron gun 31 and the neck 2.
5 and a role of electrical connection for supplying the anode voltage to the anode electrode. This role is achieved when the outwardly swelling portion of each contact element 36a contacts a graphite film 37 formed on the inner wall of the bulb.

[0005] In recent years, as the color cathode ray tube 21 has become widespread, for example, as a display device as a terminal device, the market demand level in terms of function and quality has been increased, for example, the size, thickness, brightness, and resolution have been increased. ing. These market demands are accompanied by difficulties, particularly because they are improvements with reduced power consumption. This power consumption is mainly determined by the deflection power, and power saving can be realized by suppressing the deflection power.

As described above, the deflection power of the color cathode ray tube 21 is mainly controlled by the horizontal deflection power P.
As shown in FIG. 5, the inner diameter of the envelope formed by the horizontal deflection coil 28a forming the deflection yoke 28 is Dc, the axial dimension is Lc, and the acceleration voltage applied to the electron gun 31 is E.
b, if the horizontal deflection frequency is f h and the horizontal deflection angle of the electron beam 31a is θ h, it is determined by the following relational expression. . Pн∝fн × Dc × Eb × sin ² (θн / 2) / Lc

That is, in order to reduce the horizontal deflection power P н, from the above equation, one of the horizontal deflection frequency f н, the inner diameter Dc of the envelope surface, the acceleration voltage Eb, and the horizontal deflection angle θ н Alternatively, it is necessary to increase the axial dimension Lc of the horizontal deflection coil.

Here, although detailed description is omitted, an example of means for improving the deflection sensitivity in order to reduce the horizontal deflection power Pн will be described. FIG. 14 is a partially enlarged cross-sectional view of a cathode ray tube bulb with reduced power consumption. In this example, a means for reducing the inner diameter Dc of the envelope formed by the horizontal deflection coil 41a of the deflection yoke 41 to reduce the horizontal deflection power P.sub.н is adopted.

More specifically, as shown in FIG. 14, a neck portion 39 of the cathode ray tube bulb has a small-diameter neck portion 39a in which a deflection yoke 41 having a small outer diameter is disposed and a large-diameter neck portion in which the electron gun 31 is accommodated. This configuration corresponds to the deflection yoke 3841 having the neck portion 39b and the inner diameter Dc of the envelope surface of the horizontal deflection coil 41a reduced, thereby achieving power saving.

[0010]

However, the first problem is that the cylindrical shield cup 36 shown in FIG. 12 is replaced with a deflection yoke 4 having a small outer diameter.
1 and a large-diameter neck 39b for accommodating and disposing the electron gun 31 in a power-saving cathode ray tube, the cylindrical shield cup 36
Cannot be arranged in the small-diameter neck portion 39b, and the length of the large-diameter neck portion 39b must be increased. As a result,
This increases the overall length of the color cathode ray tube, which is not preferable. Further, if the length of the cylindrical portion of the shield cup portion 36 is shortened and the total length is made conventional, the strength of the cylindrical shield cup portion 36 is reduced, and the cylindrical shield cup portion 36 is reduced.
The cylindrical shield cup 36 is deformed by the elastic stress of the contact element 36a that is welded to the shaft, and the axis of the electron gun 731 is displaced, thereby giving rise to a problem that convergence is adversely affected.

Further, as a second problem, in the structure in which the diameter of the shield cup portion 36 is reduced as shown in FIG. 15, a high voltage is applied to the electron gun sealed in the neck portion during the operation of the color cathode ray tube. When applied, the electron beam 31a
Positive ions of the residual gas in the tube generated by collision with the gas scatter from the screen side to the electron gun 31 side, but are not blocked by the shield cup portion 36, and scatter to the inner wall portions of the electron gun 31 and the neck portion 39. As a result, there arises a problem that the electric field of the electron lens formed between the electrodes of the electron gun 36 is affected to cause a deviation in the traveling direction of the electron beam 36a, that is, a so-called charge convergence drift is caused.

In order to solve the above-mentioned problems, the present invention provides a neck portion of a power-saving cathode ray tube having a small-diameter neck portion for arranging a deflection yoke and a large-diameter neck portion for accommodating an electron gun. Another object of the present invention is to provide a color cathode ray tube having a structure in which a shield cup portion can be easily arranged.

Further, according to the present invention, in a cathode ray tube bulb having a small diameter neck portion and a large diameter neck portion, the shield cup portion can be attached to the electron gun without making the outer diameter of the shield cup base smaller than the outer diameter of the electron gun. It is an object of the present invention to provide a color cathode ray tube which prevents charge convergence drift due to scattering of cations generated by electron beam collision by being attached.

[0014]

The color cathode ray tube of the present invention for attaining the above object is characterized in that, for the first problem, a screen side end of an electron gun built in a bulb neck is provided. The point that the outer diameter of the screen side of the shield cup portion attached to the final acceleration electrode is smaller than the outer diameter of the final acceleration electrode side. As a specific shape, for example, the shield cup portion is formed in a truncated cone shape or a truncated polygonal pyramid shape having a reduced diameter on the screen side. As described above, the shield cup portion has a shape in which the diameter decreases toward the screen side, so that the total length is increased at the inclined portion at the boundary between the small-diameter neck portion and the large-diameter neck portion of the cathode ray tube bulb. It is possible to dispose the shield cup without reducing the strength.

The feature of the color cathode ray tube of the present invention is that, for the second problem, the shape of the shield cup portion is changed to the outer diameter of the final accelerating electrode by attaching it to the mounting portion with the final accelerating electrode constituting the electron gun. It has a flange (disk portion) with an equal or larger diameter, and the diameter of the shield cup portion so that the tip of the shield cup fits into the boundary between the small diameter neck portion and the large diameter neck portion. Is smaller than the mounting portion. By doing so, when cations generated by collision with the electron beam are scattered to the electron gun side, the flange portion of the shield cup located at the mounting portion with the final acceleration electrode,
The scattering of cations can be shielded so that the electric field formed between the electrodes of the electron lens is not affected, and so-called charge convergence drift can be prevented.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention.
FIG. 2 is a sectional view showing a structure of a neck portion accommodating the electron gun assembly for a color cathode ray tube according to the embodiment, and FIG. 2 is a perspective view of a shield cup portion thereof. In FIG. 1, a neck portion 2 is fixed to a funnel portion 1 of a color cathode ray tube bulb through a small diameter neck portion 2a.
b, an electron gun 8 composed of a control electrode 4, an accelerating electrode 5, a converging electrode 6, and a final accelerating electrode 7 arranged in the insulating support 2 is enclosed.
Is attached. Side wall 9 of shield cup 9
a, a plurality of contact elements 10 are fixedly mounted on the graphite film 1.
1 electrically. As can be seen from the enlarged view of FIG. 2, the shield cup portion 9 is formed in a truncated cone shape in which the outer diameter of the screen side opening 9b is smaller than the outer diameter of the bottom opening 9c. That is, the side wall portion 9a of the shield cup portion 9 is formed to be inclined in a truncated cone substantially parallel to the inclined portion 2c at the boundary between the small diameter neck portion 2a and the large diameter neck portion 2b. 9
Can be easily stored in the neck portion 2. A contact element (valve spacer) 10 which is welded to the side wall 9a of the shield cup 9 and supplies an anode voltage to the anode electrode.
Is in electrical contact with the graphite film 11 on the inner wall of the inclined portion 2c at the boundary between the small-diameter neck portion 2a and the large-diameter neck portion 2b.

As shown in FIG. 3, the contact element 10 is fixed to the tip of the shield cup 9, and the small-diameter neck portion 2a and the large-diameter neck portion 2 of the cathode ray tube bulb as shown in FIG.
b, but not the slanted portion 2c at the boundary with
Electrical contact may be made with the graphite film 11 on the inner surface portion b.

Next, FIG. 4 shows a perspective view of a shield cup portion according to a second embodiment of the present invention. In this example,
As can be seen from the figure, the shield cup portion 12 has a shape of a regular hexagonal pyramid, and facilitates positioning of the plurality of contact elements 10 at the time of welding to the side wall portion of the shield cup portion 12. In this shape, the same effect as in the first embodiment can be obtained.

FIG. 5 is a perspective view of a shield cup portion which is a modification of the second embodiment. As can be seen from this figure, a cut 13b is formed in the inclined side wall portion 13a in the shield cup portion 13, but this shape is larger than that in the above-described FIG. 4 shape in which the side wall portion is formed continuously. It can be easily formed into a regular hexagonal truncated pyramid shape by bending and is therefore advantageous in terms of cost.

In each of the above-described embodiments, the shape of the shield cup portion is described using a truncated cone or a truncated hexagonal pyramid. Other shapes may be used as long as they are formed substantially parallel to the inclined portion at the boundary with the large neck portion.

Next, various embodiments of the present invention that address the second problem will be described. FIG. 6 is a sectional view showing the structure of a main part of a neck portion of a color cathode ray tube according to a third embodiment of the present invention, and FIG. 7 is an enlarged view of a shield cup portion thereof. Note that, in FIG.
The same parts as those described above are denoted by the same reference numerals and description thereof will be omitted. As clearly shown in FIG. 7, a disc-shaped flange portion 14a having an outer diameter larger than or equal to the outer diameter of the final acceleration electrode 7 is formed in a portion of the shield cup portion 14 in contact with the final acceleration electrode 7. Have been.

Next, the role, operation and effect of the flange 14a provided on the base of the shield cup 14 will be described.
That is, when a high voltage is applied to the electrode of the electron gun by operating the color cathode ray tube, the cations of the residual gas in the tube generated by collision with the electron beam 31a are scattered from the screen side toward the electron gun 8 direction. come. When the cations scatter near the flange 14a of the shield cup 14, the gap between the inner wall of the large-diameter neck portion 2b and the flange 14a is small, and the cations have a high mass and a high straightness. The part 14a prevents the movement in the direction of the electron gun 8.
Therefore, the influence of the cations on the electric field of the electron lens formed between the electrodes of the electron gun 8 is reduced. This makes it possible to suppress the occurrence of a so-called charge convergence drift, which causes a deviation in the traveling direction of the electron beam 31a.

FIG. 8 is a sectional view of a neck portion of a color cathode ray tube according to a fourth embodiment of the present invention, and FIG. 9 is an enlarged view of the shield cup portion. This embodiment is the same as the above-described third embodiment except for the shield cup portion, and therefore, the same portions are denoted by the same reference characters and description thereof will be omitted. In this embodiment, the side wall of the shield cup portion 15 is formed in a tapered shape, and the enlarged portion 1 is formed.
5a, the distance between the inner wall of the inclined portion 2c at the boundary between the small-diameter neck portion 2a and the large-diameter neck portion 2b is reduced due to the tapered side wall, and many portions have a cation shielding effect. Become more effective.

[0024]

As described above, according to the present invention, in a color cathode-ray tube in which the cathode ray tube bulb is provided with a small-diameter neck portion and a large-diameter neck portion to save power, the shield cup portion is formed into a truncated cone. By adopting the shape or the truncated polygonal pyramid shape, it is possible to arrange the shield cup portion without increasing the overall length of the neck portion and without reducing the strength.

Further, the flange portion or the side wall portion is tapered to form an enlarged portion at the base portion of the shield cup portion, that is, the portion for attachment to the final acceleration electrode, so that the cations during the operation of the color cathode ray tube are provided. The scattering to the electron gun side can be shielded, and the occurrence of charge convergence drift can be prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a neck portion accommodating an electron gun structure for a color cathode ray tube according to an embodiment of the present invention.

FIG. 2 is a perspective view of the shield cup part.

FIG. 3 is a cross-sectional view of a neck portion accommodating an electron gun assembly according to a second embodiment of the present invention.

FIG. 4 is a perspective view of the shield cup part.

FIG. 5 is a perspective view of a shield cup portion according to a modified example of the second embodiment of the present invention.

FIG. 6 is a sectional view of a neck portion accommodating an electron gun assembly according to a third embodiment of the present invention.

FIG. 7 is a perspective view of the shield cup part.

FIG. 8 is a sectional view of a neck portion accommodating an electron gun assembly according to a fourth embodiment of the present invention.

FIG. 6 is a perspective view of the shield cup part.

FIG. 10 is a sectional view of a main part of a conventional general color cathode ray tube device.

FIG. 11 is a cross-sectional view of a neck portion accommodating a conventional electron gun assembly for a color cathode ray tube.

FIG. 12 is a front view of a conventional shield cup portion.

FIG. 13 is a sectional view of an essential part of a conventional neck portion provided with a deflection yoke for explaining deflection power.

FIG. 14 is a sectional view of a principal part of a neck having a small-diameter neck provided with a deflection yoke for explaining deflection power;

FIG. 15 is a cross-sectional view of a neck portion having a small-diameter neck portion accommodating a conventional electron gun assembly for a color cathode ray tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Funnel part 2 Neck part 2a Small diameter neck part 2b Large diameter neck part 2c Inclined part 3 Insulating support 4 Control electrode 5 Acceleration electrode 6 Focusing electrode 7 Final acceleration electrode 8 Electron gun 9,12,13,14,15 Shield cup Part 9a, 13a Side wall part 10 Contact element 11 Graphite film 13b Cut 14a Flange part 15a Enlarged part

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[Procedure amendment]

[Submission date] March 13, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a sectional view of a neck portion accommodating an electron gun structure for a color cathode ray tube according to an embodiment of the present invention.

FIG. 2 is a perspective view of the shield cup part.

FIG. 3 is a sectional view of a neck portion accommodating an electron gun assembly according to a second embodiment of the present invention.

FIG. 4 is a perspective view of the shield cup part.

FIG. 5 is a perspective view of a shield cup portion according to a modification of the second embodiment of the present invention.

FIG. 6 is a sectional view of a neck portion accommodating an electron gun assembly according to a third embodiment of the present invention.

FIG. 7 is a perspective view of the shield cup part.

FIG. 8 is a sectional view of a neck portion accommodating an electron gun assembly according to a fourth embodiment of the present invention.

FIG. 9 is a perspective view of the shield cup portion.

FIG. 10 is a sectional view of a main part of a conventional general color cathode ray tube device.

FIG. 11 is a cross-sectional view of a neck portion accommodating a conventional electron gun assembly for a color cathode ray tube.

FIG. 12 is a front view of a conventional shield cup portion.

FIG. 13 is a cross-sectional view of a main part of a conventional neck portion provided with a deflection yoke for explaining deflection power.

FIG. 14 is an essential part cross-sectional view of a neck portion having a small-diameter neck portion in which a deflection yoke is arranged for explaining deflection power;

FIG. 15 is a sectional view of a neck portion having a small-diameter neck portion accommodating a conventional electron gun assembly for a color cathode ray tube.

[Description of Signs] 1 Funnel part 2 Neck part 2a Small diameter neck part 2b Large diameter neck part 2c Inclined part 3 Insulating support 4 Control electrode 5 Acceleration electrode 6 Converging electrode 7 Final acceleration electrode 8 Electron gun 9, 12, 13, 14, 15 Shield cup part 9a, 13a Side wall part 10 Contact element 11 Graphite film 13b Cut 14a Flange part 15a Enlarged part

Claims (7)

[Claims] An electron gun comprising a cathode, a control electrode, an accelerating electrode, a focusing electrode, and a final accelerating electrode is provided in a cathode ray tube bulb having a small-diameter neck portion on which a deflection yoke is disposed and a large-diameter neck portion for accommodating an electron gun. In the enclosed cathode ray tube, a collar characterized in that a shield cup portion fixed to the final accelerating electrode is located at an inclined portion at a boundary between a small diameter neck portion and a large diameter neck portion of the cathode ray tube bulb. Electron gun structure for cathode ray tube. 2. The method according to claim 1, wherein said shield cup portion is formed in a truncated cone shape, and a side wall portion thereof is inclined substantially in parallel with an inclined portion at a boundary portion between the small diameter neck portion and the large diameter neck portion of the cathode ray tube bulb. Item 7. An electron gun structure for a color cathode ray tube according to Item 1. 3. The shield cup portion is formed in a truncated polygonal pyramid shape, and its side wall portion is inclined substantially in parallel with the inclined portion at the boundary between the small-diameter neck portion and the large-diameter neck portion of the cathode ray tube bulb. An electron gun assembly for a color cathode ray tube according to claim 1. 4. The shield cup portion is formed in a truncated polygonal pyramid shape, and its side wall portion is inclined substantially in parallel with an inclined portion at a boundary portion between a small-diameter neck portion and a large-diameter neck portion of a cathode ray tube bulb,
2. The electron gun assembly for a color cathode ray tube according to claim 1, wherein a cut is provided in the inclined portion. 5. An electron gun comprising a cathode, a control electrode, an accelerating electrode, a converging electrode, and a final accelerating electrode is provided in a cathode ray tube bulb having a small-diameter neck portion for arranging a deflection yoke and a large-diameter neck portion for accommodating an electron gun. In the enclosed cathode ray tube, the diameter of the fixed portion of the base of the shield cup portion fixed to the final accelerating electrode to the final accelerating electrode and the diameter of the tip portion accommodated in the small diameter neck portion of the cathode ray tube bulb are made different. An electron gun assembly for a color cathode ray tube. 6. An electron gun assembly for a color cathode ray tube according to claim 5, wherein a flange portion is provided at a fixed portion of said shield cup portion with a final acceleration electrode. 7. The electron gun assembly for a color cathode ray tube according to claim 5, wherein an enlarged portion obtained by forming a taper on a side wall of the shield cup portion is provided in a fixed portion of the shield cup portion and the final acceleration electrode.