JP2001176424A - In-line type color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem where projecting bodies tend to be easily deformed through manual and mechanical contact from the outside after fixing the bodies, causing easy fluctuation of convergence in characteristics and the need for paying through attention in working, so as not to deform the projected bodies. SOLUTION: The projected body 4 is fixed to a cup bottom face 2b at welded spots 8, and a pair of parallel nonmagnetic metal projections 5 and 6 are provided at upper and lower portions of electron beam passing holes 3S in the direction of shield cup opening so as to cross at a right angle with the cup bottom 2b, and support portions 7 support the projection 5 or 6, which extend up to a seal face 2a and formed integrated in a body with the support portions 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-line type color cathode ray tube in which a projection for controlling eddy current is installed in a shield cup of an electron gun in order to satisfy the convergence performance of a cathode ray tube used at a high horizontal deflection frequency. About pipes.

[0002]

2. Description of the Related Art When an in-line type color cathode ray tube is used as a color television receiver of a standard broadcast system and a display for a personal computer, the number of horizontal scanning lines is large and the horizontal deflection frequency is high. Among the three electron beams arranged side by side, there is a problem that the difference between the scanning area by the center beam, that is, the image reproducing area, and the scanning area by the electron beams at both ends becomes conspicuous.

In general, in an in-line type color cathode ray tube, an end of the electron gun which forms three electron beams in-line on a fluorescent screen side is shielded from an electrostatic charge charged on a wall surface of the tube. Non-magnetic metal bottomed cylindrical shape having a cylindrical shield surface surrounding three electron beams and a bottom plate positioned near the cathode and having an electron beam passage hole for each of the three electron beams. The shield cup is arranged. In this structure, a deflection yoke for generating a deflection magnetic field for deflecting the electron beam is arranged outside the funnel portion of the tube, but the end near the cathode side of the deflection magnetic field is just at the shield side wall of the shield cup. , An eddy current is induced in the conductive shield sidewall by the time-varying deflection magnetic field, and the eddy current weakens the original deflection magnetic field.

FIG. 7 shows a state of an image reproducing area in an in-line type color cathode ray tube. In FIG. 7, a screen 17C scanned by a center beam is a screen 1 scanned by a side beam.
It is shifted to the right as compared to 7S. This aberration increases with the recent increase in the horizontal deflection frequency.

FIG. 5 shows the structure of an electron gun in an in-line type color cathode ray tube described in Japanese Patent Application Laid-Open No. 63-190232 in order to eliminate the above-mentioned aberration shift.
In the figure, 0 is the central axis of the electron gun 1, 2 is a shield cup formed in a cup shape for shielding an electron beam from charging of the tube wall surface, 2 a is a cylindrical shield surface which is a side surface of the shield cup 2, Reference numeral 2b denotes a cup bottom which is the bottom of the shield cup 2, 3S denotes an electron beam passage hole on both sides of three electron beam passage holes formed in parallel in a horizontal plane on the cup bottom 2b, and 3C denotes a horizontal plane on the cup bottom 2b. The center electron beam passage hole among the three electron beam passage holes drilled in parallel inside, 4 is the welding point 8 and the cup bottom surface 2b
A pair of parallel non-magnetic metal projecting portions 9 and 9 projecting from upper and lower portions of the electron beam passage hole 3S in the direction of opening the shield cup so as to be orthogonal to the cup bottom surface 2b. Is a projecting bottom surface connected to the projecting portions 5 and 6 and in contact with the cup bottom surface 2b. FIG. 6 is an enlarged perspective view of the protrusion 4.

With the above configuration, the action of the horizontal deflection magnetic field can be made equal for each electron beam in the in-line arrangement due to the influence of the magnetic field formed by the eddy current flowing through the projecting portions 5 and 6 of the projecting body 4. As a result, even if the horizontal deflection frequency is increased, misconvergence caused by eddy current can be suppressed within a range in which no problem occurs.

[0007]

The conventional electron gun for a cathode ray tube is constructed as described above, and the protruding portions 5 and 6 constituting the protruding body 4 are provided with the electron beam passing holes 3S and 3S of the protruding body 4. 3C
Is bent at 90 degrees from a flat portion having a thickness of about 0.3 mm to 0.6 mm, and a length extending in the electron beam traveling direction is about 4 mm to 8 mm. Therefore, after the projecting member 4 is fixed, it tends to be deformed by external human or mechanical contact, and eddy currents generated in the deformed projecting portions 5, 6 tend to vary, and convergence varies in characteristics. Easy to occur. Furthermore, in the work, the projecting portion 5,
It was necessary to work with great care so as not to deform the No. 6.

Further, since the projecting member 4 is welded to the cup bottom 2b at the projecting bottom surface 9, the shield cup 2 and the projecting member 4 must be welded in advance to form a sub-assembly and attach it to the electron gun 1. However, the shape of the electron gun had to be determined at the design stage. Therefore, when the use of the horizontal deflection magnetic field is increased and the deflection yoke is changed due to the change of the horizontal deflection magnetic field, the electron gun must be redesigned, resulting in a large time loss and large inventory loss.

The present invention has been made in order to solve the above-mentioned problems, and enhances the strength of the protruding body 4 to stabilize the quality and satisfy the convergence performance.
An object of the present invention is to obtain an electron gun which can be easily manufactured quickly by easily changing the design.

[0010]

According to the present invention, there is provided an in-line type color cathode ray tube according to the present invention. And a support portion corresponding to the three electron beam passage holes formed in the bottom surface of the cup.
A non-magnetic metal projecting body having a bottom portion having a plurality of electron beam passage holes having substantially the same size was formed in the electron beam passage hole formed in the bottom surface of the cup and the bottom portion. The electron beam passage holes are aligned and fixed to the shield cup.

Further, the support portion and the shield surface are welded.

Further, the protruding bottom surface is separated so as to include holes for passing electron beams on both sides.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described with reference to the drawings showing the embodiments. Embodiment 1 FIG. 1 is a diagram showing an in-line type color cathode ray tube according to Embodiment 1 of the present invention. In the figure, 1 is an electron gun,
Reference numeral 2 denotes a shield cup formed in a cup shape for shielding an electron beam from charging of a wall surface of the tube, 10 denotes an electron beam emitted from the electron gun 1, 11 denotes a panel portion forming a tube, 12
Is a fluorescent screen formed on the inner surface of the panel section 11 and emits light by the electron beam 10;
A color selection electrode fixed to the panel portion 11 for each of the two fluorescent colors, a funnel portion 14 constituting a tubular body and fixed to the panel portion, and an internal magnetic shield 15 for shielding the electron beam 10 from terrestrial magnetism , 16 are deflection yokes that deflect the electron beam 10 and are fixed to the funnel 14. With this configuration, the shield cup 2 is located at the side end of the fluorescent screen 12 of the electron gun 1 and shields the electron beam from charging the tube.

FIG. 2 is a view showing an electron gun 1 provided in the color cathode ray tube according to the first embodiment. FIG. 2A is a front view and a view as seen from a downstream side in a traveling direction of an electron beam. 2
2B is a side view showing a tip portion of the electron gun, and FIG. 2C is an enlarged perspective view of the protruding body. In the figure, reference numeral 2a denotes a cylindrical shield surface which is a side surface of the shield cup 2, 2
b denotes a cup bottom which is a bottom surface of the shield cup 2; 3S denotes an electron beam passage hole on both sides of three electron beam passage holes formed in parallel in a horizontal plane on the cup bottom surface 2b;
Are the central electron beam passage holes of three electron beam passage holes formed in parallel in a horizontal plane on the cup bottom surface 2b;
Is a projecting body fixed to the cup bottom surface 2b at the welding point 8, and 5 and 6 are a pair of parallel non-protrusions projecting above and below the electron beam passage hole 3S in the opening direction of the shield cup so as to be orthogonal to the cup bottom surface 2b. A projecting portion of the magnetic metal, 7 is a support portion for supporting the projecting portion 5 or 6, and 9 is a projecting bottom surface connected to the projecting portions 5 and 6 and in contact with the cup bottom surface 2b. The electron beam passage holes 3S, 3C and 3S are formed to be the same as or slightly larger than the electron beam passage holes formed in the bottom surface of the shield. The protruding portions 5 and 6 extend to the sealing surface 2a and are formed integrally with the support portion 7.

The projecting member 4 constructed as described above can hold the upper and lower projecting members 5 and 6 by the support portion 7, so that its mechanical strength is higher than that of the conventional projecting portions 5 and 6, and Body 4
Is hardly deformed by human and mechanical contact after fixing, and desired quality of convergence performance can be stabilized.

In addition, delicate attention to contact necessary after fixing the projecting body 4 is reduced, and workability is improved.

Second Embodiment FIG. 3 is a view showing an electron gun 1 provided in an in-line type color cathode ray tube according to a second embodiment of the present invention.
FIG. 3B is a front view seen from the downstream side in the traveling direction of the electron beam, FIG. 3B is a side view showing the tip of the electron gun, and FIG.
FIG. 3 is an enlarged perspective view of a protruding body. In the drawing, the protruding bottom surface is separated at the center, and the welding point 8 is located at the joint surface between the support portion 7 and the shield surface 2a.

According to the above configuration, as in the first embodiment, the mechanical strength is higher than that of the conventional projecting portion 4, so that it is hardly deformed by human and mechanical contact after the screen is fixed, and the desired quality of convergence performance is obtained. In addition to stabilizing, depending on the position of the welding point 8, the sub-assembly is previously welded to the shield cup bottom 2b in advance as in the case of the conventional projecting body 4, and it is not necessary to mount the sub-assembly. When the deflection yoke is changed and the horizontal deflection frequency is UP, only the protruding body 4 is designed and can be attached later to the electron gun 1 to which the shield cup 2 is fixed. Therefore, it is easy to change the design quickly and the manufacturing is easy.

[0019]

Since the present invention is configured as described above, it has the following effects.

By providing the support portions for supporting the upper and lower projecting portions, the strength of the projecting portions is increased, so that the quality can be stabilized.

Further, since the support portion and the shield surface are welded, the projecting member can be attached after the electron gun is prepared. Therefore, a design change involving a change in the horizontal deflection magnetic field and an early introduction of a performance improvement with respect to variations are provided. it can.

Further, since the protruding bottom surface is separated so as to include the electron beam passage holes on both sides, the welding dimensions can be easily made, the parts can be made smaller, and the mold cost for manufacturing can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing an inline color cathode ray tube according to a first embodiment of the present invention.

2 (a) is a front view, FIG. 2 (b) is a side view showing a tip portion of the electron gun, and FIG. 2 (c) is a view showing an electron gun according to Embodiment 1 of the present invention. It is an enlarged perspective view of a protrusion.

3A and 3B are diagrams showing an electron gun according to a second embodiment of the present invention, wherein FIG. 3A is a front view, FIG. 3B is a side view showing a tip portion of the electron gun, and FIG. It is an enlarged perspective view of a protrusion.

FIG. 4 is a diagram showing misconvergence caused by an in-line type color cathode ray tube due to a high-frequency horizontal deflection magnetic field.

5A and 5B are views showing a conventional in-line type electron gun for a cathode ray tube, wherein FIG. 5A is a front view and FIG. 5B is a side view.

FIG. 6 is an enlarged perspective view showing a conventional protruding body.

[Explanation of symbols]

1 electron gun, 2 shield cup, 2a shield surface, 2b cup bottom surface, 3 electron beam passage hole,
3s electron beam passage hole, 4 projecting body, 5, 6 projecting portion, 7 support portion, 8 welding point, 9 projecting bottom surface, 10 electron beam, 11 panel portion, 12
Phosphor screen, 13 color selection electrode, 14 funnel,
15 internal magnetic shield, 16 deflection yoke.

Claims (3)

[Claims] 1. A non-magnetic metal shield cup, which has a cylindrical shield surface and a cup bottom surface having three electron beam passage holes for an electron beam and is opened toward a fluorescent screen, is used as a fluorescent light source for an electron gun. In the in-line type color cathode ray tube having an end portion on the side of the surface, a projecting portion orthogonal to the bottom surface of the cup and projecting from the upper and lower phosphor screens on both sides of the electron beam passage hole, and the upper and lower projecting portions are supported. Support part, and 3
An electron beam drilled on the bottom surface of the cup, wherein a protruding body made of a non-magnetic metal having a bottom surface with three substantially identical electron beam apertures corresponding to the three electron beam apertures is formed. An in-line type color cathode ray tube wherein the position of the passage hole and the position of the electron beam passage hole formed in the bottom portion are aligned and fixed to the shield cup. 2. The in-line color cathode ray tube according to claim 1, wherein the support portion and the shield surface are welded. 3. The in-line type color cathode ray tube according to claim 2, wherein the protruding bottom surface is separated so as to include holes for passing electron beams on both sides.