JPH06260111A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To position an electron gun precisely against a neck part center axis (tube axis) and insert the electron gun in the inside of the neck part and support the gun without damaging the inner wall of the neck part and peeling the inner conductive film. CONSTITUTION:An electron gun has a plurality of valve spacer contacts 13 extruded in the outer circumference of the shield cup in the panel part side of the electrode gun wherein a valve spacer 13 contact is composed of a projected arm part 13-1 to be fixed in the outer circumference of the shield cup and a folded back arm part 13-3 which has a contact part 14 with a wavy shape in the free end side in the insertion direction to the center axis of a neck part 4 to have point-contact with the inner wall of the neck part while being folded back on the opposite side to the fixed side. Consequently, the valve spacer contacts 13 are smoothly inserted in the neck part 2 through the opened periphery and the insertion pressure is applied evenly to the plurality of the valve spacer contacts 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube such as a color picture tube or a display tube, and more particularly to a cathode ray tube having an electron gun assembly having an improved structure for accommodating and supporting it in the neck of the cathode ray tube.

[0002]

2. Description of the Related Art A cathode ray tube is composed of a panel portion which is an image screen, a neck portion which houses an electron gun, and a funnel portion which connects the panel portion and the neck portion, and an electron beam emitted from the electron gun is panel portion. The image is reproduced by being projected onto the fluorescent surface formed on the inner surface.

FIG. 5 is a sectional view for explaining the schematic structure of a color picture tube which is an example of a cathode ray tube.
Reference numeral 2 is a shadow mask suspended in the panel portion, 3 is a funnel portion, 4 is a neck portion, and 5 is an electron gun housed and supported in the neck portion. Reference numeral 13 is a valve spacer contact for contacting the electron gun and the conductive film in the tube to apply an anode voltage to the electron gun and to support the electron gun on the inner wall of the neck portion.
Reference numeral 17 is a fluorescent screen formed on the inner surface of the panel portion, 18 is a magnetic shield, 19 is a getter, 20 is a deflection yoke, and 21 is an electron beam.

If necessary, the outer surface of the panel portion 1 may be, for example, SnO ₂ or In ₂ O ₃ for reflection and antistatic purposes.
A thin film including the above is formed in a single layer or multiple layers. The in-tube conductive film contains a resistance substance such as titanium dioxide in graphite and is applied to a part of the inner surface of the funnel portion and the inner surface of the neck portion, and is connected to a high voltage terminal (not shown) for supplying an anode voltage on the inner surface of the funnel portion. .

In the cathode ray tube having the above-described structure, the electron beam 21 emitted from the electron gun 5 is deflected in the horizontal and vertical directions by the deflection yoke 20 so that the electron beam 21 is projected onto the fluorescent screen 17 by two.
Play a three-dimensional image. FIG. 6 is a cross-sectional view of a main part of a color cathode ray tube showing an example of the structure of an electron gun housed in the neck portion 4 of the color cathode ray tube, 6 being a first lattice electrode, 7 a second lattice electrode, and 8 Is a third grid electrode, 9 is a fourth grid electrode, 1
Reference numeral 0 is a fifth grid electrode, 11 is a sixth grid electrode, 12 is a shield cup, 13 is a valve spacer contact, 14 is an electron emission surface (cathode), 15 is a stem, 16 is each grid electrode fixedly held at a predetermined position. It is a bead glass.

In the figure, the electron gun 5 is housed in the neck portion 4, and an electron beam controlled according to a signal applied to the first grid electrode 6 is used as a second grid electrode 7 and a third grid electrode 8. , The fourth grid electrode 9, the fifth grid electrode 10, and the sixth grid electrode 11 are converged by the electron lens and reach the fluorescent screen through the shadow mask to reproduce an image. The electron gun 5 is inserted into the neck portion 4 and supported by the valve spacer contact 13 on the inner wall of the neck.

As a disclosure of the prior art relating to this type of cathode ray tube, there is JP-A-59-215640.

[0008]

FIG. 7 is an explanatory view showing the structure of a conventional valve spacer contact and a state in which the electron gun is inserted into the neck portion. In the figure, the valve spacer contacts 13 are made of a thin plate of elastic metal, and a plurality of valve spacer contacts 13 are provided so as to project on the outer peripheral portion of the cylindrical shield cup 12. The valve spacer contact 13 is folded back at the protruding arm portion 13-1 fixed to the shield cup and on the side opposite to the fixed side thereof, and has a partially spherical contact portion 13 on the free end side.
-2 and the folding arm part 13-3.

When the electron gun 5 is inserted into the neck portion 4 of the cathode ray tube, the valve spacer contact 13 has its folded arm portion 13-3 in contact with the open portion of the neck portion 4 and slides inside the neck portion 4. It is pushed in the direction of arrow A so as to invade. Therefore, the valve spacer contact 13
The folded arm portion 13-3 is compressed in the direction of arrow B and enters the pipe.

A contact portion 13-2 formed on the folded arm portion 13-3 of the illustrated valve spacer contact 13.
Is formed with a partial spherical portion having a step from the surface of the folding arm portion 13-3, the electron gun is not smoothly inserted into the neck tube, and when the open end of the neck portion gets over the step, An excessive compressive force is exerted on the valve spacer contact 13 and its elastic action is obstructed, the central axis of the electron gun deviates from the central axis of the neck portion, the convergence characteristics are impaired, and the inner wall of the neck portion 4 is damaged.
There is a problem that the internal conductive film is peeled off at the portion of the internal conductive film, and the withstand voltage characteristic is deteriorated.

An object of the present invention is to solve the above-mentioned problems of the prior art, reduce an excessive force applied to the valve spacer when inserting the electron gun into the neck portion, and reduce the central axis (tube axis) of the electron gun neck portion. (EN) Provided is a cathode ray tube having an electron gun which is accurately positioned, does not damage the inner wall of the neck portion 4 and does not peel off the inner conductive film, and inserts and supports the electron gun in the neck portion. is there.

[0012]

In order to achieve the above object, the present invention provides a panel section having a fluorescent surface formed on its inner surface, a neck section for accommodating an electron gun, and a funnel for connecting the panel section and the neck section. And a plurality of valve spacer contacts projecting from the outer periphery of the shield cup at the panel side end of the electron gun. The valve spacer contacts are supported in contact with the inner wall of the neck portion to predetermine the electron gun. In a cathode ray tube which holds an electron beam emitted from the electron gun on the fluorescent surface formed on the inner surface of the panel portion and reproduces an image, the outer periphery of the shield cup on the panel portion side of the electron gun is held. A plurality of valve spacer contacts 13 projecting on the side of the shield are fixed to the outer periphery of the shield cup at the end on the panel side and the opposite side from the fixed side. The folded arm portion 13-3 is formed by folding back and forming a contact portion 14 having a flow shape in the insertion direction toward the central axis of the neck portion 4 and having a shape that makes point contact with the inner wall of the neck portion on the folded free end side. It is characterized by having an electron gun provided.

The flow-shaped contact portion 14 formed on the folded-back portion 13-3 stands up on the neck inner wall side surface of the folded-back portion 13-3 with a continuous curved surface without a step, and at the top thereof, the neck inner wall. It may have a shape that makes point contact with, and the surface shape may be a partial spherical shape, a partial oval shape, a partial conical shape, or any other curved surface having a curvature in two directions.

[0014]

With the above-described structure of the present invention, when the electron gun is inserted into the neck portion, the valve spacer contact is smoothly pushed into the open edge of the neck portion. Therefore, the insertion pressure applied to the plurality of valve spacer contacts becomes uniform, and the central axis of the electron gun is housed and held in a state where it coincides with the tube axis.

Further, since the insertion pressures applied to the plurality of valve spacer contacts are equalized, the force of the valve spacer contact applied to the inner wall of the neck portion does not become excessive at a specific valve spacer contact, so that the neck portion is prevented. Does not damage the inner wall of the film or peel off the internal conductive film.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a first cathode ray tube according to the present invention.
FIG. 4A is a side view and FIG. 4B is a front view showing only a main part including a valve spacer contact for explaining an embodiment, where 4 is a neck part, 12 is a cylindrical shield cup, 13 is a valve spacer contact, and 13 is a valve spacer contact. -1 is a protruding arm portion, 13
-3 is a folding arm part, and 14 is a contact part.

In the figure, a valve spacer contact 13 has a protruding arm portion 13-1 whose one end is spot-welded to the outer periphery of the shield cup 12, and the protruding arm portion 1.
3-1 Fold-back arm part 13-folded back at the other end
3 and the contact portion 14 formed on the free end side of the folding arm portion 13-3. In this embodiment, the contact portion 14 has a partially oval curved surface having a streamlined shape that gradually rises toward the free end direction on the inner wall side of the neck portion 4 and gradually falls from the top.

By providing the contact portion 14 having such a curved surface shape, when the electron gun is inserted into the neck portion 4 in the arrow A direction, the contact portion 14 is the open end of the neck portion 4 in the arrow B direction. Is pressed smoothly. FIG. 2 is an explanatory view showing a state in which the valve spacer contact is pushed into the neck portion 4 beyond the open end of the neck portion 4.

As shown in the figure, the valve spacer contact 13 holds the electron gun at a predetermined position while being in pressure contact with the internal conductive film 4 '. Therefore, since the insertion pressure applied to the plurality of valve spacer contacts 13 is equalized, the force of the plurality of valve spacer contacts 13 applied to the inner wall of the neck portion 4 does not become excessive at a specific valve spacer contact, and the neck portion does not become excessive. It does not damage the inner wall of 4 or peel off the inner conductive film 4 '.

3A and 3B are a side view and a front view of a valve spacer contact portion for explaining a second embodiment of the cathode ray tube according to the present invention. 13 'is a projecting arm portion 13'-one end of which is spot welded to the outer circumference of the shield cup.
1, the folding arm portion 13′-3 folded back at the other end of the protruding arm portion 13′-1, and the contact portion 14 ′ formed on the free end side of the folding arm portion 13′-3. Composed.

In this embodiment, the contact portion 14 'has a partially spherical curved surface having a flow shape which gradually rises toward the free end direction on the inner wall side of the neck portion 4 and gradually falls from the top. By providing the contact portion 14 ′ having such a curved shape, when the electron gun is inserted into the neck portion 4 in the direction of arrow A, the contact portion 14 ′ of the neck portion 4 is provided as in the above-described embodiment. It is pressed smoothly in the direction of arrow B at the open end.

Therefore, since the insertion pressure applied to the plurality of valve spacer contacts 13 'becomes equal, the force of the plurality of valve spacer contacts 13' applied to the inner wall of the neck portion 4 becomes excessive at a specific valve spacer contact. The inner wall of the neck portion 4 is not damaged and the inner conductive film is not peeled off. FIG. 4 is a graph showing the insertion pressure of the valve spacer contact in each of the embodiments of the present invention in comparison with the insertion pressure of the valve spacer contact of the prior art.

In the figure, the curve A shows the insertion pressure of the valve spacer contact according to the prior art, and the curve B shows the insertion pressure of the valve spacer contact according to the present invention. As is clear from both curves, according to the present invention, the insertion pressure of the valve spacer contact is at most half the value of that of the prior art, and can be made 1/4 on average.

[0024]

As described above, according to the present invention,
Without hindering the strength of the valve spacer contact,
Further, it is possible to accurately hold the electron gun around the tube axis without damaging the inner conductive film on the inner wall of the neck portion, and to provide a cathode ray tube having excellent withstand voltage characteristics.

[Brief description of drawings]

FIG. 1 shows only a main part including a valve spacer contact for explaining a first embodiment of a cathode ray tube according to the present invention (a).
It is a side view and the (b) front view.

FIG. 2 is an explanatory view showing a state in which a valve spacer contact has been pushed into the neck portion 4 beyond the open end of the neck portion 4;

3 (a) is a side view of a valve spacer contact portion for explaining a second embodiment of the cathode ray tube according to the present invention, FIG.
It is a front view.

FIG. 4 is a graph showing the insertion pressure of the valve spacer contact in each of the above-described embodiments of the present invention in comparison with the insertion pressure of the valve spacer contact of the prior art.

FIG. 5 is a cross-sectional view illustrating a schematic structure of a color picture tube which is an example of a cathode ray tube.

FIG. 6 is a cross-sectional view of a main part of a color cathode ray tube showing a configuration example of an electron gun housed in a neck portion 4 of the color cathode ray tube.

FIG. 7 is an explanatory view showing a structure of a valve spacer contact of the related art and a state in which an electron gun is inserted into a neck portion.

[Explanation of symbols]

 4 Neck part 12 Cylindrical shield cup 13 Valve spacer contact 13-1 Projecting arm part 13-3 Folding arm part 14 Contact part.

Claims (1)

[Claims] 1. A shield at a panel-side end of the electron gun, comprising a panel portion having a fluorescent surface formed on its inner surface, a neck portion for accommodating an electron gun, and a funnel portion connecting the panel portion and the neck portion. A plurality of valve spacer contacts are provided on the outer circumference of the cup so as to contact and support the valve spacer contacts on the inner wall of the neck portion to hold the electron gun at a predetermined position, and to direct the electron beam emitted from the electron gun to the above In a cathode ray tube that reproduces an image by projecting it onto a fluorescent screen formed on the inner surface of the panel section, a plurality of valve spacer contacts projecting on the outer periphery of the shield cup on the panel section side of the electron gun are provided on the panel section side. The protruding arm fixed to the outer circumference of the shield cup at the end is folded back on the side opposite to the fixed side, and is inserted into the folded free end facing the central axis of the neck. A cathode ray tube comprising an electron gun provided with a folding arm portion having a contact portion having a flow shape in a direction and having a shape of point contact with the inner wall of the neck portion.