JPH0334238A - Braun tube and its shape recovery treatment method - Google Patents

Abstract

PURPOSE:To prevent the scratching of a conductive coat by fixing a contact surface with a glass inner wall between a neck glass inner wall and the partition board of a shield cup, and providing an intermediate metal fitting capable of sliding with the partition board to clog a gap. CONSTITUTION:A partition board 1 of cylindrical contact made of shape memory alloy mounted on the top end of a shield cup 3 mounted on the anode electrode 4 of an electron gun and a spiral ring 2 of an intermediate metal fitting made of shape memory alloy material capable of sliding with the partition board 1 are deformed and inserted into a tube 2 in such a manner as not to scratch the inner wall of a neck glass tube 5. When their shapes are returned, the ring 2 is closely adhered and fixed to a conductive coat 6 on the inner wall of the tube 5, and the gap between the partition board 1 and the inner wall of the tube 5 is clogged without scratching the film 6. Hence, the fine particle formation by scratching never occurs, and the withstand voltage of the electron gun is stably held.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electron gun inside a cathode ray tube, and in particular, the electron gun housing part can be sealed, and the conductive coating film of the element can be sealed by external impact. The present invention relates to an electron gun suitable for high-voltage insulation, which has a particulate blocking element that prevents the element from scratching the conductive coating due to external impact, and which allows the electron gun compartment to be hermetically sealed.

[Conventional technology]

The conventional cathode ray tube particulate blocking element
As described in Publication No. 27, a gap between the neck glass tube and the shield cup was partitioned off by a partition plate attached to the connection between the shield cup and the anode electrode.

This known example is shown in FIG. 11 and will be explained. In the electron gun, an anode electrode 4 is attached to the lower part of a shield cup 3, and each electrode is held by a bead glass 14. A valve spacer contact 12 is attached to the upper end of the shield cup, thereby holding it to the cathode ray tube. An annular metal partition plate 1 between the shield cup and the neck glass
3 was provided to prevent particles from entering the electron gun storage space from the funnel glass.

[Problem to be solved by the invention]

A cathode ray tube electron gun is composed of multiple stages of electrodes such as a cathode electrode, multiple stages of grid electrodes, and an anode electrode.
Appropriate potentials are applied to each to generate an electron beam with good convergence. It is known that the presence of fine particles between the electrodes constituting the electron gun significantly reduces the withstand voltage of the electron gun. In order to increase the withstand voltage of an electron gun, it is effective to prevent particles from entering the electron gun storage space.

The above-mentioned conventional technology generates a high electric field at the contact portion of the neck glass 5 at the tip of the metal partition plate 13, and in the long term, a tree-shaped dielectric breakdown mark that gradually develops inside the neck glass material is generated, causing the glass to deteriorate. There is a problem in that through-holes are formed. In order to prevent this, even if the partition plate is brought into contact with the conductive coating applied to the inner wall of the neck glass.

When the electron gun is inserted into the neck glass, a problem arises in that fine particles generated by peeling off due to contact friction with the conductive coating enter the electron gun.

The purpose of the present invention is to shield the gap between the neck glass and the shield cup, eliminate contact friction with the conductive coating applied to the inner wall of the neck glass tube when inserting the electron gun, and create a high electric field at the contact part with the inner wall of the neck glass tube. An object of the present invention is to provide an electron gun equipped with a particulate blocking element that does not cause particles.

Another object of the present invention is to attach a partition plate made of a shape memory alloy to the upper end of the shield cup, deform the shape, insert it into the neck glass, and recover the shape by increasing the temperature, thereby separating the inner wall of the neck glass and the shield cup. If the gap is closed, if an external impact is applied to the CRT with the partition plate attached, the partition plate and the inner surface of the neck glass will slide and generate particles, so even if an external impact is applied, particles will not be generated. An object of the present invention is to provide an electron gun equipped with such a particle blocking element.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a structure in which the contact surface with the inner surface of the neck glass is fixed between the inner wall of the neck glass and a cylindrical partition plate made of shape memory alloy attached to the upper end of the shield cup, and the outer periphery of the partition plate is fixed. A slidable intermediate metal fitting is placed on the contact surface with the surface to close this gap.

[Effect]

The maximum diameter of the intermediate fitting is made larger than the inner diameter of the neck glass so that the contact portion with the conductive coating film applied to the inner wall of the neck glass is fixed by the restoring force. Further, the contact portion between the outer circumferential surface of the partition plate and the intermediate fitting is made slidable. As a result, the gap between the neck glass and the partition plate is closed, and the electron gun storage space is sealed. When an impact is applied to the cathode ray tube, sliding occurs between the partition plate and the intermediate metal fitting, and the conductive coating film is not scratched, so generation of fine particles can be prevented.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. A cylindrical contact l made of a shape memory alloy material is attached to the inside of the upper end of the shield cup 3, and a spiral ring 2 made of a shape memory alloy material is provided that can closely adhere to the conductive coating film and the cylindrical contact and close the gap therebetween.

At least one protrusion 1a is formed at the upper end of the cylindrical contact to prevent the spiral ring from falling.

When inserting the electron gun into the neck glass, as shown in Figure 3, the spiral ring 2 and cylindrical contact 1 are deformed into a shape that will not scratch the inner wall, and after insertion, the spiral ring is coated with a conductive coating. The cylindrical contact is restored to its shape so that it is in contact with the helical ring, and the cylindrical contact is restored to its shape so that it is in close contact with the helical ring. According to this embodiment, the electron gun storage space can be sealed and external impact is absorbed by the sliding movement of the single cylindrical contact and the helical ring, so there is an effect that scratching of the conductive coating film can be eliminated.

Furthermore, a second embodiment of the present invention will be explained with reference to FIG.
The difference from FIG. 1 is that the cylindrical contact 1 is attached to the outside of the upper end of the shield cup 3, and projections are provided above and below the cylindrical contact. This makes it easier to attach the cylindrical contact to the shield cup compared to FIG. 1.

A third embodiment of the present invention will be explained with reference to FIG.

The conical cylinder element 7 and the shield cup 3 are made slidable.

The difference from FIG. i is that an upper fall prevention plate 8 and a lower protrusion 9 are provided. When inserting the electron gun into the neck glass,
As shown in the figure, the conical cylindrical element and the upper fall prevention plate are deformed into a shape that does not scratch the inner wall, and after insertion, the conical cylindrical element is restored to its shape so as to come into contact with the conductive coating. As a result, the amount of shape memory alloy material used can be reduced compared to FIG.

A fourth embodiment of the present invention will be described with reference to FIG.

The difference from FIG. 1 is that a conical cylindrical contact 10 made of a shape memory alloy material is attached to a shield cup 3 whose upper end is widened, and a cylindrical ring 11 made of a shape memory alloy material is provided at the inner wall contact portion of the upper end of the 1 conical cylindrical contact. do. Due to this,
Mounting the element on the shield cup is easier than in FIG. 1.

〔Effect of the invention〕

According to the present invention, since the electron gun storage section can be sealed, it is possible to prevent fine particles from entering the electron gun, and after sealing, the element does not scratch the conductive coating, so that fine particles can be prevented from entering the electron gun. Does not occur.

Since the electron gun storage space can be made dust-free, the withstand voltage of the electron gun can be stably maintained, and the dark current flowing through the grid electrode of the electron gun can always be maintained at 10''gA or less.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a perspective sectional view of FIG. 1, FIG. 3 is a perspective view illustrating the operation of FIG. A sectional view of the second embodiment, FIG. 5 is a perspective sectional view of FIG. 4, FIG. 6 is a sectional view of the third embodiment of the present invention, FIG. 7 is a perspective sectional view of FIG. 6, Figure 8 is the 6th
FIG. 9 is a sectional view of the fourth embodiment of the present invention; FIG. 10 is a perspective sectional view of FIG. 9;
FIG. 1 is a sectional view of a conventional example. 1... Cylindrical contact, 2... Spiral ring, 3...
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Claims (1)

[Claims] 1. Covering the conductive coating film on the inner wall surface of the neck glass with a conductive solid layer in the gap between the inner wall of the neck glass and the tip of the shield cup attached to the anode electrode of the internal electron gun, A cathode ray tube, wherein the shield cup contacts the conductive solid layer from above to close the gap. 2. In claim 1, a cylindrical partition plate made of a shape memory alloy is attached to the inside or outside of the shield cup of the internal electron gun, and a conductive coating film is formed on the partition plate and the inner wall surface of the neck glass. An intermediate metal fitting is arranged between the intermediate metal fitting and the conductive coating film so that the contact surface of the intermediate metal fitting is fixed and the contact surface with the outer periphery of the partition plate is slidable to close this gap. A cathode ray tube that is characterized by 3. The cathode ray tube according to claim 2, wherein the intermediate fitting is a spiral ring made of a shape memory alloy. 4. In claim 2, a conical cylindrical intermediate fitting made of a shape memory alloy is disposed between the shield cup of the internal electron gun and the conductive coating on the inner wall surface of the neck glass. A cathode ray tube. 5. The cathode ray tube according to claim 2, further comprising at least one protrusion or fall prevention plate provided on the electron gun side to prevent the intermediate fitting from falling. 6. In claim 2, the intermediate fitting is a cylindrical ring made of a shape memory alloy,
A cathode ray tube, characterized in that the partition plate in the shape of a conical cylinder made of a shape memory alloy is attached to the upper end of the shield cup, so that the outer circumference of the tip of the conical cylinder contacts the inner surface of the cylindrical ring. 7. In claim 2, after deforming the shape of the intermediate metal fitting made of a shape memory alloy, inserting it into the neck glass and increasing the temperature to recover the shape of the intermediate metal fitting so as to contact the conductive coating film, The shape-memory alloy partition plate attached to the shield cup of the electron gun is deformed, the electron gun is inserted into the neck glass, and the temperature is raised again so that it comes into contact with the intermediate metal fitting. A method for restoring the shape of a cathode ray tube by restoring the shape of the partition plate. 8. In claim 2, the intermediate metal fitting made of a shape memory alloy is deformed, and the partition plate made of a shape memory alloy attached to the shield cup of the electron gun is deformed, and the intermediate metal fitting and the electron gun are deformed. After inserting the gun together into the neck glass, the intermediate fitting and the partition plate are simultaneously restored to their shape so that the intermediate fitting and the conductive coating are in contact with each other and also in contact with the partition plate. Shape recovery processing method.