KR200147983Y1 - A cathode-strap of the crt - Google Patents

Abstract

The present invention discloses an improved strap for supporting a cathode in an electron gun of a CRT.

In order to solve the problem of heat deformation and large heat loss due to a large amount of heat transfer due to the conventional W-shaped strap surface contact with the cathode, in the present invention, the cathode support part of the strap is composed of linearly extending surfaces so that the cathode and the strap are in line contact. It was. Accordingly, the amount of heat transfer to the strap is reduced, thereby reducing its heat deformation and enabling efficient electron emission of the cathode, thereby improving the performance and reliability of the CRT.

Description

Cathode ray tube cathode strap

1 is a cross-sectional view of an electron gun showing a supported state of a cathode.

Figure 2 is a longitudinal cross-sectional view showing the coupling state of the cathode assembly and the strap.

Figure 3 is a plan view of the strap support state to explain the conventional problem.

Figure 4 is a perspective view showing the configuration of the subject innovation strap.

5 is a plan view showing the cathode support state of the present invention strap.

* Explanation of symbols for main parts of the drawings

K: cathode assembly S1: inner sleeve

S2: outer sleeve S3: support sleeve

1 strap 2 cathode support

2a to 2c: straight extension surface 3a, 3b: bend

C1 to C3: contact line

The present invention relates to a cathode ray tube, and more particularly to a strap for supporting a cathode assembly to bead glass.

The CRT is an apparatus that displays an image by focusing electrons generated at the cathode into a plurality of electrodes to form an electron beam, and by accelerating the electron beam to selectively emit a fluorescent surface.

One cathode is provided for each electron gun. In an electron gun of a general in-line type CRA, three cathodes K are respectively bonded to a W-shaped strap T as shown in FIG. This strap T is supported by the electron gun by being embedded in bead glass B. FIG.

However, the cathode K emits hot electrons by heating a disc containing the electron-emitting material with a heater, and thus the cathode K includes a support structure on the strap T. It consists of an assembly made up of.

However, since the cathode assembly is directly bonded to the strap T, the strap T is thermally deformed by heat transfer, so that the outer sleeve S1 surrounding the inner sleeve S1 is shown in FIG. The support sleeve (S3) spaced apart from this by a predetermined interval is again bonded to the outer circumference. The support sleeve S3 is generally joined at one end with the outer sleeve S2 of the assembled cathode assembly in a state of being integrally bonded with the strap T. FIG.

The remaining symbol D is a disc coated or impregnated with the electron-emitting material.

However, since the outer sleeve (S2) and the support sleeve (S3) are bonded to each other at one end thereof, heat conduction occurs through this, and since the space between the two sleeves (S2, S3) does not have a very large gap, propagation of radiant heat therethrough. Is done.

As a result, a large portion of the heat generated by the heater (not shown) in the inner sleeve S1 must propagate to the strap T. The strap T surrounds only a portion of the outer circumference of the support sleeve S3. It is formed in a W-shape to cause a problem as shown in FIG. 3 (hereinafter, each component of a cathode assembly such as an outer sleeve S3 is collectively referred to as a cathode K).

In FIG. 3, the strap T is heated by heat transfer from the cathode K to thermally expand, whereby only the contact portion with the cathode K is expanded so that the cathode K is opened in the strap T. In FIG. It is pushed up to the side, that is, the upper side of the drawing. As a result, the cathode K deviates from the center of the electron gun during the operation of the CRT, causing a problem of deterioration of the image, such as a decrease in screen brightness or a change in white balance due to a decrease in electron emission efficiency.

In addition, when the amount of heat transfer to the strap T is large, the loss of the amount of heat for heating the disk D increases, so that efficient electron emission is not achieved.

In view of such a conventional problem, an object of the present invention is to provide a cathode strap that ensures efficient electron emission of the cathode to ensure stable support for the heat transfer of the cathode.

In order to achieve the above object, the cathode strap according to the present invention is a W-shaped strap that surrounds the cathode assembly, wherein at least the cathode support portion of the strap consists of straight federal surfaces that are bent at a predetermined angle at each bent portion. It is characterized by.

According to this configuration, since the cathode and the strap which are conventionally in contact with the surface are in line contact, the amount of heat transfer to the strap is reduced, thereby solving the problem of thermal deformation, and the heat loss is also reduced, resulting in efficient electron emission.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 4, the cathode strap 1 according to the present invention is generally formed in a W shape as in the prior art, and according to the feature of the present invention, the cathode support 2 on which the cathode K is to be supported is two bent portions 3a and 3b. It consists of three linear extension surfaces (2a, 2b, 2c) each bent at a predetermined angle in the). Even if the remaining surfaces are formed in a curved surface as in the prior art, the construction of the present invention does not interfere.

According to this configuration, when the cathode K is placed on the cathode support 2, the cylindrical cathode K has three linear extension surfaces 2a to 2c and one contact line C1, respectively, as shown in FIG. C2, C3) in a linear contact. The cathode K is joined to the strap 1 by seam welding or the like at each contact line C1 to C3.

This configuration actually means that when the cathode assembly is constructed as shown in FIG. 2, the support sleeve S3 is seam welded at three contact lines C1 to C3 with respect to the strap 1, and the disk D and inner The outer sleeve S2 containing the functional parts such as the sleeve S1 is inserted into the support sleeve S3 bonded to the strap 1 and joined in the same manner as in the prior art.

According to such a structure, the contact area of the cathode K and the strap 1 changes from the conventional curved surface to the line contact in three contact lines C1 to C3. As the heat transfer area is reduced, the heat transfer amount to the strap 1 is reduced, and the heat deformation is suppressed. Since the heat transfer amount is concentrated on the electron-emitting material of the disk D, the electron emission efficiency is improved.

Accordingly, the present invention ensures stable and efficient operation of the cathode, thereby greatly improving the performance and reliability of the CRT.

Claims (3)

In the W-shaped strap that surrounds the cathode and supports it in the bead glass, at least the cathode support portion 2 surrounding the cathode K is linearly stretched at a predetermined angle at the bent portions 3a and 3b. A cathode strap of a cathode ray tube consisting of faces (2a to 2c), wherein said cathode (K) makes line contact with said strap (1) at a plurality of contact lines (C1 to C3). The cathode strap according to claim 1, wherein the cathode (K) and the strap (1) are seam welded at each of the contact lines (C1 to C3). The support sleeve (S3) in which the said cathode (K) is joined to the said strap (1), and the outer sleeve (S2) which accommodates the functional part of the cathode (K). Cathode of the CRT, wherein the support sleeve S3 is seam-welded to the strap 1 at the contact lines C1 to C3 and then bonded to the outer sleeve S2. Strap.