KR100823186B1 - Mask assembly for cathode ray tube having means of relieving external shock - Google Patents

Abstract

The present invention relates to a mask assembly for a cathode ray tube, and more particularly to an external impact mitigation means to effectively suppress the deformation or vibration of the shadow mask due to an external impact applied to the cathode ray tube and to improve the doming phenomenon. A cathode ray tube mask assembly is provided.

In the present invention, a plurality of beam passing apertures are formed, and edges are bent in one direction to form a skirt portion, and at least one pair of beads are formed in parallel along the circumference of the skirt portion, and cushioned between the beads. A shadow mask having a dragon hole or a recess; A mask frame welded to the skirt to support the shadow mask; It is fixed to the outer periphery of the mask frame provides a mask assembly for a cathode ray tube including a plurality of spring members for mounting the mask frame inside the face panel.

Cathode ray tube, mask assembly, shadow mask, skirt section, buffer hole

Description

MASK ASSEMBLY FOR CATHODE RAY TUBE HAVING MEANS OF RELIEVING EXTERNAL SHOCK}

1 is an exploded perspective view showing a mask assembly for a cathode ray tube having an external impact mitigating means according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view seen from the direction A-A of FIG. 2.

3 is a cross-sectional view illustrating a state in which a shadow mask according to the first embodiment of the present invention is mounted on a mask frame.

4 is a cross-sectional view showing a shadow mask having an external impact mitigating means according to a second embodiment of the present invention.

5 is a schematic diagram illustrating a process in which an external shock is transmitted to a shadow mask.

* Description of the symbols for the main parts of the drawings *

10: shadow mask 10a: aperture for beam passing

10b: skirt part 10c: hole part

10d: No study 12: Bead

14: buffer hole 16: welding point

20: mask frame 20a: bottom

20b: side portion 22: spring member                 

34: recess

The present invention relates to a mask assembly for a cathode ray tube, and more particularly to an external impact mitigation means to effectively suppress the deformation or vibration of the shadow mask due to an external impact applied to the cathode ray tube and to improve the doming phenomenon. A cathode ray tube mask assembly is provided.

In general, a cathode ray tube is a display device that reproduces a predetermined screen by scanning three electron beams emitted from an electron gun onto a fluorescent screen, and a mask assembly mounted thereon is a shadow having a plurality of apertures for beam passing therethrough. It comprises a mask, a mask frame serving as a support of the mask, and a spring member provided on the frame and supporting the frame inside the face panel.

The shadow mask is formed by forming a plurality of apertures on a thin iron plate by photolithography, and then bending the periphery thereof by a press process. The completed mask is fixed to the frame by welding. A plurality of spring members are fixedly installed on the outer circumference, and the spring members are fitted to the stud pins formed inside the face panel to complete the mask assembly.

Here, the shadow mask functions as a color-coded electrode that separates three electron beams into corresponding R, G, and B fluorescent films through a plurality of apertures, so that the apertures formed in the mask during the cathode ray tube driving are maintained as they are. It is very important to do.

However, the shadow mask is very weak in its strength characteristics, causing a howling phenomenon, where the howling phenomenon causes deformation or vibration to cause the mask to be turned off by such an impact, particularly when an impact is applied to the cathode ray tube. I'm talking about the phenomenon. Both the deformation and the vibration of the mask act as a factor to deteriorate the image quality characteristics of the cathode ray tube by changing the positions of the apertures.

5 is a diagram illustrating a process in which an impact applied to a cathode ray tube is transmitted to a shadow mask, and an external shock is transmitted to the bulb surrounded by the explosion-proof band and the explosion-proof band through the jig wire, which is again masked through the stud pin and the spring member. It is delivered to the frame and finally delivered to the shadow mask through a weld with the mask frame.

For the purpose of damping such shocks and vibrations, Korean Laid-Open Patent Publication No. 2001-000990 discloses a vibration damping device which is installed to be in contact with a through-hole formed in an ineffective surface of a shadow mask and at the same time a predetermined portion is welded and fixed to the frame. Korean Patent Laid-Open Publication No. 2001-002082 discloses a shadow mask in a horizontal direction along an effective surface having a hole serving as color selection of an electron beam, an invalid surface not forming a screen, and a short side edge of the invalid surface. Disclosed is a howling prevention member formed by extending a bent plate having a predetermined horizontal length.

On the other hand, the shadow mask exhibits a doming phenomenon due to the electron beam emitted from the electron gun, where the 'Doming phenomenon' refers to an electron shadow mask emitted from the electron gun and the shadow mask heated by the beam thermally expands. In this case, the shadowing phenomenon of the shadow mask causes a change in the landing of the electron beam, thereby causing unwanted colors such as reddish and blueish.

In order to improve heat transfer in the shadow mask in order to improve the doming phenomenon, Korean Laid-Open Patent Publication No. 2000-061591 forms an opening by partially cutting the side portion of the mask frame, and the skirt portion of the shadow mask. Disclosed is a mask assembly structure in which an uneven portion is formed and a convex portion is seated in the opening.

However, the related arts have a problem in that the external shock transmitted to the frame through the welding point of the shadow mask is transmitted to the hole of the shadow mask without reduction, and also, there is a problem in that the howling phenomenon and the doming phenomenon cannot be simultaneously improved. .

The present invention has been made to solve the above problems, the object is to reduce the amount of shock transmitted to the shadow mask through the welding point in the mask frame to the deformation or vibration of the shadow mask due to the external impact applied to the cathode ray tube To provide a mask assembly for the cathode ray tube to effectively suppress the.

Another object of the present invention is to provide a mask assembly for a cathode ray tube which can improve the doming phenomenon by reducing the extent to which the shadow mask is convexly expanded by thermal expansion by the electron beam emitted from the electron gun.

In order to achieve the above object, the present invention, a plurality of beam passing apertures are formed, the edge is bent in one direction to form a skirt portion, at least a pair of beads are formed parallel to the periphery of the skirt portion A shadow mask having a buffer hole between the beads; A mask frame welded to the skirt to support the shadow mask; And a plurality of spring members fixedly installed at an outer circumference of the mask frame to mount the mask frame inside a face panel.

Here, the buffer hole may be formed to be located at the upper end of the welding portion of the skirt portion of the shadow mask and the mask frame.

Meanwhile, a recess may be provided between the beads formed along the circumference of the skirt instead of the buffer hole, and the recess may be formed above the skirt of the shadow mask and the weld point of the mask frame. have.

In addition, the recess may be formed by deep half etching.

By forming beads and recesses or buffer holes in the skirt portion of the shadow mask as described above, external shocks transmitted from the mask frame to the perforations of the shadow mask through the welding point can be alleviated.

In addition, the skirt portion is bent in the bow shape during thermal expansion of the shadow mask, thereby improving the degree of convex expansion of the pores of the shadow mask.

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

1 is an exploded perspective view showing a mask assembly for a cathode ray tube having an external impact mitigating means according to a first embodiment of the present invention, Figure 2 is a cross-sectional view seen from the A-A direction of FIG.

As shown in FIG. 1, the mask assembly according to the present exemplary embodiment has a mask inside frame assembly (MIFA) in which a side portion 20b of the mask frame 20 is wrapped around the skirt portion 10b of the shadow mask 10. As a method, the outer surface of the skirt portion 10b of the shadow mask 10 and the inner surface of the side portion 20b of the mask frame 20 are fixed by welding.

In this case, the shadow mask 10 includes a perforated part 10c having a plurality of beam passing apertures 10a formed therein, an unperforated part 10d around the perforated part 10c, and a perforated part 10d. Consists of a skirt portion 10b that is bent toward the frame 20, and a plurality of beam passing apertures 10a are formed by a photolithography method, and then formed by a pressing process to be completed.

In the skirt portion 10b of the shadow mask 10, a pair of beads 12 are formed in parallel along the circumference thereof, and a buffer hole 14 is provided between the beads 12.

2, the bead 12 is formed in a shape protruding to the outside of the skirt portion 10b facing the frame 20 at a predetermined width and height, and has a buffer hole ( 14 is formed at the upper end of the skirt portion 10b of the shadow mask 10 and the welding point 16 of the mask frame 20, so as to have a constant width in the width direction of the skirt portion 10b. It is preferably formed.

FIG. 1 illustrates an embodiment in which a pair of rectangular buffer holes 14 corresponding to upper ends of a pair of welding spots are formed on each surface of the skirt portion 10b, but is not limited thereto. A dragon hole may be formed, and the form can also be modified by oval shape or the like.

On the other hand, the mask frame 20 is composed of a bottom portion 20a having an opening formed therethrough for electron beam passage, and a side portion 20b bent toward the shadow mask 10 around the bottom portion 20a. The spring member 22 detachably couples to a stud pin (not shown) fixed to a face panel (not shown) of the cathode ray tube to serve to fix and support the mask frame 20 inside the face panel.

3 is a cross-sectional view illustrating a state in which a shadow mask according to the first embodiment of the present invention is mounted on a mask frame.

In Figure 3, the shadow mask 10 according to the present invention before the thermal expansion by the electron beam emitted from the electron gun (part shown by the solid line) and the post-expansion portion 10c is convexly expanded form (shown in dashed lines) And a portion of the conventional shadow mask without the beads and the buffer holes were also thermally expanded to compare the degree of expansion of the perforations 10c.

By forming the beads 12 at the upper end of the welding point 16 of the skirt portion 10b of the shadow mask 10 and forming the buffer holes 14 therebetween, the supporting force of the skirt portion 10b is weakened. Because of this, the skirt portion 10b is bent into a bow shape as shown in FIG. 3 due to thermal expansion of the shadow mask 10, and thus the convex expansion degree of the perforated portion 10c of the shadow mask 10 according to the present invention is increased. (d1) is reduced than the degree of convex expansion d2 of the conventional shadow mask perforations.

Therefore, it is possible to realize a more stable landing by improving the thermal drift (doming phenomenon) in which the shadow mask 10 hole portion 10c is convexly expanded due to the collision with the electron beam.

In addition, the beads 12 and the buffer holes 14 are formed in the skirt portion 10b so that the beads 12 and the buffer holes 14 are connected to the welding point 16 from the mask frame 20. It serves to act as a damper (damper) to reduce the external shock transmitted to the hole (10a) of the shadow mask 10 through.

This suppresses deformation or vibration of the shadow mask 10 due to external impact, and as a result, it is possible to minimize the positional change of the aperture 10a for beam passing.

4 is a cross-sectional view showing a shadow mask having an external impact mitigating means according to a second embodiment of the present invention.

 As shown in FIG. 4, the shadow mask 30 according to the second embodiment has a pair of parallel beads 32 formed in the skirt portion 30b as in the first embodiment. Unlike the example, a recess 34 is provided between the beads 32.

The concave portion 34 is preferably positioned at the upper end of the welding portion of the skirt portion 30b of the shadow mask 30 and the mask frame, and may be formed by so-called deep half etching. Can be.                     

The concave portion 34 plays a role similar to that of the buffer hole in the first embodiment, and reduces external shock transmitted from the mask frame to the hole 30a of the shadow mask 30 through the welding point. In addition to acting as a damper, the support force of the skirt portion 30b is weakened to improve thermal drift (doming phenomenon) in which the shadow mask 30 perforated portion 30c is convexly expanded by collision with the electron beam. It makes it possible to realize stable landing.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

As described above, according to the mask assembly for a cathode ray tube having an external impact mitigating means according to the present invention, a bead, a buffer hole or a recess is formed in a skirt portion of a shadow mask, and is transmitted to the shadow mask through a welding point in the mask frame. By mitigating the impact amount and effectively suppressing the deformation or vibration of the shadow mask caused by the external shock applied to the cathode ray tube, the positional change of the aperture for beam passing can be minimized, and as a result, the image quality of the cathode ray tube can be reduced. There is an effect that can be minimized.

In addition, by reducing the extent that the shadow mask is convexly expanded by thermal expansion by the electron beam emitted from the electron gun, it is possible to improve thermal drift (doming phenomenon) to achieve a more stable landing.

Claims (5)

A plurality of beam passing apertures are formed, the edges are bent in one direction to form a skirt portion, and at least one pair of beads are formed in parallel along the circumference of the skirt portion, and a buffer hole is provided between the beads. A shadow mask; A mask frame welded to the skirt to support the shadow mask; And And a plurality of spring members fixedly installed at an outer circumference of the mask frame to mount the mask frame inside a face panel. The method of claim 1, The buffer hole is a cathode ray tube mask assembly is formed so as to be located above the skirt portion of the shadow mask and the welding point of the mask frame. A plurality of beam passing apertures are formed, the edges are bent in one direction to form a skirt portion, and at least one pair of beads are formed in parallel along the circumference of the skirt portion, and a shadow having recesses therebetween. Mask; A mask frame welded to the skirt to support the shadow mask; And And a plurality of spring members fixedly installed at an outer circumference of the mask frame to mount the mask frame inside a face panel. The method of claim 3, wherein The concave portion is a mask assembly for a cathode ray tube is formed so as to be located on the upper end of the skirt portion of the shadow mask and the mask frame. The method of claim 3, wherein And the concave portion is formed by deep half etching.

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