KR20020073060A - An explosion proof band and a cathode ray tube having the same - Google Patents

Abstract

PURPOSE: An explosion proof band and cathode ray tube having explosion proof band is provided to supplement a magnetic field shielding function of an inner shield by providing magnetic field characteristics to the explosion proof band, while reducing influence of terrestrial magnetic field on the electron beam path. CONSTITUTION: A cathode ray tube comprises a vacuum bulb(8) where a face panel, a funnel(4) and a neck part(6) are integrally coupled into a single unit; a fluorescent screen formed at the inner surface of the face panel; an electron gun for emitting three electron beams toward the fluorescent screen; a deflection yoke(12) mounted to the outer periphery of the funnel, and which deflects electron beams by generating a deflection magnetic field; an inner shield mounted within the bulb, and which reduces influence of terrestrial magnetic field on the electron beam; and an explosion proof band(22) mounted to the outer periphery of a skirt portion of the face panel, and which applies a predetermined tension force. The explosion proof band has a pair of longer sides arranged to be opposed with each other in the vertical direction of the screen, wherein the longer sides are made of a high permeability material.

Description

Explosion proof band and cathode ray tube having same {An explosion proof band and a cathode ray tube having the same}

The present invention relates to a cathode ray tube, and more particularly, to an explosion-proof band for minimizing the amount of change in landing of an electron beam by a geomagnetic field by blocking a horizontal geomagnetic field affecting an electron beam path, and a cathode ray tube including the same.

In general, a cathode ray tube is a display device that implements a predetermined screen by scanning a fluorescent film screen with an electron beam emitted from an electron gun. The three-stem electron beam emitted from an electron gun is deflected by a magnetic field in which a deflection yoke is generated, and thus a raster ( While forming a raster, it is separated into corresponding R, G, and B fluorescent films by a shadow mask, which is a color-selective electrode, to realize accurate colors.

Thus, in order for the three-stem electron beam emitted from the electron gun to emit the designated fluorescent film, an accurate raster must be formed by the deflection magnetic field and exactly matched at one point of the shadow mask. However, since the electron motion inside the cathode ray tube is affected by the geomagnetic field, the geomagnetic field influences the convergence characteristics of the electron beam (the degree to which the three-beam electron beams coincide in one point), the raster position, and the purity (color purity) characteristics. Get mad.

These geomagnetic fields are divided into horizontal components parallel to the ground and vertical components perpendicular to the ground, and their values vary according to the location and location on the earth. Particularly, the horizontal magnetic fields parallel to the ground are used to change the direction of the cathode ray tube. It is very important to block the raster as it affects the electron beam path, causing the raster to shift and inducing convergence changes.

Therefore, an inner shield, which is a kind of magnetic shield, is installed inside the cathode ray tube to reduce the amount of change in the landing of the electron beam by the geomagnetic field by about 50%. There is a limit that does not effectively block the electron beam toward the geomagnetic field, especially the horizontal geomagnetic field.

Meanwhile, the bulb constituting the cathode ray tube is integrally sealed with a face panel made of glass, a funnel and a neck portion, and as shown in FIG. 7, a constant tension is applied to the bulb 3 to the outer circumferential surface of the face panel 1. Explosion-proof band (5) is mounted serves to prevent the glass from scattering during the explosion of the bulb (3) due to cracks.

In the process of mounting the explosion-proof band 5 to the bulb 3, the tape (not shown) is wound around the outer surface of the bulb 3 where the vane 5 is to be placed, and the band 5 is heated to about 500 to 600 ° C. By inserting the bulb (3) therein in a state of inflating it and then cooling the band (5). As a result, the explosion-proof band 5 is firmly fixed while applying continuous tension to the outer circumferential surface of the bulb 3.

The explosion-proof band 5 is generally made of low-carbon steel having a low price and low permeability, and its use is insufficient for the purpose of improving the magnetic field characteristics of the cathode ray tube in addition to its own explosion-proof function.

Therefore, the present invention is to solve the above problems, an object of the present invention is to impart the magnetic field characteristics to the explosion-proof band to compensate for the magnetic shielding function of the inner shield, and in particular, the ground for the electron beam path between the fluorescent film screen in the inner shield It is to provide an explosion-proof band and a cathode ray tube having the same that can reduce the influence of the system.

Another object of the present invention is to provide a magnetic field characteristic to the long side of the explosion-proof band to effectively block the geomagnetic field affecting the electron beam path, in particular the horizontal geomagnetic field by explosion-proof band that can minimize the amount of landing change of the electron beam by the geomagnetic field and It is to provide a cathode ray tube having the same.

1 is a perspective view of a cathode ray tube according to the present invention.

2 is a cross-sectional view of a cathode ray tube according to the present invention.

3 is a front view of the explosion-proof band according to the present invention.

4 is a schematic diagram showing a path of the explosion-proof band and the horizontal geomagnetic field shown in FIG.

5 is a front view of the explosion-proof band according to another embodiment of the present invention.

6 is a schematic view showing a path of the explosion-proof band and the horizontal geomagnetic field shown in FIG.

7 is a perspective view of a cathode ray tube according to the prior art;

In order to achieve the above object, the present invention,

Explosion-proof band mounted on the outer circumferential surface of the bulb while applying a predetermined tension to the bulb to prevent glass from scattering, wherein a pair of long sides facing each other in the vertical direction is made of a high permeability material. To provide.

In addition, the present invention to achieve the above object,

A vacuum bulb in which the face panel and the funnel and the neck portion are integrally integrated, a fluorescent screen formed on the inner surface of the face panel, an electron gun emitting a three-stage electron beam toward the fluorescent screen, and mounted on the outer peripheral surface of the funnel A deflection yoke for generating a magnetic field to deflect the electron beam, an inner shield mounted inside the bulb to surround the electron beam path, and reducing the influence of the geomagnetic field on the electron beam, and mounted on an outer circumferential surface of the skirt of the face panel to a predetermined tension An explosion-proof band for applying

The explosion-proof band provides a cathode ray tube, characterized in that the pair of long sides facing in the vertical direction is made of a high permeability material.

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

1 and 2 are a perspective view and a cross-sectional view of a cathode ray tube equipped with an explosion-proof band according to the present embodiment, respectively.

As shown in the drawing, the cathode ray tube is integrally coupled to the face panel 2, the funnel 4, and the neck portion 6 to form a vacuum bulb 8, and an inner surface of the screen portion 2a of the face panel 2. As a result, a fluorescent screen 10 including a plurality of R, G, and B fluorescent films is formed, and the deflection yoke 12 and the electron gun 14 are integrally formed into the inner circumferential surface of the funnel 4 and the neck 6, respectively. Is mounted.

In addition, a shadow mask 16 having a plurality of beam passing apertures 16a formed therein is mounted inside the skirt portion 2b of the face panel 2 by the mask frame 18 so as to be spaced apart from the fluorescent screen 10 by a predetermined distance. The inner shield 20 surrounding the electron beam path is mounted on one side of the mask frame 18 facing the electron gun 14, and an explosion-proof band is formed on the outer circumferential surface of the skirt portion 2b of the face panel 2. 22) is attached.

With the above-described configuration, when the electron gun 14 emits a three-stem electron beam (shown by a broken line) corresponding to the screen signal, the electron beam is deflected by the magnetic field in which the deflection yoke 12 is generated, forming a raster on the screen. The shadow mask 16 separates the corresponding R, G, and B fluorescent films to emit the designated fluorescent film.

In this cathode ray tube operation, the inner shield 20 shields the geomagnetic field causing a change in the landing of the electron beam to a certain level, but the effect is about 50%, leaving the inner shield 20 and the fluorescent screen 10 The electron beam path toward the cathode ray tube front side toward) does not reach the shielding effect.

As such, the present embodiment imparts a magnetic field characteristic to the explosion-proof band 22 to reduce the influence of the geomagnetic field on the electron beam passing therein, and in particular, the convergence characteristics of the electron beam tube, raster position and To effectively block the horizontal geomagnetic field affecting the purity characteristics.

To this end, the explosion-proof band 22 provided in the present embodiment constitutes the long side portion of the high permeability material. FIG. 3 is a front view of the explosion-proof band, and the explosion-proof band 22 has a pair of short sides facing in the horizontal direction ( 24 and a pair of long side portions 26 facing each other in the vertical direction and four corner portions 28 connecting the pair of short side portions 24 and the long side portions 26.

In particular, the pair of long side portions 26 and the four corner portions 28 are made of high permeability material exhibiting high coercive force and permeability characteristics, and the pair of short sides 24 are made of low permeability material, four corner portions A fixing piece 30 for fixing with the cathode ray tube chassis is integrally attached to the 28.

The high permeability material constituting the long side portion 26 and the four corner portions 28 is made of a nickel-iron alloy having a nickel content of 70 to 90 wt%, aka permalloy, or 0.01 wt% carbon content. Or less, and the silicon content is 0.5 to 3.0% by weight and may be made of an alloy for electrical steel sheet containing other iron and unavoidable impurities.

The low permeability material constituting the pair of short sides 24 may be made of low carbon steel, which is a material constituting an existing explosion-proof band, and may be made of, for example, SPCC-1, which is a general low carbon steel.

As the pair of long side portions 26 and the four corner portions 28 are formed of a high permeability material, as shown in FIG. 4, the horizontal earth field parallel to the ground has a high permeability characteristic of the long side portion 26. The traveling path is changed in the direction of enclosing the outer periphery of the explosion-proof band 22. As such, the explosion-proof band 22 can prevent the horizontal geomagnetic field from penetrating therein and reduce the influence of the horizontal geomagnetic field on the electron beam path.

Accordingly, the electron beam emitted from the electron gun 14 passes through the inner shield 20 and receives the magnetic shielding protection of the inner shield 20 to form a designated raster, and leaves the inner shield 20 to exit the fluorescent film screen 10. Explosion-proof band 22 with enhanced magnetic field characteristics can be effectively blocked from the influence of the geomagnetic field, in particular the horizontal geomagnetic field.

5 is a front view of the explosion-proof band according to another embodiment of the present invention, the explosion-proof band 22 is a pair of long sides 26 facing each other in the vertical direction is made of a material with a permeability, a pair of facing in the horizontal direction The short side portion 24 and the four corner portions 28 are made of a low permeability material, and the specific components of the high permeability material and the low permeability material may be the same as described in the foregoing embodiments.

Therefore, as shown in FIG. 6, instead of penetrating into the explosion-proof band 22, the horizontal geomagnetic field is led by the high investment characteristic of the long side portion 26 to change the traveling path in the direction surrounding the outer periphery of the explosion-proof band 22. In this way, the explosion-proof band 22 can effectively reduce the influence of the horizontal geomagnetic field on the electron beam path.

The explosion-proof band 22 having such a structure attaches a plurality of members made of different materials by welding or the like, is fitted to the outer peripheral surface of the bulb 8 in a state of thermal expansion by heating, and then cooled to It can be firmly fixed while applying a predetermined tension to the outer circumferential surface, particularly the outer circumferential surface of the skirt portion 2b of the face panel 2.

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, the present invention can effectively reduce the influence of the horizontal geomagnetic field on the electron beam path by constructing the long side portion of the explosion-proof band with a high permeability material. Therefore, the function of the inner shield can be supplemented to shield the electron beam path around the fluorescent screen from the influence of the horizontal geomagnetic field, thereby minimizing the deterioration of the convergence characteristics of the electron beam, the change of the raster position, and the degradation of the purity characteristics due to the horizontal geomagnetic field. The quality of the cathode ray tube can be improved.

Claims (13)

In the explosion-proof band that is attached to the outer peripheral surface while applying a predetermined tension to the bulb to prevent the glass from scattering when the bulb is expanded, Explosion-proof band for cathode ray tubes, characterized in that the pair of long sides facing the vertical direction of the screen is made of a high permeability material. The method of claim 1, An explosion-proof band for cathode ray tubes comprising: a pair of short sides facing the horizontal direction of the screen, a pair of long sides facing each other in the vertical direction of the screen, and four corner portions. The method of claim 2, The pair of long side portions and four corner portions are made of a high permeability material, and a pair of short side portions are made of a low permeability material explosion-proof band for cathode ray tubes. The method of claim 2, The pair of long sides made of a high permeability material, a pair of short sides and four corners of the explosion-proof band for cathode ray tube made of a low permeability material. The method according to claim 3 or 4, An explosion-proof band for cathode ray tubes, wherein the high permeability material is made of a nickel-iron alloy having a nickel content of 70 to 90 wt%. The method according to claim 3 or 4, An explosion-proof band for cathode ray tubes, wherein the high permeability material is an alloy for electrical steel sheet containing 0.01 wt% or less of carbon, 0.5 to 3.0 wt% of silicon, and other iron. The method according to claim 3 or 4, Explosion-proof band for cathode ray tube wherein the low permeability material is made of general low carbon steel. A vacuum bulb in which the face panel, the funnel, and the neck portion are integrally coupled; A fluorescent screen formed on an inner surface of the face panel; An electron gun that emits three stem electron beams toward the fluorescent screen; A deflection yoke mounted on an outer circumferential surface of the funnel and generating a deflection magnetic field to deflect the electron beam; An inner shield mounted inside the bulb to surround the electron beam path to reduce the influence of the geomagnetic field on the electron beam; An explosion-proof band mounted to an outer circumferential surface of the face panel of the face panel to apply a predetermined tension; The explosion-proof band is a cathode ray tube, characterized in that the pair of long sides facing the vertical direction of the screen is made of a high permeability material. The method of claim 8, The explosion-proof band is a cathode ray tube consisting of a pair of long sides and four corners made of a high permeability material, a pair of short sides made of a low permeability material. The method of claim 8, The explosion-proof band is a cathode ray tube of a pair of long side portion is made of a high permeability material, a pair of short sides and four corner portions of a low permeability material. The method according to claim 9 or 10, A cathode ray tube, wherein the high permeability material of the explosion-proof band is made of a nickel-iron alloy having a nickel content of 70 to 90 wt%. The method according to claim 9 or 10, A high-permeability material of said explosion-proof band is a cathode ray tube made of an alloy for electrical steel sheet containing 0.01 wt% or less of carbon, 0.5 to 3.0 wt% of silicon, and other iron. The method according to claim 9 or 10, Cathode ray tube of the low permeability material of the explosion-proof band is made of general low carbon steel.