KR20000010590U - Cathode ray tube - Google Patents

Abstract

It is a cathode ray tube which can prevent the deterioration of image quality by minimizing the influence of the earth's magnetic field which changes the electron beam path by improving the element effect and the shielding effect of the inner shield. It expands the influence of device current applied to the funnel, and expands and enhances the shielding effect of the inner field of the inner shield by attaching an explosion-proof band made of iron alloy to the outer peripheral surface of the panel and the body of the funnel. Accordingly, the explosion-proof band has a geomagnetic shielding effect on the entire mask assembly and the inner shield, so that the inner shield may exhibit the geomagnetic shielding effect reinforced by the explosion-proof band while improving the device effect.

Description

Cathode ray tube

The present invention relates to a cathode ray tube, and more particularly, to a cathode ray tube capable of preventing the deterioration of image quality by minimizing the effect of the earth's magnetic field that changes the electron beam path by simultaneously improving the element effect and the shielding effect of the inner shield. It is about.

In general, the cathode ray tube consists of a combination of a panel, a front body forming a fluorescent screen on the inner surface, and a funnel, a rear body inserting and mounting an electron gun into the neck, and an electron beam emitted from the electron gun is disposed on a path toward the fluorescent screen. Under the influence of the earth's magnetic field, the path is slightly changed.

FIG. 6 is a partial cross-sectional view of a cathode ray tube according to the prior art, and FIG. 7 is a schematic perspective view of a cathode ray tube for illustrating a relationship between an electron beam and an earth magnetic field, and is inner on an electron beam 1 path to shield the earth magnetic field. Explosion-proof band 9 is attached to the outer circumferential surface of the side surface portion 7a of the panel 7 to attach the shield 3, and to prevent the explosion of the bulb 5, the explosion-proof band 9 is made of a high permeability iron alloy By changing the path of the earth's magnetic field to the surrounding inner space, that is, part of the mask assembly 11, the influence of the earth's magnetic field is minimized.

However, the inner shield 3 has a geomagnetic field shielding efficiency of about 50%, and the explosion-proof band 9 is mounted only on the outer circumferential surface of the side portion 7a of the panel 7, that is, the portion indicated by the broken line as shown, that is, explosion-proof. The space between the band 9 and the inner shield 3 could not block the influence of the geomagnetic field, especially the vertical magnetic field, which affects the image quality.

The vertical magnetic field is a magnetic field having a direction perpendicular to the ground surface, and is flammed based on the direction (I) of the current opposite to the moving direction of the electron beam 1 and the direction (B) perpendicular to the ground surface. When the left hand law is applied, the direction of force (F) becomes the horizontal direction on the screen to move the electron beam (1) in the horizontal direction of the screen. Accordingly, such as horizontal raster shift (HRS) and color purity degradation, etc. This results in deterioration of image quality.

At this time, the earth magnetic field has a different effect on the cathode ray tube according to the position of the earth and the direction of the cathode ray tube. Therefore, each time the cathode ray tube is turned on, the inner shield 3 is magnetized in the inner magnetized state when the cathode ray tube is activated. It is necessary to remove the to effectively shield the geomagnetic field in response to the geomagnetic field having a different effect depending on the position and direction of the cathode ray tube.

For the degaussing of the inner shield 9, the element cable 15 is wound around the outer circumferential surface of the funnel 13 as shown in FIG. 8, and initially 3 to 4 when the cathode ray tube is turned on. The inner shield 3 is applied by applying a device current for a second, and the inner shield 3 increases the device effect as the inner shield 3 approaches the funnel 13, but the inner shield 3 is used to increase the device effect. When disposed close to the funnel 13, the shielding efficiency of the geomagnetic field on the path of the electron beam 1 is lowered, so that the inner shield 3 has to be maintained at a constant distance from the funnel 13.

Therefore, the present invention was devised to solve the above problems, and an object of the present invention is to simultaneously improve the element effect of the inner shield and the shielding effect of the geomagnetic field, to minimize the amount of landing movement of the electron beam by the geomagnetic field, and to prevent deterioration of image quality. To provide a cathode ray tube that can be.

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

FIG. 2 is a partial cross-sectional view taken along line A-A of FIG. 1.

3 is a perspective view of a cathode ray tube according to a second embodiment of the present invention;

4 is a partial cross-sectional view taken along line BB of FIG. 3.

5 is a schematic perspective view of a cathode ray tube according to the present invention for explaining a relationship between an electron beam and a geomagnetic field.

6 is a partial cross-sectional view of a cathode ray tube according to the prior art.

7 is a schematic perspective view of a cathode ray tube according to the prior art for explaining the relationship between an electron beam and a geomagnetic field.

8 is a rear view of a cathode ray tube according to the prior art;

In order to achieve the above object, the present invention extends the bottom and circumference of the inner shield toward the funnel to expand the influence of the current for the device applied to the funnel, and improves the magnetic field shielding effect of the inner shield disposed in close proximity to the funnel. To reinforce, the magnetic field shield reinforcement means are provided on the side surface of the panel and the outer peripheral surface of the body of the funnel.

The geomagnetic shield reinforcing means may be made of an explosion-proof band of iron alloy material having an enlarged width, it may be made of a combination of the metal film and the explosion-proof band.

Therefore, the geomagnetic shield reinforcing means has a geomagnetic shielding effect on the entire mask assembly and the inner shield, and thus the inner shield may exhibit the reinforced geomagnetic shielding effect while improving the device effect.

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

FIG. 1 is a perspective view of a cathode ray tube according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of the line AA of FIG. 1, as shown in FIG. The panel 2 is combined to form a bulb 100, and the panel 2 has a screen portion 2a for forming a fluorescent screen 6 on its inner surface and a side portion 2b bent from four edges of the screen portion 2a. )

The funnel 4 seals the neck portion 4a into which the electron gun 8 is inserted and the opening portion 4b is sealed to the side portion 2b of the panel 2 so as to be integrated with the panel 2 and deflected toward the outer circumferential surface. It consists of a body portion 4c for mounting the yoke 10 and the element cable 12.

The side portion 2b of the panel 2 mounts the mask assembly 14 to the inner surface, and the mask assembly 14 is disposed on the rear surface of the fluorescent screen 6 and forms a shadow forming a plurality of beam passing holes. A mask 16 and a mask frame 18 supporting the shadow mask 16.

Accordingly, the three stem electron beams 20 emitted from the electron gun 8 are deflected up, down, left, and right under the influence of the deflection magnetic field generated by the deflection yoke 10 to sequentially scan all the phosphors on the fluorescent screen 6. At this time, the electron beam 20 passes through the beam-passing hole of the shadow mask 16 before reaching the fluorescent screen 6 to separate and land the respective phosphors to realize accurate colors.

As such, the electron beam 20 that emits the fluorescent film screen 6 to implement a predetermined image has a landing position that is changed by the influence of the earth's magnetic field acting inside the bulb 100, and thus, the electron beam 20 is prevented. The inner shield 22 is mounted on the path.

The inner shield 22 is made of a material of high permeability and low coercive force and is transformed into a kind of magnetic material by the earth's magnetic field to cause offset or constructive interference with the earth's magnetic field to change the path of the earth's magnetic field. 22 forms a bottom portion 22a attached to one surface of the mask frame 18 in an extended size toward the funnel 4 to bend from four edges of the bottom portion 22a. It is placed close to the inside of the body portion 4c of the funnel (4).

Therefore, when the element current is applied to the element cable 12 for the first 3 to 4 seconds during the cathode ray tube acting for the element of the inner shield 22, the peripheral portion 22b of the inner shield 22 is the funnel 4 Since it is disposed in close proximity to the inner surface of the) it is further affected by the magnetic field by the application of the current for the device can improve the device effect.

However, when the circumferential portion 22b of the inner shield 22 is disposed close to the inner surface of the funnel 4 as described above, the magnetic field shielding effect on the path of the electron beam 20 is lowered. Provide shielding reinforcement means.

The geomagnetic shield reinforcing means consists of an explosion-proof band 24 made of iron alloy material which is attached to the outer circumferential surface of the side portion 2b of the panel 2 and the body portion 4c of the funnel 4.

As shown, the explosion-proof band 24 is formed in a wider width so that it can be attached to the outer circumferential surface of the entire side portion 2b of the panel 2 and a part of the body portion 4c of the funnel 4.

As described above, the explosion-proof band 24 made of a high permeability iron alloy material exhibiting an earth magnetic field shielding effect to the surrounding space has an enlarged width, so that the inner shield 22 is surrounded by an inner space surrounded by the explosion-proof band 24. This will enhance the geomagnetic shielding efficiency of the inner shield 22.

FIG. 3 is a perspective view of a cathode ray tube according to a second embodiment of the present invention, and FIG. 4 is a cross-sectional view of the BB line of FIG. 3, and as shown, the inner shield 22 has a bottom portion 22a to improve the device effect. The periphery 22b is formed close to the inside of the body portion 4c of the funnel 4 by forming the expanded size toward the inside of the funnel 4.

In addition, a geomagnetic shielding reinforcing means is provided to reinforce the geomagnetic shielding effect lowered on the path of the electron beam 20, which is the outer peripheral surface of the side portion 2b of the panel 2 and the body portion 4c of the funnel 4. And an explosion-proof band 32 attached to the outer surface of the metal film 30 and disposed on an outer circumferential surface of the side portion 2b of the panel 2.

The metal film 30 is made of the same iron alloy material as the explosion-proof band 32, and has a relatively thin thickness compared to the explosion-proof band 32, the side portion 2b and the funnel 4 of the panel 2 Attached to the outer circumferential surface of a portion of the body portion (4c) of the) changes the path of the earth's magnetic field to the inner space surrounded by the metal film (30).

In this case, the explosion-proof band 32 is generally an iron alloy material having a thickness about 10 times larger than that of the inner shield 22 and explosion-proof the metal film 30 having a thickness thinner than the explosion-proof band 32. By placing the inner surface of the band 32, it is possible to efficiently perform the geomagnetic shielding without increasing the weight of the cathode ray tube.

As described above, since the metal film 30 and the explosion-proof band 32 are both made of a high permeability iron alloy material, the inner shield including the inner shield 22 is an inner space surrounded by the metal film 30 and the explosion-proof band 32. The geomagnetic field shielding efficiency of (22) is reinforced.

FIG. 5 is a schematic perspective view of a cathode ray tube for explaining the influence of an electron beam and a geomagnetic field on the basis of the cathode ray tube according to the first embodiment. As shown, the explosion-proof band 24 is perpendicular to the ground surface. Offset or constructive interference with the vertical magnetic field (B) having a change in the direction of the vertical magnetic field in the left and right directions (B1, B2) of the screen.

Accordingly, based on the direction (I) of the current which is opposite to the scanning direction of the electron beam 20 emitted from the electron gun 8 toward the screen, and the directions B1 and B2 of the earth's magnetic field changed in the left and right directions of the screen. Applying Fleming's left hand law, the directions of forces F1 and F2 that affect the path of the electron beam 20 become the vertical direction of the screen.

Therefore, the electron beam 20 has a landing movement amount in the vertical direction due to the influence of the earth's magnetic field when reaching the screen, the conventional fluorescent film screen 6 is a stripe to arrange each green, blue, red phosphors perpendicular to the screen Since it is made of a type, even if the landing position of the electron beam 20 fluctuates in the vertical direction, it lands on the phosphor of the same color, so that no other color emission occurs.

Accordingly, the inner shield 22 improves the device effect by being close to the inner surface of the funnel 4, and has an enlarged width so that the explosion-proof band 24 includes the body of the funnel 4 so that the magnetic field shielding efficiency is improved. Reinforce and improve.

In addition, the explosion-proof band 24 may be mounted to the outer circumferential surface of the body portion 4c of the funnel 4 to prevent the glass fragments of the funnel 4 from scattering toward the rear side of the cathode ray tube.

This action is the same in the cathode ray tube according to the second embodiment of the present invention.

In the above description of the preferred embodiment of the present invention, the present invention is not limited to this, but can be implemented in various ways within the scope of the utility model registration claims and the detailed description of the invention and the scope of the accompanying drawings. It is also natural to fall within the scope of the present invention.

As such, the present invention improves the element effect of the inner shield to perform a geomagnetic shielding function suitable for the location and direction of the cathode ray tube, and the inner shield is disposed close to the inner surface of the funnel to reduce the geomagnetic shielding efficiency. By reinforcing and improving by an explosion-proof band or metal film having an enlarged width, it is possible to simultaneously improve the element effect of the inner shield and the shielding effect of the geomagnetic field, thereby minimizing the amount of landing movement of the electron beam in the horizontal direction by the vertical magnetic field. This can prevent degradation of image quality.

Claims (5)

A panel which is a front body comprising a screen portion for forming a fluorescent film screen on an inner surface and a side portion bent from four edges of the screen portion to mount a mask assembly on the inner surface; It consists of a neck part for inserting and mounting an electron gun into the inside, and a body part sealing the opening to the side part of the panel to be integrated with the panel. The rear body receives the current for the element during the initial action of the cathode ray tube by winding the element lead to the outer peripheral surface. Phosphorus funnels; It is made of high permeability material to change the path of the earth's magnetic field on the electron beam path, and the bottom part mounted on one side of the mask assembly is extended toward the funnel so that the peripheral part bent from the four edges of the bottom part is close to the inner surface of the funnel. An inner shield for expanding the influence of the current for the device to be applied; And a geomagnetic shielding reinforcement means attached to an outer circumferential surface of the panel and the body of the funnel to reinforce the geomagnetic shielding effect of the inner shield disposed adjacent to the funnel. The cathode ray tube according to claim 1, wherein the geomagnetic shielding reinforcing means is formed of an explosion-proof band made of iron alloy. The cathode ray tube according to claim 1, wherein the geomagnetic shielding reinforcing means comprises a metal film attached to an outer circumferential surface of a portion of the panel and a body of the funnel, and an explosion-proof band of iron alloy material attached to the outer circumferential surface of the panel. The cathode ray tube of claim 3, wherein the metal film is made of an iron alloy material. The cathode ray tube of claim 3, wherein the explosion-proof band is attached to an outer surface of the metal film.