KR20010091292A - Cathode ray tube - Google Patents

Abstract

PURPOSE: A cathode ray tube is provided to obtain an improved screen quality by eliminating magnetic field interference with respect to the adjacent deflection yoke. CONSTITUTION: A cathode ray tube comprises a face panel(4) having a fluorescent screen(2) formed at an inner surface of the face panel; a funnel(8) which is fixed to the face panel, and connected to a plurality of neck parts(6); an electron gun(10) mounted at the inner periphery of each of neck parts, and which emits three electron beams toward the fluorescent screen; a plurality of deflection yokes(12) mounted at the outer periphery of a cone section(8a) of the funnel opposed to each neck part, and which generates deflection magnetic field so as to allow electron beams(18R,18G,18B) emitted from the corresponding electron gun to be scanned onto a specific area of the fluorescent screen; a shadow mask(14) mounted inside of the face panel, and which has a plurality of electron beam passage apertures for dividing three electron beams to the corresponding fluorescent screen; and a plurality of magnetic field shield units(16) arranged around each of deflection yokes so as to shield magnetic field interference affecting deflection yokes.

Description

Cathode ray tube {Cathode ray tube}

The present invention relates to a cathode ray tube in which a cathode ray tube having a plurality of electron guns and a deflection yoke is provided to reduce electric field and implement a large screen, thereby reproducing more improved image quality by removing magnetic field interference on an adjacent deflection yoke.

In general, a cathode ray tube is a display device that implements a predetermined screen by emitting a fluorescent screen by using an electron beam emitted from an electron gun. The cathode ray tube is most widely used in televisions and monitors because of its relatively high image quality and low manufacturing cost compared to other display devices. .

According to the driving principle of the cathode ray tube, when the electron gun emits three stem electron beams corresponding to the R, G, and B fluorescent films, the emitted electron beams are deflected in the horizontal and vertical directions by the magnetic field in which the deflection yoke is generated. The raster is formed on the surface of the fluorescent film and separated into the corresponding R, G, and B fluorescent films in the fluorescent screen by a shadow mask, which is a color-selective electrode, to realize accurate colors.

The cathode ray tube mounts the electron gun at a certain distance from the center of the fluorescent screen so that the electron beam emitted from the electron gun can be deflected to each part of the fluorescent screen to form a raster, and is deflected between the electron gun and the fluorescent screen. The yoke is provided.

However, as the current cathode ray tube is gradually enlarged and planarized, a wider electric field is required. To compensate for this, the electric field must be shortened by deflecting the electron beam at a wider angle. However, the focus characteristic of the electron beam is deteriorated by the wide angle deflection. . As the size of the cathode ray tube increases as the screen becomes larger, the cathode ray tube is inevitably expanded compared to a thin liquid crystal display or a plasma display, and there are many technical difficulties in improving image quality.

To solve this problem, U.S. Patent No. 5,498,921 and U.S. Patent No. 5,584,738 are equipped with a plurality of electron guns to realize a large screen with a reduced overall length, and a single screen is divided into several areas of Camel ( camel) type cathode ray tube.

8 is a cross-sectional view of a Camel type cathode ray tube according to the prior art, in which the cathode ray tube forms a bulb 5 in combination with a face panel 3 and a face panel 3 forming a fluorescent film screen 1 on an inner surface thereof. And a funnel 9 having a plurality of neck portions 7, a plurality of electron guns 13 mounted on the inner circumferential surface of each neck portion 7 to emit three stem electron beams 11R, 11G and 11B, respectively. A plurality of deflection yokes 15 mounted on the cone portion 9a of the funnel 9 facing the neck portion 7 of the plurality of deflection yokes 15 for deflecting the electron beam emitted from the electron gun 13, and facing the fluorescent film screen 1; It includes a shadow mask 17 mounted inside the face panel 3.

The deflection yoke 15 generates a deflection magnetic field so that the electron beam emitted from the electron gun 13 scans only a specific area of the fluorescent screen 1, and the entire fluorescent screen 1 is as many as the number of electron guns 13. It is divided into regions and receives an electron beam to emit light. As a result, the screens implemented in each area of the fluorescent screen are combined into one image so that the user recognizes the combined screen.

As described above, the Camel type cathode ray tube is provided with a plurality of electron guns 13 and a deflection yoke 15 so as to solve the enlargement of the electric field due to wide-angle deflection or the deterioration of the focus characteristics by dividing one screen so that the electric field can be improved while implementing a large screen. It has the advantage that can be effectively reduced.

However, since high frequency deflection signals of approximately 15.75 kHz or more are simultaneously generated by the plurality of deflection yokes 15 to deflect the electron beam, magnetic field interference can be caused to adjacent deflection yokes.

Therefore, when driving a cathode ray tube, it is highly likely that the deflection signal generated in the deflection yoke is distorted by the high frequency signal generated from the adjacent deflection yoke, and the deflection signal distortion prevents the accurate deflection of the electron beam, thereby improving the image quality of the scanning region. It not only degrades, but also impairs the balance of the entire combined screen, resulting in deterioration of picture quality characteristics.

Therefore, the present invention was devised to solve the above problems, and an object of the present invention is to provide a cathode ray tube capable of realizing improved image quality by deflecting an electron beam more accurately by eliminating magnetic field interference generated between a plurality of deflection yokes. .

Another object of the present invention is to provide a cathode ray tube that can easily implement a large screen while having a reduced overall length, and can effectively improve the image quality of the entire combination screen as well as the image quality of the individual scanning area.

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

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

3 is a perspective view of the magnetic shield structure shown in FIG.

4 is a cross-sectional view of the magnetic shield structure.

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

6 is a perspective view of the magnetic shield structure shown in FIG.

7 is an enlarged view of a portion B of FIG. 5;

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

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

A face panel which forms a fluorescent screen on the inside;

A funnel fixed to one side of the face panel and connected to a plurality of neck portions;

An electron gun mounted on an inner circumferential surface of each neck portion to emit a three-stem electron beam toward a fluorescent screen;

A plurality of deflection yokes mounted on an outer circumferential surface of the cone portion of the funnel facing each neck portion, generating a deflection magnetic field and scanning an electron beam emitted from the electron gun to a specific area of the fluorescent screen;

A shadow mask mounted inside the face panel and forming a plurality of beam passing apertures to separate three stem electron beams into a corresponding fluorescent film;

Provided around each deflection yoke provides a cathode ray tube comprising means for blocking magnetic field interference to adjacent deflection yokes.

Here, the means is provided as a magnetic shield structure consisting of a ferromagnetic material having a high permeability to block the magnetic influence between the plurality of deflection yoke. In particular, the magnetic shield structure may be manufactured in a cylindrical shape corresponding to each of the deflection yoke, or may be manufactured in one piece to separate the deflection yokes by forming a separator therein while surrounding the plurality of deflection yokes.

In both cases, as the magnetic shielding structure blocks the influence of the magnetic flux applied toward the deflection yoke from the outside, distortion of the deflection signal caused by the adjacent deflection yoke driving is prevented, leading to more accurate electron beam deflection, thereby improving image quality. Can be.

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

1 is a perspective view of a cathode ray tube according to the present embodiment, and FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1.

As shown in the drawing, the cathode ray tube according to the present embodiment is coupled to a face panel 4, which forms a fluorescent film screen 2 on the inner surface, and is connected to a plurality of neck parts 6, which are coupled to the rear of the face panel 4. Funnel 8, a plurality of electron guns 10 mounted on the inner circumferential surface of each neck portion 6, and a plurality of electron guns 10 mounted on the outer circumferential surface of the cone portion 8a of the funnel 8 facing each neck portion 6, respectively. A deflection yoke 12, a shadow mask 14 fixed inside the face panel 4 so as to face the fluorescent film screen 2, and a plurality of magnetic shield structures provided around each deflection yoke 12 ( 16).

The fluorescent screen 2 is formed by continuously forming a plurality of R, G, B fluorescent stripe stripes between the black matrix film of the graphite component, and receives the electron beam (18R, 18G, 18B) emitted from the electron gun 10 to emit light As the cathode ray tube includes a plurality of electron guns 10 and the deflection yoke 12, the screen implemented by the cathode ray tube is divided into a plurality of regions as shown by a dotted line and implemented in each region. The screens are combined to form one image.

That is, for example, when the cathode ray tube is provided with twelve electron guns 10 and deflection yokes 12 arranged in a width of 4 × 3, the fluorescent film screen 2 is divided into twelve regions, and each deflection yoke Reference numeral 12 deflects the electron beam emitted from the electron gun 10 so as to scan the region in a limited manner so that only a part of the entire screen is realized.

As described above, when a single screen is divided and provided with a plurality of electron guns 10 and a deflection yoke 12, a large screen can be easily realized and the electric field can be reduced. However, a high frequency deflection magnetic field is applied to the deflection yoke 12. Are simultaneously generated to cause magnetic field interference in adjacent deflection yokes, and are provided with a plurality of magnetic shielding structures 16 to prevent this.

More specifically, the magnetic shield structure 16 is provided in an individual deflection yoke 12 to surround the deflection yoke 12, as shown in FIG. 3, for example the magnetic shield structure 16 is a deflection yoke. (12) A cylindrical shape corresponding to the shape, one surface facing the cone portion 8a is open, and one surface facing the neck portion 6 forms a circular opening 6a corresponding to the diameter of the neck portion 6, It is formed with a diameter larger than the deflection yoke 12 so as to completely cover one deflection yoke 12.

The magnetic shield structure 16 having the above-described configuration is made of a ferromagnetic metal exhibiting a high permeability. For example, a ferromagnetic metal containing iron (Fe) as a main component or a paramagnetic metal containing iron (Fe) and nickel (Ni) as a main component. In another embodiment, as illustrated in FIG. 4, the support 20 for determining the appearance of the magnetic shield structure 16 and the material component of the above-described ferromagnetic and paramagnetic materials or applied to the surface of the support 20 or It can be produced as a magnetic shielding coating film 22 mainly composed of ultra-fine graphite.

When the individual deflection yoke 12 is made of a ferromagnetic material or surrounded by the magnetic shield structure 16 having the magnetic shielding coating film, the magnetic shielding structure ( 16) The inner deflection yoke 12 may be blocked from magnetic influences from the outside to minimize magnetic field interference by the adjacent deflection yoke.

The magnetic shield structure 16 having the above-described configuration can be firmly fixed to the outer circumferential surface of the neck portion 6 by using, for example, a tightening member such as a yoke clamp used to fix the deflection yoke to the neck portion.

On the other hand, in addition to being individually attached to the respective deflection yoke 12 as mentioned above, the magnetic shield structure 16 may also be provided in one piece, which simultaneously surrounds the plurality of deflection yokes 12. An embodiment in which the integrated magnetic shield structure is applied to a planar cathode ray tube will be described as follows.

5 is a cross-sectional view of a cathode ray tube according to another embodiment of the present invention, Figure 6 is a perspective view of a magnetic shield structure, the same reference numerals are used for the same components as the previous embodiment.

As shown in the drawing, the cathode ray tube according to the present embodiment has a flat face plate 24 that forms a fluorescent film screen 2 on its inner surface, and is integrally fixed to the face plate 24 by sidewalls 26 to be bulb 28. ), A plurality of funnels 8 fixed to the rear plate 30, a plurality of electron guns 10 mounted on an inner circumferential surface of the neck portion 6 of the funnel 8, and And a plurality of deflection yokes 12 attached to the outer circumferential surface of the funnel 8 and an integral magnetic shield structure 32 that simultaneously encloses the plurality of deflection yokes 12.

A plurality of support partitions 34 are provided between the face plate 24 and the rear plate 30 constituting the bulb 28 to support the bulb 28 from the influence of atmospheric pressure, and the fluorescent film screen 2 and A shadow mask (not shown) is provided inside the facing bulb 28 to separate the electron beam emitted from the electron gun 10 into the corresponding fluorescent film. In addition, the plurality of deflection yokes 12 are integrally mounted by screw 38 to the coupling plate 36 attached to the rear plate 30, for example.

At this time, the magnetic shielding structure 32 according to the present embodiment is an integral type provided with one per cathode ray tube, and more specifically, the magnetic shielding structure 32 includes an outer wall 40 and an outer wall which simultaneously cover a plurality of deflection yokes 12. 40 is provided in the interior of the separation membrane 42 for separating the deflection yoke (12) individually. One side facing the rear plate 30 is open toward the rear plate 30, and the other side facing the neck portion 6 forms a circular opening 32a through which the neck portion 6 penetrates.

The magnetic shielding structure 32 having the above-described configuration is also made of a ferromagnetic metal such as iron having a high permeability, as in the previous embodiment, or made of a magnetic shielding coating film applied to the support and the surface of the support as shown in FIG. 4. Can be.

As described above, the magnetic shield structure 32 surrounds the plurality of deflection yokes 12 with the outer wall 40, and the individual deflection yokes 12 are adjacent with the deflection yoke 12 by the separator 42 formed inside the outer wall 40. By separating from and, each deflection yoke is protected from the influence of the magnetic flux generated in the adjacent deflection yoke, thereby effectively blocking magnetic field interference caused by the high frequency deflection signal generated in the adjacent deflection yoke.

In order to be firmly fixed to the cathode ray tube, the integrated magnetic shield structure 32 having the above-described configuration has a coupling plate 36 having an end of the outer wall 40 facing the rear plate 30 as shown in FIG. It extends so as to surround the side of, and can be fixed integrally to the coupling plate 36 by tightening the outer wall 40 to the fixing means 46 using a screw (44).

As such, the present embodiment provides a magnetic shield structure that is provided separately or integrally in a cathode ray tube having a plurality of electron guns 10 and a deflection yoke 12 so as to provide a high frequency magnetic field generated simultaneously in the plurality of deflection yokes 12. By physically blocking, magnetic field interference between the deflection yoke 12 can be eliminated, thereby inducing more accurate electron beam deflection, thereby achieving an improved image quality.

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 such, the present invention provides a magnetic shielding structure made of a ferromagnetic metal or coated with a magnetic shielding coating film to surround magnetic deflection yokes or separate a plurality of deflection yokes to eliminate magnetic interference between the deflection yokes. Therefore, the deflection signal distortion caused by the high frequency magnetic field generated by the adjacent deflection yoke is prevented to more accurately deflect the electron beam, so that the improved image quality can be realized and the large screen can be easily realized even with the reduced electric field.

Claims (11)

A face panel forming an inner surface of the fluorescent film screen; A funnel fixed to one side of the face panel and connected to a plurality of neck portions; An electron gun mounted on an inner circumferential surface of each neck portion to emit a three-stem electron beam toward a fluorescent screen; A plurality of deflection yokes mounted on an outer circumferential surface of the cone portion of the funnel facing each neck portion, generating a deflection magnetic field and scanning an electron beam emitted from the electron gun to a specific region of the fluorescent film screen; A shadow mask mounted inside the face panel and forming a plurality of beam passing apertures to separate three stem electron beams into a corresponding fluorescent film; And a means provided around each deflection yoke to block magnetic field interference to adjacent deflection yokes. The cathode ray tube according to claim 1, wherein said means is made of a magnetic shield structure that blocks magnetic influence between a plurality of deflection yokes. The cathode ray tube of claim 2, wherein the magnetic shield structure is provided in a cylindrical shape surrounding an individual deflection yoke. The cathode ray tube of claim 2, wherein the magnetic shield structure comprises an outer wall that simultaneously surrounds a plurality of deflection yokes, and a separator provided in the outer wall to separate the deflection yokes separately. The cathode ray tube according to claim 2, wherein the magnetic shield structure is made of a ferromagnetic metal or a paramagnetic metal having a high permeability. The cathode ray tube according to claim 5, wherein the ferromagnetic metal contains iron (Fe) as a main component. The cathode ray tube according to claim 5, wherein the paramagnetic metal contains iron (Fe) and nickel (Ni) as main components. The cathode ray tube according to claim 2, wherein the magnetic shield structure comprises a support constituting an external appearance and a coating film for magnetic shield applied to the surface of the support. The cathode ray tube according to claim 8, wherein the magnetic shielding coating film contains iron (Fe) as a main component. The cathode ray tube according to claim 8, wherein the magnetic shielding coating film contains iron (Fe) and nickel (Ni) as main components. The cathode ray tube according to claim 8, wherein the magnetic shielding coating film is composed of ultra-fine graphite.