KR20020019338A - Bi-potential mask type cathode ray tube - Google Patents

Abstract

PURPOSE: A bi-potential mask type cathode ray tube is provided to prevent a getter film from being deposited inside of the skirt part in face panel by controlling a path of getter material discharged in getter flashing process. CONSTITUTION: A face panel(4) includes a skirt part extended vertically from the screen edge. A phosphor film screen(2) forms a plurality of R, G, B phosphor films inside of the face panel screen and is supplied with a predetermined high voltage. A shadow mask(12) keeps in insulation with the phosphor screen and forms an acceleration electric field between the phosphor and the shadow mask by being supplied a bi-potential. A mask frame(18) fixes the shadow mask to the skirt part in face panel. An inner shield(24) is fixed to the rear side of the mask frame and shields a path of the electron beams from the geomagnetic field. A getter(26) makes an inside of bulb high vacuum state by discharging of getter material when the getter filler is heated. A prevent unit prevents the getter film from being deposited inside of the skirt part by blocking a path of the getter material that goes from the getter to the skirt part in face panel.

Description

Bi-potential mask type cathode ray tube}

The present invention relates to a bi-potential mask type (hereinafter referred to as a "BIP type") cathode ray tube for supplying a differential potential to a fluorescent screen and a shadow mask, and more particularly, to a path of a getter material. It relates to a BIP-type cathode ray tube configured to control and maintain the fluorescent screen and the shadow mask insulated even after flashing getter.

In general, a cathode ray tube is a display device that emits a fluorescent screen by using an electron beam emitted from an electron gun, and implements a predetermined screen. The known configuration includes a face panel 1 and a funnel 3 as shown in FIG. When the neck portion 5 is fused to form a vacuum bulb 7, and the electron beam 9 is emitted from the electron gun 9 mounted on the inner circumferential surface of the neck portion 5, the electron beam 11 is deflected. The yoke 13 is deflected by the generated magnetic field to form a raster on the fluorescent screen 15, and the corresponding R, G, in the fluorescent screen 15 by the shadow mask 17, which is a color screening electrode. It is separated by B fluorescent film to express accurate color.

Here, the cathode ray tube of the general configuration is the final acceleration of the fluorescent film screen 15, the shadow mask 17 and the electron gun 9 through the internal graphite film 21 coated on the inner surface of the anode button 19 and the funnel 3 A high voltage of approximately 20 to 32 kV is applied to the electrode (G4 electrode or anode) 23 to finally accelerate the electron beam focused on the G1 electrode to G3 electrode 25 of the electron gun 9 to form a fluorescent screen 15. Control to reach

On the other hand, the BIP type cathode ray tube insulates the fluorescent screen 15 and the shadow mask 17, and has a V1 voltage lower than 20 to 32 kV to the final acceleration electrode 23 and the shadow mask 17 of the electron gun 9, The fluorescent screen 15 is applied with a voltage V2 higher than the voltage V1 to form an accelerating electric field between the shadow mask 17 and the fluorescent screen 15. As a result, the beam passing apertures 17a formed in the shadow mask 17 become electron lenses to focus and deflect the electron beam 11 passing therethrough.

Therefore, the BIP-type cathode ray tube effectively improves the brightness of the screen by focusing the electron beam 11, shortens the electric field of the cathode ray tube by deflection of the electron beam 11, and internals the funnel 3 facing the deflection yoke 13. Lowering the voltage V1 has an advantage of reducing the deflection power.

However, the BIP-type cathode ray tube must secure an insulating structure between the fluorescent film screen 15 and the shadow mask 17 due to its characteristics, and stably supply differential potentials to these members. There is considerable technical difficulty in isolating 15) and the shadow mask 17 and stably supplying the differential potential to these members.

In particular, the insulation holding of the fluorescent screen 15 and the shadow mask 17 is mainly prevented from coating the graphite film on the inner surface of the skirt 1a of the face panel 1 so that the fluorescent screen 15 and the stud pins 27 ), The shadow mask 17 electrically connected to the stud pins 27 is insulated from the fluorescent film screen 15 by keeping the insulated state.

However, even when the fluorescent film screen 15 and the shadow mask 17 are kept in an insulated state as described above, in the process of getter flashing to secure high vacuum inside the bulb 7, the conductive getter film is formed by a conductive getter film. The fluorescent screen 15 and the shadow mask 17 may be energized.

That is, a getter 29 containing a getter filler (typically a mixture of nickel powder and barium-aluminum alloy powder) is attached to one side of the shield cup of the electron gun 9 to exhaust the inside of the bulb 7 and then heat the getter filler. When added, the barium vaporizes with the residual gas in the bulb 7 to maintain the inside of the bulb 7 at a high vacuum of about 10 ⁻⁷ Torr.

At this time, the getter 29 instantaneously emits a large amount of barium at the same time, and since the released barium has a property of going straight in vacuum, the barium is evenly diffused into the interior of the bulb 7, and part of the released barium is an inner shield ( 31) The propagation path is changed while hitting the outer wall and deposited on the inner surface of the skirt portion 1a of the face panel 1, and the barium scattered into the inner shield 31 partially escapes through the gap of the inner shield 31. Naga is deposited on the inner surface of the opposite skirt portion 1a.

Thus, after completion of the getter flashing, the barium film 33 is deposited on the inner surface of the skirt portion 1a of the face panel 1 between the fluorescent film screen 15 and the stud fins 17, so that the stud fins ( As the shadow mask 17 which maintains the same potential as 27) is energized to the fluorescent film screen 15, it is impossible to apply the differential potential of the target, which causes a problem of driving failure of the BIP type cathode ray tube. .

Therefore, the present invention is designed to solve the above problems, an object of the present invention is to control the progress path of the getter material released during the getter flashing process BIP type configured to prevent the getter film is deposited on the inner surface of the skirt portion of the face panel To provide a cathode ray tube.

Another object of the present invention is to provide a BIP type cathode ray tube configured to stably supply a differential potential to the fluorescent screen and the shadow mask by keeping the fluorescent screen and the shadow mask in an insulated state even after the getter flashing.

1 is a cross-sectional view of a bi-potential mask type cathode ray tube according to the present invention.

2 is a perspective view of a mask frame-shadow mask assembly with a getter shield coupled thereto.

3A and 3B are enlarged cross-sectional views illustrating one example of a panel assembly to which a getter shield is attached.

4 and 5 are partially enlarged views of FIG. 1.

6 is a cross-sectional view of a typical cathode ray tube.

7 is a partially enlarged view of FIG. 6.

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

A face panel having a skirt portion vertically extending from the edge of the screen portion,

A fluorescent film screen on which a plurality of R, G, and B fluorescent films are formed on an inner surface of the face panel to receive and emit electron beams, and to receive an arbitrary high voltage;

A shadow mask which is supplied with a differential potential while maintaining an insulation state with the fluorescent screen and forms an acceleration field between the fluorescent screen;

A mask frame for fixing the shadow mask to the skirt portion of the face panel;

An inner shield fixed behind the mask frame to shield an electron beam path from a geomagnetic field;

A getter which highly vacuums the inside of the bulb by the release of getter material upon heating the getter fill,

Provided is a bi-potential mask type cathode ray tube comprising means for blocking the path of getter material from the getter toward the skirt of the face panel to prevent deposition of getter film onto the inner surface of the skirt.

The means here is provided with a getter shield that forms a barrier wall of a predetermined height towards the getter outside the mask frame to block the skirt of the face panel from the getter. As a result, the present invention has the advantage that the differential potential can be stably supplied to the members by preventing electric current between the fluorescent film screen and the shadow mask by the getter film.

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

1 is a cross-sectional view of a BIP type cathode ray tube according to the present embodiment. As shown in FIG. 1, the BIP type cathode ray tube has a funnel 6 and a neck portion behind the face panel 4 that forms a fluorescent screen 2 on its inner surface. (8) is integrally combined to constitute a vacuum bulb 10, and the shadow mask 12 having a plurality of beam passing apertures 12a to face the fluorescent film screen 2 includes a face panel 4 ) And a deflection yoke 14 and an electron gun 16 are mounted on the outer circumferential surface of the funnel 6 and the inner circumferential surface of the neck portion 8, respectively.

The face panel 4 extends vertically toward the electron gun 16 at four edges of the rectangular screen portion 4a on which the fluorescent screen 2 is formed, and at the four edges of the screen portion 4a, and is fused with the funnel 6. And a coupling spring 20 while the mask frame 18 supports the circumference of the shadow mask 12 so that the shadow mask 12 faces the fluorescent screen 2 at regular intervals. Is attached to the stud pin 22 to fix the shadow mask 12 inside the skirt portion 4b.

An inner shield 24 is fixed behind the mask frame 18 to shield the electron beam path from the geomagnetic field. Thus, when the electron gun 16 emits a three-stem electron beam, the electron beam is deflected by the magnetic field in which the deflection yoke 14 is generated while minimizing the path change caused by the geomagnetic field, and the beam passing aperture 12a of the shadow mask 12 ) Is separated into the corresponding R, G, B fluorescent film in the fluorescent film screen 2 to express an accurate color.

In this case, the fluorescent screen 2 and the shadow mask 12 are provided with high voltages of different sizes while maintaining an insulating state. In particular, the fluorescent screen 2 is provided with a higher voltage than the shadow mask 12 to provide a shadow. The electron beam passing through the shadow mask 12 is focused by forming an accelerating electric field with the mask 12.

As described above, it is very important for the BIP type cathode ray tube which supplies the differential potential to the fluorescent film screen 2 and the shadow mask 12 for electron beam focusing to keep these members in an insulated state. However, since these members may be energized by the getter material during the getter flashing process, the present embodiment blocks the propagation path of the getter material from the getter 26 toward the skirt portion 4b of the face panel 4 so that the skirt portion ( 4b) provide means for preventing the getter film from being deposited on the inner surface.

The means provided by this embodiment comprises a getter shield 28 that forms a barrier wall of a predetermined height toward the getter 26 outside the mask frame 18, and FIG. 2 is a mask with the getter shield attached thereto. 3A and 3B are enlarged cross-sectional views illustrating an example of a panel assembly to which a getter shield is attached, respectively.

As shown, the getter shield 28 is composed of a plurality of blocking members 28a having a predetermined height toward the getter 26 outside the mask frame 18. For example, the getter shield 28 is a mask frame. Four blocking members 28a may be provided to correspond to the shape of the eighteen members, and the four blocking members 28a may be integrally coupled to form a getter shield 28.

In another embodiment, the getter shield 28 may be formed as a separate type in which each blocking member 28a is installed independently, and in both the integrated type and the separate type, the blocking member 28a is formed on the outer surface of the mask frame 18. It may be fixed by spot welding or the like, and fixedly installed in the bulb 10.

In particular, the getter shield 28 is fixed to the outer side portion 18a of the mask frame 18 at which the end of the blocking member 28a is welded to the coupling spring 20, as shown in FIG. 3A, or as shown in FIG. 3B. As described above, the end of the blocking member 28 is bent vertically to a predetermined length so that the vertically bent portion can be integrally fixed to the outside of the bottom surface 18b of the mask frame 18 on which the inner shield 24 is installed. have.

As a result, the blocking member 28a blocks the inner surface of the skirt portion 4b of the face panel 4 from the getter 26. The blocking member 28a having the above-described configuration is the outer surface of the mask frame 18 by welding or the like. When attached to the substrate, it is preferable to arrange the blocking member 28a in sufficient width to overlap the outer surface of the mask frame 18 in order to secure a sufficient welding area between these members and to improve the fixing strength of the blocking member 28a. Do.

However, since a plurality of coupling springs 20 for coupling with the stud pins 22 are fixed to the outer surface of the mask frame 18, each blocking member 28a is secured while securing a space to which the coupling springs 20 are fixed. In order to overlap the outer surface of the mask frame 18 with a sufficient width, a cutout 30 is formed at one end of each blocking member 28a facing the coupling spring 20 so that the mask frame 18 of the existing configuration may be formed. The blocking member 28a may be easily attached to the coupling spring 20 structure.

4 and 5 are partially enlarged views of the getter flashing process. When the inside of the bulb 10 is exhausted and heat is applied to the getter filling such as high frequency induction heating, the barium reaching the flash temperature is evaporated. The barium film is formed on the inner surface of the bulb 10 while being combined with the residual gas inside the bulb 10.

At this time, a getter shield 28 is attached to the outside of the mask frame 18 to prevent the barium emitted from the getter 26 from being deposited on the inner surface of the skirt portion 4b. A portion of the inner shield 24 may hit the outer wall of the inner shield 24 to change the path of travel, or may exit through the gap 24a of the inner shield 24 to travel toward the inner surface of the skirt 4b.

In this way, even if the path of the barium is changed by the collision with the inner shield 24 and proceeds toward the inner surface of the skirt portion, as shown in FIG. 4, the barium is skirted by the blocking member 28a of the getter shield 28 described above. It is deposited on the inner surface of the blocking member 28a instead of the portion 4b to effectively prevent the deposition on the inner surface of the skirt portion 4b.

In addition, even if a portion of the barium scattered toward the inner shield 24 escapes through the gap 24a formed in the inner shield 24, the barium is a blocking member of the getter shield 28 as shown in FIG. Deposition on the inner surface of the blocking member 28a instead of the skirt portion 4b by 28a effectively prevents deposition on the inner surface of the skirt portion 4b.

Accordingly, the getter shield 28 may maintain the fluorescent screen 2 and the shadow mask 12 in an insulated state even after the getter flashing, and the blocking member 28a which substantially blocks the barium's traveling path may be a bulb 10. One end facing the electron gun 16 is mounted high enough so that it does not come into contact with the inner surface of the funnel 6 when it is mounted inside, thereby increasing the barium's blocking efficiency and at the same time being in contact with the inner surface of the funnel 6. 6) prevent damage.

In addition, the blocking member 28a is, for example, a magnetic material that causes an offset or reinforcement interference with an external magnetic force. The blocking member 28a may reinforce the function of the inner shield 24 to shield the electron beam path from the geomagnetic field. ) May be made of a magnetic material based on iron or a magnetic material based on nickel.

In another embodiment, the blocking member 28a may be formed of a nonmagnetic material that does not cause mutual interference with an external magnetic force when the inner shield 24 exhibits sufficient geomagnetic shielding effect, for example, stainless steel or ceramic. It can be produced as.

As such, according to the present exemplary embodiment, the getter shield 28 is installed outside the mask frame 18 to block the inner surface of the skirt portion 4b of the face panel 4 from the getter 26, thereby being emitted during the getter flashing process. It is possible to prevent the barium from being deposited on the inner surface of the skirt portion 4b to keep the fluorescent film screen 2 and the shadow mask 12 in an insulated state.

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 getter shield structure that forms a barrier wall of a predetermined height toward the getter outside the mask frame to block a path of getter material from the getter toward the skirt of the face panel. This prevents the getter shield from blocking the barium and depositing the barium film on the inner surface of the skirt even if a portion of the barium emitted from the getter collides with the inner shield outer wall or escapes through the gap formed in the inner shield and proceeds toward the skirt. .

Therefore, the BIP-type cathode ray tube equipped with the getter shield structure maintains the fluorescent screen and the shadow mask in an insulated state even after the getter flashing, so that the differential potential can be stably supplied to the members, thereby improving the driving characteristics and the screen quality of the BIP-type cathode ray tube. Can be improved.

Claims (10)

A face panel having a skirt portion vertically extending from the edge of the screen portion; A fluorescent film screen on which a plurality of R, G, and B fluorescent films are formed on the inner surface of the face panel to receive and emit electron beams, and receive a certain high voltage; A shadow mask which is supplied with a differential potential while maintaining an insulation state with the fluorescent screen and forms an acceleration field between the fluorescent screen; A mask frame for fixing the shadow mask to the skirt portion of the face panel; An inner shield fixed behind the mask frame to shield an electron beam path from a geomagnetic field; A getter for highly vacuuming the interior of the bulb by release of getter material upon heating of the getter fill; And means for blocking a path of getter material from the getter toward the skirt portion of the face panel to prevent deposition of getter film onto the skirt portion inner surface. The method of claim 1, A bi-potential mask type cathode ray tube, wherein said means comprises a getter shield composed of a plurality of blocking members forming a blocking wall of a predetermined height toward the getter outside the mask frame. The method of claim 1, A bi-potential mask type cathode ray tube, wherein said means comprises a getter shield composed of an integral barrier member for forming a barrier wall of a predetermined height toward the getter outside the mask frame. The method of claim 2, A bi-potential mask type cathode ray tube, wherein the getter shield is composed of four blocking members corresponding to the mask frame shape. The method of claim 2, A bi-potential mask type cathode ray tube of which the getter shield is formed of a separate type in which a plurality of blocking members are independently installed. The method of claim 2 or 3, And a plurality of blocking members are fixed to an outer surface of the mask frame such that a getter shield is fixed inside the bulb. The method of claim 2 or 3, A bi-potential mask type cathode ray tube made of a magnetic material in which the getter shield interacts with a geomagnetic field. The method of claim 7, wherein A bi-potential mask type cathode ray tube, wherein the getter shield is made of a magnetic material containing iron as a main component or a magnetic material containing nickel as a main component. The method of claim 2 or 3, A bi-potential mask type cathode ray tube made of a nonmagnetic material in which the getter shield is not influenced by a geomagnetic field. The method of claim 9, A bi-potential mask type cathode ray tube, wherein the getter shield is made of stainless steel or ceramic.