KR840001696B1 - Crt with magnetic shield - Google Patents

Abstract

An annular recuperator comprises a number of matrices, each comprising stacked parallel layers of integrally fused non porous crystalline ceramic oxide tubes, the tubes in each layer being parallel to each other and transverse to tube in adjacent layers. The tubes forming parallel passages through the matrix have an internal diameter at least 3 times the wall thickness. The open front area of each face of a matix is at least 31% of the cross sectional area of each face end a wedge shaped spacer(ceramic oxide) is bonded to the opposing surfaces of adjacent matrices.

Description

Funnel assembly of Color Television Awards

1 is a plan view of a funnel portion of a cathode ray tube.

FIG. 2 is a cross-sectional view corresponding to a portion 2-2 in FIG. 1.

FIG. 3 is a view similar to FIG. 2 showing an open view of the magnetic shield mounting.

FIG. 4 is a cutaway view of the magnetic shield fastener of FIG. 3. FIG.

5 is a partial cross-sectional view showing the deformation of the surface of the lug.

6 is a partial cross-sectional view showing yet another protrusion supporting embodiment.

FIG. 7 is a view similar to FIGS. 5 and 6, showing another embodiment of the base protrusion.

8 is another cross-sectional view showing another embodiment of the protrusion.

BACKGROUND OF THE INVENTION Field of the Invention [0001] The present invention relates to a cathode ray tube, which relates to a cathode ray tube (hereinafter referred to as CRT) used in color television receivers. In particular, the present invention relates to an improvement in the pedestal of a magnetic shield supported entirely by the funnel portion of the CRT.

In CRTs, which are used as receivers for color TVs, it is well known that magnetic shields are used to eliminate the influence of disturbing magnetic fields generated by the electric circuits of the geomagnetic and TV receivers and the surrounding electrical equipment. It is a known fact. It is also known that the proper location of the magnetic shield in the funnel portion of the CRT enhances the magnetic shielding effect.

Magnetic shields installed inside CRT tubes are commonly referred to as "internal magnetic shields" and have been conventionally fixed in shadow masks or pedestal positions by attachments.

However, especially in CRTs for color awards, magnetic shields may be installed when they are secured near or near the shadow mask (usually close to the inner surface of the CRT face plate) or near the stand position. It is cumbersome to handle them properly and properly.

Therefore, it is desirable to fix the position of the magnetic shield and install it irrespective of the face plate and the shadow mask associated with it.

The prior art is outlined as follows.

The prior art shows and describes the magnetic shield device installed inside the CRT tube. US Patent No. 3,821,583 (June 28, 1974) shows a magnetic shield mounted on a lug that is considered an integral part of the CRT funnel. In this patent the protrusions project radially inwards and are generally situated perpendicular to the longitudinal axis of the entire CRT. Although the above patent states that the protrusion is an integral part of the funnel, the practical method of making the integral protrusion and making its cost within the cost required as a highly competitive product is not appropriate.

The prior art also shows an attachment point located inside the CRT funnel. Such attachment points in the form of notches or grooves are shown in US Pat. No. 3,971,490 (June 27, 1976). The attachment point shown in the patent helps to secure the face plate structure to the funnel portion of the CRT. With this position, the grooves described in the patent may press the funnel in a matched mold or apply centrifugal force to spin the funnel into the desired shape in a spinning mold. I can make it.

Several bosses formed integrally have been manufactured from glass parts for CRT. An example of an integrally formed boss is shown in US Pat. No. 3,735,179 (May 22, 1973). These bosses are used to properly align the shadow mask within the face plate structure.

An integrally formed boss or protrusion for securing the shadow mask in the CRT face plate is shown in US Pat. No. 2,951,167 (August 30, 1960). The boss is formed by a matched metal mold used to compress the hot deformable glass into the desired shape.

The present invention will now be described.

TECHNICAL FIELD This invention relates to the cathode ray tube (CRT) used for multicolor, ie, a color television water image. In particular, the present invention relates to the manufacture of the CRT tube funnel portion and a smooth installation example of the magnetic shield attached to the interior of the funnel.

During the assembly of the CRT for the award of color television, the faceplates are generally compression molded into final form and the protruding edges of the faceplate flanges are ready for attachment to the funnel.

An apparatus, such as an internally located metal stud, is embedded in the face plate flange to support the shadow mask assembly. Thus, the face plate and shadow mask become CRT tube attachments.

The funnel portion of the CRT is produced by compression molding a hot deformable glass into a desired form or by a centrfugal process, in which a portion of the hot deformable glass is formed into a cone-shaped mold. After filling the bottom of the mold, rotate the mold to distribute the glass to the inner surface of the mold.

However, making the funnel for rotation has an approximate outer contour, while the inner contour is less accurate due to changes in the mass of the glass, the speed of rotation of the mold, and the temperature of the glass.

The upper side and wide side of the funnel are polished to match the face plate flange side. This allows the face plate and funnel side to be in adjacent positions, fixing them together using a seal, ie, adhesive glass, to form a bulb, or wider part of the CRT tube. .

During the centrifugal process, ie the manufacture of the funnel by the mold rotation method, the hot deformable glass is scattered on the inner surface of the mold. The extra glass moves to the wide side of the funnel, ie outside. When the so-called "quadron CRT funnel" is produced, the extra glass tends to move to the upper outer edge of the funnel. It has been found that this extra glass can be used to make good bosses, or lugs, for the installation of magnetic shields. The protrusions are aligned with the longitudinal axis of the CRT and are further processed, polished or unnecessary. The protrusion made as described above receives the attachment point of the magnetic shield, so that the accessory is newly made. The attachment of the face plate and its accompanying shadow mask, as indicated above, are paired with the funnel attachment to form a CRT valve.

Referring now to the drawings, a top view of a CRT funnel is illustrated in FIG. The funnel is generally represented by the number 10, and the drawing shows the viewer looking down into the funnel. The funnel 10 is commonly known as a "conical pyramid" in the form of a quadrilateral CRT. The head face 12 is of uniform thickness and mated with a corresponding flange of the face plate of the same thickness.

The bottom end, i.e. the small end 14, is coupled to a neck tube into which an electron gun and associated electrical components not shown here are fitted. The funnel 10 depicted in FIG. 1 is manufactured by centrifugal rotation technique, so that a boundary line 16 appears between the slightly thinner lower portion 18 of the funnel 10 and the thicker upper portion 20 of the funnel. . Since the edge portion 22 is farthest from the axis of rotation of the mold in which the funnel 10 rotates therein, the hot glass tends to accumulate, i.e., accumulate at the edge 22.

The cast glass, stacked on the edges 22, is suitably utilized to achieve satisfactory fixation of the magnetic shield in the CRT, which is one of the main objectives of the present invention. A typical magnetic shield backrest 24 is shown at all four corners of the funnel 10.

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1, showing a portion of the magnetic shield 26 attached to this portion.

The magnetic shield 26 is not shown in FIG. The magnetic shield 26 has a suitable clip mounting strip 28 attached to the body.

The backing strips 28 each include a hole 30 of sufficient size to fit over the side walls of the mounting lugs 24. The backing strip 28 is maintained in solid contact with the base of the backing protrusion 24 by a spring metal fastener 32 which is fitted over the protrusion 24 and is firmly fixed to its side wall.

FIG. 3 is a modification of the funnel and magnetic shield assembly shown in FIG.

Instead of the backing strips 28 shown in the embodiment of FIG. 2, the holes 36 are situated directly in the main structure of the modified magnetic shield 34. The modified magnetic shield device 34 may be fixed using the spring metal clamp shown in FIG. 2, or may be fixed using the clamp device described later.

4 shows a partial cutaway view of clamp 88 which is an integral part of a modified magnetic shield 34. It is therefore easy to see that magnetic shields of one-piece construction can also be used in the present invention.

During the formation of the funnel 10 and the integrally attached protrusions 24, it has been found that satisfactory protrusions can be formed from the extra glass material that has conventionally existed naturally in the edge region 22. Thus, there is no need to add glass for the protrusions 24 while increasing the weight and volume of the glass.

It is formed by the so-called "spin against a ring technique" of the funnel 10, wherein the metal ring is located against the outer side of the centrifugal mold. As the mold rotates, the molten glass rises up the wall of the mold and eventually stops against the mold's ring, forming an upper surface 12 that requires little finishing before being joined to the CRT faceplate. . In order to make projections 24 on each of the corner portions 22, a hollow, suitable cavity in the ring of the mold, to receive the glass when the molten glass is spread throughout the mold by centrifugal force due to the rotation of the mold, this cavity (cavity) is located.

Therefore, it is possible to improve the assembly of the CRT through the present invention, which is possible by forming two assembly parts, namely, faceplate-shadow mask assembly and funnel-magnetic shield device assembly.

The advantages of this system are obvious when considering that faceplates and their associated shadow masks must be combined at least three times, as several fluorescent materials must be co-cured inside the faceplate when creating a CRT for color awards. .

5 shows a deformed protrusion 24 that rounds the upper side 40 so that the magnetic shield device 26 can be easily settled.

In addition, the outside of the projection 24 is knurling, that is, roughened.

Roughening the outer surface 42 causes the spring metal clamp 32 to be tightened more firmly.

Because of the electrical nature of the CRT (32), the same fasteners should be loose and never move freely inside the CRT.

Such reckless movement inside the CRT of the clamp immediately adversely affects the function of the CRT.

6 shows another embodiment of the present invention. The protruding portion 24 may have a round shape as in FIG. 5 or may have a flat upper side as shown in FIG. 2 and FIG. A metal cap 44 sits over the protrusion 24, and the bottom side 46 lies on the glass of the funnel 10 at the base of the protrusion 24. In order to firmly attach the metal cap 44 to the protrusion 24, a low temperature sealing, ie, adhesive glass 48, is filled in the bottom side 46 of the cap 44.

The sealing glass is placed before or after the metal cap 44 rests on the protrusion 24.

Thereafter, after heating to make the sealing glass molten, the surfaces of both the funnel 10 and the bottom side 46 of the cap 44 are wetted. The use of the metal cap 44 ensures that metal clamps, such as 32, do not accidentally drop small pieces of glass from the sides of the protrusions 24 during or after installation of the magnetic shield 26. can do.

7 shows yet another embodiment of the present invention, where the protrusions 24 are not only rounded at the top, but are tapered 50 in the reverse direction, as shown in the figure at an angle of K. In FIG.

The larger diameter of the protrusion 24 toward the upper end prevents the spring metal clip 32 from loosening and falling out of the installed position due to carelessness during CRT assembly or when using the receiver set with a real TV.

8 shows a deformation of the spring metal club 32 into a more aggressive support.

The glass ring 52 is formed on the side wall of the protrusion 24. The glass ring 52 is positioned so that the extending finger of the clip 32 finally lies just below the ring 52. Again this embodiment provides a method of preventing accidental peeling off of the position where the clip 32 is installed.

Claims (1)

A generally truncated pyramid-shaped glass body that accommodates a necktube at the small end and a face plate at the large end, and a color television positioned within and supported by the long hollow glass body. In the funnel assembly of the water pipe, located at each of the four corners of the funnel described above, the end of the funnel which is inclined and has a free end and a base having a longitudinal axis parallel to the longitudinal axis of the funnel and which receives the neck pipe; A plurality of integrally formed protrusions having free ends furthest away from and a magnetic shield which acts together with the protrusions of the funnel by means of perforated support strips attached to the magnetic shield are also funnel magnetic shields. A number of clamps located on the protrusions that press the magnetic shield against the protrusions to secure against a funnel assembly comprising: a stener.

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