KR960005642Y1 - Shadow mask in crt - Google Patents

Abstract

None.

Description

Shadow Mask Fixture

1 is a side sectional view showing a state in which frit is applied to a shadow mask bonded to a frame.

Figure 2 is a bottom perspective view showing a part of the shadow mask fixing device of the present invention.

3 is a side cross-sectional view showing a state in which the frit is applied after supporting the shadow mask to the fixation device of the present invention.

* Explanation of symbols for main parts of the drawings

S: shadow mask K: skirt (with shadow mask)

1: jig 6: holder

2: support of jig 7: magnet

3: Jig part space 8: Bracket

5: holder

FIELD OF THE INVENTION The present invention relates to the production of color CRTs, and more particularly to a fixture for fixing a shadow mask when applying an insulating layer to the inner surface of the shadow mask.

The shadow mask is not only used for color screening of color CRTs, but is also used as an exposure mask when forming fluorescent surfaces of CRTs, which is one of the core components of color CRTs. In operation of the CRT, the shadow mask repels the electron beam emitted from the electron gun assembly to the fluorescent surface through the dividing holes formed therein, and hot electrons that do not pass through the dividing holes collide with the shadow mask to thermally expand it. However, the shadow mask is deformed out of plane since the frame of the shadow mask having a large heat capacity does not expand in the initial stage of the CRT operation. Such a phenomenon is generally referred to as a doming phenomenon, which causes an initial drift of the electron beam landings, resulting in deterioration of image quality.

Therefore, various means are used to reduce the landing effect due to the domming. For example, a method of bringing a shadow mask closer to a fluorescent surface by bonding a bimetal plate to a support holder of a frame. However, in the case of a flat square tube, such a method cannot be used. Thus, a tension mask is used or a method of applying an insulating layer to the inner surface of the shadow mask as shown in FIG. . The latter method is performed by applying a frit solution, which is crystalline powder glass, to the inner surface of a shadow mask and then firing or sintering it.

When the frit coating operation is performed, the shadow mask S is a porous thin plate having hundreds of thousands of color-specific holes, and thus, there is a high risk of damage. Accordingly, the pre-coating molding operation was performed in the mask frame M assembly in which the shadow mask S was bonded to and supported by the frame F. Thus, the remaining parts except the inner surface of the shadow mask S, ie, the frame F, were applied. Is covered with a separate protective cover (not shown) to prevent the frit solution is attached.

However, the work of covering the protective cover on the frame (F) is very cumbersome, and no matter how well the protective cover is covered, there is a small gap between the frame (F) and the protective cover, and the frit sprayed from the nozzle (N) The solution was attached to the frame F and the like through the gap. In this state, when the mask frame M is moved to a sintering or sintering process, only the inner surface of the shadow mask S is fired, the frit adhered to the frame F is not fired, but the shadow mask (in the subsequent process) By dropping to the inner surface of S) and closing the color-selective holes, the hole of the shadow mask S is blocked, resulting in deterioration of the finished CRT.

In order to solve this problem, even after attempting to remove the frit particles that obstruct the color-selective holes of the shadow mask S through vibration or ultrasonic vibration, it is difficult to remove them. Many defects occurred and there was a problem of low productivity.

In view of these conventional problems of the present invention, an object of the present invention is to provide a fixing device for fixing a shadow mask so that frit coating molding operations on the inner surface of the shadow mask can be performed before forming the mask frame assembly.

In order to achieve the above object, the shadow mask fixing device of the present invention includes a jig formed to support the shadow mask circumferential shape of the shadow mask, and having a jig for supporting the shadow mask and a magnet for tightly fixing the shadow mask to the jig. It is characterized by comprising a pair of holders.

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

As shown in FIG. 2 and FIG. 3, the shadow mask fixing device according to the present invention has a jig (1) for supporting and mounting the shadow mask (S) in a shape corresponding to an inner circumferential shape of the shadow mask (S), The holder 5 which fixes the mask S is provided.

A space 3 is formed at the center of the jig 1 so that the frit solution can be applied to the inner surface of the shadow mask S from the nozzle N, and the shadow mask S is formed at the edge of the space 3. The support part 2 which contacts and supports the skirt | seat K of () is formed protruded. It is preferable that this support part 2 is formed in the shape corresponding to the inner peripheral shape of the skirt K so that the shadow mask of a very thin thin plate can be stably supported.

On the other hand, at a position close to the support 2 of the jig 1, at least one pair of holders 5 for fixing the shadow mask S are installed to face each other, and each holder 5 supports each of them rotatably. The bracket 8 is fixed to the jig 1 by a plurality of brackets 8. The holder (5) has a support (6) rotatably coupled to the bracket (8) at both ends to restrain or release the shadow mask (S) with respect to the jig (1), and according to the operation of the support (6). A magnet 7 for selectively attaching the skirt K of the shadow mask S to the support 2 of the jig 1 is provided. The support 6 is formed in an approximately C shape, and has a supporting portion 6a formed by bending an intermediate portion of the body so as to support the outer edge of the shadow mask S. Preferably, the support 6 is formed by continuously bending one long material such as a steel bar or a wire. The magnet 7 is coupled to the inner surface of the support 6, that is, the inner surface of the position outside the support 6a so that it can be attached to the outer surface of the support 2 of the jig 1. Two magnets (7) are provided with two, respectively, coupled to both inner sides of the support (6), but does not interfere with the action of the device of the present invention, preferably as shown to firmly fix the shadow mask (S) tightly Likewise, both ends are composed of a single body of sufficient length to be respectively joined to both inner sides of the support 6.

Referring to the operation of the shadow mask fixing device according to the present invention configured as described above are as follows. First, the support 6 of the holder 5 is flipped as shown by the imaginary line in the drawing so that the magnet 7 is separated from the support 2 of the jig 1, and then the support 2 of the jig 1 is supported. The shadow mask S is coupled so that the inner side of the skirt K is in contact with the outer side.

Next, the support 6 in the retracted state (virtual line shown) is rotated to the initial position so as to be in the solid line state shown in FIG. Then, the magnet 7 of the holder 5 is attached to the outer surface of the skirt (S) of the shadow mask (S) to fix the shadow mask (S), wherein the magnet (7) is a skirt of the shadow mask (S) It extends to the support part 2 of the jig 1 via the at least part K, and the skirt K is fixed to the support part 2 evenly. In addition, the supporting portion 6a of the support 6 comes into contact with the outer edge of the shadow mask S, so that the shadow mask S is extremely firm and stable.

When the shadow mask S is fixed as described above, frit solution is applied to the inner surface of the shadow mask S from the nozzle N through the space portion 3 of the jig 1 as shown in FIG. 3. Att K is protected by the support part 2 of the jig 1 which is formed in the same shape and is in close contact, so that application of the frit solution is prevented. Subsequently, the shadow mask S on which the frit coating is completed is transferred to the firing process and fired so that an insulating layer is formed on the inner surface of the shadow mask S. FIG.

According to the present invention as described above, since the coating and firing of the frit for forming the insulating layer on the inner surface of the shadow mask can be performed before the formation of the mask frame assembly, the shadow mask generated by applying the frit to the frame as in the prior art It is possible to prevent the hole blocking defect in advance, thereby improving the productivity of the mask frame assembly and exerting a great effect on improving the quality of the CRT.

Claims (1)

A jig 1 having a space 3 formed in the center thereof and a support 2 for contacting and supporting the skirts K of the shadow mask S at the edges of the space 3; A support 6 rotatably supported by a bracket 8 fixed to the jig 1 to contact and support an outer edge of the shadow mask S, and an inner surface of the support 6 coupled to the shadow Shadow mask fixing, characterized in that it has at least a pair of holders (5) each having a magnet (7) magnetically attached to the outer surface of the skirt (K) of the mask (S) and installed opposite to the jig (1) Device.