KR20030088562A - Shadowmask for color CRT - Google Patents

Abstract

PURPOSE: A shadow mask is provided to achieve improved strength of shadow mask, while allowing the skirt portion of the shadow mask to be easily fixed to the mask frame. CONSTITUTION: A shadow mask comprises an aperture portion having a plurality of beam passing holes, a non-aperture portion formed around the aperture portion and connected to the aperture portion, a skirt portion bent around the non-aperture portion, a plurality of slits(400,500) having bridges(410,510) formed in the skirt portion, and convex-concave portions(420,520). The slits and the convex-concave portions are formed in the vertical direction of the skirt portion of the shadow mask.

Description

Color Cathode Ray Shadow Mask {Shadowmask for color CRT}

The present invention relates to a shadow mask in a color cathode ray tube.

More specifically, the present invention relates to a shadow mask tube for color cathode ray tube having an improved structure which reduces curvature occurring in the skirt portion during press shaping of the shadow mask so that there is no curved distortion or strength degradation of the shadow mask. .

In general, the color cathode ray tube is one of the most common display devices, which is used in color televisions, color display monitors for OA devices, etc., and is red, green, and patterned on the inner surface of the front panel by an electron beam controlled by video signals. A fluorescent image is emitted by an electron beam controlled by the image signal on a fluorescent film screen including blue (R, G, B) phosphors to reproduce a color image.

As shown in FIG. 1, the general color cathode ray tube as shown in FIG. 1 has a substantially rectangular panel portion 1 (Pannel), which is a front body, and a substantially cylindrical neck portion 14 (Neck), which is a rear body, and the panel portion. (1) and a funnel portion (2, Funnel), which is a substantially funnel-type vacuum casing connecting the neck portion 14, and emits red, green, and blue light on the inner surface of the face plate of the panel portion (1). The fluorescent surface 4 is coated, and a shadow mask 3, which is a porous thin metal material serving as a color selection electrode, is installed while maintaining a predetermined distance from the fluorescent surface 4. In addition, the neck portion 14 is provided with an electron gun 12 for generating three electron beams 6 of red, green, and blue (R, G, B), and moves the electron beam 6 along a coplanar path. The fluorescent surface 4 is reached through the shadow mask 3.

The electron gun 12 emits an electron beam 6 controlled by a screen signal, and the electron beam 6 generates a deflection yoke 5 around the connection portion between the neck portion 14 and the funnel portion 2. After deflecting up, down, left, and right under the influence of the deflecting magnetic field, the light passes through the beam passing hole 15 formed in the shadow mask 3, and then sequentially scans the respective phosphors in the fluorescent surface 4, and is separated and landing. The predetermined image is realized.

In addition, the funnel portion 2 connects the panel portion 1, which is a cathode ray tube front body, and the neck portion 14, which is a rear body, and has a shielding role inside so that the cathode ray tube is less affected by an external geomagnetic field during operation. The inner shield 9 and the inner shield 9 and the frame 7 supporting the shadow mask 3 by the fixing spring 16 and the frame assembly are coupled to the panel unit 1. It includes a spring (8) and a reinforcing band (11) surrounding the outside of the funnel to ensure safety.

The shadow mask 3, which is a main component in connection with the present invention, will be described in more detail with reference to FIG.

The shadow mask 3 is a thin sheet metal material having a thickness of approximately 0.1 to 0.12 mm. The shadow mask 3 is a portion which will be positioned to face the fluorescent surface 4 to form a disk having the plurality of electron beam through holes 15 formed by etching. The skirt portion 130, which is punched into a predetermined shape and then press-molded, is curved to form the same curved surface as the screen of the panel portion 1, and the four peripheral surfaces of the curved portion are bent by 90 degrees to be welded to the mask frame 7. ) To complete.

Here, the curved molding and the bending molding are continuously performed in one process.

Accordingly, the shadow mask 3 has a curved hole portion 100 having a plurality of electron beam through holes 110 and a curved portion that is in contact with the hole portion 100 around the hole portion 100. Study 120 and the skirt unit 130 is bent back from the periphery of the non-120 is configured.

As the shadow mask 3 is shaped as described above, a spring back occurs due to a so-called material property in the skirt 130, and thus the bow mask 3 is bent in a direction falling from the outside in the skirt 130. In other words, if a certain time elapses after pressing with a press, the skirt 130 is opened at a predetermined interval. Deformation due to the bending of the skirt portion 130 occurs in a portion of the curved perforated portion (hereinafter curved portion) of the shadow mask 3. As the skirt portion 130 opens, the support force for supporting the curved portion is weakened, thereby lowering the curved strength of the shadow mask 3 and compressing and compressing it as much as the amount of spreading. The repulsive force is applied to the curved portion to change the curvature of the curved portion. do.

As described above, in order to minimize the amount of curl of the skirt 130 due to the spring back of the shadow mask 3 and to prevent deformation and distortion of the shadow mask 3, Referring to the Republic of Korea Patent Application No. 10-1998-0008030 (published on November 25, 1998; Publication No. 1998-0080110) below with reference to the drawings, the front cross-sectional view of the shadow mask (3) shown in Figure 2 and the long side of Figure 3 As shown in the side view of the short side, a plurality of slits (200, 300) and slits (210, 310) of a predetermined shape are provided with a pair of a plurality of slits on both sides with respect to the center point of the long and short sides in the skirt portion 130 of the shadow mask. ) Are alternately formed in parallel.

The slits 210 and 310 and the irregularities 200 and 300 formed in the skirt 130 are intended to return to the initial shape of the skirt 130 by absorbing surplus material due to press molding during the curved and bending molding of the shadow mask. And greatly reduce curl generated in the skirt portion 130 and minimize the occurrence of curl into a relatively small area over the entire periphery of the skirt portion.

However, as shown in FIG. 3, the slits 210 and 310 and the irregularities 200 and 300 in the skirt 130 of the conventional shadow mask 3 are alternately positioned in parallel to each other at regular intervals at a given position. In this case, the amount of curl of the skirt 130 received in the transverse direction during the shaping of the shadow mask 3 is received in both the slits 210 and 310 and the irregularities 200 and 300 of the linear shape located in parallel, thereby increasing the strength at the time of molding. When the surface of the slit (210,310) and irregularities (200,300) does not sufficiently absorb the compressive force and the slit (210,310) and irregularities (200,300) too much wrinkles and the deformation of the contour of the curved surface of the shadow mask (3) Will appear.

Since the above problems have a significant effect on the quality of the CRT, the CRT (cathode ray tube, cathode ray tube) is generally made using the conventional shadow mask 3 as shown in FIG. Among them, a drop test is performed by using a strength test experiment, in which a cathode ray tube is dropped at a certain height to see if deformation occurs in a shadow mask.

If the impact force is weak during the drop test of the CRT, the shadow mask 3 immediately returns to its original state even when a slight deformation occurs. However, when the impact force is large, the shadow mask 3 vibrates up and down greatly and the surface is crushed. As a result of the deformation, it cannot be returned to its original state.

There may be various causes of the problem, but it is related to the structure of the shadow mask 3.

The slits 210 and 310 and the unevenness 200 and 300 in the skirt portion 130 of the shadow mask 3 do not adequately distribute the load and thus cannot withstand the impact force so that the deformation of the shadow mask occurs severely during the drop test.

When the plastic deformation of the shadow mask occurs as described above, the electron beam 6 emitted from the electron gun 12 does not pass properly through the beam passing hole 15 of the shadow mask 3 and hits the mask, causing deterioration in the shadow mask. In addition, the phosphor is not hitting the phosphor of the fluorescent surface 4 of the panel 1 properly, the screen is poor, thereby causing a problem that the productivity is lowered.

In addition, in the acoustic shock test, the vibration of the mask is not sufficiently absorbed, so that the screen of the CRT violently shows a phenomenon that the strength is lowered.

That is, in the related art, in order to minimize the amount of curl, which is the springback amount of the skirt 130 of the shadow mask 3, the irregularities 200 and 300 and the slits 210 and 310 of a predetermined shape are alternately placed in parallel, but the spring back There was a limit on relief, and it was insufficient to fulfill its function on the strength of the shadow mask and the deterioration of the mask.

Accordingly, the present invention has been made with the following technical idea by the necessity of a shadow mask having a stronger intensity.

The present invention provides a plurality of slits and a plurality of slits provided in the skirt portion of the shadow mask to form a predetermined bridge in the plurality of slits or by tilting them at an angle to minimize the amount of curl of the skirt portion and the intensity of the shadow mask. The purpose of the present invention is to improve the workability when the shadow mask is fixed to the mask frame by improving the surface distortion of the shadow mask, thereby improving the quality and productivity of the color cathode ray tube.

1 is a cross-sectional view of a typical cathode ray tube equipped with a conventional shadow mask.

2 is a front sectional view of a conventional shadow mask.

Figure 3 is a long side, short side side view of a conventional shadow mask.

Figure 4 is a long side, short side side view according to an embodiment of the shadow mask in the present invention.

Figure 5 is a long side, short side side view according to an embodiment of the shadow mask in the present invention.

Figure 6 is an embodiment of the shape of the slit formed in the skirt portion of the shadow mask in the present invention.

Figure 7 is another embodiment of the shape of the slit formed in the skirt portion of the shadow mask in the present invention.

In order to achieve the above object, in order to achieve the above object, in forming the alternatingly arranged slits 210 and 310 and the unevenness 200 and 300 included in the skirt 130 of the shadow mask 3, the bridge is applied to the slits 210 and 310 by deformation. 410, 510 is added. In addition, in order to arrange the slit (210,310) forming the bridge in the skirt portion is another feature to achieve a predetermined angle.

More specifically, the configuration of the present invention will be described in detail with reference to the embodiments with reference to FIGS. 4 and 5 as follows.

The present invention provides a curved hole-shaped portion 100 including a plurality of beam-passing holes 110 and the beam-passing holes 110, and a curved-shaped hole-free portion 120 connected with the hole-holes around the hole-holes. ) And a shadow mask 3 including a slit (400, 500, 600, 700) and a skirt portion (130) having unevenness (420, 520, 620, 720) formed with a bridge that is a strength reinforcing means that is bent backward in the periphery of the hollow portion (120).

As a more specific embodiment of the present invention, in the side views of the short side and the long side of the shadow mask of FIG. 4, the bridges 410 and 510 added to the slits 400 and 500 in the skirt 130 of the shadow mask as a means for strengthening the shadow mask. can see.

Looking in more detail in the side view of FIG. 4, the horizontally long portion having a predetermined thickness above the skirt portion while forming a slightly curved surface of the upper portion represents a shape due to the curved surface of the shadow mask seen from the side, and under the skirt portion. A pair of the plurality of slits 400 and 500 are disposed at both sides of the central point of the short side, and the rest of the plurality of slits 400 and 500 are alternately arranged in parallel with the unevenness 420 and 520, as shown in the drawing. Done.

The plurality of slits 400 and 500 are divided into two upper and lower stages to form bridges 410 and 510 having a predetermined shape, and extend from the end of the skirt portion to a depth of approximately 30 to 70% of the height of the skirt portion, and the plurality of irregularities 420 and 520 are skirts. It extends from the end of the skirt to the entire height of the skirt, and its cross section is arcuately shaped into the skirt.

According to another embodiment of the present invention, as shown in FIG. 5, the slits 600 and 700 including the bridges 610 and 710 of the skirt 130 of the shadow mask are disposed at predetermined angles in side views of the short side and the long side of the shadow mask. It is characterized by tilting.

In this case, when tilting the plurality of slits 600 and 700, a pair of slits 600 and 700 are disposed to be inclined toward the central axis with respect to the height direction of the skirt at predetermined intervals on both sides of the central axis of the long and short sides of the skirt portion, and the unevenness (620 and 720). One and a pair of slits 600 and 700 inclined toward the unevenness 620 and 720 with respect to the height of the skirt on both sides thereof are arranged in parallel at predetermined intervals on both sides of the central axis.

The other detailed configuration is not different from the configuration of FIG. 4 and will not be described.

When the predetermined angle θ of the plurality of slits 600 having the bridges is between 60 and 90 degrees from the height direction of the shadow mask skirt to the skirt end, the skirt 130 of the shadow mask may be bent. At the time of molding, the slit is wrinkled a lot and there is no significant improvement in spring back phenomenon and strength. However, when the angles of the slits 600 and 700 are continuously changed to 0 to 60 degrees from the height direction of the skirt portion to the skirt end portion, the slit 600 and 700 are not weak in terms of strength during molding and the deformation shrinkage and curl of the shadow mask are not weak. Could reduce the amount of. In this case, the slits that are not inclined in the above-described embodiment are divided into two upper and lower stages to have the same strength as the bridge.

That is, when the angle θ of the slit forming the bridge is inclined at a predetermined angle selected within a range of 0 degrees to 60 degrees with respect to the skirt end portion direction from the skirt portion height direction of the shadow mask The effect of the present invention is to reduce the amount of curl, and increase the strength of the shadow mask and reduce the occurrence of curl in the skirt.

In the present invention, a shadow mask including a slit having six bridges formed on the long side of the skirt portion and a slit including four bridges arranged on the short side of the slit in parallel at regular intervals is taken as an example. It can be applied to the shadow mask for color cathode ray tube having more irregularities and slits or less irregularities and slits than the above embodiment in other dimensions.

In addition, although not included in the drawing, as another embodiment, it is also preferable to position one unevenness on the central axis of the long and short sides of the skirt portion.

That is, in the long and short sides of the skirt portion of the shadow mask, one of the plurality of irregularities is positioned on the central axis, and slits forming a pair of bridges on both sides are arranged at regular intervals, and the other irregularities and slits are alternately arranged in parallel.

In the above embodiment, the slits forming the bridges located on both sides of the unevenness on the central axis are inclined from the skirt height direction toward the unevenness on the central axis at an angle of 0 to 60 degrees from the skirt end direction, and the remaining slits are paired. With the concave-convex in the center, and inclined toward the adjacent concave-convex at a predetermined angle selected from 0 degrees to 60 degrees as described above, alternately arranged in parallel.

In the above-mentioned concave-convex and slit, the concave-convex is characterized in that it is formed over the entire height of the shadow mask skirt portion, and the slit is characterized in that formed up to 30 ~ 70% of the height of the shadow mask skirt portion.

Meanwhile, some embodiments of the shape of the slit in the present invention are shown in FIGS. 6 and 7.

In FIG. 6, the slits are divided into two upper and lower ends 800 and 830 by the bridge 810 at the long side and the short side of the shadow mask skirt, and the shape of the slits 800 relatively separated from the end of the skirt is circular. You can see that it is achieved.

In FIG. 7, the slit is divided into two upper and lower ends 900 and 930 by the bridge 910 at the long and short sides of the shadow mask skirt, and the shape of the slit 900 relatively separated from the end of the skirt is triangle. You can see that it is achieved.

In the above-described embodiment of the present invention, the shape of the slit relatively far from the end of the mask skirt is described as an example, but the shape of the slit is not limited thereto and may be formed by forming a circle 800 or a triangle 900. .

In the above, the present invention is not limited thereto, and various modifications can be made in addition to the above-described embodiments within the scope of the claims and the detailed description of the invention and the accompanying drawings.

In addition, the above modifications are not limited to the bridge included in the slit and the angle (θ) applied to the slit, but can be viewed by those skilled in the art in terms of the shape of the slit, the shape of the bridge, and the shape of the irregularities. It is natural that it falls within the scope of the invention.

As described above, in forming the plurality of slits and irregularities included in the skirt portion of the shadow mask for the color cathode ray tube in the present invention, a bridge is added to the slits and the angle is 30 degrees or more in the slits. By tilting the slits on both sides, the amount of curl can be reduced during press shaping of the skirt, which makes it easier to fix the skirt of the shadow mask to the mask frame. The contour of the shape is not distorted, and as a result, the degradation caused by the collision of the electron beam with the shadow mask is prevented, so that the color selection characteristic is improved and the shadow mask is further enhanced.

In addition, in the present invention, in the drop test during the reliability test, which is a problem in the conventional CRT, the deformation applied to the mask caused by failing to properly distribute the load due to the impact in the straight slit in the skirt portion of the shadow mask. The drop slit absorbs the drop impact sufficiently to make the deformation less than the shadow mask deformation during the conventional drop tube test, thereby increasing the strength of the shadow mask and absorbing the masking phenomenon in the sonic shock test, which causes the screen of the tube to shake. Reducing the phenomena has solved the conventional problems and has the effect of improving the quality, workability and productivity of the product.

Claims (10)

A hole forming a plurality of beam passing holes; A non-perforated part that connects with the perforated part around the perforated part; A skirt portion that is bent around the air hole; A shadow mask for color cathode ray tube, characterized in that a plurality of slits and a plurality of irregularities are formed in the skirt portion. The method of claim 1, The shadow mask for color cathode ray tube, characterized in that the slit and the irregularities are formed in the height direction of the shadow mask skirt portion. The method of claim 2, The unevenness is a shadow mask for shadow mask tube, characterized in that formed over the entire height in the shadow mask skirt height direction. The method of claim 2, The slit is a shadow mask for shadow mask tube, characterized in that formed to 30 to 70% of the height of the shadow mask skirt portion. The method of claim 1, And the slit is inclined from the height direction of the shadow mask skirt to the skirt end direction. The method of claim 5, The shadow mask for a color cathode ray tube, characterized in that the slit is inclined at a predetermined angle selected from the skirt height direction to the skirt end portion in the range of 0 degrees to 60 degrees. The method of claim 1, Both end slits of the long side or short side of the skirt portion is a shadow mask for color cathode ray tube, characterized in that the slit without a bridge. The method of claim 1, The shadow mask for color cathode ray tube, characterized in that the shape of the slit relatively apart from the end of the mask skirt portion of the slit is a square. The method of claim 1, The shadow mask for color cathode ray tube, characterized in that the shape of the slit relatively separated from the end of the mask skirt portion of the slit is circular. The method of claim 1, The shadow mask for color cathode ray tube, characterized in that the shape of the slit relatively apart from the end of the mask skirt portion of the slit is a triangle.