KR930009358B1 - Shadow mask frame assembling structure for cathode-ray tube - Google Patents

Abstract

This device comprises a hole part where many electron beam through-holes are formed, a none-hole part extending outward from the brink of the hole part, a shadowmask including a skirt part extending outward from the brink of the none-hole part, and a frame. Around the edge of the skirt part of the shadowmask is formed the cutting part having fixed length and depth in the long and short sides, thereby reducing the difference of the doming quantity between the edge part and the brink part of the vertical and horizontal center.

Description

Shadow Mask Frame Assembly for Color Cathode Ray Tube

1 is a side cross-sectional view of a typical colored cathode ray tube.

2 is a perspective view of a conventional shadowmask frame assembly.

Figure 3 is an exploded view of the shadow mask of the shadow mask frame assembly according to the present invention.

* Explanation of symbols for main parts of the drawings

10: shadow mask frame assembly 11: shadow mask

11a: Perforation (of shadow mask) 11b: Perforation (of shadow mask)

11c: Skirt portion (of the shadow mask) 12: Frame

13: cutting part (of shadow mask) A: corner part

B: Edge (of the vertical and horizontal center of the shadow mask)

The present invention relates to a shadow mask frame assembly for a color cathode ray tube, and more particularly to a shadow mask having a color sorting function located inside a panel.

The color cathode ray tube is typically a panel 5 having a shadow mask frame assembly 4 mounted therein coupled to a shadow mask 2 and a frame 3, as shown in FIG. 1, and a neck portion thereof. The funnel 6 in which the electron gun 7 is enclosed in 6a is sealed. In the color cathode ray tube 1 configured as described above, the electron beam emitted from the electron gun 7 does not pass all of the electron beam through holes of the shadow mask 2, but only partially passes through and lands on the fluorescent film to form one pixel. The shadow mask 2 is heated by the electron beams, that is, the hot electrons, which do not cause the doming acid. However, the dominant phenomenon of the shadow mask 2 fixed to the frame 3 is that the vertical and horizontal center edges B of the shadow mask 2 shown in FIG. 2 are larger than the corner portion A. FIG. Therefore, when correcting the dominant amount of the shadow mask 2 to an absolute amount, the color purity is lowered due to the difference in the purity drift due to the difference in the dominant amount at the edge portion B and the corner portion A. . That is, when the electron beam 9 is emitted from the electron gun 9 and landed on the fluorescent surface, the electron beam landing trajectory at the edge portion B moves toward the center of the shadow mask 2 as the shadow mask 2 is heated, and the difference frame ( As 3) is heated, the landing trajectory of the electron beam is moved outwardly of the shadow mask 2, and the landing trajectory of the electron beam at the corner portion A is almost unchanged at the time of thermal expansion of the initial shadow mask 2. The frame 3 is heated and thermally expanded so that the frame 3 moves to the outside of the shadow mask 2. Therefore, the amount of electron beam mis-landing that lands on the fluorescent surface at the edge portion B and the corner portion A of the horizontal and vertical centers of the shadow mask 2 is different, and the angle of correction of the absolute mis-landing amount of the shadow mask 2 is different. The color purity is lowered due to the difference in the amount of correction at the site.

The present invention has been made to solve the above problems, by reducing the amount of purity drift (purity drift) by equalizing the initial amount of the dominant at the edges and corners of the horizontal and vertical centers, and further adopts the cathode ray tube It is an object of the present invention to provide a shadow mask frame assembly for a color cathode ray tube that can improve the resolution of the.

In order to achieve the above object, the present invention provides a shadow mask having a hole portion formed with a plurality of electron beam through holes, a non-hole portion extending outwardly from the edge of the hole portion, and a skirt portion extending outwardly from the edge portion and the edge portion; ; In the shadow mask frame assembly for a color cathode ray tube coupled to the frame, the shadow mask is formed on each corner of the skirt portion of the shadow mask so as to form cutouts cut at a predetermined length and a predetermined depth with a long side and a short side around the corner. And it is characterized in that to reduce the difference in the dominant amount of the edge portion and the corner portion of the vertical center.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment according to the present invention.

The shadow mask frame assembly 10 for the color cathode ray tube shown in FIG. 1 is a combination of the shadow mask 11 and the frame 12 in which a plurality of electron beam through holes are formed, and the shadow mask 11 having a color selection function is provided. The fluorescent film formed on the inner surface of the panel is installed inside the panel to maintain a predetermined distance. Here, the shadow mask 11 fixed to the frame 12 includes a hole 11a having a plurality of electron beam through holes formed therein, and a predetermined length extending from an edge of the hole as shown in FIG. 3. The ballless portion 11b and the skirt portion 11c which is fixed to the frame 12 by extending a predetermined length from the edge of the holeless portion are configured to be provided, and the shadow mask 11 comprises the present invention. According to the characteristic of the shadow mask 11, the cutout part 13 formed in predetermined length and predetermined depth toward the long side and the short side part from each corner is formed. And the cutting portion 13 has a predetermined length (c) of the long side portion , The predetermined length d on the short side , The predetermined depth (e) on the long side , The predetermined depth f of the short side It is formed to a value satisfying. Where a and b are the distances from the edges of the shadow mask to the centers of the long and short sides, and g and h are the skirt widths of the long and short sides.

Referring to the operation of the shadow mask assembly 10 for the color cathode ray tube according to the present invention configured as described above are as follows.

The shadow mask 11 of the shadow mask frame assembly 10 is heated by an electron beam that is emitted from the electron gun and does not pass through the electron beam through hole of the shadow mask 11, and is formed at each corner of the shadow mask 11. Since the cutout portion 13, which is cut to a predetermined length and a predetermined depth, is formed at the long and short sides of the corner, the heat content of the corner portion A is lower than that of the edge portion B of the horizontal and vertical centers. And the initial domming amount of the corner portion A is relatively larger than the edge portion B of the vertical center, and as a result, the difference in the domming amount of the edge portion B and the corner portion A of the horizontal and vertical centers can be reduced. do.

That is, according to the experiments of the present inventors, the difference in the amount of purity drift was 25 µm when the cutout portion was not formed at the edge portion of the shadow mask; The cut lengths (c, d) of the long and short sides are 1/5 of the distance (a, b) from the edge to the center of the long and short sides, and the cut depths (e, f) of the long and short sides are respectively long and short sides. When 1/5, 1/2, and 4/5 of the negative skirt width g and h are used, the difference in the amount of purity drift between the corner portion A and the edge portion B is 24 µm or 22 µm. , 20 µm; The cutting lengths (c, d) of the long and short sides are 1/3 of the distance (a, b) from the edge to the center of the long and short sides, and the cutting depths (e, f) of the long and short sides are the length When 1/5, 1/2, and 4/5 of the skirt widths (g, h) of the short sides are set, the difference in the amount of purity drift between the corner portions (A) and the edge portions (B) is 24 μm, 14 It was 8 micrometers. And the cutting lengths (c, d) of the long and short sides are 1/2 of the distances (a, b) from the centers of the long and short sides, and the cutting depths (e, f) of the long and short sides are the lengths. When 1/5, 1/2, and 4/5 of the skirt widths (g, h) of the short sides are set, the difference in the amount of purity drift between the corner portions (A) and the edge portions (B) is 23 μm, 18 탆, 12 탆; The cut lengths (c, d) of the long and short sides are 2/3 of the distances (a, b) from the centers of the long and short sides, and the cut depths (e, f) of the long and short sides are the long, When 1/5, 1/2, and 4/5 of the skirt widths g and h of the short sides are used, the difference in the amount of purity drift between the corner portion A and the edge portion B is 24 μm, 22 It was 20 micrometers.

Therefore, as shown in the results of this experiment, the deeper the depth of cut (e, f) of the long and short sides, the smaller the difference in the amount of electron beam drift, and the cut length (c, d) of the long and short sides to the center of the long and short sides. It can be seen that the difference in the drift amount of the electron beam is minimized in the vicinity of 1/3 of the distances a and b.

As described above, the shadow mask frame assembly for a color cathode ray tube of the present invention forms cutouts at each corner of the shadow mask, thereby minimizing the difference in the amount of doming, that is, the difference in electron beam drift between the edges and the edges of the horizontal and vertical centers. Absolute dominant amount correction of the shadow mask can be made constant over the entire area, and further, brightness and resolution of the cathode ray tube employing the shadow mask can be improved.

Claims (3)

A shadow mask having a hole portion formed with a plurality of electron beam through holes, a hole portion extending outwardly from an edge of the hole portion, and a skirt portion extending outwardly from an edge of the hole portion; In a shadow mask assembly for a color cathode ray tube, in which a frame is coupled, an ablation cut out of each of the skirt portions 11c of the shadow mask 11 at a predetermined length and a predetermined depth in the direction of the long and short sides of the edge portion, respectively. The shadow mask assembly for the color cathode ray tube, characterized in that to form a portion 13, so as to reduce the difference between the dominant amount of the edge portion (B) and the corner portion (A) of the horizontal and vertical center of the shadow mask (11). . The shadow mask assembly of claim 1, wherein the cutout portion (13) is formed to satisfy the following equation. [expression] However, a, b: distance from the edge of the shadow mask to the center of the long and short sides c, d: Cutting length of long and short sides e, f: Depth of c, d g, h: Skirt width of long side and short side The method of claim 2, wherein the cutting portion 13 , Shadow mask assembly for a color cathode ray tube, characterized in that formed with a value of.