KR100274826B1 - Shadow mask and its manufacturing method _ - Google Patents

Abstract

The present invention relates to a shadow mask used in a color cathode ray tube for a display and a method of manufacturing the shadow mask, and more particularly, to a method for facilitating the progress of an electron beam and improving a mechanical strength of a shadow mask in manufacturing a color display tube cathode ray tube.

According to the shadow mask of the present invention and the method for manufacturing the shadow mask, it is possible to manufacture the shadow mask with a polygonal shape and the circular hole with a circular shape, mount the shadow mask on the cathode ray tube, rotate the ridge polygon so as to coincide with the advancing direction of the electron beam, The hole and the tube panel can be uniformly formed and the electron beam can be sufficiently passed therethrough according to the position of the through hole in the shadow mask so that the portion not related to the passage of the electron beam is not etched, A taper was formed so that the strength could be improved and the electron beam could pass sufficiently according to each position.

Description

Shadow mask and manufacturing method thereof

The present invention relates to a shadow mask used in a color cathode ray tube for a display and a method of manufacturing the shadow mask. More particularly, the present invention relates to a shadow mask used for a color cathode ray tube A shadow mask and a manufacturing method thereof.

Generally, a shadow mask is a device that functions as a color-selecting electrode that makes an electron beam emitted from an electron gun come in contact with a pixel corresponding to each of R, G, and B on the inner surface of a cathode ray tube panel.

FIG. 1 is an overall view of a shadow mask, which comprises an effective portion 10 formed of a through hole through which an electron beam passes, and an outer peripheral portion 20 capable of being mounted on a cathode ray tube.

FIG. 3 is a cross-sectional view of a through hole formed at the center of the effective portion of the shadow mask according to the prior art, and FIG. 3B is a cross- Sectional view of a through hole formed at the center peripheral portion of the effective portion of the shadow mask according to the embodiment of the present invention.

At the center point A, the small hole 12 is located at the center of the air hole 14 and the small holes 24 are formed in the direction of the electron beam toward the air hole 22 at the points B, C and D around the center.

The electron beam travels from the pores on the side of the electron gun of the shadow mask to the air on the side of the screen and is incident on the inner surface of the cathode ray tube panel. The electron beam passing through the effective portion 10 having a constant arrangement of the through-holes is vertically incident at the central portion of the shadow mask, and incident at a peripheral portion thereof obliquely at an angle by the deflection yoke.

2, 3A, and 3B. In order to facilitate the passage of the electron beam at the peripheral portion, the shadow mask is formed at the positions B, C, and D with respect to the taper 16 of the through- The taper 18 of the formed through hole is formed to be larger so as to facilitate electron beam transmission.

Recently, CDT cathode ray tubes are becoming more and more fixed, such as increasingly flattened, flat-square tube (FST), larger size, and increasing electron beam transmission angle through reduction of tube length. As a result, the shadow mask tends to become finer and larger in all areas, such as the pitch and pore size of the through-hole. Further, due to the dome phenomenon caused by the thermal expansion of the shadow mask, There is also a demand for countermeasures against the occurrence of problems, and also for improving the mechanical strength of the shadow mask in order to alleviate the impact of the cathode ray tube and to enhance the characteristics thereof.

As the cathode ray tube becomes FST and larger, the inclination of the electron beam transmitted to the peripheral portion of the shadow mask is made larger, and the electron beam is required to sufficiently pass through the shadow mask and enter the cathode ray tube panel. For this reason, the taper shown in Fig. 3 should be formed in the peripheral portion of the shadow mask to have a shape larger than that of the prior art.

As a countermeasure for improving the shadowing phenomenon and mechanical strength of the shadow mask, a method of changing the material and thickness of the shadow mask is used, or the pores and the air holes are maintained in the minimum form through which the electron beam can pass and the unnecessary portions are not etched Thereby increasing the volume of the shadow mask and improving the mechanical strength.

However, according to the conventional shadow mask and the method for fabricating the shadow mask constructed as described above, in order to secure the taper 18 of the through hole formed in the peripheral portion of the shadow mask, the small hole 24 and the air hole 22 are moved You have to make a lot of center shift in the direction. In this case, there is a problem that the pore shape on the actual CRT panel is not uniform, the deviation becomes worse, and the quality of the CRT panel is adversely affected.

Accordingly, it is an object of the present invention to provide a shadow mask which facilitates the progress of an electron beam during manufacture of a color display tube (CDT) cathode ray tube and improves the mechanical strength of the shadow mask, And a method of manufacturing the same.

Fig. 1 is an overall configuration diagram of a general shadow mask

2 is a plan view showing a shape of a through hole seen from the screen side of a shadow mask according to the related art

FIG. 3A is a cross-sectional view of a through hole formed at the center of an effective portion of a conventional shadow mask

FIG. 3B is a cross-sectional view of the through hole formed in the center peripheral portion of the effective portion of the shadow mask according to the prior art

FIG. 4 is a plan view showing the movement of the center of the hole for securing taper of the shadow mask according to the related art.

5 is a plan view showing an effective portion of the shadow mask according to the present invention.

6 is a view showing the shape of the through hole formed in the peripheral portion of the effective portion of the shadow mask according to the present invention

FIG. 7 is a cross-sectional view of a shadow mask according to the present invention,

FIG. 8 is a cross-sectional view of a through hole formed in an effective portion and a peripheral portion of a shadow mask according to the present invention

Description of the Related Art [0002]

10: valid part

14, 32: air hole formed in the center portion

12, 34: Pores of the through hole formed at the center portion

16: center taper 18: peripheral taper

20:

22, 42: air hole formed in the peripheral portion

24, 44: Pore of the through hole formed in the peripheral part

71: a large circular large plate formed on the taper plate

72: a small circular large plate formed on the taper plate

73: Small plate plate plate

In order to achieve the above object, a shadow mask manufacturing method of the present invention comprises:

A step of forming a through hole at a central portion where diagonal lines of an approximately square plate intersect with each other to form pores and apertures having different diameters of through holes on the front surface and the back surface,

Forming a through hole of the through hole so as to vary in size and shape from the central portion toward the peripheral portion, and connecting the two circular portions having different sizes to each other;

A step of forming a circular hole in the air hole,

Applying a photosensitive liquid to a shadow mask on which the large holes and small holes are formed;

A step of exposing and developing both surfaces of the iron plate coated with the photosensitive liquid,

And simultaneously etching the developed steel sheet on both sides.

According to another aspect of the present invention, there is provided a method of manufacturing a shadow mask,

A step of forming a through hole at a central portion where diagonal lines of an approximately square plate intersect with each other to form pores and apertures having different diameters of through holes on the front surface and the back surface,

Forming a through hole of the through hole so as to vary in size and shape from the central portion toward the peripheral portion, and connecting the two circular portions having different sizes to each other;

A step of forming a circular hole in the air hole,

Applying a photosensitive liquid to a shadow mask on which the large holes and small holes are formed;

A step of exposing and developing both surfaces of the iron plate coated with the photosensitive liquid,

And a step of etching a predetermined amount of the developed steel plate at one time by etching the same at both sides simultaneously.

In order to attain the above object, in the shadow mask of the present invention,

A through hole is formed at a central portion where diagonal lines of an approximately square plate cross each other. A through hole and a through hole having different through hole diameters are formed on the front surface and the rear surface,

A plurality of circular protrusions having different sizes are formed by connecting the protrusions of the through holes so that the size and the shape of the protrusions are changed from the central portion toward the peripheral portion,

And a circular hole is formed in the center of the air hole.

At this time, the air hole is arranged so as to coincide with the traveling direction of the electron beam in the central portion,

It is preferable that the peripheral portion is formed by moving the central point of the air hole with respect to the small hole in the advancing direction of the electron beam.

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

In all the drawings for explaining the embodiment, those having the same function are denoted by the same reference numerals, and a repetitive description thereof will be omitted.

FIG. 5 is a plan view showing an effective portion of a shadow mask according to the present invention, and FIG. 6 is a view showing the shape of a through hole formed around the effective portion of the shadow mask according to the present invention.

As shown in the drawings, the shadow mask according to the present invention is formed by circularly forming the air hole, which is a circular shape in the prior art, and changing the size and shape while moving to the peripheral portion.

The pores are formed in a circular shape as in the conventional art, and the long axis (a) of the large aperture is made to coincide with the central portion of the shadow mask, that is, the incident direction of the electron beam, The portion not related to the passage of the electron beam is not etched, thereby improving the mechanical strength of the shadow mask.

The center point of the circular disk plat 52 is moved in the electron beam advancing direction to the small circular plate plat 54 at the peripheral portions B, C, and D formed as described above to secure a sufficient amount of taper so as to facilitate electron beam transmission .

In addition, the shadow mask manufacturing method of the present invention is a method of manufacturing a shadow mask by using a circular circular plate platters 71 and 72 and circular circular circular plate platters 73 having a large circular shape and a small circular shape as shown in FIG. 7 The steel plate coated with the photosensitive liquid is exposed, developed, and etched.

Then, the holes in the air platelet plates 71 and 72 are set in the direction of the major axis (a) of the air gap according to the center direction, that is, the traveling direction of the electron beam, thereby forming the disk platelet.

That is, in the shadow mask of the related art, both the air hole and the pore shape have a circular shape as shown in Fig. 2, whereas the shadow mask of the present invention has a circular shape like the conventional one, And the other two circular shapes 71 and 72 are connected to each other. Further, the direction of the long axis (a) of the entire shape of the air hole 42 is made to coincide with the center direction of the shadow mask, that is, the traveling direction of the electron beam.

As shown in FIG. 5, the air hole 32 is formed in a circular shape at the central portion, and the other two members are connected to each other while gradually moving toward the peripheral portion. As a result, the size of the through hole in the effective portion 10 of the shadow mask and the direction of the long axis (a) of the through hole are determined according to the corresponding positions.

In this way, the formation of the taper 18 in the peripheral portion of the shadow mask can be ensured in the large circular portion 71 through which the electron beam is transmitted, so that the size can be made larger than in the prior art. Further, the small circular portion 72, Can increase the volume or weight of the shadow mask without increasing the etching area as much as possible, thereby improving the mechanical strength.

Next, a method of manufacturing the shadow mask will be described with reference to the accompanying drawings.

As shown in FIG. 7, the large circular plate fitter has a shape in which the other two circular rings 71 and 72 are connected to each other, and the size and the major axis (a) direction are formed differently according to the positions of the through holes of the shadow mask . Herein, the pores are formed into a round shape as in the conventional shape.

The central point of the platen disc plate is moved to the small disc platters at the peripheral portions B, C, and D so as to secure a sufficient amount of taper so as to facilitate the electron beam penetration. The thus fabricated circular disk plate and small circular disk plate are mounted on an exposure machine to expose the both surfaces of the iron plate coated with the photosensitive liquid, respectively, and then subjected to development processing. After the development process, the steel plate is simultaneously etched on both sides or a certain amount of etching is performed on both sides simultaneously, and only one side is etched to form a desired through-hole.

As shown in FIG. 8, the thickness of the shadow mask used is different from that of the conventional shadow mask. In the case of an Invar steel plate having a thickness of 0.12 mm, μm , Major axis = 110 μm , A circular plate R having a large circular portion R = 40 and a small circular portion R = 39 or less (the minimum area securing the desired through-hole can be ensured => 25 to 39) at the opposite side of the tapered portion is prepared Developing and etching in each direction using a circular disk plate of 90 mu m in the pores, the large air gap is defined as 240 μm , Tapered portion large circular portion = 225 μm , Tapered portion small circular portion = 220 μm And the shape of the shadow mask in which the through hole (small hole) is formed by 120 mu m is shown. Then, with respect to the pores, μm By moving the center point, the taper amount is 80 μm Respectively.

As described above, according to the shadow mask of the present invention and its manufacturing method, the air holes are formed by connecting the other two circular shapes, and the small holes are formed in a circular shape, and the shadow mask is mounted on the cathode ray tube, And the pores of the through-hole and the tube panel are uniformly secured, and at the same time, the electron beam passes through the shadow mask in such a manner that the electron beam can sufficiently pass therethrough according to the position of the through-hole, It is possible to improve the mechanical strength of the shadow mask and to form the taper so that the electron beam can pass sufficiently according to each position.

Also, in the manufacturing method as well, the airplane platelet is formed by connecting the other two circles and drawing the major axis direction and the size differently depending on the positions of the through holes. Further, since the airplane side shape makes it easier to secure the peripheral portion taper in exposure and etching There is a possible effect.

It will be apparent to those skilled in the art that various modifications, additions and substitutions are possible, within the spirit and scope of the invention, and that such modifications are intended to fall within the scope of the following claims something to do.

Claims (4)

In the shadow mask manufacturing method, A step of forming a through hole at a central portion where diagonal lines of an approximately square plate intersect with each other to form pores and apertures having different diameters of through holes on the front surface and the back surface, Forming a through hole of the through hole so as to vary in size and shape from the central portion toward the peripheral portion, and connecting the two circular portions having different sizes to each other; A step of forming a circular hole in the air hole, Applying a photosensitive liquid to a shadow mask on which the large holes and small holes are formed; A step of exposing and developing both surfaces of the iron plate coated with the photosensitive liquid, And simultaneously etching the developed steel plate on both sides. In the shadow mask manufacturing method, A step of forming a through hole at a central portion where diagonal lines of an approximately square plate intersect with each other to form pores and apertures having different diameters of through holes on the front surface and the back surface, Forming a through hole of the through hole so as to vary in size and shape from the central portion toward the peripheral portion, and connecting the two circular portions having different sizes to each other; A step of forming a circular hole in the air hole, Applying a photosensitive liquid to a shadow mask on which the large holes and small holes are formed; A step of exposing and developing both surfaces of the iron plate coated with the photosensitive liquid, Wherein the step of etching the surface of the developed steel sheet comprises etching the surface of only one surface of the steel sheet after etching the predetermined amount of the steel sheet on both surfaces at the same time. In the shadow mask, A through hole is formed at a central portion where diagonal lines of an approximately square plate cross each other. A through hole and a through hole having different through hole diameters are formed on the front surface and the rear surface, A plurality of circular protrusions having different sizes are formed by connecting the protrusions of the through holes so that the size and the shape of the protrusions are changed from the central portion toward the peripheral portion, Wherein a circular hole is formed in the center of the air hole. The method of claim 3, The air- The center portion is arranged so as to coincide with the traveling direction of the electron beam, And the central point of the air hole is moved in the direction of travel of the electron beam with respect to the pores at the peripheral portion.