KR100869101B1 - Shadow Masks for Color Cathode Ray Tubes - Google Patents

Abstract

The present invention discloses a shadow mask for color cathode ray tubes. According to the present invention, each of the holes and holes formed on the side from which the electron beam is emitted and the small holes formed on the side where the electron beam is incident, the hole is arranged, and extending from the edge of the hole to a predetermined width In the shadow mask for a color cathode ray tube provided with no holes, the holes have an ellipse shape having an area smaller than a circle so as to minimize the amount of etching, and the major axis thereof is formed to coincide with the diagonal direction of the hole. In order to maintain the electron beam transmittance at a predetermined size and to ensure the margin of rudder color in each direction, the elliptical shape is formed at least in the dominant region of the perforated part, and its major axis is formed perpendicular to the diagonal direction of the perforated part.

Description

Shadow mask for color cathode ray tube}

1 is a side view showing an example of a conventional color cathode ray tube.

FIG. 2 is a perspective view of the shadow mask of FIG. 1. FIG.

Figure 3 is a graph showing the dominant phenomenon over time.

FIG. 4 is a cross-sectional view of an electron beam through hole of the shadow mask of FIG. 1. FIG.

5 is an explanatory diagram for a punching color margin.

6 is a perspective view showing a shadow mask for a color cathode ray tube according to an embodiment of the present invention.

7 is a plan view showing the shape and arrangement of the pores in the dominant maximum region of the hole.

8 is a plan view showing the shape and arrangement of the pores in the central region of the hole.

9 is a plan view showing the shape and arrangement of the pores in the edge region of the hole.

10 is a plan view showing the shape and arrangement of the small holes and large holes in the hole.

FIG. 11 is a plan view illustrating the shapes of the small holes and the large holes of FIG. 10; FIG.

12 is a graph showing the difference between the major and unidirectional sizes of the large hole with respect to the distance from the center of the hole.                 

<Brief description of the major symbols in the drawings>

61..shadow mask 62..holes

63..electron beam passing through

63b .. 64 .. No study

65. Skirt L1. Long axis direction of pore

L2..Long axis direction of large hole D..Diagonal direction of hole part

The present invention relates to a color cathode ray tube, and more particularly, to a shadow mask for color cathode ray tube installed in proximity to a fluorescent film inside a panel of a color cathode ray tube to perform a color discrimination function.

1 shows an example of a conventional colored cathode ray tube.

Referring to the drawings, the color cathode ray tube is a panel 10 having a fluorescent film 11 formed on an inner surface thereof, and a funnel 20 encapsulated with the panel 10 and having an electron gun 22 installed inside the neck portion 21. And a deflection yoke 23 provided in the cone portion of the funnel 20 and an electron beam emitted from the electron gun 22 by being spaced apart from the fluorescent film 11 at predetermined intervals in the panel 10. The shadow mask frame assembly 30 includes a shadow mask 31 having a color discrimination function and a frame 39 supporting the shadow mask 31.

Here, as shown in FIG. 2, the shadow mask 31 includes a hole 32 formed with a plurality of electron beam through holes 33 in a predetermined pattern and a predetermined length from an edge of the hole 32. And a skirt portion 35 which is bent at a right angle from the edge of the hollow portion 34.

In the color cathode ray tube configured as described above, after the electron beam emitted from the electron gun 22 is deflected by the deflection yoke 23, the color cathode ray tube passes through the electron beam through hole 33 formed in the shadow mask 31, and thus, of the panel 10. Landing on the red, green, and blue phosphors R, G, and B of the phosphor film 11 formed on the inner surface, that is, the screen surface, excites the phosphor to form an image.

On the other hand, as described above, the electron beam that is emitted from the electron gun 22 and landed on the fluorescent film 11 to excite it, that is, the hot electrons do not pass all the electron beam through hole 33 of the hole 32, 15% to 20 Only about% will pass. About 80% of the electron beams that do not pass impinge on the hole 32 of the shadow mask 31 so that most of the kinetic energy is converted into thermal energy. As a result, the shadow mask 31 thermally expands and thermal deformation occurs in the screen direction. The thermal deformation causes the shadow mask 31 to shift relative to the electron beam through hole 33 and the phosphor of the shadow mask 31, that is, the electron beam through hole ( 33), a drift phenomenon occurs, causing mis-landing of the electron beam. Thus, a doming phenomenon that degrades the color purity of the overall image quality is caused.

As shown in FIG. 3, the dominant phenomenon is divided into three stages according to time, and the initial dominant interval is mainly generated due to thermal expansion of the shadow mask 31 so that the dominant phenomenon reaches a maximum value. The domming correction interval is caused by the heat conduction to the frame 39, and finally reaches the thermal equilibrium in the color cathode ray tube to reach a stable state.

Initial doming is most prominent in the area of the hole 32 of the shadow mask 31 having a dome-shaped curvature in a region 1/2 to 2/3 of the entire length from the center to the edge, and the shadow mask It has a directionality to proceed radially outward of (31).

As a method for controlling the initial domming characteristics, a shadow mask made of a material having a low thermal expansion coefficient or an inorganic coating method for reducing the absorption of thermal energy by an electron beam impinging on the shadow mask has been applied. However, these methods have a problem of increasing material costs and process costs, although they show satisfactory domming characteristics. Accordingly, there is a demand for a clear image quality that does not cause a decrease in color purity by using a shadow mask made of a lower cost material to improve the doming characteristic.

On the other hand, in the hole 32 of the shadow mask 31, the electron beam through hole 33 may be formed in various ways, the cross-sectional view of an example of the electron beam through hole 33 is shown in FIG. .

As shown, the electron beam through hole 33 is a large hole 33a formed outside the shadow mask 31 so as to face the panel 10, and a small hole 33b formed inside thereof. Consists of                         

The small hole 33b affects the electron beam transmittance, the shape of the phosphor dot, and the transmitting electron beam diameter. In order to improve the other color margin (CM, see FIG. 5), the small hole 33b may be designed to have a small size, but the electron beam transmittance This decreases the luminance characteristics, so it is important to secure the other color margin (CM) while maintaining an appropriate electron beam transmittance.

Here, as shown in FIG. 5, the other color margin CM refers to another phosphor dot adjacent to the electron beam boundary BB, such as a green phosphor dot R, in the electron beam striking the red phosphor dot R. As shown in FIG. To this extent, if the secured color margin (CM) is largely secured, even if the initial doming occurs, the color purity may not be deteriorated and a clean image quality may be obtained.

In addition, the electron beam through hole 33 of the shadow mask 31 is typically formed by an etching method. If the etching is performed more than necessary, the weight of the mask disc is reduced, which adversely affects the curved support strength after molding. do. Therefore, a hole having an optimal size in a range that does not cause beam clipping in the incident direction of the electron beam, that is, the electron beam collides with the electron beam passing hole 33 surface of the shadow mask 31 to deteriorate color purity. It will be required to etch it.

As related technologies, there are those disclosed in Japanese Patent Laid-Open No. Hei 11-238474 and Japanese Patent Laid-Open No. Hei 11-54062.

The present invention is to solve the above problems, by improving the shape of the small holes and large holes constituting the electron beam through hole, to provide a shadow mask for color cathode ray tube that can improve the dominant characteristics and the support strength There is a purpose.

The shadow mask for color cathode ray tube according to the present invention for achieving the above object,

A hole having a plurality of electron beam through holes formed of a large hole formed on the side from which the electron beam is emitted and a small hole formed on the side from which the electron beam is incident, and a non-hole extending to a predetermined width from an edge of the hole. In the shadow mask for colored cathode ray tube,

The large hole has an elliptic shape having an area smaller than the round so as to minimize the amount of etching, the long axis is formed so as to coincide with the diagonal direction of the hole,

The small pores have an elliptic shape at least in the dominant region of the perforated part so that the electron beam transmittance can be maintained at a predetermined size and the other color margins can be secured in each direction. It is characterized by.

In the final end region of the hole, it is preferable that the ratio of the longitudinal size / unidirectional size of the large hole is 0.70 to 0.85.

In the central region of the pore portion, the ratio of the longitudinal size / unidirectional size of the large hole is preferably 0.85 or more.

를 만족하고, 여기서 A와 B는 설계에 따라 결정될 수 있는 상수인 것이 바람직하다. When the longitudinal direction of the large hole is a, the unidirectional size of the large hole b is b, and the distance from the center of the hole is r.

, Where A and B are constants that can be determined according to design.

Small pores arranged in the center region and the edge region except the dominant maximum region of the perforated portion have an elliptic shape, and the long axes of the small pores are formed to have a predetermined angle with the diagonal direction of the perforated portion.

Small pores arranged in the center region and the edge region except the maximum dominant region of the hole are preferably formed in a circular shape.

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

The shadow mask for a color cathode ray tube according to an embodiment of the present invention has a color discrimination function of an electron beam emitted from an electron gun installed at a predetermined interval apart from a fluorescent film formed on an inner surface of a panel of a color cathode ray tube. It is.

Referring to the drawings, the shadow mask 61 includes a hole 62 formed with a plurality of electron beam through holes 63, a hole 64 extending to a predetermined length from the edge of the hole 62, and It is comprised including the skirt part 65 bent vertically downward from the non-hole part 64. As shown in FIG.

The electron beam passing holes 63 of the hole 62 have a color discriminating function, and are formed with a large hole 63a formed at a side from which the electron beam, which is outside the shadow mask 61, is emitted so as to face the panel. It consists of a small hole (63b) formed in the side which the electron beam which is inside is incident.

The small holes 63b and the large holes 63a of the electron beam passing hole 63 may be formed by etching, and the size and shape of the small holes 63b and the large holes 63a may depend on the deflection angle of the electron beam and the thickness of the mask. According to the etching characteristics, electron beam transmittance and the like can be variously made.

Typically, the electron beam transmittance Tm is calculated as in Equation 1 below. As can be seen from this equation, it can be seen that the electron beam transmittance Tm is adjusted according to the horizontal size SW and the vertical size SL of the small holes, and the horizontal pitch Ph and the vertical pitch Pv of the through holes.

[Equation 1]

According to one feature of the invention, as shown in Figs. 7 to 9 to increase the electron beam transmittance Tm, the small holes 63b are formed and arranged, respectively.

7 to 9 illustrate small holes formed in respective regions to be described later. Here, the holes are omitted.

In the perforation part 62 of the shadow mask 61, for convenience of explanation, an area of 1/2 to 2/3 with respect to the entire length from the center to the edge of the perforation part 62 (hereinafter, referred to as the dominant area) And B) and the area from the center of the perforation portion 62 to the inner boundary of the dominant maximum area B (hereinafter referred to as the central area, A), and the outer boundary to the edge of the dominant maximum area B. If the area is divided into an area (hereinafter referred to as an edge area C), the dominant phenomenon of the shadow mask 61 is, as described above, the curvature of the shadow mask 61 which is domed in the deformation of the initial shadow mask 61. In view of the characteristics, the largest occurrence occurs in the dominant maximum region B. Accordingly, deterioration of color purity, i.e., landing movement, has a directionality extending radially outward from the center of the shadow mask 61.

Therefore, the horizontal size SW and the vertical size SL of the small holes 63b are particularly preferably adjusted in the dominant area B of the perforations 62. That is, as the horizontal size SW and the vertical size SL of the small holes 63b are adjusted, the small holes 63b have an elliptical shape rather than a round shape.

In addition, the small hole 63b has a predetermined rotational angle θ. The rotation angle θ of the small holes 63b is an angle formed between the major axis direction L1 of the small holes 63b and the diagonal direction D of the hole part 62, and has an acute angle having a range of 0 ° to 90 °. Is defined. In addition, the diagonal direction D of the pore 62 is defined as the direction of an imaginary line extending radially from the center of the pore 62.

The rotation angle θ of the small hole 63b is the maximum axis B of the small hole 63b in the long axis direction L1 of the small hole 63b and the diagonal direction D of the small hole 63. It is desirable to have a maximum angle perpendicular to each other.

On the other hand, in the region other than the dominant region B of the hole 62, the small hole 63b may have various shapes. As shown in the drawing, as in the dominant region B, Small holes 63b each have an ellipse shape in the center area A and the edge area C of the hole part 62, and the major axis direction L1 of each hole hole 63b is diagonal to the hole part 622. It may be formed to be perpendicular to the direction (D).

As another example, small pores may be formed in a circular shape in the central region and the edge region of the perforation portion.                     

As another example, the pores may have an elliptic shape in the center region and the edge region of the perforated portion, respectively, and may be formed to rotate at a predetermined angle. In this case, in the central region of the perforated portion, each of the pores gradually increases as the rotation angle increases toward the inner boundary of the dominant maximum region, and reaches a maximum value, that is, 90 °, at the inner boundary of the dominant maximum region. In the edge region of, each pore may be formed such that its rotation angle gradually decreases from the maximum to reach 0 ° from the outer boundary of the dominant maximum region to the edge end.

At least each of the small holes 63b in the dominant maximum region B is formed such that its major axis direction L1 is perpendicular to the diagonal direction D of the shadow mask 61, so that in the shadow mask 61, X Corresponding to the doming phenomenon having a radial direction in the region other than the Y-axis, the other color margin (CM, see FIG. 5) for each direction can be secured while maintaining an appropriate electron beam transmittance (Tm). Therefore, the margin for color purity deterioration can be increased.

As described above, in the perforations 62 of the shadow mask 61, the shape of the small holes 63b, that is, the horizontal size SW and the vertical size SL, is changed while the long axis direction of the small holes 63b is changed. By forming the small holes 63b so that L1 is perpendicular to the diagonal direction D of the shadow mask 61, it is possible to increase the margin for deterioration of color purity, and thus the overall electron beam transmittance Tm. While maintaining the uniformity, the rudder color margin CM in each direction may be enlarged so that the electron beam does not emit other phosphors.

In addition, it is possible to replace the shadow mask made of ordinary Invar material with the shadow mask made of ultra-Invar material containing high cost Co or Nb-containing aluminum material having low thermal expansion characteristics. The manufacturing cost of the cathode ray tube can be reduced.

In addition to the small holes 63b formed as described above, each shape of the large holes 63a and the state in which they are arranged are shown in FIG. 10, and the shapes of the small holes and the large holes are shown in FIG. 11.

10 and 11, according to one feature of the present invention, the large hole 63a positioned at the center of the perforation portion 62 of the shadow mask 61 has a circular shape and is arranged in other regions. The large holes 63a each have an elliptic shape.

That is, the long axis direction L2 of the hole 63a is positioned to coincide with the diagonal direction D of the hole portion 62 of the shadow mask 61, and the holes 63a are etched in this manner. Further, the major axis direction L1 of the small hole 63b and the major axis direction L2 of the large hole 63a are perpendicular to each other. However, as described above, since the shape of the pores may be modified in various ways in each area, it is not necessarily limited to the illustrated.

As the large hole 63a has an elliptic shape having an area smaller than the round shape, as shown in FIG. 11, the etching of the original shadow mask 61 disc is prevented while preventing clipping of the electron beam to a minimum level. It becomes possible to suppress it. Therefore, the supporting strength of the shadow mask 61 can be improved by increasing the weight of the shadow mask 61 disc.

The shape of the large hole 63a arranged in the hole 62 of the shadow mask 61 will now be described.

As shown in FIG. 11, when the longitudinal direction of the large hole 63a is a and the unidirectional size is b, the size ratio b / a in each of the large holes 63a is determined in the final end region of the hole 62. It is preferable that they are 0.70-0.85.

On the other hand, in the central region A of the hole portion 62, it is preferable that the ratio b / a of each of the large holes 63a is 0.85 or more, which is larger than that of the shadow mask 61 when b / a is large. This is because staining may occur.

In order to arrange the large holes 63a as described above, as shown in FIG. 12, ab, the value obtained by subtracting the unidirectional size b from the long direction size a of the large hole 63 a, is the center of the hole 62. For r, which is a distance from, it is preferable to form a parabolic equation of three or more equations as in Equation 2.

[Equation 2]

Here, A and B represent constants that can be determined according to design.

Table 1 shows the results of comparing the shadow mask 61 and the conventional shadow mask according to an aspect of the present invention as described above.

TABLE 1

Conventional shadow mask Shadow mask according to an embodiment of the present invention B / a ratio in the final stage 0.86 0.72 Weight of mask 53.7 g 58.3 g Support strength 37.1G 42.6G stain Does not occur Does not occur

Experimental conditions, respectively, in the shadow mask 61 according to an embodiment of the present invention, the hole ratio 62 in accordance with the graph shown in Figure 12 starting from 1 at the center of the ratio b / a of the large hole (63a) Formed by arranging the pores 63a such that b / a in the final end region of the diagonal direction D of becomes 0.72. In contrast, a shadow mask according to the related art has a center of 1 at a size of b / a. Starting with, linearly reduced to form the formation by arranging the pores so that b / a at the end of the diagonal direction is 0.86.

As can be seen from the table, the shadow mask 61 according to an embodiment of the present invention increases the weight of the shadow mask by about 10% compared to the related art, without causing problems such as staining as in the prior art, and supporting strength It can be seen that the increase of 14.8%.

As described above, according to the present invention, at least the small holes in the dominant maximum region are formed in an elliptical shape, while the major axis direction is formed to be perpendicular to the diagonal direction of the perforated portion, thereby maintaining the appropriate electron beam transmittance. Star margin can be secured. Therefore, the domming characteristic can be improved by increasing the margin for color purity deterioration.

In addition, by forming the hole shape of the hole portion so that its major axis direction coincides with the diagonal direction of the hole portion, the etching amount can be minimized, and the weight of the shadow mask can be increased to improve the supporting strength.

In addition, by improving the shape of the small hole and the large hole of the electron beam through-hole as described above, the shadow mask made of ultra-invar material containing high cost Co or Nb-containing aluminum material having low thermal expansion characteristics currently used as a general Invar material Substituting the shadow mask made there is an effect that can reduce the manufacturing cost of the color cathode ray tube.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Could be. Accordingly, the true scope of protection of the invention should be defined only by the appended claims.

Claims (7)

A hole having a plurality of electron beam through holes formed of a large hole formed on the side from which the electron beam is emitted and a small hole formed on the side from which the electron beam is incident, and a non-hole extending to a predetermined width from an edge of the hole. In the shadow mask for colored cathode ray tube, The large hole has an elliptic shape having an area smaller than a circle so as to minimize the amount of etching, the long axis is formed so as to coincide with the diagonal direction of the hole, The small pores have an elliptic shape at least in the dominant region of the perforated part so that the electron beam transmittance can be maintained at a predetermined size and the other color margins can be secured in each direction. Shadow mask for color cathode ray tube, characterized in that. The method of claim 1, The shadow mask for color cathode ray tube, characterized in that the ratio of the longitudinal direction / unidirectional size of the large hole in the final end region of the hole. The method of claim 1, The shadow mask for color cathode ray tube, characterized in that the ratio of the longitudinal direction / unidirectional size of the large hole in the central region of the hole. The method of claim 1, When the longitudinal direction of the hole is a, the unidirectional size of the hole is b, and the distance from the center of the hole is r,

Where A and B are constants that can be determined according to the design of the shadow mask for color cathode ray tube. The method of claim 1, The small holes arranged in the center area and the edge area of the hole except the maximum dominant area of the hole have an elliptic shape, and the long axis of the hole is formed to have a predetermined angle with the diagonal direction of the hole. Mask. The method of claim 5, In the pores arranged in the center region and the edge region except the dominant maximum region of the hole portion, the long axis of each hole is perpendicular to the diagonal direction of the hole portion, the shadow mask for color cathode ray tube. The method of claim 1, Small pores arranged in the center region and the edge region except the dominant maximum region of the perforated portion, each of the shadow mask for color cathode ray tube, characterized in that the circular shape.

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