KR20010097160A - Tension-mask frame assembly of color picture tube - Google Patents

Abstract

According to the present invention, a plurality of strips formed with slots spaced apart from each other by a predetermined distance on a thin plate, tie bars for partitioning the slots to a predetermined pitch by interconnecting the adjacent strips, at least in the slots partitioned by the tie bars A tension mask having dummy bridges extending from one strip to a corresponding strip;

A frame for supporting a corresponding edge of the tension mask to apply a tensile force to the tension mask, wherein the tension mask includes a dummy bridge area uniform area in which the area of the dummy bridge is constant in the peripheral direction of the tension mask; It has a decreasing area gradually decreasing from the uniform area to the periphery of the tension mask.

Description

Tension-mask frame assembly of color picture tube

The present invention relates to a color cathode ray tube, and more particularly, to a tension mask frame assembly for a color cathode ray tube having an improved structure of a tension mask fixed to a frame.

In the color cathode ray tube, the electron beam emitted from the electron gun is landed on the fluorescent film through the electron beam passing hole of the tension mask to excite the fluorescent film to form an image.

The screen surface of the conventional color cathode ray tube which forms an image as described above is designed to have a predetermined curvature in view of the deflection trajectory of the electron beam emitted from the electron gun and deflected by the deflection yoke. The mask is designed to have a curvature corresponding to that of the screen surface.

As described above, a mask manufactured to have the same curvature as the inner surface of the screen surface is heated by an electron beam emitted from the electron gun, that is, hot electrons, and a domming phenomenon that swells toward the panel is generated. This doming phenomenon causes the electron beam to not land correctly on the fluorescent film. In addition, the screen surface is formed to have a predetermined curvature, thereby narrowing the viewing angle and distorting the image formed by excitation of the fluorescent film at the edge of the screen surface.

In order to solve the problems described above, a color cathode ray tube having a flat screen surface has been developed. The color cathode ray tube is fixed to the panel so that the tension mask is spaced apart from the fluorescent film formed on the inner surface of the panel by a predetermined force. The tensioner mask fixed to the panel may have a structure in which a plurality of strips spaced apart from each other by a predetermined distance may be mounted to apply tension to the frame, or the tension mask fixed to the frame may have a plurality of strips, and the strips may be connected by tie bars. It has a structure that does not form a long slot.

FIG. 1 shows an example of a long slot tension mask frame assembly of the tension mask frame assembly mounted on the color cathode ray tube.

As shown, a frame 10 having support members 11 and 12 installed in parallel with each other, and elastic members 13 and 14 having elasticity and interconnecting the support members 11 and 12. And a tension mask in which the slots 23 are formed by the plurality of strips 21 and the tie bars 22 connecting the strips to the thin plate by welding the long side portions so that tension is applied to the support members 11 and 12. 20 is provided. In the slot, a plurality of dummy bridges 24 formed of first and second protrusions 24a and 24b extending from the strip to the opposite side of the strip are positioned so that the slot 23 has a predetermined vertical pitch PV. Is divided into

In the tension mask frame assembly configured as described above, an electron beam emitted from an electron gun (not shown) is spaced apart from the fluorescent film formed on the inner surface of the panel to form an image by exciting the fluorescent film through the slots 23 of the tension mask.

In this process, since the slot 23 is divided by the tie bar 22 and the dummy bridge 24, the tie bar 22 and the dummy bridge 24 do not land the electron beam on the fluorescent film of the corresponding region. This prevents the phosphor from being excited. Therefore, the main body of the tie bar 22 and the dummy bridge 24 is shown in the image, the slots 23 are arranged to have a uniform vertical pitch (PV) by the tie bar 22 and the dummy bridge (24). Therefore, the visibility can be improved.

However, since the dummy bridge 24 extends to the opposite sides, the first and second protrusions 24a and 24b are not in contact with each other, and the electron beam passes through them to excite the fluorescent film. . Therefore, the area difference between the area of the main area where the fluorescent film is covered by the tie bar 22 and the area of the main area where the fluorescent film is covered by the dummy bridge is generated, so that visibility is somewhat lowered. To overcome this, the dummy bridge ( A large area of 24) is formed.

FIG. 2A illustrates a state in which an electron beam is scanned at the center of the tension mask to excite the fluorescent film, and FIG. 2B illustrates a state in which an electron beam is scanned at the periphery of the tension mask to excite the fluorescent film.

As shown, since the vertical length L1 of the dummy bridge 24 is uniformly formed at the center and the periphery, the clipping phenomenon of the electron beam passing through the dummy bridge 24 positioned at the periphery of the mask is severe. appear.

That is, as shown in FIG. 2A, the electron beam passing between the first and second protrusions 24a and 24b of the dummy bridge positioned at the center of the tension mask has a large incident angle, so that the amount of electron beams is high. Part of is excited. However, as shown in FIG. 2B, the electron beam passing between the first and second protrusions 24a and 24b of the dummy bridge 24 positioned at the periphery of the tension mask has a small incident angle, and thus the amount of light passing through the dummy bridge is It becomes relatively smaller than the center. Therefore, in order to improve visibility, when the vertical length L1 of the dummy bridge 24 is formed wider than the vertical length L2 of the tie bar, the area of the dummy bridge is equal to or slightly larger than the area of the tie bar. The difference in the area between the tie bar 22 and the dummy bridge 24 main area is caused by the difference in the clipping of the electron beam passing between the dummy bridge at the periphery and the peripheral portion. As a result, the luminance of the image is uniform in the entire area of the effective screen. There is a problem in that the resolution of the image cannot be improved.

The present invention is to solve the above problems, and the color cathode ray having a tension mask frame assembly that can prevent the visibility of the tie bar and the dummy bridge is lowered by the difference in the amount of electron beam passing through the dummy bridge according to the incident angle of the electron beam. The purpose is to provide a coffin.

1 is a perspective view showing a tension mask frame assembly of a conventional cathode ray tube,

2A and 2B are views illustrating a state in which an electron beam passing through a tension mask is landed on a fluorescent film;

3 is a perspective view illustrating a tension mask frame assembly of a cathode ray tube according to the present invention;

4 is a view schematically showing a uniform area and a reduced area of a dummy bridge area of a tension mask;

5 is a graph showing the relationship between the distance and the area in the X direction of the test mask.

6A and 6B are views illustrating a state in which an electron beam passing through a tension mask according to the present invention lands on a fluorescent film.

In order to achieve the above object, the tension mask frame assembly of the present invention includes a plurality of strips formed with slots spaced apart from each other on a thin plate, and tie bars for partitioning the slots to a predetermined pitch by interconnecting the adjacent strips; A tension mask having dummy bridges extending from a strip on at least one side to a strip on a corresponding side in a slot partitioned by the tie bar;

A frame for supporting a corresponding edge of the tension mask to apply a tensile force to the tension mask, wherein the tension mask includes a dummy bridge area uniform area in which the area of the dummy bridge is constant in the peripheral direction of the tension mask; It is characterized by having a decreasing area gradually smaller from the uniform area toward the periphery of the tension mask.

In the present invention, the boundary between the uniform area and the reduction area of the dummy bridge is located at 1/6 points in the X-axis direction from the center of the tension mask. The vertical width of the dummy bridge located in the reduced area gradually decreases toward the periphery of the tension mask, and the vertical width of the dummy bridge at the edge of the tension mask is equal to the vertical width of the tie bar.

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

Figure 3 shows an example of the tension mask frame assembly of the color cathode ray tube according to the present invention.

As shown in the drawing, the tension mask frame assembly includes a tension mask 40 having a color selection function of an electron beam, and a frame 50 supporting the tension mask 40 to have a predetermined tensile force.

3 and 4, the tension mask 40 includes a plurality of strips 41 and 41 spaced apart from each other at predetermined intervals, and the adjacent strips have a predetermined vertical pitch. A plurality of slots 43 are formed in connection with the tie bar 42. In the slot 43 defined by the tie bar 42 as described above, the dummy bridges including the first and second protrusions 44a and 44b extending from the adjacent strips 41 and 41 in the corresponding directions, respectively, 44 are partitioned into a predetermined vertical pitch PV2. Here, the protrusions forming the imaginary dummy bridge 44 are not in contact with the ends of the first and second protrusions 44a and 44b. Therefore, since the first and second protrusions 44a and 44b are spaced apart from each other by a predetermined interval, the dummy bridge made of the first and second protrusions 44a and 44b rather than the area of the tie bar 42 to improve visibility. The area of 44 is formed wide. The area uniformity area (S1) area and the area uniformity are fixed while going from the center of the tension bridge of the dummy bridge 44 to the periphery (X-axis direction) and having a larger area than the area of the tie bar 42. From the area S1 toward the periphery, the area of the dummy bridge 44 is gradually divided into an area reduction area S2.

The dummy bridge located at the outermost part of the peripheral portion of the tension mask among the dummy bridges in the area reduction area S2 where the sum of the areas of the first and second protrusions 44a and 44b gradually decreases toward the periphery of the tension mask 40. It is preferable that the sum of the areas of the first and second protrusions 44a and 44b of 44 and the area of the tie bar 42 'are the same. In addition, it is preferable that the length L3 of the tie bar 42 'positioned at the outermost part is not smaller than the length L4 of the dummy bridge 44.

In order for the area of the first and second protrusions 44a and 44b constituting the dummy bridge 44 to become smaller toward the periphery of the tension mask, the vertical lengths of the first and second protrusions 44a and 44b are the tension mask ( It gradually forms smaller toward the periphery (in the X direction) from the central portion of 40). Here, the slots formed between the ends of the first and second protrusions 44a and 44b (hereinafter, abbreviated as dummy slots 44c) are positioned adjacent to the adjacent strips from the center of the tension mask 40 toward the periphery. It is shifted toward the center of the tension mask from the horizontal center of the slot 43 formed by the (41) (41).

As shown in FIG. 6, the positions of the dummy slots 44c which are located on the left and right sides from the center of the tension mask 40 are moved to the center of the rotor of the tension mask, and the electron beams between the dummy slots according to the deflection of the electron beam. In consideration of the amount of passage and the position of landing on the fluorescent film pattern, the amount of deviation with respect to the horizontal center of the slot 43 is reduced.

In addition, the frame 50 supporting the tension mask configured as described above may support the support members 51 and 52 supporting the long sides of the tension mask 40 and the support members 51 and 52, respectively. It has elastic members (53) (54) having a.

The frame is not limited by the above-described embodiment. The frame may be any structure that can support the tension mask while tension is applied to the tension mask without reducing the effective screen when the panel is mounted on the panel.

The tension mask frame assembly according to the present invention configured as described above has a color discrimination function that is mounted on the color cathode ray tube so that the electron beam emitted from the electron gun can be accurately landed on each phosphor.

Such a tension mask is formed with a dummy bridge 44 that divides the slot 43 with respect to the area of the tie bar, that is, the area of the first and second protrusions 44a and 44b is ± 30%. As the area of the dummy bridge 44 is gradually smaller than the area of the tie bar 42 from the center to the periphery, the visibility of the tie bar and the dummy bridge remaining in the image formed when the fluorescent film is excited can be improved. . This will be described in more detail as follows.

The electron beam emitted from the electron gun (not shown) becomes smaller from the center portion to the periphery thereof, and its angle of incidence becomes smaller. When the electron beam emitted from the electron gun is scanned into the area uniform area of the dummy bridge 44 of the tension mask 40, a part of the electron beam passing through the slot is completely covered by the tie bar, but the dummy bridge 44 is piled at the center. Since the area is formed as large as the area passing through the slot 44c, the afterimage of the tie bar 42 and the dummy bridge 44 appearing on the fluorescent surface becomes the same, thereby improving visibility of the afterimage. When the electron beam emitted from the electron gun is irradiated to the area of the dummy bridge 44 area of the tension mask, the incident angle incident to the dummy slot 44c gradually decreases toward the periphery, and passes through the dummy slot 44c. The amount becomes relatively small.

Therefore, the residual of the bridge bridge becomes larger than that of the tie bar, but the area of the dummy bridge 44 gradually decreases, so that the afterimage of the tie bar 42 and the dummy bridge 44 becomes uniform.

Since the dummy slot 44c between the first and second protrusions 44a and 44b constituting the dummy bridge 44 is biased toward the central portion from the center of the tension mask toward the periphery, the dummy slot as shown in FIG. 6. Exciting the edge of the fluorescent film by the electron beam passing through 44c can prevent the edge of the fluorescent film stripe from being rough.

The tension mask frame assembly of the cathode ray tube according to the present invention configured as described above can improve the visibility of the tie bar and the dummy bridge appearing in the image by dividing the area of the dummy bridge into a uniform area and a reduced area. Uniform luminance can be obtained at.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary and those skilled in the art will understand that various modifications and variations are possible from this. Therefore, the present invention will be defined by the technical spirit of the appended claims the true technical protection scope of the present invention.

Claims (4)

A plurality of strips having slots spaced apart from each other on a thin plate to form a slot, a tie bar for connecting the adjacent strips to partition the slot at a predetermined pitch, and corresponding to at least one strip on a slot partitioned by the tie bar. A tension mask having dummy bridges extending into the strip on the side; A frame for supporting a corresponding edge of the tension mask to apply a tensile force to the tension mask, wherein the tension mask includes a dummy bridge area uniform area in which the area of the dummy bridge is constant in the peripheral direction of the tension mask; A tension mask frame assembly for a color cathode ray tube, characterized in that it has a decreasing area gradually decreasing from the uniform area toward the periphery of the tension mask. The method of claim 1, And a boundary between the uniform area and the reduced area of the dummy bridge is located at 1/6 points in the X-axis direction from the center of the tension mask. The method of claim 1, And a vertical width of the dummy bridge positioned in the reduction region gradually decreases toward the periphery of the tension mask. The method according to any one of claims 1 to 3, The area of the dummy bridge located at the outermost periphery of the tension mask is the same as the area of the tie bar formed tension mask frame assembly for a color cathode ray tube.