KR20010002147U - Shadowmask for a color cathode ray tube - Google Patents

Abstract

The present invention provides a shadow mask of a color cathode ray tube that can prevent the distortion of the screen due to the refractive index, etc. as the thickness is relatively thick at the corner portion during the planarization.

The shadow mask has a long side curvature R3 of the boundary between the effective portion 22 and the invalid portion 24 where the apertures or slits are formed is 8000 to 10,000 mm as the curvature that is convex outward, and is short side. The minor curvature R4 is a convex curvature inward, characterized in that 4,500 to 6,500mm.

Description

Shadow mask of color cathode ray tube {SHADOWMASK FOR A COLOR CATHODE RAY TUBE}

The present invention relates to a shadow mask of a color cathode ray tube, and more particularly, to a shadow of a color cathode ray tube that can prevent distortion of a screen due to refractive index, etc., due to a relatively thick thickness at a corner portion during planarization. It is about a mask.

In general, a color cathode ray tube emits red, green, and blue electron beams from an electron gun and passes through apertures or slits of regularly arranged shadow masks and collides with phosphors coated on the inner surface of the panel to create a color image. Doing.

A neck portion is formed at the end of the funnel, in which an electron gun is coupled. The mask frame is joined by stud pins at four places of the skirt part of the panel.

As a material of the shadow mask, high purity decarburized steel is mainly used, but in recent years, invar (INVAR) steel, which has a strong thermal deformation property, is mainly used as the CRT is enlarged and fixed. However, the Invar steel is not good in formability and blackening film formation capability except for its strong thermal deformation. In particular, the spring stress of the skirt after molding is high due to the high yield stress, and when the mask is inserted into the frame, the skirt portion of the mask and the frame interfere with each other, thereby degrading assembly.

1 shows a state in which a conventional shadow mask 10 is formed and assembled to a frame.

In the conventional shadow mask 10, the long side curvature R1 was generally convex outwardly in the case of 21 "and about 12,000 mm, and the short side curvature R2 was about 9,500 mm as the inner convex form.

However, as the cathode ray tube is enlarged and planarized, the relative thickness at the corner portion is thicker than at the center. Thus, the screen shape may be rectangular in a conventional tube type that is not flattened, but the flatness of the refractive index according to the glass shape becomes flat. Distortion may appear due to the difference, and as shown in FIG. 2, the screen shape may be distorted by the above-described curvature of the shadow mask 10.

Accordingly, the present invention is to solve the above-described problems, to provide a shadow mask of the color cathode ray tube that can prevent the distortion of the screen due to the refractive index, such as the relatively thick at the corner portion when flattening Its purpose is to.

1 is a plan view showing the configuration of a conventional shadow mask.

2 is a plan view showing the shape of the screen manufactured by the conventional shadow mask of FIG.

3 is a plan view showing the configuration of the shadow mask according to an embodiment of the present invention,

4 is a plan view showing the shape of the screen manufactured by the shadow mask of FIG.

5 is a plan view showing the configuration of a shadow mask according to another embodiment of the present invention.

** Explanation of symbols on main parts of the drawing **

10,20,30: shadow mask 12,22,32: effective part

14, 24, 34: invalid surface R1, R3, R5, R6: long side curvature

R2, R4, R7: Short side curvature

In order to achieve the above object, the shadow mask of the present invention has a long side curvature of the boundary between the effective portion and the invalid portion where the aperture or the slits are formed is 8000 to 10,000 mm as the curvature of the outer side, and the short side portion is short. Curvature is characterized in that the convex curvature inwardly 4,500 to 6,500mm.

In addition, the shadow mask, which is a color screening means according to another embodiment of the present invention, is composed of three curvatures divided into three equally long portions of the boundary between the effective portion and the invalid portion where the aperture or slits are formed, and the curvature of both sides is the same. The long side curvature is, in the case of 29 ", the center is 7,000 to 9,000mm, both sides are 18,000 to 22,000mm, the short side curvature is outwardly convex curvature is 14,000 to 16,000mm It is preferable.

Hereinafter, preferred embodiment (s) of the present invention will be described in detail with reference to the accompanying drawings.

3 shows a configuration of a shadow mask according to an embodiment of the present invention as a plan view.

3 shows the shadow mask 20 of the cathode ray tube of 21 ", in which the long side curvature R3 is 8,000 to 10,000 mm as the outwardly convex curvature, and the short side curvature R4 is It is characterized by the inner convex curvature of about 4,500 to 6,500mm, 10 to 30% decrease in the long side and 40 to 60% in the short side than in the case of FIG.

As shown in FIG. 4, the shape of the screen may be configured as a rectangle by the curvature configured as described above.

5, the shadow mask 30 of 29 "is shown.

The shadow mask 30 is composed of three curvatures R6, R5, and R6 divided into three equal parts of the boundary between the effective portion 32 and the invalid portion 34 where the apertures or slits are formed. It is characterized by the same curvature. In addition, the short side curvature R7 is characterized by having a curvature that is convex outward.

That is, in the case of 29 ", the long side curvatures R5 and R6 are 7,000 to 9,000 mm at the center, 18,000 to 22,000 mm at both sides, and the short side curvature R7 is 14,000 to 16,000 mm as the outwardly convex curvature. It has been shown to be desirable as it can be in the shape of a rectangular screen as shown in FIG.

In this way, the present invention obtains an effective part shape that can obtain an optimal screen shape according to the transmittance of panel glass while flattening the effective part shape of the shadow masks 20 and 30. The distortion phenomenon has been removed.

According to the configuration and operation of the shadow mask of the color cathode ray tube according to the embodiment of the present invention described above, the curvature of the shadow mask is 10-30% in the long side portion, 40-60% in the short side portion 21 "than conventional In this case, the curvature of the long side portion and the convex shape toward the outside of the short side portion can be eliminated at 29 ", thereby eliminating distortion due to the planarization.

Claims (3)

In a color cathode ray tube with a shadow mask as a means of screening: The long side curvature R3 of the boundary between the effective part 22 and the invalid part 24 in which the apertures or slits are formed is 8,000 to 10,000 mm as the outwardly convex curvature, and the short side curvature R4. The shadow mask of the color cathode ray tube, characterized in that the inner convex curvature is 4,500 to 6,500mm. In a color cathode ray tube with a shadow mask as a means of screening: It consists of three curvatures R6, R5, and R6 in which the long side portion of the boundary between the effective portion 32 and the invalid portion 34 where the apertures or slits are formed is divided into three portions, and the curvatures on both sides are the same. Shadow mask of colored cathode ray tubes. 3. The long side curvature R5, R6 has a center of 7,000 to 9,000 mm, a side of 18,000 to 22,000 mm, and a short side curvature R7 of the long side curvature R5 is 29 " Shadow mask of a color cathode ray tube, characterized in that 14,000 to 16,000 mm.