JPH05347129A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To improve picture quality by preventing the generation of creases of a slit mask, preventing the untouch between a damper wire and a grid element or preventing the irregularity of a fluorescent film due to the creases. CONSTITUTION:A protrusion part 2 is provided in the stripe part of a slit mask 1, and after the slit mask is welded to the arm part, open holes 11 are provided in the part of the protrusion part 2, thereby preventing the generation of the creases of the slit mask 1 due to tensile force partially concentrated. Thereby, it is prevented that the damper wire 4 is brought into untouch with the grid element 3 thereby generating resonance vibrations, and also the generation of the irregularity of a fluorescent film in the part of creases is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cathode ray tube, and more particularly to a cathode ray tube having a color selection electrode having a slit mask.

[0002]

2. Description of the Related Art As shown in FIG. 2, a color selection electrode has an arm portion 8 of a frame 7 composed of a pair of arm portions 8 and a pair of supporting portions 5.
A slit mask 1 in which a large number of linear grid elements 3 are arranged at a predetermined pitch is stretched between them. A damper wire 4 is provided on the surface of the grid element body 3 of the slit mask 1 in order to prevent the grid element body 3 from resonating from the outside due to vibration and causing color shift and degrading image quality. The damper wire 4 is, for example, a thin wire made of dungsten, and is attached to the spring material 6 fixed to the support portion 5 of the slit mask 1 by welding through a thin plate 9 made of stainless steel.

[0003]

In the conventional slit mask type color selection electrode, when the grid element is stretched, wrinkles occur near the welding point with the frame of the slit mask due to uneven tension. However, due to this wrinkle, the damper wire does not uniformly contact the grid element, or an error occurs in the interval between the adjacent phosphors when forming the phosphor film, and as a result, film unevenness occurs near the wrinkle and the image quality deteriorates. There was a problem of making it.

An object of the present invention is to provide a cathode ray tube having excellent image quality without the occurrence of unevenness in the fluorescent film.

[0005]

According to the present invention, there is provided a frame having a pair of arm portions and a support portion for supporting and fixing the pair of arm portions, and a predetermined number of grid elements stretched between the pair of arm portions. In a cathode ray tube provided with a color masking electrode having a slit mask having a body and a damper wire fixed to the supporting portion via a spring material and stretched on each of the grid bodies, the slit mask of A plurality of rows of convex portions are provided in parallel with a series of welding points on the strip-shaped portions on both ends of the grid element body, and a part of the convex portions is an opening.

[0006]

Embodiments of the present invention will now be described with reference to the drawings.

1A and 1B are a perspective view of a color selection electrode according to an embodiment of the present invention and a partially enlarged perspective view of a portion A thereof.

As shown in FIG. 1A, in order to stretch the slit mask 1, first, the slit mask 1 is placed in the elastic deformation range while externally applying pressure to the arm portion 8 of the frame 7. Weld fixed to 8.

Next, by releasing the pressure from the outside, tension is applied to the grid element body 3, and a curved surface according to the curvature of the arm portion 8 of the frame 7 of the slit mask 1 is formed. At this time, the uneven tension causes wrinkles, so that as shown in FIG. 1B, the forming roller having a hemispherical projection near the welding point 10 causes
A large number of hemispherical convex portions 2 in a plurality of rows are provided in parallel with.

Next, when the curved surface of the slit mask 1 is wrinkled, the convex portion 2 of the wrinkled uneven tension portion is formed with a laser heme or discharge energy to form an opening 11, and the slit mask 1 is cut. Uniform tension is promoted by changing the cross-sectional area of the strip. As a result, wrinkles can be reduced, and wrinkles can be eliminated while increasing the number of openings 11.

In the above embodiments, the convex portion 2 is described as having a hemispherical shape, but the shape of the convex portion is not limited to a hemispherical shape, and may be a conical shape or a pyramidal shape. The same effect is obtained even if the length is a semi-cylindrical shape or a rectangular tube shape having a length that is an integral multiple of the pitch of the grid element body.

[0012]

As described above, according to the present invention, a plurality of convex portions are provided in parallel to a series of welding points on the strip-shaped portions on both ends of the grid element of the slit mask, and the convex portions of the wrinkled portion are formed. The openings have the effects of eliminating wrinkles in the slit mask, preventing resonance of the slit mask due to non-contact of the damper wire with the grid element body, and suppressing unevenness of the fluorescent film to improve image quality.

[Brief description of drawings]

FIG. 1 is a perspective view of a color selection electrode according to an embodiment of the present invention and a partially enlarged perspective view of a portion A thereof.

FIG. 2 is a perspective view of an example of a conventional color selection electrode.

[Explanation of symbols]

 1 Slit Mask 2 Convex 3 Grid Element 4 Damper Wire 5 Support 6 Spring Material 7 Frame 8 Arm 9 Thin Plate 10 Welding Point 11 Opening

Claims (6)

[Claims] 1. A frame having a pair of arm portions and a supporting portion for supporting and fixing the pair of arm portions, a slit mask provided between the pair of arm portions and having a predetermined number of grid elements, In a cathode ray tube provided with a color selection electrode having a damper wire which is fixed to the support portion via a spring material and is stretched on each grid element body, a strip-shaped portion at both ends of the grid element body of the slit mask. A cathode ray tube characterized in that a plurality of rows of convex portions are provided in parallel with a series of welding points, and a part of the convex portions is an opening. 2. The cathode ray tube according to claim 1, wherein the convex portions of the plurality of rows have a hemispherical shape. 3. The cathode ray tube according to claim 1, wherein the plurality of rows of convex portions have a conical shape. 4. The cathode ray tube according to claim 1, wherein the plurality of rows of convex portions are pyramidal. 5. The cathode ray tube according to claim 1, wherein the plurality of rows of convex portions have a semi-cylindrical shape having a length that is an integral multiple of the pitch of the grid element body. 6. The cathode ray tube according to claim 1, wherein the convex portions of the plurality of rows have a rectangular tube shape having a length that is an integral multiple of the pitch of the grid element body.