JPH11329279A - Color picture receiving tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of image quality which is caused by light leakage resulting from a notch in a skirt part of a mask main body and collision of an electron beam against an inside of a panel. SOLUTION: Protrusions 38a-38c which are projected to a direction of a phosphor screen corresponding to a notch of a skirt part are provided in a phosphor screen side edge part of a side wall part 35 in a mask frame 36, in a color picture receiving tube provided with the notch at least in the skirt part, which is welded to an inside of the side wall part 35 of the mask frame 36, of a corner part of a mask main body 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color picture tube, and more particularly, to a color picture tube capable of preventing quality deterioration due to light leakage of a shadow mask.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 6, a color picture tube has an envelope comprising a substantially rectangular panel 3 provided with a skirt portion 2 around an effective portion 1 and a funnel 4 having a funnel shape. And a phosphor screen 5 including a non-light-emitting material layer and a three-color phosphor layer provided so as to be embedded in a gap between the non-light-emitting material layers. A substantially rectangular shadow mask 6 is disposed inside and spaced from the phosphor screen 5 by a predetermined distance. On the other hand, an electron gun 9 for emitting three electron beams 8B, 8G, 8R is arranged in the neck 7 of the funnel 4. Then, the three electron beams 8B, 8G, 8R emitted from the electron gun 9 are deflected by the deflecting device 10 mounted outside the funnel 4 to scan the phosphor screen 5 horizontally and vertically via the shadow mask 6. Thereby, it is formed in a structure for displaying a color image.

The above-mentioned shadow mask 6 is for selecting the three electron beams 8B, 8G, 8R emitted from the electron gun 9 so as to correctly enter the three-color phosphor layer, as shown in FIG. A substantially rectangular mask body 1 in which a large number of electron beam passage holes 12 are formed and a skirt portion 14 is provided at a peripheral portion of an effective surface 13 facing the phosphor screen.
5 and a substantially rectangular mask frame 17 having an L-shaped cross section and having a side wall 16 to which the skirt 14 of the mask body 15 is attached. The skirt portion 14 of the mask body 15 is welded in contact with the inside of the side wall portion 16 of the mask frame 17.

Generally, the mask body 15 is formed by forming a flat mask by forming a large number of electron beam passage holes in a flat mask material by a photoetching method and then press-forming the flat mask. It is formed. In order to improve the moldability and prevent deformation of the mask body due to welding with the mask frame, FIG.
As shown in FIG. 2, before press molding, notches 21a are formed at corners of the skirt surrounding the electron beam passage hole forming region 19 of the flat mask, intermediate portions of the long side and the short side, and the like.
21c are formed. The shapes and sizes of the notches 21a to 21c vary depending on the position. Particularly, corners where a large drawing process is performed at the time of press molding are largely cut off to reduce the occurrence of wrinkles and deformation. Therefore, as shown in FIG. 9, a gap 23 is formed in the skirt portion 14 at the corner portion of the press-formed mask body 15, and a part of the gap 23 is exposed when the skirt portion 14 is welded to the mask frame. .

In recent years, in order to improve the resolution, a color picture tube compatible with multimedia has a smaller arrangement pitch of the three-color phosphor layers than an ordinary color picture tube. Then, as shown in FIG. 10, the phosphor screen 5 and the effective surface 1 of the mask body 15
3 is also smaller than that of a normal color picture tube indicated by a solid line.

In such a color picture tube, when a phosphor screen is formed by a photographic printing method using a shadow mask as an optical mask, a photosensitive film for forming a non-luminescent material layer and a three-color phosphor layer are formed. The light which prints the pattern corresponding to the electron beam passage holes of the shadow mask on the photosensitive phosphor slurry layer of the above, passes through the above-mentioned gap, hits the photosensitive film or the photosensitive phosphor slurry layer, and the pattern corresponding to the gap on the inner surface of the panel. May be formed. When the pattern is formed in this manner, the portion emits undesired light when the color picture tube is operated. Further, even when the pattern corresponding to the gap is not formed, when the color picture tube is operated, the collision of the electron beam passing through the gap causes the
The non-light-emitting material layer near the corner of the panel is seen through in a pinhole shape, which causes a problem that the screen quality is deteriorated.

[0007] Such a problem also occurs in the notch on the long side and the short side if a gap is formed when the notch is welded to the mask frame.

[0008]

As described above, the skirt portion of the mask main body has a corner portion, a long side, and a short side to improve the formability and prevent the deformation of the mask main body due to welding with the mask frame. A notch is formed in the middle of the side, and a gap is formed when the skirt is welded to the mask frame. When such a gap is formed, in a color picture tube in which the distance between the phosphor screen and the effective surface of the mask body is small, a pattern corresponding to the gap is formed on the inner surface of the panel due to light leakage from the gap when the phosphor screen is formed. When the color picture tube is formed and operated, the portion may emit light undesirably. Also, even when the pattern corresponding to the gap is not formed, when the color picture tube is operated, the electron beam reaches the inner surface of the panel through the gap,
The non-light-emitting material layer near the corner of the panel is seen through in a pinhole shape, which causes a problem that the screen quality is deteriorated.

It is difficult to prevent such a problem with the shadow mask of the present design. In order to prevent such a problem, the width of the side wall of the mask frame may be increased to block light leakage and collision of the electron beam with the inner surface of the panel, but if the width of the side wall is increased, The weight of the mask frame is greatly increased, and the characteristics against shock and vibration are deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has been made in consideration of the above-mentioned problems. It is an object of the present invention to provide a color picture tube which does not cause deterioration in screen quality due to light leakage due to the notch and collision of an electron beam with the inner surface of the panel.

[0011]

A skirt portion is provided on the periphery of an effective surface provided with a large number of electron beam passage holes, facing a phosphor screen provided on the inner surface of a substantially rectangular panel. A shadow mask composed of a substantially rectangular mask body and a substantially rectangular mask frame having a side wall to which the skirt of the mask body is welded is arranged, and at least a notch is formed at a corner skirt of the mask body. In the color picture tube having the skirt portion welded to the inside of the side wall portion of the mask frame, the phosphor screen direction corresponding to the notch of the skirt portion is provided at the edge of the side wall portion of the mask frame on the phosphor screen side. A protruding portion was provided.

[0012]

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

FIG. 1 shows a color picture tube which is one embodiment of the present invention. This color picture tube has an envelope composed of a substantially rectangular panel 3 having a skirt portion 2 provided around a curved effective portion 1 and a funnel 4. On the inner surface of the effective portion 1 of the panel 3, there is provided a phosphor screen 5 composed of a non-luminescent material layer and a three-color phosphor layer provided so as to be embedded in the gap between the non-luminescent material layers. A substantially rectangular shadow mask 3 (to be described later) is provided inside and at a predetermined distance from the phosphor screen 5.
0 is arranged. On the other hand, an electron gun 9 for emitting three electron beams 8B, 8G, 8R is arranged in the neck 7 of the funnel 4. Then, the three electron beams 8B, 8G, 8R emitted from the electron gun 9 are deflected by the deflecting device 10 mounted outside the funnel 4 to scan the phosphor screen 5 horizontally and vertically via the shadow mask 30. Thereby, it is formed in a structure for displaying a color image.

As shown in FIG. 2, the shadow mask 30 has a large number of electron beam passage holes 31 formed therein, and a skirt portion 33 is provided around an effective surface 32 facing the phosphor screen. A mask body 34 having a shape,
The mask body 34 has a substantially rectangular mask frame 36 having an L-shaped cross section and a side wall 35 to which the skirt 33 is welded. Notches 37a to 37c (long-side notches 37b) are provided in the middle of the skirt portion 33 at the corner portion of the mask body 34 and the skirt portions 33 at the long and short sides.
Only the mask body 34 is formed, and the mask body 34 is welded with the skirt 33 in contact with the inside of the side wall 35 of the mask frame 36.

In particular, the shadow mask 3 in this embodiment
0 is a notch 3 of the skirt portion 33 of the mask body 34
7a to 37c, the side wall 3 of the mask frame 36
5, at the phosphor screen side edge, as shown in FIG.
Semicircular projection 38a protruding in the direction of the phosphor screen
To 38c.

When the projections 38a to 38c are provided on the side wall 35 of the mask frame 36 corresponding to the notches 37a to 37c of the skirt 33 of the mask body 34 as described above, the mask frame 36 is welded to the mask body 34. When the shadow mask 30 is assembled, the notch 3
Even if the gaps due to 7a to 37c are formed, when the phosphor screen 5 is formed by a photo printing method using the shadow mask 30 as an optical microphone, formation of a pattern corresponding to the gap due to light leakage from the gaps can be prevented. . When the color picture tube is operated, the electron beams 8B, 8G, 8R reaching the inner surface of the panel 3 through the gap can be shielded. Therefore, with the above-described configuration, when a color picture tube is conventionally operated, an undesirable light-emitting or non-light-emitting material layer of a pattern formed corresponding to a gap when a phosphor screen is formed is pinhole-shaped. It is possible to prevent the deterioration of the screen quality such as seeing through the screen.

In the above-described embodiment, the convex portion of the side edge portion of the mask frame on the phosphor screen side is formed in a semicircular shape. However, as shown in FIG.
38c may be rectangular.

Further, as shown in FIG. 5, as shown with respect to the corners of the shadow mask 30,
8a.

[0019]

As described above, when the protrusion protruding in the direction of the phosphor screen corresponding to the notch of the skirt portion of the mask body is provided at the edge of the mask frame on the side of the phosphor screen on the side wall portion, the skirt portion is provided. There is a gap due to the notch, which prevents the formation of a pattern corresponding to the gap due to light leakage from the gap when the phosphor screen is formed. The electron beam reaching the inner surface can be shielded, and conventionally, when a color picture tube was operated, the unwanted emission or non-emissive material layer of the pattern formed corresponding to the gap when the phosphor screen was formed was transparent in a pinhole shape. It is possible to prevent the deterioration of the screen quality such as seeing.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a color picture tube according to an embodiment of the present invention.

FIG. 2A is a plan view showing a configuration of a shadow mask of the color picture tube, and FIG. 2B is a sectional view thereof.

FIG. 3 is a diagram showing a main configuration of the shadow mask.

FIG. 4 is a diagram illustrating a main configuration of a shadow mask different from the shadow mask.

FIG. 5 is a diagram illustrating a configuration of a main part of a shadow mask different from the shadow mask.

FIG. 6 is a diagram showing a configuration of a conventional color picture tube.

FIG. 7 is a perspective view showing a configuration of a shadow mask of the conventional color picture tube.

FIG. 8 is a plan view showing a configuration of a flat mask before press-molding the mask body.

FIG. 9 is a view showing a configuration of a mask main body after the flat mask is formed.

FIG. 10 is a diagram showing a configuration of a color picture tube compatible with multimedia.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 3 ... Panel 5 ... Phosphor screen 30 ... Shadow mask 31 ... Electron beam passage hole 34 ... Mask main body 35 ... Side wall part 36 ... Mask frame 37b ... Notch 38a-38c ... Convex part

Claims (1)

[Claims] 1. A substantially rectangular shape having a skirt portion around an effective surface provided with a large number of electron beam passage holes, facing a phosphor screen provided on an inner surface of a substantially rectangular panel. A shadow mask consisting of a mask body and a substantially rectangular mask frame having a side wall to which the skirt of the mask body is welded is arranged, and at least a notch is provided at a skirt at a corner of the mask body. In a color picture tube in which a skirt portion is welded to the inside of a side wall portion of the mask frame, an edge portion of the side wall portion of the mask frame on a side of the phosphor screen corresponds to a notch of the skirt portion in the direction of the phosphor screen. A color picture tube characterized by being provided with a protruding portion.