JPH07282739A - Color picture tube - Google Patents

Abstract

PURPOSE:To tense a flat, rectangular mask body similarly at the center of each side and at four comers. CONSTITUTION:A color picture tube has a shadow mask whose body is tensed by an almost rectangular mask frame 21 mounted on the periphery of the almost rectangular, flat mask body with a number of electron beam passing holes. The mask frame 21 has the elastically deformed portions 23 at four corners. Specially, the elastic deformed portions are formed in a OMEGA-shape.

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 having a shadow mask in which a mask body is tensioned by a mask frame.

[0002]

2. Description of the Related Art Generally, a color picture tube has a substantially rectangular shadow mask arranged inside a phosphor screen formed of a three-color phosphor layer formed on the inner surface of a substantially rectangular panel. The shadow mask is configured to select the three electron beams emitted from the electron gun and to enter the selected phosphor layers. The shadow mask comprises a mask body having a thin rectangular plate having a large number of electron beam passage holes facing the phosphor screen, and a substantially rectangular mask frame attached to the periphery of the mask body. Consists of.

In such a color picture tube, there is known a color picture tube in which a panel is flattened so that an image drawn on a phosphor screen can be easily seen. In this color picture tube, it is necessary to make the mask main body flat to correspond to a flat panel. In order to increase the flatness of the mask body and to increase the vibration resistance against shock and vibration applied to the color picture tube, in such a color picture tube, the mask body is attached to the mask frame in a tensioned state.

As one method of attaching the mask main body to the mask frame in a tensioned state, as shown in FIG. 4A, the mask frame 1 is positioned on a shadow mask assembling apparatus equipped with a pressing jig 2, and As shown in b),
By the jig 2, each side portion of the substantially rectangular mask frame 1 is pressed inward to bend, and as shown in (c) and (d), a flat mask is formed on the bent mask frame 1. There is a method of welding the peripheral portion of the main body 3 and then releasing the pressing of the jig 2 to tension the mask main body 3 by the restoring force of each side portion of the mask frame 1. In this attachment method, there is also a method in which the mask body is tensioned in advance and the peripheral portion of the tensioned mask body is welded to the mask frame bent by the pressing of the jig to tension the mask body.

[0005]

As described above, in the color picture tube having the substantially rectangular flat panel,
It is also necessary to flatten the mask body of the substantially rectangular shadow mask arranged inside the panel, facing the phosphor screen formed on the inner surface of the panel. In order to increase the flatness of the mask body and to increase the vibration resistance against shock and vibration applied to the color picture tube, in such a color picture tube, the mask body is attached to the mask frame in a tensioned state.

As one method of attaching the mask main body to the mask frame in a tensioned state as described above, each side portion of the substantially rectangular mask frame is pushed inward by a jig to bend the mask frame and the bent mask is bent. After welding the peripheral portion of the flat mask body to the frame, the pressing of the jig is released, and the mask body is tensioned by the restoring force of each side portion of the mask frame. In this attachment method, there is also a method in which the mask body is tensioned in advance and the peripheral portion of the tensioned mask body is welded to the mask frame bent by pressing the jig to tension the mask body.

However, when the mask main body is attached to the mask frame by such a method, in the conventional mask frame, even if each side portion is pressed inward by the jig, the center portion and the four corner portions of each side portion are separated. However, since the bending amount is different, when the mask body is welded and then the pressing force of the jig is released, the tension state of the mask body is different between the central portion and the four corners of each side portion,
There is a problem that cracks and wrinkles are likely to occur in the thin mask body.

The present invention has been made to solve the above problems, and in a color picture tube having a substantially rectangular shadow mask in which a flat mask body is tensioned by a mask frame, the tension state of the mask body is Is to prevent the center part and the four corners of each side part from being significantly different from each other.

[0009]

A substantially rectangular mask frame is attached to the peripheral portion of a substantially rectangular flat mask body having a large number of electron beam passage holes, and the mask frame is tensioned by the mask frame. In a color picture tube having a shadow mask, elastic deformation portions are provided at the four corners of the mask frame.

Further, in particular, the elastically deforming portion is formed in an Ω shape.

[0011]

As described above, when the elastically deforming portions are provided at the four corners of the substantially rectangular mask frame and the elastically deforming portions are formed in the shape of Ω, the side portions of the mask frame are inwardly moved by the jig. When pressed, the elastically deformable portion bends, and the difference between the amount of movement of the central portion of each side portion and the amount of movement of the four corners can be reduced. As a result, when the mask body is welded to this mask frame and then the pressing force of the jig is released, the tension at the center of each side and the tension at the four corners that occurs in the mask body due to the restoring force of the elastically deforming portion. The difference between
The entire surface of the mask body can be tensioned almost uniformly, and cracks and wrinkles can be prevented.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described based on embodiments with reference to the drawings.

FIG. 2 shows a color picture tube which is one of the embodiments. The color picture tube has an envelope composed of a funnel-shaped funnel 14 joined to a side wall 12 of a flat panel 10 having a substantially rectangular flat surface. On the inner surface of the panel 10, there is formed a phosphor screen 15 composed of a three-color phosphor layer that emits blue, green, and red. The phosphor screen 15 faces the phosphor screen 15 and has a substantially rectangular shape described later inside thereof. A shadow mask 16 is arranged. Also funnel 1
An electron gun 18 is arranged in the neck 17 of No. 4. Then, the three electron beams emitted from the electron gun 18 are deflected by a magnetic field generated by a deflecting device (not shown) attached to the outside of the funnel 14, and the phosphor screen 15 is projected through the shadow mask 16. It is formed in a structure for displaying an image by performing horizontal and vertical scanning.

The shadow mask 16 has a substantially rectangular flat mask body 20 in which a large number of electron beam passage holes are formed in a predetermined arrangement, and a substantially rectangular mask attached to the peripheral portion of the mask body 20. And a frame 21. The mask main body 20 is supported by the mask frame 21 in a tensioned state in order to increase the flatness and the vibration resistance against shock and vibration applied to the color picture tube. In order to support the mask body 20 in such a tensioned state, in particular, the mask frame 21 of this example has four independent side edges 22 and ends of the adjacent side edges 22 as shown in FIG. And an Ω-shaped elastically deforming portion 23 made of four spring members which are welded to the inner portion of the four corners of the substantially rectangular mask frame 21.

In this shadow mask 16, a mask supporting means (not shown) is attached to the mask frame 21.
The mask main body 20 is supported in the envelope via the mask support means so as to face the phosphor screen 15 at a predetermined interval.

The method of tensioning the mask body 20 is described in FIG.
As shown in (a), the mask frame 21 whose four corners are composed of the elastically deforming portions 23 is positioned on the shadow mask assembling apparatus provided with the pressing jig 25, and as shown in (b), the jig 25. As a result, each side portion 2 of the mask frame 21
2 is pressed inward in the direction indicated by the arrow to bend the elastically deformable portion 23, and the peripheral portion of the mask main body is welded to each side portion 22 that is moved inwardly of the mask frame 21 by the elastically deformable portion 23. .. After that, the pressing of the jig 25 is released, which is performed.

When the mask main body 20 is supported by the mask frame 21 having the elastic deformation portions 23 at the four corners as described above, the entire surface of the mask main body 20 can be tensioned almost uniformly. That is, in the mask frame 21 in which the elastically deforming portions 23 are provided at the four corners, when the respective side portions 22 are pressed inward, the elastically deforming portions 23 are mainly formed.
Bends, and the difference between the amount of movement of the central portion of each side portion 22 and the amount of movement of the end portion of each side portion 22 that forms the four corners of the mask frame 21 is small, and the movement can be performed to approximately the same extent.
Therefore, when the peripheral portion of the mask main body 20 is welded to each side portion 22 of the mask frame 21 and then the pressing of the jig 25 is released, the side portion 22 has a central portion due to the restoring force of the elastically deforming portion 23. Both the edges, that is, the four corners, return to their original positions, and the entire surface of the mask body 20 is tensioned almost uniformly. As a result, it eliminates cracks and wrinkles in the mask body caused by the conventional tension state at the center of the side and the four corners, and has high flatness and sufficient vibration resistance against shock and vibration. The shadow mask 16 may be provided.

Moreover, the Ω-shaped elastically deforming portion 23 is elastically deformed as a whole except for the portion fixed to the side edge portion 22, and even if it is formed in a small size, it exerts a sufficient effect.

In the above embodiment, four independent mask frames of the substantially rectangular shadow mask are independently welded to the side portions and the end portions of the side portions are elastically deformed to form the four corner portions of the mask frame. However, the side portion and the elastically deformable portion may be integrally formed from the beginning.

Further, in the above-mentioned embodiment, the elastically deforming portion has the shape of Ω and the elastically deforming portion is located inside the mask frame. However, the elastically deforming portion is Ω.
Other than the V-shape, other shapes such as a V-shape and a U-shape can be used. The elastically deformable portion may be provided so as to be located outside the mask frame.

[0021]

In a color picture tube having a shadow mask in which a substantially rectangular mask frame is attached to the peripheral portion of a substantially rectangular flat mask body, and the mask body is strained by the mask frame, the mask frame is provided. If elastically deforming parts are provided at the four corners of the mask and the elastically deforming parts are formed in an Ω shape, when each side of the mask frame is pressed inward by a jig, each side of the mask deforms due to the bending of the elastically deforming part. The difference between the movement amount of the central portion and the movement amount of the four corners can be reduced. As a result, when the mask body is welded to this mask frame and then the pressing force of the jig is released, the tension at the center of each side and the tension at the four corners that occurs in the mask body due to the restoring force of the elastically deforming portion. It is possible to reduce the difference between the above and the above, to tension the entire surface of the mask body almost uniformly, and prevent cracks and wrinkles from occurring.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a configuration of a color picture tube according to an embodiment of the present invention.

FIGS. 3 (a) and 3 (b) are views for explaining a method of tensioning a mask main body in an embodiment of the present invention.

4A to 4D are views for explaining a conventional method of tensioning a mask main body.

[Explanation of symbols]

 10 ... Panel 15 ... Phosphor screen 16 ... Shadow mask 18 ... Electron gun 20 ... Mask body 21 ... Mask frame

Claims (2)

[Claims] 1. A shadow in which a substantially rectangular mask frame is attached to the periphery of a substantially rectangular flat mask body having a large number of electron beam passage holes, and the mask body is tensioned by the mask frame. A color picture tube having a mask, wherein the mask frame is provided with elastic deformation portions at four corners. 2. The color picture tube according to claim 1, wherein the elastically deformable portion is formed in an Ω shape.