JPH0896726A - Color image receiving tube - Google Patents

Abstract

PURPOSE: To prevent the deformation of a shadow mask by folding a no-hole part bent in an opposite side to a fluorescent screen over the total periphery of a boundary part between a holed part and the no--holed part, so as to increase strength in the vicinity of the boundary part, in a mask main unit of the shadow mask. CONSTITUTION: A mask main unit is constituted of a holed part 27 formed with many electron beam passing holes 26 by prescribed arrangement to consist of a curved surface protruding the central part to a side of a phosphor screen, no-holed part 28 surrounding the total periphery of this holed part 27 and a skirt part 29 formed to be bent in an opposite side to the phosphor screen so as to surround this no-holed part 28. In the inside of this mask main unit skirt part 29, a mask frame 22 of L-shaped section is mounted by welding. Here over the total periphery of a boundary part between the holed part 27 and the no-holed part 28, the no-holed part 28 is left as bent at a prescribed angle on an opposite side to the phosphor screen. Thus by increasing strength in the boundary part, generating deformation in the boundary part is prevented.

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 in which deformation of a shadow mask is prevented.

[0002]

2. Description of the Related Art In general, a color picture tube has a shadow mask disposed inside a phosphor screen formed of a three-color phosphor layer formed on the inner surface of a panel, and has three electrons emitted from an electron gun. The beams are selected by a shadow mask and are made incident on the three-color phosphor layer to form a structure for displaying a color image.

As shown in FIG. 4, in the shadow mask, a large number of electron beam passage holes are formed in a predetermined arrangement and a central portion is formed into a curved surface projecting toward the phosphor screen 1 side. A non-perforated portion 3 surrounding the perforated portion 2 and a skirt portion 4 bent and formed on the opposite side of the phosphor screen 1 so as to surround the non-perforated portion 3 and a mask body 5 having a relatively thin plate, The mask frame 6 has a relatively thick plate and is welded to the skirt portion 4.

Conventionally, the mask body 5 of this shadow mask has a flat plate-shaped flat mask having a large number of electron beam passage holes formed in a predetermined arrangement by a photoetching method and having a non-hole portion on the outer periphery thereof. The flat mask is formed by press molding. The press forming process is an overhanging process of forming the electron beam passage hole forming portion into a predetermined curved surface with a forming die, and bending with leaving a non-hole portion of a constant width around the electron beam passing hole forming portion, and a skirt portion. And forming process.

By the way, generally, when materials having partially different strengths are press-molded, a large force is applied to a low-strength portion, and after molding, a large stress remains in the low-strength portion. Therefore, when forming a flat plate-shaped flat mask having a relatively high-strength non-hole portion on the outer periphery of a relatively low-strength electron beam passage hole forming portion, such as a forming process of a mask main body, a skirt portion is particularly required. In the drawing process for forming, a larger stress remains in the electron beam passage hole forming portion than in the non-hole portion. Therefore, in the actual molding process of the mask main body, a measure is taken so that the force is not applied to the electron beam passage hole forming portion as much as possible, but still, it is possible to avoid the large stress remaining in the electron beam passage hole forming portion. Absent.

The problem in the molding process of the mask main body is to reduce the thermal expansion of the shadow mask.
When the mask main body is formed of a tensile strength material having a low thermal expansion such as amber (Fe-Ni alloy), as shown in FIG. 5, stress is concentrated near the boundary portion 8 between the perforated portion 2 and the non-perforated portion 3. , Deformation may occur.

Therefore, in the conventional mask body made of amber material, the non-perforated portion 3 is formed at the time of manufacturing the flat mask.
By performing half etching in which the vicinity of the perforated portion 2 is etched from only one side, the stress concentration is dispersed to reduce deformation.

[0008]

As described above, the mask main body made of a high tensile strength material such as amber has a large number of electron beam passage holes formed in a predetermined arrangement, and has a flat plate shape having a non-perforated portion on the outer periphery thereof. The flat mask of 1. is formed by press molding, and a holed part is formed in which a large number of electron beam passage holes are formed in a predetermined arrangement, a non-hole part surrounding the holed part, and a bend to surround the non-hole part. When forming a mask body composed of the formed skirt portion, there is a problem that stress is concentrated in the vicinity of the boundary between the perforated portion and the non-perforated portion, and deformation is likely to occur.

The present invention has been made in order to solve the above-mentioned problems, and increases the strength in the vicinity of the boundary between the perforated portion and the non-perforated portion of the mask main body so that the mask main body can be press-formed. The purpose of the present invention is to eliminate the deformation caused by the stress applied in the vicinity of the boundary between the perforated portion and the non-perforated portion, and to eliminate the quality deterioration of the color picture tube due to the deformation of the shadow mask.

[0010]

A shadow mask facing a phosphor screen formed on an inner surface of a panel,
This shadow mask has a perforated portion with a predetermined curved surface having a large number of electron beam passage holes, a non-perforated portion surrounding the perforated portion and a non-perforated portion surrounding the non-perforated portion on the opposite side of the phosphor screen. In a color picture tube consisting of a mask body composed of a bent skirt portion and a mask frame attached to the skirt portion, the shadow mask is
The structure is such that the non-perforated portion is bent over the entire circumference of the boundary portion between the perforated portion and the non-perforated portion so as to be on the opposite side of the phosphor screen.

Further, the shadow mask has a structure in which the boundary between the perforated portion and the non-perforated portion and the entire circumference of the intermediate portion of the non-perforated portion are bent.

[0012]

As described above, the non-perforated portion is bent to the opposite side of the phosphor screen over the entire circumference of the boundary portion between the perforated portion and the non-perforated portion, or the perforated portion and the non-perforated portion are When the structure is bent over the entire circumference of the boundary part and the non-perforated part, it is possible to strengthen the strength in the vicinity of the boundary part between the perforated part and the non-perforated part. It is possible to prevent deformation in the vicinity of the boundary portion of the.

[0013]

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

FIG. 1 shows a color picture tube which is one of the embodiments. This color picture tube has an envelope made up of a substantially rectangular panel 11 whose effective surface 10 is a curved surface and a funnel 12 integrally joined to this panel 11, and the inner surface of the panel 11 has a blue and green color. A phosphor screen 13 including a three-color phosphor layer that emits red light is formed, and a substantially rectangular shadow mask 14 described later is arranged inside the phosphor screen 13 so as to face the phosphor screen 13. on the other hand,
An electron gun 18 that emits a three-electron beam 17 is arranged in the neck 16 of the funnel 12. Then, the three electron beam 17 emitted from the electron gun 18
The fluorescent screen 13 is deflected by a magnetic field generated by a deflecting device 19 mounted on the outer side of the mirror 2, and the phosphor screen 13 is horizontally and vertically scanned through the shadow mask 14 to display a color image.

The shadow mask 14 comprises a substantially rectangular mask body 21 made of a tensile strength material having a low thermal expansion such as amber, and a substantially rectangular mask frame 22 made of low carbon steel, and is attached to the mask frame 22. The frame holder 23 made of elastic material is attached to the panel 11
By locking the stud pin 24 provided on the
It is supported inside the panel 11.

As shown in FIG. 1, the mask body 21 has a perforated portion 27 having a large number of electron beam passage holes 26 formed in a predetermined arrangement and having a curved central portion protruding toward the phosphor screen. The non-perforated portion 28 surrounds the perimeter of the perforated portion 27, and the skirt portion 29 is formed by bending the non-perforated portion 28 on the opposite side of the phosphor screen. The mask frame 22 is attached to the mask body 21.
Has an L-shaped cross section and is attached to the outside of the skirt portion 29 of the mask body 21 by welding. Moreover, in the shadow mask 14 of this example, the non-perforated portion 28 is bent at a predetermined angle on the opposite side of the phosphor screen over the entire circumference of the boundary portion between the perforated portion 27 and the non-perforated portion 28 of the mask body 21. .

The bending at the boundary between the perforated portion 27 and the non-perforated portion 28 is performed when a flat plate-shaped flat mask having a large number of electron beam passage holes formed therein is formed by press forming by photoetching. , Molded at the same time. That is, in the mask main body 21, the electron beam passage hole forming portion of the flat mask is formed into a curved surface by the overhanging process using a molding die, and then the skirt portion 29 is formed by the drawing process. It is formed by bending the boundary between the perforated portion 27 and the non-perforated portion 28 at the same time as forming the curved surface of the beam passage hole forming portion.

By the way, when the non-perforated portion 28 is bent to the opposite side of the phosphor screen by a predetermined angle over the entire circumference of the boundary portion between the perforated portion 27 and the non-perforated portion 28 of the mask body 21, the perforated portion is formed. The strength in the vicinity of the boundary between the portion 27 and the non-perforated portion 28 can be strengthened, and the deformation that has conventionally occurred at the boundary portion can be prevented during press forming of the mask body 21, particularly during drawing for bending the skirt 29. can do. Further, when the mask frame 22 is attached to the mask main body 21, even if a deformation stress is applied to the skirt portion 29 inserted inside the mask frame 22, the influence is not exerted on the perforated portion 27 having low mechanical strength. be able to. Further, even when the color picture tube is heated in the manufacturing process and further heated by the collision of the electron beam during the operation of the color picture tube, the vicinity of the boundary portion between the perforated portion 27 and the non-perforated portion 28 which is relatively easily deformed. Deformation can be prevented. As a result, it is possible to configure a color picture tube of good quality that does not cause color shift due to deformation of the shadow mask.

Next, another embodiment will be described.

In the above embodiment, the boundary between the perforated portion and the non-perforated portion of the mask body is bent, but the shadow mask shown in FIG. 3 has the perforated portion 27 and the non-perforated portion 28 of the mask body 21. The non-perforated portion 28 is bent to the opposite side of the phosphor screen along the entire circumference at the boundary of the non-perforated portion, and the intermediate portion of the non-perforated portion 28 is bent toward the skirt portion 29 over the entire circumference. .

Even if it is bent at two places in this way, it is possible to obtain a color picture tube having the same effect as that of the above embodiment.

[0022]

EFFECTS OF THE INVENTION The boundary between the perforated part and the non-perforated part of the mask body of the shadow mask is bent over the entire circumference to the opposite side of the phosphor screen, or with the perforated part and the non-perforated part. By forming the boundary part and the intermediate part of the non-perforated part in a structure bent over the entire circumference, it is possible to strengthen the strength of the boundary part between the perforated part and the non-perforated part. It is possible to prevent the deformation around the boundary portion that occurs during the molding process. When mounting the mask frame on the mask body,
Even if a deformation stress is applied to the skirt portion of the mask body, the influence can be prevented from reaching the perforated portion having low strength. In addition, even if it is heated in the manufacturing process of the color picture tube, or even if it is heated by the collision of the electron beam during the operation of the color picture tube, the deformation near the boundary between the perforated part and the non-perforated part, which is relatively easy to deform. Can be prevented. As a result, it is possible to configure a color picture tube of good quality that does not cause color shift due to deformation of the shadow mask.

[Brief description of drawings]

1A is a plan view showing the configuration of a shadow mask of a color picture tube which is an embodiment of the present invention, FIG.
FIG. 6B is a sectional view showing the configuration of the main part thereof.

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

FIG. 3 (a) is a plan view showing the structure of a shadow mask of another embodiment of the present invention, and FIG. 3 (b) is a sectional view showing the structure of the main part thereof.

FIG. 4 is a diagram showing a configuration of a conventional shadow mask.

FIG. 5 is a diagram for explaining deformation of a conventional shadow mask.

[Explanation of symbols]

 10 ... Panel 13 ... Phosphor screen 14 ... Shadow mask 21 ... Mask body 22 ... Mask frame 26 ... Electron beam passage hole 27 ... Perforated portion 28 ... Non-perforated portion 29 ... Skirt portion

Claims (2)

[Claims] 1. A shadow mask facing a phosphor screen formed on the inner surface of a panel, the shadow mask having a predetermined curved surface in which a large number of electron beam passage holes are formed. In a color picture tube comprising a non-perforated portion surrounding the non-perforated portion and a skirt portion bent and formed on the opposite side of the phosphor screen so as to surround the non-perforated portion, and a mask frame attached to the skirt portion. The color image is characterized in that the shadow mask is bent over the entire circumference of the boundary between the perforated part and the non-perforated part so that the non-perforated part is on the opposite side of the phosphor screen. tube. 2. A shadow mask facing a phosphor screen formed on the inner surface of the panel, the shadow mask having a predetermined curved surface in which a large number of electron beam passage holes are formed. A collar consisting of a non-perforated part surrounding the peripheral part and a skirt part bent and formed on the opposite side of the phosphor screen so as to surround the non-perforated part, and a mask frame attached to the skirt part. In the picture tube, the shadow mask is bent over a boundary portion between the perforated portion and the non-perforated portion and an entire circumference of an intermediate portion of the non-perforated portion.