JP2002373597A - Shadow mask structural body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent tension reduction and wrinkle on a shadow mask in a thermal process by relaxing heat creep phenomenon of the mask in heat treatment. SOLUTION: This body is constituted of respective materials in which the coefficient of linear expansion of the longer axis support body 1 is not less than 10×10<-6> , the coefficient of linear expansion of the shorter axis support body 2 is not less than 10×10<-6> , and the coefficient of linear expansion of the shadow mask 4 is not more than 5×10<-6> , and plural slits 10 and grooves 12 are installed at this shadow mask 4 at the adhering part of the frame 3 and the shadow mask 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shadow mask structure used for televisions, computer displays, and the like.

[0002]

2. Description of the Related Art Generally, a color cathode ray tube has a shadow mask for selecting colors of an electron beam emitted from an electron gun, and a shadow mask structure composed of a frame for holding the shadow mask.

[0003] As a type of the shadow mask structure, a flat plate member having a large number of openings such as rectangles, circles, and ellipses is formed into a predetermined curved shape by pressing, and is welded to a frame. 5a), a two-dimensional tension mask (FIG. 5b) stretch-welded to a frame in a state where tension is applied in two-dimensional directions of a long axis and a short axis to a flat plate member having a similar opening, and a similar number. A one-dimensional tension mask (FIG. 5c) stretch-welded to a frame in a state in which tension is applied in only one dimension in either the short axis or the long axis direction to a flat plate member having an opening of FIG. There is known an aperture grill (see Japanese Patent Application Laid-Open No. 4-163830) in which a tension is applied to a member made of a metal strip and stretch-welded to a frame.

Hereinafter, a one-dimensional tension mask will be described as a conventional example with reference to the accompanying drawings.

FIG. 6 shows a shadow mask structure of a one-dimensional tension mask. The shadow mask structure 5 includes a pair of long axis supports 1 arranged in parallel with each other at a predetermined interval.
And a frame 3 composed of a substantially U-shaped short shaft support 2 attached to the ends of the pair of long shaft supports 1 and a pair of the long shaft supports 1 at a predetermined interval and a required tension. It is composed of a shadow mask 4 which is stretched and fixed.

In the shadow mask structure 5, for example, in a state where the frame 3 is deformed under pressure, the shadow mask 4 is fixed by welding, and after the welding is fixed, the pressure of the frame 3 is released and the shadow mask 4 is stretched. After that, heat treatment is performed at a high temperature of about 450 to 470 ° C. to blacken the surface. Further, there are a frit sealing step at a high temperature of about 440 to 470 ° C. and a vacuum evacuation step at a high temperature of about 350 to 370 ° C. until the cathode ray tube is completed.

In the above-described structure of the shadow mask structure 5, when the blackening process is performed at a high temperature after the shadow mask 4 is stretched, the shadow mask 4 is stretched due to the thermal expansion of the frame 3, and plastic deformation and thermal creep phenomenon occur. This causes the shadow mask 4 to be wrinkled.

The plastic deformation and the thermal creep phenomenon may also occur in the subsequent heat treatment (about 440 to 470 ° C.) of the frit sealing step of sealing the panel and the funnel.

Therefore, in the conventional one-dimensional tension mask, heat treatment is performed so that a temperature difference between the frame 3 and the shadow mask 4 does not occur during the heat treatment at a high temperature, or the frame 3 and the shadow mask 4 are made of the same material or In order to use a material having substantially the same coefficient of thermal expansion, the invention has been devised.

[0010]

However, since the frame needs to support the shadow mask 4 to which tension is applied, the frame has a larger mass and a larger heat capacity than the shadow mask in order to secure rigidity. Therefore, in the cooling process of the heat treatment, the shadow mask is easier to cool first. Further, when a material having a smaller linear expansion than that of the frame is used as a material for the shadow mask, plastic deformation and thermal creep phenomenon further occur in the shadow mask, and wrinkles are likely to occur.

SUMMARY OF THE INVENTION In view of the foregoing, the present invention is to alleviate the thermal creep phenomenon of a shadow mask during a heat treatment, thereby preventing a reduction in mask tension and a generation of wrinkles during a thermal process.

[0012]

In order to achieve this object, the present invention provides a pair of long shaft supports opposed to each other and a pair of short shaft supports provided between the pair of long shaft supports. And a shadow mask stretched and held by the frame, and a plurality of rigidity adjusting portions are provided on a shadow mask side of a fixed portion of the frame and the shadow mask.

With these configurations, when materials having different thermal expansions are used for the frame and the mask, the plastic deformation and the thermal creep phenomenon of the shadow mask during the heat treatment are alleviated, and the tension of the mask is reduced during the thermal process. It is possible to prevent the occurrence of wrinkles.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings.

FIG. 1 is a perspective view of a shadow mask structure according to a first embodiment of the present invention. A shadow mask structure 5 has a pair of opposing linear expansion coefficients of 10 × 1.
A long axis support 1 made of a material having a linear expansion coefficient of ^10-6 or more and a pair of linear expansion coefficients
A frame 3 comprising a short axis support 2 made of a material of × 10 ^-6 or more, and a state where a tensile force is applied in one direction,
The coefficient of linear expansion held on the frame 3 is 5 × 10
^The shadow mask 4 has a plurality of slits 10 at a portion where the shadow mask 4 is fixed to the frame 3. By dividing the shadow mask 4 at a portion where the shadow mask 4 is fixed to the frame 3, even when the frame 3 expands more thermally than the shadow mask 4, a large force does not act on the shadow mask 4 by the slit 10. No plastic deformation or thermal creep occurs.

FIG. 2 is an enlarged view of a portion where the shadow mask 4 and the frame 3 are fixed, and the length of the slit 10 is 50.
mm and the pitch of the slits 10 is desirably 10 mm or less. This is because if the length of the slit 10 is small and the pitch of the slit 10 is large, stress concentration occurs at the tip of the slit 10, and the shadow mask 4 may be locally deformed.

FIG. 3 is a perspective view of a shadow mask structure according to a second embodiment of the present invention, and a pair of opposed masks each having a linear expansion coefficient of 10 × 10 ^-6 or more. A frame 3 comprising a shaft support 1 and a pair of short shaft supports 2 provided between the pair of long shaft supports 1 and made of a material having a linear expansion coefficient of 10 × 10 ⁻⁶ or more; A shadow mask 4 made of a material having a coefficient of linear expansion of 5 × 10 ⁻⁶ or less, which is stretched and held on the frame 3 in a state where a tensile force is applied in the direction. And a rigidity adjusting portion is provided at the fixed portion 11. FIG. 4 shows an example of the rigidity adjusting section, in which a groove 12 is provided by half etching. By providing the shadow mask 4 with a rigidity adjusting portion that is a portion having reduced rigidity, when the frame 3 expands more thermally than the shadow mask 4, plastic deformation and thermal creep occur only in the rigidity decreasing portion of the rigidity adjusting portion of the mask. Occurs, and the entire mask retains tension, and no wrinkles occur.

Although a groove is provided as a rigidity adjusting portion, a through hole such as a notch may be used.

[0019]

As described above, according to the present invention, there is provided a frame comprising a pair of long shaft supports opposed to each other and a pair of short shaft supports provided between the pair of long shaft supports. This frame has a shadow mask stretched and held, and a plurality of rigidity adjusting portions are provided on the shadow mask side of a fixed portion of the frame and the shadow mask, and a plastic deformation of the shadow mask during heat treatment and By alleviating the thermal creep phenomenon, it is possible to prevent a decrease in the tension of the mask and the occurrence of wrinkles during the thermal process.

[Brief description of the drawings]

FIG. 1 is a perspective view of a shadow mask structure according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged view of the shadow mask structure according to the first embodiment of the present invention.

FIG. 3 is a perspective view of a shadow mask structure according to a second embodiment of the present invention.

FIG. 4 is a partially enlarged view of a shadow mask structure according to a second embodiment of the present invention.

FIG. 5 is a perspective view of a conventional shadow mask structure.

FIG. 6 is a perspective view showing a frame structure of a conventional shadow mask structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Long axis support 2 Short axis support 3 Frame 4 Shadow mask 5 Shadow mask structure 10 Slit 12 Groove

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshifumi Nakatani 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 5C031 EE01 EE08 EE11 EH04 EH06

Claims (5)

[Claims] 1. A frame comprising a pair of long shaft supports opposed to each other and a pair of short shaft supports provided between the pair of long shaft supports, and a shadow stretched and held by the frame. A shadow mask structure, comprising: a mask; and a plurality of rigidity adjusting portions provided on a shadow mask side of a fixed portion of the frame and the shadow mask. 2. The shadow mask structure according to claim 1, wherein the linear expansion coefficient of the frame is larger than that of the shadow mask. 3. The shadow mask structure according to claim 1, wherein the rigidity adjusting section has a slit shape. 4. A long-axis support and a short-axis support having a linear expansion coefficient of 10 × 10 ⁻⁶ or more, and a shadow mask having a linear expansion coefficient of 5 × 10 ^6.
10 ^-6, the length of the slit is at least 50mm, shadow mask structure according to claim 3, the pitch of the slit is equal to or is 10mm or less. 5. The shadow mask structure according to claim 1, wherein the rigidity adjusting portion has a groove shape.