JP2568602Y2 - Shadow mask structure - Google Patents

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 of a color cathode ray tube of a shadow mask type.

[0002]

2. Description of the Related Art A shadow mask type color cathode ray tube (hereinafter referred to as "CRT") has a funnel 1 as shown in FIG.
A panel 2 for sealing an open end of the funnel 1, a fluorescent screen 3 applied to the inner face of the face of the panel 2,
A plurality of stud pins 4 provided on the side wall of the panel 2, a shadow mask structure 5 fitted to the stud pins 4 and facing the phosphor screen 3, and a neck portion 12 facing the face of the panel 2; And an electron gun 6 enclosed in the electronic gun.

As shown in FIG. 5, the shadow mask structure 5 has an aperture portion 7 having a large number of pores 7a and a curved surface substantially similar to the face curved surface of the panel 2, and the aperture portion 7 is provided. A shadow mask main body 9 comprising a mask skirt portion 8 bent at a predetermined position, a frame 10 to be welded around the shadow mask main body 9 at a plurality of locations, and a frame 10 welded to the frame 10 and fitted to the stud pins 4. And a spring 11 for holding the aperture portion 7 at a relative position of the panel 2.

The frame 10 has a thickness of 0.8 m.
frame skirt portion 13 made of hot or cold-rolled steel of m to 2.0 mm and parallel to mask skirt portion 8
And a frame flange portion 14 which is substantially perpendicular to the frame skirt portion 13. Generally, the frame 10 has a frame skirt portion 13 and a frame flange portion 14 formed by sheet metal punching and drawing by press forming.

[0005] After the frame 10 of the press-forming, to surface treatment such as pickling or shot peening, further thickness 2~3μ at Kiri囲gas of 600 to 650 ° C.
A blackening treatment for forming a black rust film of m is performed. During this blackening treatment, the frame 10 is relieved of the press residual stress,
It generates distortion such as twisting.

Generally, the shadow mask structure 5 is configured as shown in FIG.
The surface 4a generated by the stud pin 4 as shown in FIG.
The spring 11 having a hole for fitting and engaging with each stud pin 4 is fitted to the stud pin 4 while maintaining the surface 4b of the frame flange portion 14 so as to be parallel to the frame skirt portion 13. It is positioned in between and fixed to the frame skirt portion 13 at several points by resistance welding or the like. Next, the frame skirt portion 13 and the mask skirt portion 8 are opposed to each other, and the frame skirt portion 13 and the mask skirt portion 8 are arranged so that the face curved surface between the aperture portion 7 and the panel 2 has a predetermined interval as shown in FIG. When the mask skirt portion 8 is positioned and fixed at several places by resistance welding, the shadow mask structure 5 is assembled.

When the above-mentioned spring 11 and frame skirt portion 13 are fixed by resistance welding or the like, the bottom surface of frame flange portion 14 does not become parallel to surface 4b as shown in FIG. If the method of fixing and holding the frame 10 becomes inappropriate due to the relaxation of the residual strain due to processing or the like, FIG.
As shown in the figure, the bottom surface of the frame flange portion 14 becomes a twisted surface 4c with respect to the stud pin surface 4a.

[0008] Here, the inappropriate holding method is, for example, as shown in FIG.
Even if the frame 10 is supported near the center of the frame flange 14 and twisted as indicated by a broken line as shown in FIG. 2B, or if the frame 10 is held near the corner of the frame flange 14, As shown in FIG. 7 (c), if the warp due to the press forming distortion is present in the flange portion 14, the height at which the bottom surface of the frame flange portion 14 is received is not constant and the bottom surface of the frame flange portion 14 is different. Are twisted surfaces 4 as shown in FIG.
This is the case when c is reached.

If the aperture 7 is positioned and fixed to the frame skirt 13 in such a state, the shadow mask structure 5 is assembled with the bottom surface of the frame flange 14 twisted, and is repeated during the CRT manufacturing process. In the process of the automatic mask attaching / detaching mechanism, it often causes a mask attaching / detaching error. This is likely to occur when the detacher has a mask positioning mechanism mainly based on the stud pin plane.

Further, as described above, the frame flange 1
If the twisted shadow mask structure 5 on the bottom surface of the CRT 4 is subjected to a heat treatment process such as a CRT internal gas discharge and exhaust step in the CRT manufacturing process, permanent distortion occurs such that the torsion distortion of the shadow mask structure 5 is increased, and Mask structure 5
The positional relationship between the CRT and the phosphor screen 3 on the inner surface of the panel is deviated, which is one of the causes of deteriorating the color purity of the CRT.

[0011]

Since the conventional shadow mask structure is configured as described above, the residual press distortion is reduced, and the use of the frame 10 in which the bottom surface of the frame flange portion 14 is twisted makes it possible to use the shadow mask structure. When assembling the frame mask 5, depending on how the frame flange portion 14 is held, the stud pin surface 4 a may be formed in a state where the shadow mask structure 5 is assembled with the frame flange portion 14 being twisted.
If the bottom surface of the frame flange portion 14 is twisted with respect to the surface 4a of the stud pin as described above, the attaching / detaching machine causes a detaching trouble in the attaching / detaching process of the shadow mask structure 5 during the manufacture of the CRT. easy, CRT to further
There has been a problem in that a deformation that increases the torsional deformation of the shadow mask occurs in a heat process during the manufacturing, and the color purity of the CRT is deteriorated.

The present invention has been made to solve the above-mentioned problems, and assembles a bottom surface of a frame flange portion in parallel with a surface formed by a stud pin with good reproducibility and a shadow mask structure. It is an object of the present invention to obtain a shadow mask structure capable of reducing a torsional distortion of a frame flange portion when fitting the frame to a surface of a stud pin.

[0013]

A shadow mask structure according to the present invention has a projection which can be point-contacted to a reference plane parallel to a plane formed by stud pins near four corners on the bottom surface of a frame flange. And the plane of the bottom surface of the frame flange can be defined with good reproducibility by using the point contact portion of the projection as the surface reference of the bottom surface of the frame flange.

[0014]

According to the shadow mask structure of the present invention, the projections provided at the four corners of the bottom surface of the frame flange are pressed against a reference surface parallel to the stud pin surface to assemble the shadow mask structure. Without the bottom twisting with respect to the stud pin surface,
It has substantially parallel flange surfaces.

[0015]

[Embodiment 1] An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a partially cutaway perspective view showing a shadow mask structure, and FIG. 2 is a view showing a cross section of a corner portion of FIG. 1 taken along a line II-II. And the description is omitted. In the figure, 15 is provided on the corners of the bottom surface of the frame flange 14 and static
A projection which can be point-contacted with a reference plane parallel to a plane generated by the pin, and is formed by a hemispherical projection bead.

In FIG. 1, reference numeral 4a denotes a plane formed at a point passing through the center of the hole of the spring 11 fitted to the panel stud pin, and is a plane equivalent to the stud pin plane. 4b
Is a hemispherical projection bead 15 provided near the corner of the frame flange portion 14 and a surface 1 parallel to the plane of the stud pin.
6 is the surface generated at the point where it contacts. At this time, contact <br/> Sawaten any one projection bead 15 for the four of at least three surfaces 4b generated at a point contact touch of the protruding bead 15 of the stud pin plane and 4 corners of the projection bead 15 Can be made 0.5 mm or less with respect to the surface 4b, and the shadow mask structure 5 having a sufficient plane of the frame flange portion 14 can be obtained. By the way, when the surface 16 coincides with the surface 4b, the four protrusion beads 1
5 is exactly on the same plane.

Embodiment 2 FIG. In the above embodiment, the projection 15 of the frame flange 14 is a hemispherical bead. However, if the projection is a point element that can make point contact with the surface 16 parallel to the stud pin plane, FIG.
The protrusion may be a triangular pyramid as shown in FIG. 3A, or may be a hollow protrusion as shown in FIGS.
(B), it may be a real overhang shape in as shown in (c).

Embodiment 3 FIG. Further, in the above embodiment, the case where the stud pin 4 is located near the center of the long side and the short side of the panel 2 as shown in FIG. 4A is shown, but as shown in FIG. Even in the case of three pins or when pins are arranged at corners as shown in FIG. 4C, the shadow mask is formed by positioning the projections 15 of the frame flange 14 so as to be parallel to the plane generated by these pins. Similar effects can be obtained by assembling the structure 5.

[0019]

[Effects of the Invention] As described above, according to the invention , the stud pins are used near the four corners on the bottom surface of the frame flange.
Since a projection that can be point-contacted to a reference plane parallel to the plane to be generated is provided, this projection is used as a plane reference for the bottom of the frame flange, and the flatness of the bottom of the frame flange parallel to the stud pin plane This produces an effect of obtaining a shadow mask structure that can be assembled with good reproducibility.

As described above, in the shadow mask structure in which the flatness of the bottom surface of the frame flange is parallel to the plane of the stud pin, it is difficult for mask mounting / removal errors to occur in the mask automatic mounting / removing step during the CRT manufacturing process. Since the shadow mask structure is not twisted with respect to the plane, CR
Thermal relaxation deformation of the shadow mask during the T manufacturing process is unlikely to occur, and color purity deterioration of the CRT can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is the same view as FIG. 2 showing a second embodiment of the present invention;

FIG. 4 is a layout view of panel stud pins showing a third embodiment of the present invention.

FIG. 5 is a partially cutaway perspective view showing an example of a conventional color cathode ray tube.

FIG. 6 is a diagram showing an example of an assembling procedure of the shadow mask structure of FIG. 5;

FIG. 7 is an explanatory diagram of torsion in assembling the shadow mask structure of FIG. 5;

[Explanation of symbols]

 2 Panel 4 Stud pin 5 Shadow mask structure 7 Aperture 8 Mask skirt 9 Shadow mask body 10 Frame 11 Spring 13 Frame skirt 14 Frame flange 15 Projection

Claims (1)

(57) [Scope of request for utility model registration] 1. A shadow mask assembly comprising: a shadow mask; a frame to which a skirt portion of the shadow mask is fixed; and a spring fixed to the frame and mounted on a stud pin provided on an inner surface of a panel. around 4 corners of the flange portion bottom surface of the frame, the
A shadow mask structure comprising a projection which can be point-contacted with a reference plane parallel to a plane generated by stud pins .