JPH0214116Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention was developed to prevent the deterioration of color purity due to the influence of magnetism such as the earth's magnetism and television receiver circuits.
This invention relates to a color cathode ray tube that has an improved internal magnetic shield fixing device that shields these unnecessary stray magnetisms.

FIG. 1 is a vertical cross-sectional view of a color cathode ray tube excluding an electron gun, and 1 is a funnel, the inner surface of which is coated with a conductive film 2 that becomes a power feeding section. Reference numeral 3 designates a panel, the open end surface of which is welded to the tip of the funnel 1 using fritted glass or the like. 4 is a support pin provided on the side wall of the panel 3; 5 is a shadow mask; 6 is a frame; this frame 6 has a skirt portion 6a to which the shadow mask 5 is fixed;
It consists of a flange part 6b that is bent inward in the shape of a frame with respect to the skirt part 6a, and the flange part 6b has a plurality of locking holes 6c at predetermined intervals.
is drilled. 7 is a support elastic body whose one end is fixed to the frame 6 and the other end is fitted to the support pin 4 through an opening; 8 is an internal magnetic shield; a tongue piece 8a is inserted into the locking hole 6c of the frame 6; It has a plurality of locking windows (not shown in FIG. 1, but corresponding to 8b in FIG. 2) provided at predetermined intervals so as to face each of the locking holes 6c of 6. . Reference numeral 9 denotes a stop plate made of a relatively thin metal plate such as stainless steel, and has a protrusion 9a at one end that elastically engages with the lock hole 6c of the frame 6. Note that this stop plate 9 can be attached to a plurality of pieces. Reference numeral 10 denotes an elastic contact piece that connects the frame 6 with the conductive film 2 that charges the high voltage supplied from the outside of the cathode ray tube. The contact portion 10b elastically contacts the conductive film 2.

Next, a method of fixing the internal magnetic shield 8 and frame 6 in a conventional color cathode ray tube will be explained using FIGS. 2a and 2b. First, the stop plate 9 is inserted into the locking hole 6c provided in the frame flange 6b, and then the tongue piece 8a of the internal magnetic shield 8 is inserted into the locking hole 6c. The width W of this locking hole 6c is somewhat larger than the sum of the thicknesses of both the stopper plate 9 and the tongue piece 8a, and the protrusion 9a of the stopper plate 9
It is smaller than the sum of the thickness. Therefore, in this state, even if force is applied to the stop plate 9 in the direction where the protrusion 9a does not extend, the protrusion will be attached to the frame flange 6b.
You can't get caught up in it. The other end 9b of the stop plate 9, which is elastically engaged with the protrusion 9a in the lock hole 6c, is inserted through the lock window 8b of the internal magnetic shield 8, and then The inner magnetic shield 8 is bent inward from the lower edge of the inner magnetic shield 8.
and frame 6 were fixed.

However, in such a fixing method, when viewed from the manufacturing process, the stop plate 9 is a relatively thin and small component with respect to the internal magnetic shield 8, so the stop plate 9 is bent inward at the locking window 8b. It must be kept as it is until then. Moreover, when the internal magnetic shield 8 is fixed, the shadow mask 5 is already attached to the frame 6, and the projection 9a of the stop plate 9 before bending is only on the shadow mask side, so it is easy to come off on the shadow mask 5 side. It is becoming a state. Therefore, the workability is significantly reduced, and the tongue piece 8a of the internal magnetic shield 8
When inserting the stop plate 9, use the shadow mask 5.
There is a high possibility that the stop plate 9 will come into contact with the shadow mask 5 when the inner magnetic shield 8 is lifted up to insert the tongue piece 8a, thereby deforming the spherical shape of the shadow mask 5. This caused "color shift", which is fatal to color cathode ray tubes, and also caused a decrease in yield.

This invention was made in order to eliminate the above-mentioned drawbacks, and the purpose was to provide a color cathode ray tube in which the retaining plate could be attached while the internal magnetic shield and frame remained fixed. be.

Hereinafter, one embodiment of this invention will be described with reference to the drawings.

In FIGS. 3a, b, and 3c, the same reference numerals as those in FIGS. 1 to 3 indicate the same or corresponding parts.
Note that this differs from the conventional one in that a small hole 6d is provided on the long side of the locking hole 6c drilled in the frame flange 6b. Next, the dimensions of the internal magnetic shield without tongues are shown. First, the protrusion dimension h of the small hole 6d is larger than the protrusion height H of the protrusion 9a of the stop plate 9 (h)>H), and the small hole 6d is larger than the protrusion height H of the protrusion 9a of the stop plate 9.
It is large enough that there is no resistance even when it moves up and down.
Furthermore, of the dimensions from the end of the locking hole 6c to the small hole 6d, the shorter dimension la is from the side of the stopper plate 9 to the projection 9.
The dimension up to a is approximately the same as or larger than La (la
≧La), the longer dimension l-la from the end of the locking hole 6c to the small hole 6d is l-la>L-La The dimension L- from the other side of the stopper plate 9 to the protrusion 9a Make it larger than La. Note that if L-La=La as shown in the figure, then l-la>La.

Also, the length l of the locking hole 6c is the minimum length l that is the sum of the width L of the stopper plate 9 and the dimension of the protrusion 9a of the stopper plate 9.
It is necessary to set the value to the above value (l>l ₁ ). However, in practice, if the length L, which is the sum of the width L of the stop plate 9 and the dimension La from the side surface of the stop plate 9 to the protrusion _9d , is at least l2, it will always be at least _l1 (l> _l2 > _l1 However, l ₂ = L
+La). In addition, the width W of the locking hole 6c is the width of the locking plate 9.
(W<H) and larger than the thickness of the stop plate 9. By making such dimensions, the stop plate 9
When the position of the protrusion 9a and the position of the small hole 6d of the locking hole 6c are aligned, the stop plate 9 can be inserted and pulled out from the locking hole 6c from either the upper or lower direction without resistance, and the protrusion 9a also It can move within the small hole 6d without resistance. However, when the position of the protrusion 9a and the position of the small hole 6d do not match, the part of the stop plate 9 without the protrusion 9a can move up and down within the locking hole 6c, but the part with the protrusion 9a is not engaged. It hits the hole side of the stopper hole 6c, and further movement of the stopper plate 9 becomes impossible.

Next, the fixing work of this embodiment will be explained using FIGS. 4a and 4b.

First, as shown in FIG. 4a, the internal magnetic shield 8 is correctly placed in a fixed position on the frame flange 6b, and the stop plate 9 is placed in the position of the small hole 6d of the locking hole 6c.
Align the position of the projection 9a and insert the stop plate 9 into the frame flange 6b from above. Next, slide the stop plate 9 in the direction of the arrow in the figure, that is, in the long diameter direction of the locking hole 6c, and then attach the stop plate 9 to the lower edge of the locking window 8b of the internal magnetic shield 8 as in the conventional case. The internal magnetic shield 8 is fixed to the frame 6 by bending the end 9b.

Note that when the internal magnetic shield 8 has a tongue piece 8a, it goes without saying that the thickness of the tongue piece is added to the dimensions h and W mentioned above.

However, in the conventional example, the tongue piece 8a was provided on the internal magnetic shield 8 to prevent the protrusion 9a of the stop plate 9 from slipping out of the stop hole 6c after fixing. This is to make the width W substantially close to the thickness of the stop plate 9, and according to the present invention, the tongue piece 8a is not required.

As described above, according to the present invention, the internal magnetic shield only needs to be placed on the frame, and the internal magnetic shield can be fixed to the frame without lifting it by simply using the retaining plate, which is relatively easy to handle. This method is not only extremely simple, quick and reliable compared to conventional fixing methods, but also has the effect of completely solving the above-mentioned drawbacks such as deformation of the spherical surface of the shadow mask. Furthermore, since there is no need to provide a tongue on the internal magnetic shield, the press mold is simple and molding is easy, and there is also the effect of eliminating the problem of difficulty in inserting the tongue due to deformation of the tongue.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of the main part of a conventional color cathode ray tube, Figure 2 a is a perspective view showing the conventional internal magnetic shield and stop plate, and Figure 2 b is centered around the internal magnetic shield and stop plate shown in Figure 1. FIG. 3a is a perspective view of a locking hole according to an embodiment of the present invention, FIGS. 3b and 3c are a plan view and a side view of a conventional retaining plate, Figures 4a and 4b are detailed perspective views showing an embodiment of the present invention. In the figure, 5...shadow mask, 6...frame, 6c...locking hole, 6d...small hole, 8...
Internal magnetic shield, 8a... tongue piece, 8b... locking window, 9... stop plate, 9a... protrusion, 9b... other end. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A frame-shaped frame with a shadow mask attached to one side, and an internal magnet that is in contact with the other end surface of the frame and has a plurality of locking windows formed at predetermined intervals on the circumferential surface of one open end. a shield, a plurality of locking holes provided at positions facing the interlocking windows of the internal magnetic shield that are bored at predetermined intervals in the frame-shaped end surface of the frame, and elastic holes in each of the locking holes. In a color cathode ray tube, the protrusion of the stop plate can be inserted into the outer periphery of the lock hole without resistance in the color cathode ray tube, which has a stop plate whose other end engages with the stop window. A color cathode ray tube, characterized in that a small hole is provided, and the length from one end of the locking hole along the side of the frame to the small hole is longer than the width of the stop plate.