JPS628897B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color picture tube in which a magnetic shield is coupled to a mask frame holding a shadow mask.

In general, a color picture tube equipped with a magnetic shield inside the tube is constructed as shown in FIG. 4, the face plate portion 5 and the funnel portion 6
It is enclosed in an envelope consisting of.

In the case where the magnetic shield 3 is connected to the mask frame 2 with a clamp spring, the clamp spring is inserted into the holes 21 and 31 provided in the mask frame 2 and the magnetic shield 3, respectively, as shown in FIGS. 2a and 2b. 7
However, with such a connection using a clamp spring, the magnetic shield 3 may become detached from the clamp spring 7 due to vibrations or shocks during transportation of the color picture tube or television set, or the clamp spring 7 itself may be damaged. There was a danger that the material might fall out of the holes 21 and 31.

The present invention has been made to solve these conventional problems, and will be described in detail below along with embodiments shown in the drawings.

The clamp spring 8 shown in FIG. 3 has a V-shape as a whole, and there are recesses 81 inwardly curved in the center of each of the two sides from the tip end to the free end.
81'. Each tip side linear portion 8 extends from the tip to the recesses 81, 81'.
The bent portions 83, 83' between 2, 82' and the recesses 81, 81' form an acute angle α. Further, the bent portions 85, 85' between the free end side linear portions 84, 84' and the recesses 81, 81' from the free end to the recesses 81, 81' form an obtuse angle,
Each free end side linear part 84, 84' is an extension line 821, 82 of each tip side straight part 82, 82'.
1' by a distance A.

FIG. 4 shows a state in which the clamp spring 8 shown in FIG. 3 is inserted into the holes 21 and 31 provided in the mask frame and the magnetic shield, respectively. , 84' are brought closer to each other to reduce the opening of the spring, and the maximum distance B between the straight portions 82, 82' on the tip end side when contracted is
is smaller than the respective diameters of the hole 21 in the mask frame and the hole 31 in the magnetic shield.

FIG. 5 shows a state in which the magnetic shield is coupled to the mask frame by such a clamp spring 8. Since the bent portions 83, 83' form an acute angle α, the bent portions 85, 85 Since the straight shaft portion on the free end side extending from ' to the free end portion is located outside the extension line of the straight portion on the tip end side, the supporting effect of the magnetic shield 3 on the mask frame becomes very large. Moreover, as shown in FIG.
Since the concave side regions 811, 811' of the bent portions 85, 85' function as a stopper when inserted into the respective holes, there is an advantage that the insertion operation is extremely simple.

According to the experimental results of the present inventors, the angle α of the bent portions 83, 83' is within the range of 75° to 87°;
The distance A was within the range of 0.5 mm to 2 mm, and the difference between the maximum distance B and the hole diameter was 0.8 mm or less, preferably 0.5 mm or less. In other words, when the value was set within this range, even when a 65G shock was applied more than 10 times in each direction of the color picture tube, the magnetic shield did not come off or the clamp spring came off.

FIG. 7 is for explaining the method of manufacturing a clamp spring according to the present invention, and shows the step of molding an elastic band-shaped material 9 by sandwiching it between V-shaped molding jigs 10 and 10'. Both sides of the jig 10 have an acute angle α
Therefore, when the recess forming jigs 11, 11' and 12, 12' are slid in the direction of the arrow while the band material 9 is held between the V-shaped forming jigs 10, 10', the jigs are bent. 11, 11' and 1
A recess is formed between 2 and 12'. At this time, the above-mentioned acute angle α and the above-mentioned overhang distance A become set values. When the formed band material 9 is taken out of the jig and bent in the opposite direction to form a V-shape, which is the opposite of the V-shape, a clamp spring as shown in Fig. 3 is completed, and a special No manufacturing process required.

As explained above, according to the present invention, a V-shaped clamp spring is used for coupling the magnetic shield to the mask frame, and this clamp spring has two sides from the tip end to the free end. Each central portion has a recess curved inward, and the free end side linear portion between the recess and the free end is the tip end side linear portion between the tip and the recess. located outside the extension line of The bent portion between the linear portion on the protruding end side and the recessed portion is formed into an acute angle, and the above-mentioned stopper effect can be obtained when the clamp spring is inserted into each hole of the magnetic shield and the mask frame. Not only that, after insertion, the particularly acute bent portion contacts the mask frame at a small contact angle,
The magnetic shield can be firmly connected to the mask frame, and a highly reliable color picture tube without the clamp spring coming off or coming off can be obtained.

[Brief explanation of the drawing]

Figure 1 is a simplified sectional view of a color picture tube, Figures 2a and b are diagrams for explaining the relationship between the clamp spring, mask frame, and magnetic shield in a conventional color picture tube, Figures 3 and FIG. 4 is a side view of a clamp spring in an embodiment of the present invention, FIGS. 5 and 6 are cross-sectional views showing the relationship between the clamp spring, a mask frame, and a magnetic shield in the same embodiment, and FIG. 7 FIG. 3 is a diagram for explaining a method of manufacturing the clamp spring of the same embodiment. 2... Mask frame, 3... Magnetic shield, 8
... Clamp spring, 81, 81' ... Recess, 8
2, 82'...Tip side linear part, 83, 83',
85, 85'...bent portion, 84, 84'...straight portion on the free end side, 821, 821'...extension line.

Claims (1)

[Claims] 1 A mask frame that holds a shadow mask and a magnetic shield that shields an external magnetic field are connected by a clamp spring inserted into each hole, and the clamp spring has a V-shape as a whole. has an inwardly indented recess in the center of each of the two sides from the tip to the free end,
The free end side linear portion between the recess and the free end is located outside of the extension line of the tip end side linear portion between the tip and the recess, and is located on the tip side. A color picture tube characterized in that a bent part between the straight part and the recessed part forms an acute angle.