JPH0216509Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a cathode ray tube incorporating an internal magnetic shield ring.

BACKGROUND ART AND PROBLEMS FIG. 1 is a schematic diagram of a color cathode ray tube, in which 1 is a cathode ray tube body, 2 is a color phosphor screen formed on the inner surface of panel 1a, 3 is a color selection mechanism, and 4 is a color cathode ray tube. 5 shows an electron gun, and 5 shows an internal magnetic shield ring attached to the frame of the color selection mechanism 3. Generally, heat generated within the tube body 1 due to scanning of the electron beam comes from the electrode body 6 of the color selection mechanism 3 and the portion of the panel 1a where the color phosphor screen 2 is formed. In particular, nearly 70% of the total electron beam emitted from the electron gun 4 collides with the electrode body 6 of the color selection mechanism 3.
This electrode element body 6 can be considered as the main heat source within the tube body 1. These heats are released outside the tube from the panel 1a or the funnel portion 1b as radiation heat. By the way, when the internal magnetic shield ring 5 is installed inside the tube body 1, the portion of the heat that is transmitted to the funnel portion 1b as radiation heat is reflected, increasing the temperature rise of the electrode body 6. As a countermeasure for this, the internal magnetic shield is blackened to prevent radiation heat from being reflected, and a large window hole is formed in the internal magnetic shield ring 5 to allow heat to escape to the funnel portion 1b. However, in this case, a troublesome blackening process is required. On the other hand, as shown in FIG. 2, the color selection mechanism 3 has a spring support piece 9 attached to its frame 7 via a spring holder 8 having a bimetallic structure. Corrects landing changes. 10 is a stud pin provided on the panel 1a. When the color selection mechanism is a so-called shadow mask, a spring holder 8 is provided outside the frame as shown in FIG. 2, and when the internal magnetic shield ring 5 is attached, all the heat from the shadow mask passes through the frame 7. and is transmitted to the spring holder 8. Therefore, as another countermeasure, it is necessary to reduce the mechanical strength of the bimetallic spring holder 8 that corrects the temperature rise to increase the amount of correction. In any case, the manufacturing process will become complicated and the quality of the color cathode ray tube will deteriorate.

Purpose of the invention In view of the above-mentioned points, the present invention has been developed to improve beam landing while maintaining quality and performance in a cathode ray tube that has an internal magnetic shield and a bimetal structure that corrects beam landing changes due to temperature rise. The purpose of the present invention is to provide a cathode ray tube capable of efficiently correcting.

Summary of the invention The present invention provides an electrode between the surfaces of both first support members of a frame in which a pair of second support members are fixed across the back surfaces of a pair of opposing first support members. In a cathode ray tube equipped with a color selection mechanism in which the element body is stretched and bimetallic spring holders are attached to both second support members and one of the first support members, the frame of the color selection mechanism is provided. An internal magnetic shielding ring is attached to the inner magnetic shielding ring, and a notch is provided in a portion of the internal magnetic shielding ring corresponding to the spring holder of one of the first supporting members, so that radiant heat from the electrode body is directed to the spring holder. This allows the beam to be transmitted directly, allowing for efficient correction of changes in beam landing.

Embodiment Hereinafter, an embodiment of the cathode ray tube according to the present invention will be described with reference to FIGS. 3 to 6.

In this embodiment, a color cathode ray tube is provided with a so-called aperture grill as a color selection mechanism, and an internal magnetic shield ring is disposed thereon.

FIG. 3 shows the color selection mechanism 11 and internal magnetic shield ring 12. This color selection mechanism 11 includes a pair of second support members 1 which form a U-shape and extend between the back surfaces of a pair of first support members 13 and 14 facing each other.
5 and 16 are fixed to form a frame-shaped frame 17, and both first support members 13 of this frame 17
and 14, an electrode element body, for example, a large number of metal strips 18, is stretched at a predetermined pitch between the surfaces of the electrode elements 14 and 14. On the outside of each of the first support member 13 and the second support members 15 and 16, a bimetallic spring holder 21 for beam landing correction is provided.
22 and 23 are attached. A color selection mechanism 1 is attached to each spring holder 21, 22, and 23.
Spring support pieces 24, 25 and 26 are respectively fixed to support the cathode ray tube 1 on the panel of the cathode ray tube.
Reference numeral 27 denotes a fitting hole provided at each free end of the spring support piece, which is fitted into a stud pin provided within the panel. Here, the spring holder 21 of the first support member 13 is attached so as to protrude from the back side of the first support member 13, and the spring holders 22 and 23 of both the second support members 15 and 16 are both attached to the second support member 13.
It is attached so as to protrude from the surface side of the support members 15 and 16. Although this color selection mechanism 11 is not shown,
As shown in FIG. 1, it is attached to the inner surface of the panel of the cathode ray tube via its spring support pieces 24, 25 and 26.

An internal magnetic shield ring body 12 made of a low carbon steel plate with high magnetic permeability and whose surface has been subjected to anti-rust treatment is attached to the frame 17 of the color selection mechanism 11. In this case, the internal magnetic shield ring 12 is connected to the second support member 15 of the frame 17, as shown in FIG.
It is fixed by spot welding on the back side of 16. First support member 1 of internal magnetic shield ring 12
The end portions on the 3 and 14 sides are extended to cover the outside of the first support member. As shown in FIGS. 4 and 5, the radiant heat from the electrode body 18 is applied to the portion of the first support member 13 of the internal magnetic shield ring 12 corresponding to the spring holder 21. A notch 30 is provided which communicates directly with 21. The spring holders 22 and 23 of the second support members 15 and 16 are connected to the internal magnetic shield ring 12.
Not shielded by The internal magnetic shield ring 12 is provided with a window hole 31 for heat radiation.

According to this configuration, the internal magnetic shield ring 1
Spring holder 21 in the first support member of No. 2
By providing the notch 30 at a portion corresponding to the spring holder 21, the spring holder 21 is exposed to the electrode body 18 inside. On the other hand, the spring holders 22 and 2 in the other second support members 15 and 16
3 is not shielded by the internal magnetic shield ring 12. For this reason, when the internal temperature rises during operation of the cathode ray tube, the spring holders 21, 22,
In addition to the conductive heat via the frame 17, the beam 23 directly receives radiant heat from the electrode body 18, which is the main heat source, increasing the effect of beam landing correction. Incidentally, when we compared the beam landing correction effect with one in which the spring holder 21 was shielded without providing the notch 30, we found that in the case of an 18-inch color cathode ray tube, the spring holder 21
The amount of movement of the color selection mechanism toward the phosphor screen was 61 μm in the case where the color selection mechanism was blocked, whereas the amount of movement in the device of the present invention was 68 μm. Note that the spring holder 21 corresponds to a degauss coil placed just outside the tube. Therefore, it was expected that providing the notch 30 would increase the magnetic resistance there and impair the original shielding effect.
It was also confirmed that if the size of the spring holder 21 is approximately the same as that of the spring holder 21, the shielding effect will not be affected.

As described above, in this embodiment, the amount of correction can be increased without reducing the mechanical strength of the bimetallic spring holder. Moreover, this makes it possible to omit the blackening treatment on the surface of the internal magnetic shield ring 12. Therefore, manufacturing equipment required for blackening treatment becomes unnecessary. In addition, a thin iron plate that has been simply treated to prevent rust can be used for the internal magnetic shield ring.

Effects of the invention As described above, according to the invention, in a cathode ray tube that has both an internal magnetic shield ring and a function to correct beam landing changes within the tube due to temperature rise, one side of the internal magnetic shield ring By providing a notch in the support member corresponding to the spring holder, thermal radiation from the electrode body is directly transmitted to the spring holder.
Beam landing changes can be efficiently corrected without degrading the mechanical strength of the spring holder itself. Therefore, the blackening treatment for increasing the heat dissipation effect of the internal magnetic shield ring can also be omitted.

Therefore, it is possible to obtain a color cathode ray tube with a built-in internal magnetic shield ring which is easy to manufacture and has good quality and performance.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view schematically showing a color cathode ray tube;
Fig. 2 is an enlarged sectional view showing the main parts thereof, Fig. 3 is a perspective view of the color selection electrode and internal magnetic shield ring showing an embodiment of the present invention, and Fig. 4 is a side view of the main parts.
5 is a sectional view taken along the line AA in FIG. 3, and FIG. 6 is a sectional view taken along the line BB in FIG. 3. 1 is a tube body, 3 and 11 are color selection mechanisms, 5 and 12 are internal magnetic shield rings, 13 and 14 are first support members, 15 and 16 are second support members, 17 is a frame, 21, 22, 23 is a spring holder, 30
is the notch.

Claims (1)

[Scope of utility model registration request] An electrode element is stretched between the surfaces of the first supporting members of a frame in which a pair of second supporting members are fixed across between the back faces of a pair of opposing first supporting members, In a cathode ray tube equipped with a color selection mechanism in which bimetal spring holders are attached to both of the second support members and the one support member, an internal magnetic shield ring is attached to the frame of the color selection mechanism. A notch is provided in a portion of the one first support member of the internal magnetic shield ring that corresponds to the spring holder so that the radiant heat from the electrode body is directly transmitted to the spring holder. A cathode ray tube consisting of