JPS5918826B2 - cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color cathode ray tube, and particularly to a color cathode ray tube in which mislanding of an electron beam due to thermal deformation of a color selection electrode, that is, a grid device during operation, is avoided by mechanical means in the grid device. That is.

The grid device used in the present invention has a structure as shown in FIG.

That is, this grid device G consists of a pair of support rods 1 and 2 arranged parallel to each other at a predetermined interval, and an elastic rod installed between the Bessel points of the pair of support rods 1 and 2 or a position near the Bessel point. It is constructed by stretching a ribbon-shaped grid element 6 at a predetermined pitch so as to be spanned between both support rods 1 and 2 on a window frame-like frame 5 consisting of supports 3 and 4. It is mainly used as a grid device for so-called Trinitron (registered trademark) type color cathode ray tubes.

This grid device G normally consists of one support rod 1 and elastic holding members 7 attached to both elastic supports 3 and 4, respectively.
. Can be installed with 3-point support.

By the way, in a color cathode ray tube using such a grid device G, during operation, the grid element body 6 generates heat due to the collision of electron beams, and a portion of the heat is transmitted to the frame 5, causing the frame 5 to thermally expand. Mislanding of the electron beam occurs.

That is, as shown in FIG. 1, when the support rods 1 and 2 thermally expand in the longitudinal direction due to the thermal influence of the frame 5, the grid body 6 also displaces following this, and therefore the slits 14, especially in the peripheral portions, are displaced. Displaced (state shown by dotted line).

For this reason, the beam 16 that passes through the arbitrary slit 14 at the position A when no thermal expansion occurs and reaches the predetermined position P1 on the fluorescent surface 15 will appear as shown in the dotted line after the support rods 1 and 2 are thermally deformed. Slit 1 displaced to position A2 as shown at 16'
4 and reaches the position P2 of the fluorescent surface 15.

On the other hand, when the frame 5 of the grid device G thermally expands during operation of the color cathode ray tube, the grid device G itself is simultaneously displaced toward the phosphor side, causing thermal expansion. A method has been considered in which the position of the rear slit 14' is brought to a position on the trajectory of the electron beam 16 passing through the position of the slit 14 before thermal expansion, and mislanding due to thermal causes is mechanically avoided.

As a specific means of this method, a pair of support rods 1 and 2 are used.
A metal body having a coefficient of thermal expansion larger than that of the support rods 1 and 2 is fixed to the surface opposite to the surface on which the grid element body 6 is attached, respectively, so that the support rods 1 and 2 have a so-called bimetallic structure. A configuration has been considered in which, upon expansion, the bimetallic structure bends the support rods 1 and 2 toward the fluorescent surface 15, thereby substantially displacing the peripheral portions toward the fluorescent surface.

However, in the case of such a configuration, it has been confirmed that the entire surface of the grid device cannot be uniformly displaced forward and mislanding cannot be avoided due to the following reason.

That is, while one support rod 1 is entirely curved toward the fluorescent surface 15 around the support point provided by the holding member 7, the other support rod 2 has no support point for the panel 10, so the elastic support 3 and The support rod 2 is curved using two points at its respective joints as fulcrums, that is, the middle part of the support rod 2 sandwiched between the two joints faces rearward, and the part extending from each joint to the end faces forward. (toward the fluorescent surface side), and as a result, the displacement state is different from that of the support rod 1.

Further, both support rods 1 and 2 are mechanically integrated by elastic supports 3 and 4, and only one support rod 1 is attached to the panel 10.
Therefore, when the support rod 1 is displaced forward due to thermal expansion, the elastic supports 3 and 4 are rotated around the support point of the panel 10 by the holding members 8 and 9. The main reason is that the support rod 2 is displaced backward.

In view of the above-mentioned points, the present invention uniformly displaces both the support rods 1 and 2 toward the fluorescent surface side when the grid device G is affected by heat, thereby minimizing mislanding in the peripheral area as much as possible. The present invention provides a cathode ray tube that can be conditioned.

Hereinafter, the present invention will be explained in detail using FIG. 4 and subsequent figures.

FIG. 4 shows an example of a grid device according to the present invention, and 5 in the figure is a window frame-like frame having the same configuration as that explained in FIG. It is composed of a pair of support rods 1 and 2, and approximately U-shaped elastic supports 3 and 4 attached between both support rods 1 and 2. A large number of ribbon-shaped grid elements 6 are stretched at a predetermined pitch so as to be spanned between the two.

Furthermore, holding members 7.8 and 9 are provided at three points, one of the support rods 1 and both of the elastic supports 3 and 4, for supporting the frame 5 on the panel 10.

Each holding member? , 8 and 9 are pedestals 17 to 18 and 19 directly welded to the support rod 1 and elastic supports 3 and 4, respectively, and elastic support pieces 20, 21 and 22 made of, for example, plate springs, welded to each pedestal 17t18 and 19, respectively. It is composed of

The free ends of each of the elastic support pieces 20, 21 and 22 are provided with, for example, triangular through holes 23 which engage with the stud pins 11, 12 and 13 (see FIG. 2) on the panel side, respectively.

The grid device is attached to the inner surface of the cathode ray tube panel via the holding members γ, 8 and 9.

In the present invention, the grid element 6 is mounted on one of the support rods constituting the frame 5, that is, the support rod 1 to which the holding member 7 is attached, and the left and right elastic supports 3 and 4 connected thereto. A metal body 24 having a larger coefficient of thermal expansion than the support rod 1 and the elastic supports 3 and 4 is provided on the opposite side of the stretched surface.
, 25 and 26 are fixed by welding or other means, and when the frame 5 undergoes thermal deformation due to an increase in temperature, the metal bodies 24, 25 and 26, the respective support rods 1, and the elastic supports 3 and 4 The support rod 1 and both elastic supports 3 and 4 are configured to be curved toward the fluorescent surface side due to the difference in thermal expansion coefficient between the support rod 1 and the elastic supports 3 and 4.

In this case, metal bodies 23 and 2 on both elastic supports 3 and 4
4 is arranged at least in a portion extending from the fixing center of the pedestals 18 and 19 of each of the holding members 8 and 9 toward the support rod 2 side where there is no holding member.

Then, the support rods 1 and 2 are thermally expanded in the longitudinal direction from the state shown in FIG. 3 where they are not subjected to thermal deformation (the state shown by the solid line), and the arbitrary slits 14 in the periphery of the grid element 6 are moved from position A1 to the position A1. A2, the slit 14 is brought to the position A3 on the trajectory of the beam 16 passing through the slit 14 when the frame 5 is not deformed (
The shapes and sizes of the metal bodies 24, 25 and 26 relative to the support rods 1 and the elastic supports 3 and 4 are selected so that the support rods 1 and 2 are displaced up to the state shown by dotted lines.

The metal bodies 24, 25, and 26 may be selected from various materials depending on the material of the frame 5. For example, if the frame 5 is made of iron, they may be made of industrial standard 5US-27 material.

Further, each of the metal bodies 24, 25 and 26 can be formed to have a U-shaped cross section, for example, in order to be lightweight and maintain mechanical strength.

According to this configuration, when the frame 5 is subjected to a thermal influence, one of the support rods 1 and the pedestal 17 of the holding member T due to the difference in thermal expansion with the metal body 24 as shown in FIG. 5A. It curves toward the fluorescent surface side using the fixing center as a fulcrum, and is displaced from the state shown by the solid line to the state shown by the dotted line.

On the other hand, as the support rod 1 is deformed in curvature, both the elastic supports 3 and 4 connected thereto use the engagement portions of the holding members 8 and 9 with the stud pins as fulcrums, as shown in FIG. 5B. , and the support rod 2 side of the grid device tries to retreat (the state shown by the solid line). Due to the difference, each of the holding members is bent toward the fluorescent surface using the fixed center of the pedestals 18 and 19 as a fulcrum, and the support rod 2 is displaced toward the fluorescent surface.

Therefore, in the grid device, when the supporting rods 1 and 2 are both displaced toward the fluorescent surface side, the entire grid element body 6 is uniformly displaced toward the fluorescent surface side as shown by the dotted line in FIG. Mis-landing is minimized as much as possible.

In the configuration shown in FIG. 4, the through hole 23 of the elastic support piece 20 attached to the support rod 1 is of course formed so as to be located at the center of the frame 5, and at the same time, the welding center of the pedestal 17 with respect to the support rod 1 is It is also possible to make it as close to the center of the frame 5 as possible.

Specifically, as shown in FIG.
3 and the support rod 1 of the pedestal 17
When the distance from the welding center Y2 to the frame 5 is d, and the distance from one end of the frame 5 to the center Y1 is D, weld at a position that satisfies '< 0.2, preferably at a position where the distance d is within 15 mm. Make sure to select center Y2.

This is due to the following reason. That is, when the frame 5 is thermally affected and the support rod 1 is deformed in a curved manner, the support rod 1 curves around the welding center Y2 of the pedestal 17 of the holding member 7 as a fulcrum.

Therefore, for example, if the welding center Y2 of the pedestal 17 is shifted from the center Y of the frame 5 as shown in FIG.
The displacement amounts X1 and X2 at both ends of the support rod 1 are different.

However, as shown in FIG. 7, if the welding center Y2 of the pedestal 17 is sufficiently close to the center Y1 of the frame 5, the displacement amount X at both ends of the support rod 1.

and X2 can be approximately equal.

Note that the displacement state of the support rod 1 shown by the dotted line in FIG. 8 is a state diagram when the holding members on the elastic supports 3 and 4 side are not considered.
When the elastic supports 3 and 4 are actually supported by the holding members 8 and 9, the magnitude relationship between the displacement amounts X1 and X2 is opposite to that shown in the drawing.

By the way, in this case, the length l of the elastic support piece 20 cannot be made too short because it is necessary to provide appropriate springiness.

Considering this point, the through hole 23 of the elastic support piece 20 and the pedestal 1T are
The welding center Y2 of the pedestal 17 to the support rod 1 is set to the frame 5 with the length l between the welding point and the welding point set to the required length.
In order to bring it closer to the center of the image, it is possible to construct it as shown in FIG. 6, for example.

That is, an abbreviated pedestal 17 is provided, one end of which is welded at the center of the support rod 1 or a position Y2 close to the center, and the base of the elastic support piece 20 is welded to the other end.

In this way, the through hole 23 of the elastic support piece 20 having the required length l can be positioned at the center of the frame 5, and the pedestal 1 can be positioned at the center of the frame 5.
The welding center Y2 for the support rod 1 of 7 can also be brought to the center of the frame 5 or a position sufficiently close to this.

FIG. 9 is a perspective view of essential parts showing another example of the grid device according to the present invention.

This is especially true in the configuration of FIG.
Metal bodies 25 and 26 having a large coefficient of thermal expansion are arranged over the entire length of the elastic supports 3 and 4 (only one side is shown in the figure).

In such a configuration, the metal bodies 25 and 26 are disposed along the entire length of the elastic supports 3 and 4, so that when the frame 5 is subjected to thermal influence, the elastic supports 3 and 4 are thermally expanded with the metal bodies 25 and 26. Due to the difference, the pedestals 18 and 1 of the holding members 8 and 9
The whole is curved around each welding center of 9 as a fulcrum.

Therefore, on the support rod 1 side, the amount of displacement toward the fluorescent surface side can be large due to the synergistic effect of the curvature of the support rod 1 itself and the curvature of the portions of the elastic supports 3 and 4 on the support rod 1 side. .

Therefore, in this case, in order to keep the amount of displacement of the support rod 1 toward the fluorescent surface side constant, it is possible to reduce the amount of curved displacement of the support rod 1 itself, and therefore the support rod 1 itself is stable without being strained. You can expect good behavior.

1 FIG. 10 shows still another example of the grid device according to the present invention, in which a notch 27 is provided in the center of the support rod 1, and a sufficiently strong metal body 24 is placed over the notch 27. It is constructed by attaching.

In the illustrated example, the notch 27 is provided in the support rod 1, but similar notches may be provided in the mounting portions of the metal bodies 25 and 26 of both the elastic supports 3 and 4.

When the notch 27 is provided in this way, the bending action of the support rod 1 or the elastic supports 3 and 4 toward the fluorescent surface side becomes easy, so that the size of the metal body 24 or 25, 26 can be reduced. It can be made small in size and is suitable for application to small pipes.

As described above, according to the present invention, one of the support rods 1 supported by the three-point grid device and the left and right elastic supports 3 and 4 are provided with metal bodies 24 having a large coefficient of thermal expansion, respectively. By fixing 25 and 26, both support rods 1 and 2 are equally displaced toward the fluorescent surface side when the frame 5 is affected by heat, and mislanding of the beam can be avoided.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a mislanding state for explaining the present invention, FIG. 2 is a plan view showing an example of a conventional grid device, FIG. 3 is a schematic diagram showing an operating state of the present invention, and FIG. A perspective view of the grid device according to the present invention, FIGS. 5A and 1B are diagrams showing its deformed state due to thermal expansion, FIG. 6 is a perspective view of essential parts showing another example of the grid device according to the present invention, and FIG. 8 are operational state diagrams of the frame for explaining the present invention, and FIGS. 9 and 10 are perspective views of essential parts showing still other examples of the grid device according to the present invention, respectively. 1 and 2 are support rods, 3 and 4 are elastic supports, 5 is a frame, 6 is a ribbon-shaped grid element body, and 25 and 2627 are metal bodies having a large coefficient of thermal expansion.

Claims (1)

[Claims] 1. A large number of ribbon-like grid elements are stretched over a frame consisting of a pair of support rods facing each other and a pair of elastic supports installed between the support rods, and are stretched against the inner surface of the panel of the cathode ray tube. A grid device is provided which is supported at three points on one of the support rods and both of the elastic supports, and each of the one of the support rods and both of the elastic supports has a surface opposite to the tension surface of the grid element. A cathode ray tube comprising a metal body having a larger coefficient of thermal expansion than one of the support rods and the elastic support member.