JP2001023543A - Cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cathode-ray tube restraining decrease of a correction effect on a vertical pincushion distortion by a permanent magnet caused by heat generation of a deflection yoke. SOLUTION: This cathode-ray tube is provided with a funnel 2 and a deflection yoke 1 connected to the rear of the funnel 2. Total of four fixing members are provided on the top, bottom, left and right of the connected part between the funnel 2 and the deflection yoke 1. The funnel 2 and the deflection yoke 1 are fixed each other with the fixing members 3a, 3b, and 3 after up, down, left, and right tilt adjustment (referenced as swing adjustment) for the deflection yoke 1. A permanent magnet 5a is arranged on an end part of the fixing member 3a to correct a vertical pincushion distortion of a raster image. In the same manner, a permanent magnet 5b is arranged on an end part of the fixing member 3b to correct the vertical pincushion distortion of the raster image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a cathode ray tube, and more particularly, to a cathode ray tube provided with a permanent magnet for correcting a vertical pincushion distortion of a raster image, in which an arrangement of the permanent magnet is improved. It is about.

[0002]

2. Description of the Related Art FIG. 8 is a side view showing a part of a structure of a conventional cathode ray tube. As shown in FIG. 8, a conventional cathode ray tube includes a funnel 102 and a funnel 102.
And a deflection yoke 101 connected to the rear of the device. At the connecting portion between the funnel 102 and the deflection yoke 101, a total of four fixing members 103 made of an insulator are provided on the upper, lower, left and right sides.
1 are fixed to each other by a fixing member 103 after adjusting the tilting of the deflection yoke 101 up and down and left and right (so-called swing adjustment). The funnel 102 has an anode 104, and the deflection yoke 101 has a vertical deflection coil and a horizontal deflection coil (not shown) for deflecting the electron beam in the vertical and horizontal directions, respectively.

The funnel 10 of the deflection yoke 101
Above and below the opening on the second side, a permanent magnet 105 for correcting the upper and lower pincushion distortion (also referred to as "upper and lower pincushion distortion") of the raster image, and a VLMF coil for reducing the leakage magnetic field (leakage magnetic field cancellation) Coil 106). The VLMF coil 106 is arranged in a state of being wound a predetermined number of turns so as to surround the permanent magnet 105. Further, a cover 107 that covers a substrate (not shown) attached to the upper part of the deflection yoke 101 is arranged on the deflection yoke 101.

FIG. 9 shows a permanent magnet 10 of a deflection yoke 101.
FIG. 9 is a cross-sectional view illustrating a cross-sectional structure when a portion where a reference numeral 5 is arranged is viewed from an arrow Y direction illustrated in FIG. 8. Permanent magnet 1
If the pixels 05 are not arranged vertically, the distance from the center of deflection to the phosphor screen becomes longer in the upper and lower parts of the raster image, and therefore, a large pincushion distortion of 1 mm or more occurs in the raster image. However, by arranging the permanent magnets 105 vertically as shown in FIG. 9, the magnetic flux 108 generated by the permanent magnets 105 causes the upper and lower barrel directions (that is, upward in the upper part of the raster image, downward in the lower part of the raster image). ), The electron beam can be deflected, as shown in FIG.
A good raster image without upper and lower pincushion distortion can be obtained.

The permanent magnets 105 arranged vertically are
Is generated at the top and bottom of the raster image.
It also has a function of correcting vertical misconvergence of d and Blue.

[0006]

However, in such a conventional cathode ray tube, a permanent magnet 105 is provided with a deflection yoke 101.
Due to the arrangement above and below the opening, there is the following problem.

The deflection yoke 101 has a VL shown in FIG.
An MF coil 106, and vertical and horizontal deflection coils (not shown) are arranged. For this reason, the deflection yoke 101 generates heat due to the continuous operation of the cathode ray tube. However, the permanent magnets 105 are arranged above and below the opening of the deflection yoke 101, and the heat radiation effect is low due to the presence of the cover 107. The permanent magnet 105 is the deflection yoke 1
01 is easily affected by heat generation.

Accordingly, the temperature of the permanent magnet 105 gradually increases due to the continuous operation of the cathode ray tube, the magnetic flux 108 weakens, and the force for deflecting the electron beam in the vertical direction is reduced. There is a problem that the effect of correcting the cushion distortion is reduced.

FIG. 11 is a view showing a raster image in which upper and lower pincushion distortions have occurred due to a rise in the temperature of the permanent magnet 105. FIG. 12 shows a state in which a 17-inch cathode ray tube is mounted in a chassis. 9 is a graph showing a measurement result obtained by actually measuring a vertical pincushion distortion amount K with respect to a temperature change amount of a magnet 105. When the operation of the cathode ray tube starts (that is,
At the time when the temperature change amount is zero in FIG. 12), the upper and lower pincushion distortion amount K is zero, and the raster image at this time is a good raster having no upper and lower pincushion distortion as shown in FIG. 10. It becomes an image. The upper and lower pincushion distortion K increases substantially in proportion to the temperature change of the permanent magnet 105. For example, when the temperature change is 50 ° C., the upper and lower pincushion distortion K is about 0.5 mm. I have.

The present invention has been made in order to solve such a problem, and provides a cathode ray tube capable of suppressing a decrease in the effect of correcting a vertical pincushion distortion caused by permanent magnets caused by heat generated from a deflection yoke. The purpose is to do so.

[0011]

Means for Solving the Problems Claim 1 of the present invention
Has a funnel, a deflection yoke connected to the funnel, and a magnet for correcting upper and lower pincushion distortion of the raster image, the magnet is closer to the funnel than the connection end face between the funnel and the deflection yoke. It is characterized by being arranged.

A cathode ray tube according to a second aspect of the present invention is the cathode ray tube according to the first aspect, wherein the cathode ray tube is disposed at a connection portion between the deflection yoke and the upper and lower outer surfaces of the funnel, respectively. It further comprises first and second fixing members for fixing the deflection yoke and the funnel to each other, and the magnet is arranged on the first and second fixing members, respectively. .

According to a third aspect of the present invention, the cathode ray tube is the cathode ray tube according to the first aspect, wherein the magnets are respectively disposed on the upper outer surface and the lower outer surface of the funnel. It is a feature.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a side view partially showing a structure of a cathode ray tube according to Embodiment 1 of the present invention, and FIG. 2 is an enlarged perspective view showing a connecting portion between a deflection yoke 1 and a funnel 2. It is. The cathode ray tube according to the first embodiment includes a funnel 2 and a deflection yoke 1 connected to a rear portion of the funnel 2. At a connection portion between the funnel 2 and the deflection yoke 1, a total of four fixing members made of an insulator are provided in the vertical and horizontal directions. However, in FIGS. 1 and 2, among the four fixing members, the fixing member 3 a arranged at the connecting portion between the deflection yoke 1 and the upper outer surface of the funnel 2 and the lower part of the deflection yoke 1 and the outer surface of the funnel 2 are connected. Only one of the fixing member 3b disposed at the connection portion and one of the two fixing members 3 disposed at the connection portion between the deflection yoke 1 and the outer surface side of the funnel 2 appear. The funnel 2 and the deflection yoke 1 are adjusted after tilting the deflection yoke 1 up, down, left and right (so-called swinging adjustment).
The members are fixed to each other by the fixing members 3a, 3b, 3.
The funnel 2 has an anode 4 and a deflection yoke 1
Has a vertical deflection coil and a horizontal deflection coil (not shown) for deflecting the electron beam in the vertical and horizontal directions, respectively.

VLMF coils 6 for reducing the leakage magnetic field are arranged above and below the opening of the deflection yoke 1 on the funnel 2 side, and are mounted on the deflection yoke 1 above the deflection yoke 1. A cover 7 that covers a substrate (not shown) is disposed.

FIG. 3 is an enlarged perspective view showing the structure of the fixing member 3a. At an end of the fixing member 3a, a permanent magnet 5a for correcting vertical pincushion distortion of a raster image is disposed. Such a fixing member 3a
Can be formed by processing the end of the conventional fixing member 103 shown in FIG. 8 into a predetermined shape. Further, as shown in FIG. 1, a permanent magnet 5b is similarly arranged at an end of the fixing member 3b. In the design stage of the deflection yoke 1, the sizes and shapes of the permanent magnets 5a and 5b are taken into consideration in consideration of upper and lower pincushion distortion and convergence.
By appropriately adjusting the magnetic force and the like, the permanent magnets 5a and 5b can have the same function as the conventional permanent magnet 105 shown in FIG. For example, the size and shape of the permanent magnets 5a and 5b vary depending on the size and type of the cathode ray tube, the system configuration of the deflection yoke 1, and the like.

FIG. 4 shows the permanent magnets 5a and 5 of the funnel 2.
FIG. 2 is a cross-sectional view illustrating a cross-sectional structure when a portion where “b” is disposed is viewed from a direction of an arrow X illustrated in FIG. 1. Permanent magnet 5
By arranging the permanent magnets 5a, 5b vertically,
The electron beam can be deflected in the upper and lower barrel directions by the magnetic flux 9 generated by 5b, whereby a good raster image without upper and lower pincushion distortion as shown in FIG. 10 can be obtained.

As described above, according to the cathode ray tube according to the first embodiment, the permanent magnets 5a and 5b for correcting the upper and lower pincushion distortion of the raster image are not fixed to the upper and lower portions of the opening of the deflection yoke 1, but are fixed. It was arranged on the members 3a and 3b.
Therefore, as compared with the conventional permanent magnet 105 shown in FIG. 8, the influence of the heat generated from the deflection yoke 1 on the permanent magnets 5a and 5b can be reduced, and the heat generated from the deflection yoke 1 can be reduced. It is possible to suppress a decrease in the effect of correcting the vertical pincushion distortion due to the permanent magnets 5a and 5b. Specifically, when the 17-inch cathode ray tube is mounted in the chassis and the pincushion distortion of the deflection yoke 1 with respect to the temperature change is measured, the numerical value is reduced by about 40% compared with the conventional cathode ray tube. It has been confirmed that it was done.

As a countermeasure against the temperature rise of the permanent magnet, a heat radiating member made of aluminum is replaced with a conventional permanent magnet 10.
5 is also conceivable. However, in fact, since the heat generated from the substrate, the copper wire, the core, etc. of the deflection yoke 1 is large, the heat radiation from the heat radiation member alone is not enough.
The cathode ray tube according to the first embodiment is larger. On the other hand, it is possible to increase the heat radiation effect by increasing the surface area of the heat radiation member, but it is not practical because the material is aluminum, which increases the cost.

Embodiment 2 FIG. 5 is a side view showing a part of the structure of the cathode ray tube according to the second embodiment of the present invention, and FIG. 6 is an enlarged perspective view showing a connecting portion between the deflection yoke 1 and the funnel 2. It is. At the connecting portion between the funnel 2 and the deflection yoke 1, a total of four fixing members 3 made of an insulator are provided on the upper, lower, left and right sides, similarly to the conventional cathode ray tube shown in FIG. Further, fixing members 8a and 8b each having a predetermined shape are arranged on the upper and lower outer surfaces of the funnel 2, respectively.

FIG. 7 is an enlarged perspective view showing the structure of the fixing member 8a. The fixing member 8a includes a permanent magnet 5 for correcting a vertical pincushion distortion of a raster image.
a is arranged. Further, as shown in FIG. 5, a permanent magnet 5b is similarly arranged on the fixing member 8b. As in the first embodiment, in the design stage of the deflection yoke 1, the size, shape, magnetic force, and the like of the permanent magnets 5a and 5b are appropriately adjusted in consideration of vertical pincushion distortion, convergence, and the like. The permanent magnets 5a and 5b can have the same function as the conventional permanent magnet 105 shown in FIG. Other structures of the cathode ray tube according to the second embodiment are the same as those of the cathode ray tube according to the first embodiment shown in FIG.

As described above, according to the cathode ray tube according to the second embodiment, the fixing members 8a and 8b are disposed on the upper and lower outer surfaces of the funnel 2, respectively. Then, the permanent magnets 5a and 5b for correcting the vertical pincushion distortion of the raster image are provided not on the upper and lower portions of the opening of the deflection yoke 1 but on the upper and lower outer surfaces of the funnel 2 via the fixing members 8a and 8b. Respectively. Therefore,
As compared with the conventional permanent magnet 105 shown in FIG. 8, the influence of the heat generated from the deflection yoke 1 on the permanent magnets 5a and 5b can be reduced, and the permanent magnet generated due to the heat generated from the deflection yoke 1 can be reduced. It is possible to suppress a decrease in the effect of correcting the upper and lower pincushion distortion due to 5a and 5b. Specifically, when the 17-inch cathode ray tube is mounted in the chassis and the amount of vertical pincushion distortion with respect to the temperature change of the deflection yoke 1 is actually measured, the same as the cathode ray tube according to the first embodiment, the conventional cathode ray tube is used. 4 numerically compared to pipe
It has been confirmed that it has been reduced by about 0%.

[0023]

According to the first aspect of the present invention, since the magnet is hardly affected by the heat generated from the deflection yoke, the temperature rise of the magnet due to the heat generated from the deflection yoke can be reduced. As a result, it is possible to suppress a decrease in the correction effect of the upper and lower pincushion distortion caused by the temperature rise of the magnet.

According to the second aspect of the present invention, the first and second fixing members can be formed by processing an existing fixing member. Without providing, the magnets can be arranged on the first and second fixing members, respectively.

According to the third aspect of the present invention, the magnets can be arranged at arbitrary positions on the upper and lower outer surfaces of the funnel, so that the magnet can be sufficiently separated from the deflection yoke as a heat source. A magnet can be arranged at a remote place.

[Brief description of the drawings]

FIG. 1 is a side view partially showing a structure of a cathode ray tube according to Embodiment 1 of the present invention.

FIG. 2 is an enlarged perspective view showing a connection portion between a deflection yoke 1 and a funnel 2;

FIG. 3 is an enlarged perspective view showing a structure of a fixing member 3a.

FIG. 4 is a cross-sectional view showing a cross-sectional structure of a portion of the funnel 2 where the permanent magnets 5a and 5b are arranged, as viewed from the direction of arrow X shown in FIG.

FIG. 5 is a side view showing a partially extracted structure of a cathode ray tube according to a second embodiment of the present invention.

FIG. 6 is an enlarged perspective view showing a connecting portion between the deflection yoke 1 and the funnel 2;

FIG. 7 is an enlarged perspective view showing a structure of a fixing member 8a.

FIG. 8 is a side view showing a part of the structure of a conventional cathode ray tube extracted.

FIG. 9 is a cross-sectional view showing a cross-sectional structure of a portion of the deflection yoke 101 where the permanent magnets 105 are arranged, as viewed from the direction of arrow Y shown in FIG.

FIG. 10 is a diagram showing a favorable raster image without upper and lower pincushion distortion.

FIG. 11 is a diagram showing a raster image in which upper and lower pincushion distortions have occurred due to a temperature rise of the permanent magnet 105.

FIG. 12 is a graph showing a measurement result obtained by actually measuring a vertical pincushion distortion amount K with respect to a temperature change amount of a permanent magnet 105;

[Explanation of symbols]

1 deflection yoke, 2 funnel, 3a, 3b, 8a,
8b Fixing member, 5a, 5b Permanent magnet.

Claims (3)

[Claims] 1. A funnel, a deflection yoke connected to the funnel, and a magnet for correcting upper and lower pincushion distortions of a raster image, wherein the magnet is more than a connecting end face between the funnel and the deflection yoke. A cathode ray tube, which is arranged on a funnel side. A first and a second fixing member for fixing the deflection yoke and the funnel to each other, the first and second fixing members being disposed at a connection portion between the deflection yoke and the upper and lower outer surfaces of the funnel, respectively. The cathode ray tube according to claim 1, wherein the magnet is disposed on each of the first and second fixing members. 3. The cathode ray tube according to claim 1, wherein the magnet is disposed on an upper portion of an outer surface and a lower portion of the outer surface of the funnel.