JP2003178689A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device using a cathode-ray tube capable of realizing excellent high definition by restraining the variation of electron beam start caused by external magnetic field in a tube axis direction by improving magnetic shield effect, reducing electron beam drift, and reducing color drift compared to a conventional display device. <P>SOLUTION: A skirt part located at an upper-lower part of an inner magnetic shield 12 is extended from an color selection electrode 20 to a display panel side and bent to contact the color selection electrode 20 so that a part having a low magnetic resistance is inserted in parallel with a welded part of an angle 21a and the color selection electrode 20 and thus the magnetic resistance in the cathode-ray tube in the tube shaft direction is reduced collectively. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cathode ray tube (hereinafter,
It is called "CRT". And a display device such as a television.

[0002]

2. Description of the Related Art Generally, in a CRT, an electron beam emitted from an electron beam emitting means such as an electron gun passes through pores of a color selection electrode and is landed on a phosphor.
Emits one of the predetermined colors of red, green, and blue.

Hereinafter, referring to FIGS. 14 to 18,
A display device including a conventional CRT, for example, a color television will be described. Each figure shows only the structure closely related to the change of the orbit of the electron beam due to the external magnetic field of the color television.

In the conventional color television shown in FIG. 14, a color selection electrode assembly including a color selection electrode 20 and a frame 21 is provided between a display panel 10 having a phosphor screen and an electron gun 13. Further, the color television includes an external magnetic field shield structure 18 including the color selection electrode structure and the internal magnetic shield 12. Further, the color television includes the funnel 14 joined to the display panel 10 so as to cover the electron gun 13 and the external magnetic field shield structure 18, and the explosion-proof band 1.
5 and a degaussing coil 16 arranged in the funnel 14.

FIG. 15 is a side view of the conventional display device shown in FIG. 14, in which a color selection electrode 20 and an angle 21a which are housed inside the CRT and are not normally visible.
3 is a side view showing the side projection positions of the upper and lower inner magnetic shields 12 in the side view of the display device and showing the positional relationship between the degaussing coil 16 and the external magnetic field shield structure 18. FIG.

As shown in FIG. 16, a shadow mask structure 11a can be exemplified as a typical color selection electrode structure composed of the color selection electrode 20 and the frame 21. This shadow mask structure 11a is one in which a color selection electrode 20 having a large number of pores formed therein is curved into a predetermined shape by press working and is fixed to a frame 21 by welding. In order to flatten the screen of the CRT, it is necessary to bring the shadow mask structure (color selection electrode) close to flat, but the amount of deformation due to thermal expansion of the shadow mask caused by the temperature rise due to the collision of the electron beam is The shadow mask may increase as it approaches a flat shape, and the positional relationship with the phosphor may shift to impair its function.

As a solution to this inconvenience, as shown in FIG. 17, as a color selection electrode structure, a tension is applied only in the vertical direction of the screen to the color selection electrode 20 in which a large number of pores are formed. A method using a so-called tension mask structure 11b for fixing is proposed. According to this method, the tension mask 11b in the tensioned state absorbs the expansion caused by the thermal expansion caused by the collision of the electron beam and prevents the deformation.

However, when the electron beam receives an external magnetic field such as terrestrial magnetism from the electron gun 13 to the phosphor screen of the display panel 10, the electron beam undergoes Lorentz force, its orbit changes, and the original landing occurs. Landing is performed at a point deviated from the point, and a part or all of the beam spot hits a phosphor different from the phosphor to emit light, causing so-called color shift.

In order to suppress the color shift, an internal magnetic shield 12 is provided, and an external magnetic field shield structure 18 is constituted by the internal magnetic shield 12 and the color selection electrode structure to magnetically shield the magnetic field to suppress a change in the orbit of an electron beam due to an external magnetic field. A structure that suppresses color misregistration is adopted.

The external magnetic field shield structure 18 includes an angle 21a which is a first frame made of, for example, an Fe material,
For example, the arm 21 which is the second frame made of Fe material
b, a tension mask structure 11b composed of a color selection electrode 20 composed of, for example, an Fe material, and an internal magnetic shield 12 composed of, for example, an Fe material.

The inner magnetic shield 12 usually uses a ferromagnetic metal plate whose main component is iron and has a thickness of about 0.1 mm to 0.3 mm. As shown in FIG. It has a shape and magnetically shields the geomagnetism in the electron beam passage region by the degauss operation. When the external magnetic field shield structure 18 including the color selection electrode structure such as the tension mask structure 11b is considered as a magnetic circuit, the degauss operation is performed on the external magnetic field shield structure 18 in the presence of a bias magnetic field, which causes a decaying alternating magnetic field. Is the operation of applying
This can be done by passing a damped alternating current through the degaussing coil 16. The demagnetization coil 16 has a magnetomotive force of 1000
It is about 4000 AT.

In this degauss operation, since the geomagnetism is applied as the bias magnetic field, after the degauss operation, the external magnetic field shield structure 18 including the tension mask structure 11b is more likely than the case where only the geomagnetism is present in the direction of the bias magnetic field. Also generates large magnetization. Due to the magnetization generated in the direction of the geomagnetism, a magnetic field that cancels the geomagnetism is generated inside the external magnetic field shield structure. Thereby, the magnetic shielding effect is exhibited.

[0013]

However, the magnetic resistance in the tube axis direction in the CRT is high because of the welded portion of the angle 21a, which is the first frame, and the color selection electrode 20. Therefore, it is difficult for the magnetic flux to flow from the internal magnetic shield 12 to the color selection electrode 20, and a sufficient magnetic shielding effect cannot be obtained.

In view of the above problems, the present invention has a sufficient magnetic shielding effect to enhance the effect of reducing the amount of beam deviation due to an external magnetic field in the tube axis direction, thereby reducing the color deviation as compared with the prior art and remarkably. It is an object of the present invention to provide a display device that can realize high image quality.

[0015]

The above-mentioned problems can be solved by the present invention described below.

That is, the display device of the invention according to claim 1 is
A display device comprising a cathode ray tube having an electron gun for irradiating an electron beam, a display panel for emitting light by an electron beam reaching through a color selection electrode, and an internal magnetic shield for magnetically shielding the electron beam. The skirt portions located above and below the inner magnetic shield are extended toward the display panel side from the color selection electrode.

Further, in the display device of the present invention, it is preferable that the skirt portions located above and below the inner magnetic shield are extended from the color selection electrode to the display panel side and are bent so as to contact the color selection electrode.

Further, in the display device of the present invention, it is preferable that skirt portions located above and below the inner magnetic shield are extended from the color selection electrode to the display panel side and are bent so as to face the color selection electrode with a gap. .

Further, in the display device of the present invention, the skirt portions located at the upper and lower portions of the inner magnetic shield are extended from the color selection electrode to the display panel side, and are formed by separate members, which are joined by spot welding. Is preferred.

The display device of the invention according to claim 5 is
A display device comprising: an electron gun for irradiating an electron beam; a display panel that develops color by an electron beam that reaches through a color selection electrode; and a cathode ray tube having an internal magnetic shield that magnetically shields the electron beam. , A magnetic material that connects the upper part of the inner magnetic shield to the inside of the inner magnetic shield and connects the upper part of the color selection electrode, and the lower slope of the inner magnetic shield to the inside of the inner magnetic shield to connect the color selection electrode It is characterized in that a magnetic material for connecting the lower part of the is inserted.

In the display device of the present invention, the magnetic material connecting the upper slope portion of the inner magnetic shield to the upper portion of the color selection electrode and the lower slope portion of the inner magnetic shield to the inner magnetic shield. It is preferable that a magnetic material that connects the lower portion of the color selection electrode is inserted through the inside.

In the display device of the present invention, a magnetic body connecting the upper slope portion of the inner magnetic shield to the upper portion of the color selection electrode through the inner side of the inner magnetic shield, and the lower slope portion of the inner magnetic shield to the inner portion. It is preferable that the magnetic permeability of the magnetic material that passes through the inside of the magnetic shield and connects the lower portion of the color selection electrode is higher than that of the internal magnetic shield.

[0023]

According to the display device of the first aspect of the invention, the first frame has the structure in which the skirt portions located at the upper and lower portions of the inner magnetic shield are extended from the color selection electrode toward the display panel. It is considered that a portion having a small magnetic resistance was inserted in parallel with the welding portion of the angle and the color selection electrode. Therefore, the magnetic resistance in the tube axis direction in the CRT becomes small in total. As a result, the magnetic flux absorbed from the electron gun side opening of the internal magnetic shield flows to the color selection electrode, avoiding the angle and the welded portion of the color selection electrode, which is the first frame having particularly high magnetic resistance. Therefore, the magnetic shielding effect is enhanced, the change of the electron beam trajectory due to the external magnetic field in the tube axis direction can be suppressed, and the electron beam deviation can be reduced.

According to the display device of the fourth aspect of the present invention, since the magnetic resistance of the welded portion does not increase, the upper and lower skirt portions are further attached while being extended to the display panel side from the color selection electrode. It has the effect of facilitating.

According to the display device of the fifth aspect of the present invention, by inserting the magnetic material, it is considered that a portion having a small magnetic resistance is inserted in parallel with the welding portion of the angle and the color selection electrode which is the first frame. Be done. Therefore, the magnetic resistance in the tube axis direction in the CRT becomes small in total. As a result, the magnetic flux absorbed from the electron gun side opening of the internal magnetic shield flows to the color selection electrode, avoiding the angle and the welded portion of the color selection electrode, which is the first frame having particularly high magnetic resistance. Therefore, the magnetic shielding effect is enhanced, the change of the electron beam trajectory due to the external magnetic field in the tube axis direction can be suppressed, and the electron beam deviation can be reduced.

According to the display device of the sixth aspect of the present invention, the lower slope portion of the inner magnetic shield and the magnetic body connecting the upper portion of the inner magnetic shield from the upper slope portion of the inner magnetic shield to the upper portion of the color selection electrode. Insert a magnetic material that connects the lower part of the color selection electrode through the inside of the internal magnetic shield, and insert a small magnetic resistance part in parallel with the angle of the first frame and the welded part of the color selection electrode. Considered to have been done. Therefore, the magnetic resistance in the tube axis direction in the CRT becomes small in total. As a result, the magnetic flux absorbed from the electron gun side opening of the internal magnetic shield flows to the color selection electrode, avoiding the angle and the welded portion of the color selection electrode, which is the first frame having particularly high magnetic resistance. For this reason,
The magnetic shielding effect is enhanced, the change of the electron beam trajectory due to the external magnetic field in the tube axis direction can be suppressed, and the electron beam deviation can be reduced. Furthermore, from the upper slope of the inner magnetic shield to the inside of the inner magnetic shield, the part of the magnetic material that connects the upper part of the color selection electrode and the lower slope of the inner magnetic shield to the inside of the inner magnetic shield, By providing a protrusion on the part of the magnetic material that connects the lower part of the selection electrode so that it is perpendicular to the electron beam, the electrons hitting this protrusion are either reflected by the electron gun side or absorbed by the protrusion. Thus, it is possible to suppress halation that causes the electron beam to be reflected and scattered on the effective screen to cause deterioration of the displayed image.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION In order to facilitate understanding of the present invention, the present invention will be described below with reference to embodiments.

In each drawing, only the structure relating to the change in the orbit of the electron beam due to the external magnetic field of the color television as the embodiment is shown. As the display device, a color television having a CRT is illustrated.

(Embodiment 1) As shown in the exploded perspective view of FIG. 1, a color television which is a display device according to a first embodiment of the present invention displays a display panel 10 having a phosphor screen and an electron beam. A tension mask structure 1 which is a color selection electrode structure is formed between the electron gun 13 and the electron gun 13 which is emitted toward the panel 10.
An external magnetic field shield structure 18 composed of 1b and an internal magnetic shield 12 is provided. Further, the funnel 14, the neck 19, and the funnel 14 which are joined to the display panel 10 so as to cover the electron gun 13 and the external magnetic field shield structure 18.
And a degaussing coil 16 disposed above and below the. Further, the tension mask structure 11b includes a color selection electrode 20 and a frame 21 that supports the end sides of the color selection electrode 20 in a state where tension P is applied.
1 is a first frame 21a that supports the color selection electrode 20.
And a second frame 21b supporting the first frame 21a
Composed of and. Further, the electron beam emitted from the electron gun 13 passes through the pores of the color selection electrode 20 and is landed on the phosphor screen of the display panel 10 to emit any one of red, green and blue colors. Make it glow.

Further, FIG. 2A shows a color selection electrode 20 which cannot be normally seen because it is housed inside the CRT of the display device according to the first embodiment shown in FIG.
The side projection positions of the angle 21a and the upper and lower inner magnetic shields 12 are shown in the side view of the display device, and the degaussing coil 1
6 shows the positional relationship between 6 and the external magnetic field shield structure 18. Further, FIG. 2B is a rear view showing the arrangement state of the degaussing coil in FIG. The demagnetizing coil has a magnetomotive force of 2
It is 300 AT.

Next, the external magnetic field shield structure 18 will be described. The external magnetic field shield structure 18 is composed of a tension mask structure 11b and an internal magnetic shield 12. This tension mask structure 11b is
The color selection electrode 20 includes a first frame that is supported in the vertical direction by applying tension and extends in the horizontal direction, and a second frame that supports the upper and lower first frames in the vertical direction. The angle 21a, which is the first frame, has a thickness of 1.4 mm, for example.
Of Fe material. The arm 2 which is the second frame
1b is made of an Fe material having a thickness of 15 mm, for example. Furthermore, the color selection electrode 20 is made of a Fe material having a thickness of 0.1 mm, for example. The inner magnetic shield 12 is made of a Fe material having a thickness of 0.15 mm, for example.

The color selection electrode 20 forming the tension mask structure 11b will be described.

In this display device, the edge of the color selection electrode 20 is supported by a tension of about 80 to 160 kg so that the color selection electrode 20 approaches a flat surface in order to make the screen flat. The expansion of thermal expansion that is increased by the collision is absorbed, and the deformation of the color selection electrode 20 is prevented. However, the relative magnetic permeability of the color selection electrode 20 is about 500 before the tension is applied, but is lowered to about 200 by the tension. For this reason,
Color selection electrode 20 more than when supported without applying tension
It is difficult for the magnetic flux to flow, and it is difficult to magnetize enough to cancel the geomagnetism. Further, the edge of the color selection electrode 20 and the angle 21a, which is the first frame, are welded, and the magnetic resistance in the tube axis direction is high.

Furthermore, the explosion-proof band 15 has a high magnetic permeability, a width of 5% to 20% of the diagonal dimension of the display panel 10, and is arranged so as to surround the color selection electrode 20. The 29-inch CRT has a diagonal dimension of 664 mm, and the explosion-proof band has a width of 55 mm, a thickness of 1.0 mm, and a relative magnetic permeability of about 3
000 Fe material.

Further, FIG. 3 shows the internal magnetic shield 12 and
A first frame 21a supporting the color selection electrode 20, and a first frame 21a
It is a perspective view which shows the positional relationship with the 2nd frame 21b which supports the frame 21a.

In this display device, the skirt portions located at the upper and lower portions of the inner magnetic shield 12 are extended by 0.1 mm from the color selection electrode 20 to the display panel 10 side, and a bent portion of 5 mm is formed so as to come into contact with the color selection electrode 20. 40 is provided.

Next, in this display device, the skirt portions located above and below the inner magnetic shield 12 are extended from the color selection electrode 20 to the display panel side, and the bent portion 40 is provided so as to be in contact with the color selection electrode. The details of the effect by will be described.

It is considered that a portion having a small magnetic resistance is inserted in parallel with the welded portion 50 of the angle 21a, which is the first frame, and the color selection electrode 20. Therefore, the CRT
The magnetic resistance in the inner tube axis direction is reduced in total. As a result, the magnetic flux sucked from the opening of the inner magnetic shield 12 on the electron gun 13 side avoids the welded portion 50 between the angle 21a and the color selection electrode 20, which is the first frame having particularly high magnetic resistance, and performs color selection. It flows to the electrode 20. Therefore, the magnetic shielding effect is enhanced, the change of the electron beam trajectory due to the external magnetic field in the tube axis direction can be suppressed, and the electron beam deviation can be reduced.

Here, in this display device, the skirt portions located above and below the inner magnetic shield 12 are extended from the color selection electrode 20 to the display panel side, and the color selection electrode 20
In order to further clarify the effect of bending so that the inner magnetic shield 12 comes into contact with, the comparison with the conventional example in which the upper and lower skirt portions of the inner magnetic shield 12 are not extended to the display panel side is shown below.

When the internal magnetic shield of the conventional example shown in FIG. 14 and the internal magnetic shield 12 shown in FIG. 3 are set, the color selection electrode 20 after the degauss operation is performed.
Numerical analysis was performed on the beam deviation amount in the above. In the above numerical analysis, the non-linear magnetic field analysis was performed by the three-dimensional finite element method considering the hysteresis magnetic characteristics of the magnetic material by the curling model theory, and the analysis region was about 250.
It is divided into finite elements of 000. Further, as shown in FIG. 5, the beam deviation analysis point is the color selection electrode 20.
There are 26 points at equal intervals from the center of the upper side portion toward the end.
As shown in FIG. 6, the beam deviation amount is reduced by 13 μm on average as compared with the case where the skirt portions located above and below the inner magnetic shield 12 are not bent.

(Second Embodiment) As compared with the display device according to the first embodiment, the display device according to the second embodiment of the present invention is, as shown in FIG. By extending the skirt portion located at the position of 0.1 mm from the color selection electrode 20 to the display panel 10 side,
The difference is that there is no bent part.

Next, in this display device, the effect obtained by extending the skirt portions located above and below the inner magnetic shield 12 from the color selection electrode 20 to the display panel side will be described in detail.

Since the skirt portions located above and below the inner magnetic shield 12 are extended from the color selection electrode 20 to the display panel 10 side, the angle 21a, which is the first frame, and the color selection electrode 20 are welded. It is considered that a portion having a small magnetic resistance is inserted in parallel with the portion 50. Therefore, the magnetic resistance in the tube axis direction in the CRT becomes small in total. As a result, the electron gun 1 of the inner magnetic shield 12
The magnetic flux sucked from the opening on the side of 3 has the angle 21a and the color selection electrode 2 which are the first frame having particularly high magnetic resistance.
It flows to the color selection electrode 20 while avoiding the welded portion 50 with 0. Therefore, the magnetic shielding effect is enhanced, the change of the electron beam trajectory due to the external magnetic field in the tube axis direction can be suppressed, and the electron beam deviation can be reduced.

Here, in this display device, in order to further clarify the effect of extending the skirt portions located above and below the inner magnetic shield 12 from the color selection electrode 20 to the display panel side, the inner magnetic shield 12 is made clear. The following is a comparison with the conventional example in which the upper and lower skirts of the above are not extended to the display panel side. When the internal magnetic shield of the conventional example shown in FIG. 14 and the internal magnetic shield 12 shown in FIG. 7 were respectively set, a numerical analysis was performed on the beam shift amount in the color selection electrode 20 after the degauss operation. The above-mentioned numerical analysis is performed by taking the hysteresis magnetic characteristics of the magnetic material into consideration by the curling model theory, performing a non-linear magnetic field analysis by the three-dimensional finite element method, and dividing the analysis region by about 250,000 finite elements. Further, as shown in FIG. 5, the beam deviation analysis points are 26 at equal intervals from the center to the end of the upper side of the color selection electrode 20.
It is a point. As compared with the conventional one, as shown in FIG.
The beam shift amount is reduced by m.

(Third Embodiment) A display device according to a third embodiment of the present invention is different from the display device according to the second embodiment in that, as shown in FIG.
With reference to the opening on the side of the electron gun 13, the upper and lower slope portions having a height of 100 mm pass through the inside of the inner magnetic shield 12 to connect the upper and lower sides of the color selection electrode 20, and the width on the side of the electron gun 13 is Magnetic body 4 having a width of 200 mm, a width on the color selection electrode 20 side of 250 mm, and a height of 80 mm
The difference is that 1 is inserted.

Next, in this display device, the magnetic material 41
The effect of inserting is explained.

By inserting this magnetic body 41, as shown in FIG.
It is considered that a portion having a low magnetic resistance is inserted in parallel with the welded portion 50 of the angle 21a, which is the first frame, and the color selection electrode 20, as shown in FIG. Therefore, the CRT
The magnetic resistance in the inner tube axis direction is reduced in total. As a result, the magnetic flux sucked from the opening of the inner magnetic shield 12 on the electron gun 13 side avoids the welded portion 50 between the angle 21a and the color selection electrode 20, which is the first frame having particularly high magnetic resistance, and performs color selection. It flows to the electrode 20. Therefore, the magnetic shielding effect is enhanced, the change of the electron beam trajectory due to the external magnetic field in the tube axis direction can be suppressed, and the electron beam deviation can be reduced.

Here, in this display device, the magnetic material 4
In order to further clarify the effect of inserting 1, the comparison with the conventional example in which the magnetic body 41 is not inserted is shown below. When the internal magnetic shield of the conventional example shown in FIG. 14 and the internal magnetic shield 12 shown in FIG. 10 were set, numerical analysis was performed on the beam shift amount in the color selection electrode 20 after the degauss operation. In addition,
In the above-mentioned numerical analysis, the hysteresis magnetic property of the magnetic material is taken into consideration by the curling model theory, and the non-linear magnetic field analysis is performed by the three-dimensional finite element method.
It is divided by zero finite elements. Further, as shown in FIG. 5, the beam deviation analysis points are 26 points at equal intervals from the center to the end of the upper side of the color selection electrode 20. As compared with the case where the magnetic body 41 is not inserted into the internal magnetic shield 12, the beam shift amount is reduced by 3 to 10 μm as shown in FIG.

(Embodiment 4) The display device according to the fourth embodiment of the present invention is compared with the display device according to the third embodiment, as shown in FIG.
With reference to the opening on the side of the electron gun 13, the upper and lower slope portions having a height of 100 mm pass through the inside of the inner magnetic shield 12 to connect the upper and lower sides of the color selection electrode 20, and the width on the side of the electron gun 13 is Magnetic body 4 having a width of 200 mm, a width on the color selection electrode 20 side of 250 mm, and a height of 80 mm
1 is inserted, and a protrusion 42 having a width of 250 mm is provided at a position of a height of 35 mm with respect to the color selection electrode 20 side of the magnetic body 41 so as to be perpendicular to the electron beam trajectory 17.

Next, in this display device, the magnetic material 41
The effect of inserting the protrusion and providing the protrusion 42 will be described.

By inserting this magnetic body 41, as shown in FIG.
It is considered that a portion having a low magnetic resistance is inserted in parallel with the welded portion 50 of the angle 21a, which is the first frame, and the color selection electrode 20, as shown in FIG. Therefore, the CRT
The magnetic resistance in the inner tube axis direction is reduced in total. As a result, the magnetic flux absorbed from the opening of the inner magnetic shield on the electron gun 13 side has a welded portion 50 between the angle 21a and the color selection electrode 20, which is the first frame having particularly high magnetic resistance.
And flow to the color selection electrode 20. Therefore, the magnetic shielding effect is enhanced, the change of the electron beam trajectory due to the external magnetic field in the tube axis direction can be suppressed, and the electron beam deviation can be reduced. Further, by providing the protrusion 42, the protrusion 4
Since the electron hitting 2 is reflected by the electron gun 13 side or absorbed by the protrusion 42, the electron beam is reflected and scattered on the effective screen, and halation that causes deterioration of the image on the display device does not occur.

In each of the above embodiments, the case where the internal magnetic shield 12 made of Fe material is used has been described as an example, but it is also applicable to the display device using the internal magnetic shield made of other magnetic material such as permalloy material. Applicable.

Further, in each of the above embodiments, the 29-inch color television is described as an example, but the present invention can be applied to a display device using another inch-sized cathode ray tube.

In each of the above embodiments, the color television is described as an example, but the present invention is not limited to this, and can be applied to a display device using a cathode ray tube such as a CRT display monitor.

[0055]

According to the display device of the first aspect of the present invention,
The skirts located above and below the internal magnetic shield are extended from the color selection electrode to the display panel side, and it is transmitted that a small magnetic resistance portion is inserted in parallel with the angle of the first frame and the welded portion of the color selection electrode. Achieved a unique configuration, C
The magnetic resistance in the tube axial direction inside the RT is totally reduced, and the magnetic flux absorbed from the electron gun side opening of the internal magnetic shield is the first frame with particularly high magnetic resistance. By avoiding this, the magnetic shielding effect can be enhanced by allowing the current to flow to the color selection electrode, the change of the electron beam trajectory due to the external magnetic field in the tube axis direction can be suppressed, and the electron beam deviation can be reduced.

According to the fifth aspect of the present invention, it is transparent that a magnetic body is inserted and a portion having a small magnetic resistance is inserted in parallel with the angle of the first frame and the welded portion of the color selection electrode. Realized, the magnetic resistance in the tube axis direction in the CRT was reduced in total, and the magnetic flux absorbed from the electron gun side opening of the internal magnetic shield was the first frame with particularly high magnetic resistance, which was the angle and color selection electrode. It is possible to improve the magnetic shielding effect by making it flow to the color selection electrode while avoiding the welded portion, to suppress the change of the electron beam trajectory due to the external magnetic field in the tube axis direction, and to reduce the electron beam deviation.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a configuration of a display device according to a first embodiment of the present invention.

FIG. 2A is a side explanatory view showing a positional relationship between the degaussing coil and the outer shield structure of the display device according to the first embodiment of the present invention, and FIG. 2B is a rear view of FIG. It is a figure.

FIG. 3 is a perspective view of an internal magnetic shield, a frame, and a color selection electrode in the display device according to the first embodiment of the present invention.

FIG. 4 is a partial cross-sectional view showing the flow of magnetic flux from the internal magnetic shield to the color selection electrode in FIG.

FIG. 5 is a diagram showing positions on a color selection electrode where a beam shift amount is calculated in the display device according to the first embodiment of the present invention.

FIG. 6 is a diagram showing a comparison result of beam shift amounts of a conventional display device and the display device according to the first embodiment of the present invention.

FIG. 7 is a perspective view of an internal magnetic shield, a frame, and a color selection electrode in the display device according to the second embodiment of the present invention.

FIG. 8 is a partial cross-sectional view showing the flow of magnetic flux from the internal magnetic shield to the color selection electrode in FIG.

FIG. 9 is a diagram showing a comparison result of beam shift amounts of a conventional display device and a display device according to a second embodiment of the present invention.

FIG. 10 is a perspective view of an internal magnetic shield and a magnetic body inserted in a display device according to a third embodiment of the present invention.

11 is a partial cross-sectional view showing the flow of magnetic flux from the internal magnetic shield to the color selection electrode in FIG.

FIG. 12 is a diagram showing a comparison result of beam shift amounts of a conventional display device and a display device according to a third embodiment of the present invention.

FIG. 13 is a partial cross-sectional view showing an internal magnetic shield and a frame, a color selection electrode, a magnetic body inserted, and a magnetic flux flow from the internal magnetic shield to the color selection electrode in a display device according to a fourth embodiment of the present invention. Is.

FIG. 14 is an exploded perspective view showing a configuration of a conventional display device.

FIG. 15 is a side view illustrating the positional relationship between the degaussing coil and the external magnetic field shield structure in the conventional display device.

FIG. 16 is a perspective view showing a shadow mask structure in an external magnetic field shield structure of a conventional CRT.

FIG. 17 is a perspective view showing a tension mask structure in an external magnetic field shield structure of a conventional CRT.

FIG. 18 is a perspective view showing the shape of an internal magnetic shield.

[Explanation of symbols]

10 Display panel 12 Internal magnetic shield 13 electron gun 20 color selection electrode 41 Magnetic 42 Projection

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroto Inoue             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 5C031 CC01

Claims (7)

[Claims] 1. An electron gun for irradiating an electron beam (13)
And a display device including a cathode ray tube having a display panel (10) that develops color by the electron beam that has reached through the color selection electrode (20) and an internal magnetic shield (12) that magnetically shields the electron beam. The skirt portions located above and below the inner magnetic shield (12) are connected to the display panel (1) by the color selection electrode (20).
A display device which is extended to the 0) side. 2. A skirt portion located above and below the inner magnetic shield (12) extends from the color selection electrode (20) to a display panel (10) side and contacts the color selection electrode (20). The display device according to claim 1, which is bent as described above. 3. A skirt portion located above and below the inner magnetic shield (12) extends from the color selection electrode (20) to a display panel (10) side and has a gap in the color selection electrode (20). The display device according to claim 1, which is bent so as to face each other. 4. A portion of a skirt portion located above and below the inner magnetic shield (12) extending in front of the color selection electrode (20) is formed of a separate member and joined by spot welding. The display device according to any one of claims 1 to 3. 5. A display device comprising a display panel (10), an electron gun (13), a color selection electrode (20) and a cathode ray tube having an internal magnetic shield (12) for magnetically shielding an electron beam. A magnetic body (41) that connects the upper portion of the color selection electrode (20) from the upper slope portion of the inner magnetic shield (12) to the inside of the inner magnetic shield (12), and the inner magnetic shield (12). 2.) A display device, wherein a magnetic body (41) for connecting the lower portion of the color selection electrode (20) is inserted from the lower slope portion through the inside of the internal magnetic shield (12). 6. A magnetic body (41) for connecting the upper portion of the color selection electrode (20) from the upper slope portion of the inner magnetic shield (12) through the inside of the inner magnetic shield (12).
Beam and a part of the magnetic body (41) connecting the lower part of the color selection electrode (20) through the inner slope of the inner magnetic shield (12) from the lower slope part of the inner magnetic shield (12). Projection (4
The display device according to claim 5, wherein 2) is provided. 7. A magnetic body (41) for connecting the upper portion of the color selection electrode (20) from the upper slope portion of the inner magnetic shield (12) through the inside of the inner magnetic shield (12).
And a magnetic body (41) that connects the lower portion of the color selection electrode (20) from the lower slope portion of the inner magnetic shield (12) through the inner side of the inner magnetic shield (12) has an internal magnetic permeability. Higher than magnetic permeability of the shield (12).
Alternatively, the display device according to claim 6.