JP3150042B2 - Cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube, and more particularly to a color cathode ray tube having an internal magnetic shield for correcting raster distortion.

[0002]

2. Description of the Related Art Depending on software such as a personal computer, there is a case where information is displayed very frequently around the screen, as represented by windows. Therefore, a color cathode ray tube used for a display monitor or the like of a personal computer is required to display a fine image in a peripheral portion of a screen. One of the important factors that determine the image quality in the peripheral portion of the screen is raster distortion. Particularly recently, the left and right inner xen distortions and the upper and lower inner xen distortions (Japan Electronic Machinery Association standard, ED
-2101A, CRT with deflection yoke test method, 1
Rasters referred to as revised in May 989, paragraph 7.8) are each mentioned as one of the causes of image quality deterioration, and it is necessary to avoid them.

In general, the distortion of the vertical deflection magnetic field of the deflection yoke is a strong barrel distortion from the viewpoint of self-convergence. Therefore, for example, when a cross hatch pattern is projected on the screen of a cathode ray tube, the vertical lines exhibit pincushion distortion. For this reason, the correction circuit provided on the set side of the color cathode ray tube corrects the vertical line so as to be linear. However, as shown in FIG. 8, even if the vertical line 101 forming the lateral outline of the cross hatch pattern is corrected to be a straight line, the vertical line 102 at a position inward toward the center of the screen is a straight line. Pincushion distortion may remain without the shape. This is called the left and right inner xen distortion Δ. The cause of this is that the electron gun side opening 10 of the internal magnetic shield 103 shown in FIG.
This is because the barrel deflection 105 in the vertical space 104 near the vertical axis of the vertical deflection magnetic field leaking near 3a is excessive.

FIG. 10 shows the shape of the internal magnetic shield 103 when viewed from the electron gun side. The inclined planes 108 and 109 of the magnetic plate constituting the internal magnetic shield 103 form a rectangular space in the opening 103 a on the electron gun side of the internal magnetic shield 103. The vertical deflection magnetic field leaking from the screen-side opening of the deflection yoke is attracted and focused by the inclined planes 108 and 109 of the magnetic plate, and the vertical space 110 near the vertical axis of the electron gun-side opening 103a.
The magnetic field lines 112 having strong barrel distortion 111 are shown in FIG. Therefore, when the cross hatch pattern is projected on the fluorescent screen surface of the cathode ray tube, the distortion shape of the vertical line becomes the shape 113 formed by the normal line of the line of uniform magnetic force 112, and the left and right inner xen distortion Δ may occur. Understand.

On the other hand, the distortion of the horizontal deflection magnetic field of the deflection yoke is pincushion distortion from the viewpoint of self-convergence and free vertical raster distortion. However,
As shown in FIG. 12, even if the horizontal line 121 that forms the outer edge of the cross hatch pattern in the vertical direction is linear, the horizontal line 122 at a position that enters inside toward the center of the screen does not become linear. In some cases, pincushion distortion remains. This is called upper and lower inner xen distortion Λ, and the cause of this is the internal magnetic shield 1 shown in FIG.
03 of the horizontal deflection magnetic field leaking near the electron gun side opening,
Barrel distortion 125 in the horizontal space 124 near the horizontal axis
(The distortion of the horizontal deflection magnetic field near the electron gun-side opening of the internal magnetic shield is generally barrel distortion).

FIG. 14 shows the shape of the internal magnetic shield 103 as viewed from the electron gun side, similarly to FIG. The horizontal deflecting magnetic field leaking from the screen side opening of the deflecting yoke is applied to the inclined flat side surfaces 108 and 109 of the magnetic plate.
In the left and right space portions 130 near the horizontal axis of the electron-gun-side opening portion 103a, the lines of uniform magnetic force 132 having the barrel distortion 131 are exhibited. Therefore, when the cross hatch pattern is projected on the fluorescent screen surface of the cathode ray tube, the distortion shape of the horizontal line is the shape 13 formed by the normal line of the line of equal magnetic force 132.
3, which indicates that the upper and lower inner xen distortion Λ occurs.

The left and right inner xensen distortion Δ is greatly affected by the distortion of the vertical deflection magnetic field leaking to the vicinity of the opening on the electron gun side of the internal magnetic shield provided inside the color cathode ray tube. On the other hand, the upper and lower inner xen distortion Λ is greatly affected by the distortion of the horizontal deflection magnetic field leaking to the vicinity of the opening of the internal magnetic shield on the electron gun side. Therefore, these distortions can be reduced by optimizing the shape of the internal magnetic shield at the opening on the electron gun side. Regarding the shape of the internal magnetic shield, several shapes have been proposed from the viewpoint of preventing the landing characteristics from being deteriorated by the influence of an external magnetic field, which is the original purpose of the internal magnetic shield. For example, JP-A-4-188543 and JP-A-63-1
Japanese Patent Application Publication No. 08151 proposes a method of providing an arc-shaped notch on a side surface of an internal magnetic shield. This is shown in FIGS. These shapes are
It is effective in improving the left and right inner xen distortions Δ and the upper and lower inner xen distortions す る, respectively, because it prevents the deterioration of the landing characteristics and has a good effect on the distortion of the vertical deflection magnetic field or the horizontal deflection magnetic field.

[0008] As shown in FIG.
When the arc-shaped notch 107 is formed in the long-side inclined surface 106 in the electron gun-side opening of No. 03, the barrel distortion 105 in the vertical space 104 near the vertical axis of the vertical deflection magnetic field is weakened due to the nature of this shape. And the left and right inner xen distortion Δ can be reduced. On the other hand, FIG.
As shown in FIG. 5, the arc-shaped notch 12 is formed in the short-side inclined surface 126 at the electron gun-side opening of the internal magnetic shield 103.
7, the horizontal deflection magnetic field,
Barrel distortion 125 in the horizontal space 124 near the horizontal axis
Can be reduced, so that the upper and lower inner xen distortion Λ can be reduced.

[0009]

However, only by forming the arc-shaped notch 107 on the long-side inclined surface 106 in the opening 103a on the electron gun side of the internal magnetic shield 103 on the electron gun side, the internal magnetic shield 103 is not provided on the electron gun side. Opening 10
There is a problem that the effect of attracting and converging the vertical deflection magnetic field leaking to the vicinity of 3a is weak, and the magnetic field intensity required to sufficiently reduce the left and right inner xen distortions Δ cannot be secured. Similarly, only by forming the arc-shaped notch 127 on the short side inclined surface 126 in the electron gun side opening 103 a of the internal magnetic shield 103, the internal magnetic shield 1 is formed.
The horizontal focusing magnetic field leaking to the vicinity of the electron gun-side opening 103a of FIG.
However, there is a problem that the magnetic field intensity required to sufficiently reduce the magnetic field cannot be secured.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is intended to attract and converge a vertical deflection magnetic field or a horizontal deflection magnetic field leaking to the vicinity of an electron gun side opening of an internal magnetic shield. It is an object of the present invention to provide a color cathode ray tube having an internal magnetic shield that enhances the effect, secures the required magnetic field strength, and sufficiently reduces the left and right inner xen distortions Δ or the upper and lower inner xen distortions Λ.

[0011]

In order to achieve the above object, a first color cathode ray tube according to the present invention has a long side inclined surface and a short side each having a long phosphor screen side terminal edge and a short electron gun side terminal edge. A notch formed on the long-side inclined surface with the electron gun-side terminal edge as a base, and a funnel provided on each of two sides connected to the bottom of the notch. And an internal magnetic shield having a partition protruding in the direction of the inner wall. Further, the second cathode ray tube of the present invention comprises a long side inclined surface and a short side inclined surface each having a long fluorescent screen side terminal edge and a short electron gun side terminal edge. A notch provided on each of the short side inclined surfaces, and an internal magnetic shield having a partition provided on each of two sides connected to the bottom side of the notch and protruding toward an inner wall of a funnel. I do.

In each of the above configurations, the shape of the notch is preferably any one selected from a V-shape, an arc shape, and a trapezoidal shape. In the above configuration, the partition preferably has a trapezoidal shape. Further, in the above configuration, it is preferable that the partition portion protrudes substantially perpendicularly to the long side inclined surface or the short side inclined surface. Further, in the above configuration, it is preferable that the partition portion is formed by bending a long side inclined surface or a short side inclined surface. Alternatively, in the above-described configuration, it is preferable that the partition portion is formed by welding a magnetic plate to the long-side inclined surface or the short-side inclined surface.

[0013]

According to the first cathode ray tube of the present invention constructed as described above, the terminal end edge of the long side inclined surface in the electron gun side opening of the internal magnetic shield is set to the bottom side, and the fluorescent screen side. A notch is formed so that its width becomes narrower as it goes, and a partition is provided on each of two sides connected to the bottom of the notch. At the same time can reduce the barrel distortion of the leakage vertical deflection magnetic field (notch effect)
Since the magnetic field strength can be increased (partition effect), the left and right inner xensen distortions Δ can be sufficiently reduced.

On the other hand, according to the second cathode ray tube of the present invention constructed as described above, the fluorescent screen is formed by setting the terminal edge of the short side inclined surface in the electron gun side opening of the internal magnetic shield to the bottom side. A notch whose width decreases toward the side and a partition is provided on each of the two sides connected to the bottom of the notch, so that the electron gun-side opening of the internal magnetic shield is near the horizontal axis. The barrel distortion of the leaked horizontal deflection magnetic field in the space can be reduced (notch effect)
At the same time, the magnetic field strength can be increased (partition effect), so that the upper and lower inner xen distortion Λ can be sufficiently reduced.

Further, by setting the shape of the notch to any one selected from a V-shape, an arc shape and a trapezoidal shape, it is possible to obtain an optimum notch effect according to the size and shape of the cathode ray tube. Can be. Further, by forming the partition portion in a trapezoidal shape, the partition portion effect can be obtained as much as possible within a range that does not conflict with the funnel of the cathode ray tube. In addition, by making the partition portion project substantially perpendicularly to the long-side inclined surface or the short-side inclined surface, handling during processing and assembly of the internal magnetic shield is facilitated. Further, by forming the partition portion by bending the long-side inclined surface or the short-side inclined surface, the processing of the internal magnetic shield is facilitated and the material yield is improved. Or, by arranging the partition part by welding a magnetic plate to the long side inclined surface or the short side inclined surface, it is possible to cope with special shapes that cannot be pressed, etc. The effect can be obtained.

[0016]

【Example】

(First Embodiment) A first embodiment of a color cathode ray tube according to the present invention will be described with reference to FIGS. 1, 2, 3 and 4. FIG. FIG.
1 is a cross-sectional view showing the configuration of a first embodiment of a color cathode ray tube according to the present invention, FIG. 2 is a perspective view showing the configuration of an internal magnetic shield in the first embodiment, and FIG. FIG. 4 is a characteristic diagram showing a relationship between the notch depth a of the V-shaped notch formed on the surface and the left and right inner xen strains Δ. FIG. 4 fixes the notch depth of the V-shaped notch, Total length and trapezoidal distortion Δ of the trapezoidal screen arranged on the edge
FIG. 4 is a characteristic diagram showing a relationship between

In FIG. 1, a color cathode ray tube is, for example, a 41 cm (17 ″)-90 ° color cathode ray tube, and includes a funnel 1 made of glass or the like, a panel 2 made of glass or the like, and an inner surface of the panel 2. Screen, a shadow mask 3 provided substantially parallel to the fluorescent screen 8, a frame 4 for supporting the shadow mask 3, an internal magnetic shield 5, and a neck 6 of the funnel unit 1. For example, an RG emitted from an in-line type electron gun is provided.
The electron beam 7 corresponding to each of the B colors passes through a predetermined hole provided in the shadow mask 3 and reaches a phosphor on the fluorescent screen 8 corresponding to each of the RGB colors. Each phosphor irradiated with the electron beam 7 emits each color of RGB, and a color image is formed on the screen of the panel 2.

As shown in FIGS. 1 and 2, the internal magnetic shield 5 is formed by a long side inclined surface 51 and a short side inclined surface 52, and the long side inclined surface 51 has an electron gun side opening 50.
A V-shaped notch 53 having a long side end edge 50a as a bottom side is formed. The internal magnetic shield 5 is made of, for example, a mild steel plate having a thickness of 0.15 mm, and the lengths of the long side and the short side on the fluorescent screen 8 side are each 305 mm × 229 m.
m, and the length on the electron gun side is 158 mm x 12
0 mm. Also, the notch depth a of the V-shaped notch 53
= 66 mm. Each side 53a and 53b of the V-shaped notch 53 has a height b = 12 mm and a total length c = 70, respectively.
A trapezoidal partition portion 54 of mm is formed by bending at right angles to the long-side inclined surface 51 and in the direction of the inner wall of the funnel 1.

FIG. 3 shows the relationship between the notch depth a of the V-shaped notch 53 formed on the long side inclined surface 51 of the internal magnetic shield 5 and the left and right inner xen strains Δ. When the notch depth a is 66 mm, the left and right inner xen strains Δ are reduced from 2.0 mm to 1.6 mm, but the notch depth a is further increased and increases toward the fluorescent screen 8 side. Even if it does, the reduction effect is saturated. This is because the intensity of the vertical deflection magnetic field leaking from the deflection yoke gradually attenuates toward the fluorescent screen 8 of the cathode ray tube, and eventually becomes zero.

FIG. 4 shows a V-shaped notch 53 with a notch depth a fixed at 66 mm, and a total length c of a trapezoidal partition part 54 having a height b of 12 mm and left and right inners disposed at the left and right edges thereof. It shows the relationship with xen distortion. When the total length c is 70 mm, the left and right inner xen strains are 2.
Although it is reduced from 0 mm to 0.5 mm, the reduction effect is saturated even if the total length c is further increased toward the screen surface due to the attenuation of the vertical deflection magnetic field. Here, the reason why the height b of the trapezoidal partition 54 is fixed to 12 mm is that the height b is set to the maximum possible height in consideration of the contact with the inner wall of the funnel. It should be noted that as the height b is increased, the effect of inducing and condensing the vertical deflection magnetic field leaking from the deflection yoke is increased.

As described above, the left and right sides 5 of the V-shaped notch 53 formed on the long side inclined surface 51 of the internal magnetic shield 5.
By adding the trapezoidal partitions 54 to the edges of 3a and 53b, the effect of reducing the left and right inner xen distortion Δ is reduced by 20%.
It can be seen that this is greatly improved to 75%.

(Second Embodiment) A color cathode ray tube according to a second embodiment of the present invention will be described with reference to FIGS. 5, 6, and 7. FIG. FIG. 5 is a perspective view showing the configuration of the internal magnetic shield according to the second embodiment, and FIG. 6 is a cutout depth a of a V-shaped notch formed on the short side inclined surface of the internal magnetic shield, and upper and lower inner xen strains. FIG. 7 is a characteristic diagram showing the relationship between Λ, and FIG. 7 shows the relationship between the total length of the trapezoidal partitions arranged at the left and right edges of the V-shaped notch and the upper and lower inner xen distortions 固定. FIG. The configuration of the color cathode ray tube according to the second embodiment is substantially the same as the configuration of the first embodiment shown in FIG. 1 when the longitudinal section and the transverse section are exchanged, so that the sectional view is omitted.

As shown in FIG. 5, the internal magnetic shield 5 is formed by a long-side inclined surface 51 and a short-side inclined surface 52. The short-side inclined surface 52 has a short side of the electron gun side opening 50. A V-shaped notch 55 having the side end edge 50b as the bottom is formed. Notch depth a of V-shaped notch 55 a = 60 mm
It is. On each side 55a and 55b of the V-shaped notch 55, a trapezoidal partition 56 having a height b = 12 mm and a total length c = 65 mm is perpendicular to the short side inclined surface 52,
And it is formed by bending in the direction of the inner wall of the funnel 1.

FIG. 6 shows the relationship between the notch depth a of the V-shaped notch 55 formed on the short side inclined surface 52 of the internal magnetic shield 5 and the upper and lower inner xen strains Λ. When the notch depth a is 60 mm, the upper and lower inner xen strain Λ is reduced from 1.5 mm to 1.1 mm, but the notch depth a is further increased and increases toward the fluorescent screen 8 side. Even if it does, the reduction effect is saturated. This is because the intensity of the horizontal deflection magnetic field leaking from the deflection yoke gradually attenuates toward the fluorescent screen 8 of the cathode ray tube, and eventually becomes zero.

FIG. 7 shows a V-shaped notch 55 having a notch depth a fixed to 60 mm, and a total length c of a trapezoidal partitioning portion 56 having a height b of 12 mm and disposed on the left and right edges thereof, and an upper and lower inner portion. This shows the relationship with the xen distortion Λ. When the total length c is 65 mm, the upper and lower inner xen strain Λ is reduced from 1.5 mm to 0.3 mm. However, due to the attenuation of the horizontal deflection magnetic field, the total length c is further increased by the fluorescent screen.
However, the reduction effect is saturated even if it is increased toward the side 8. Here, the height b of the trapezoidal partition portion 56 is fixed to 12 mm because the height is set to the maximum possible height in consideration of the contact with the inner wall of the funnel. In addition, height b
It is needless to say that the effect of reducing the upper and lower inner xen distortions 増 加 increases as the value of increases, because the effect of inducing and converging the horizontal deflection magnetic field leaking from the deflection yoke increases.

As described above, the left and right sides 5 of the V-shaped notch 55 formed on the short side inclined surface 52 of the internal magnetic shield 5
By adding the trapezoidal partitioning portions 56 to the edges of 5a and 55b, the effect of reducing the upper and lower inner xen distortion is 27%.
It can be seen that it is greatly improved from 80% to 80%.

In each of the above embodiments, the shape of the cutout 53 or 55 formed on the long side inclined surface 51 or the short side inclined surface 52 of the internal magnetic shield 5 is V-shaped. An arc shape or a trapezoid shape may be used. Notch 53 or 5
The shape of the partitions 54 or 56 disposed on the left and right edges of the inner magnetic shield 5 is not limited to a trapezoidal shape, and the angle formed between the long side inclined surface 51 or the short side inclined surface 52 of the internal magnetic shield 5 is also a right angle. It is not limited to. Further, the partitions 54 and 56 are formed by bending the long-side inclined surface 51 and the short-side inclined surface 52 of the internal magnetic shield 5, respectively, but may be provided by separately welding a magnetic plate.

[0028]

As described above, according to the first cathode ray tube of the present invention, the terminal edge of the long side inclined surface in the opening on the electron gun side of the internal magnetic shield is set to the bottom side, and is set to the fluorescent screen side. A notch is formed so that its width becomes narrower as it goes, and a partition is provided on each of two sides connected to the bottom of the notch. , The barrel distortion of the leaked vertical deflection magnetic field can be reduced (notch effect), and at the same time, the magnetic field strength can be increased (partition effect). As a result, there is a remarkable effect that the left and right inner xen strains Δ can be sufficiently reduced.

On the other hand, according to the second cathode ray tube of the present invention constituted as described above, the fluorescent screen is formed by setting the terminal edge of the short side inclined surface in the electron gun side opening of the internal magnetic shield to the bottom side. A notch whose width decreases toward the side and a partition is provided on each of the two sides connected to the bottom of the notch, so that the electron gun-side opening of the internal magnetic shield is near the horizontal axis. The barrel distortion of the leaked horizontal deflection magnetic field in the space can be reduced (notch effect)
At the same time, the magnetic field strength can be increased (partition effect). As a result, there is a remarkable effect that the upper and lower inner xen distortion Λ can be sufficiently reduced.

Further, by setting the shape of the notch portion to any one selected from a V-shape, an arc shape, and a trapezoidal shape, an optimum notch portion effect can be obtained according to the size and shape of the cathode ray tube. Can be. Further, by forming the partition portion in a trapezoidal shape, the partition portion effect can be obtained as much as possible within a range that does not conflict with the funnel of the cathode ray tube. In addition, by making the partition portion project substantially perpendicular to the long-side inclined surface or the short-side inclined surface, handling during processing and assembling of the internal magnetic shield is facilitated. Further, by forming the partition portion by bending the long-side inclined surface or the short-side inclined surface, the processing of the internal magnetic shield is facilitated and the material yield is improved. Or, by arranging the partition part by welding a magnetic plate to the long side inclined surface or the short side inclined surface, it is possible to cope with special shapes that cannot be pressed, etc. The effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a first embodiment of a cathode ray tube of the present invention.

FIG. 2 is a perspective view showing the shape of an internal magnetic shield according to the first embodiment of the present invention.

FIG. 3 is a diagram showing the relationship between the notch depth of a V-shaped notch formed on the long side inclined surface of the internal magnetic shield and the left and right inner xen strains Δ in the first embodiment of the present invention.

FIG. 4 is a diagram showing the relationship between the total length of a trapezoidal partition arranged on the left and right edges of a V-shaped notch and the left and right inner xen strains Δ.

FIG. 5 is a perspective view showing the shape of an internal magnetic shield according to a second embodiment of the present invention.

FIG. 6 is a diagram showing the relationship between the notch depth of a V-shaped notch formed on the short side inclined surface of the internal magnetic shield and the upper and lower inner xen strain Λ in the second embodiment of the present invention.

FIG. 7 is a diagram showing the relationship between the total length of the trapezoidal partition arranged on the left and right edges of the V-shaped notch and the upper and lower inner xen strains.

FIG. 8 is a diagram for explaining a left and right inner xen distortion Δ.

FIG. 9 is a view for explaining barrel distortion in a vertical space near a vertical axis of a vertical deflection magnetic field leaking near an electron gun side opening of a conventional internal magnetic shield.

FIG. 10 is a diagram showing the shape of a conventional internal magnetic shield when viewed from the electron gun side.

FIG. 11 is a view showing an arc-shaped notch formed on a long-side inclined surface in an electron gun-side opening of a conventional internal magnetic shield.

FIG. 12 is a diagram for explaining upper and lower inner xen distortions Λ;

FIG. 13 is a view for explaining barrel distortion in a horizontal space near a horizontal axis of a horizontal deflection magnetic field leaking near an electron gun side opening of a conventional internal magnetic shield.

FIG. 14 is a diagram showing the shape of a conventional internal magnetic shield when viewed from the electron gun side.

FIG. 15 is a diagram showing an arc-shaped notch formed on a short-side inclined surface in an electron gun-side opening of a conventional internal magnetic shield.

[Explanation of symbols]

1: Funnel 2: Panel 3: Shadow mask 4: Frame 5: Internal magnetic shield 6: Neck 7: Electron beam 8: Fluorescent screen 50: Electron gun side opening 50a: Long side end edge 50b: Short side end end Edge 51: Long-side inclined surface 52: Short-side inclined surface 53: V-shaped notch 53a: Notch side 53b: Notch side 54: Partition 55: V-shaped notch 55a: Notch Side 55b: Notch side 56: Screen part 101: Vertical line forming a lateral outline of the cross hatch pattern 102: Vertical line at a position inward toward the center of the screen surface 103: Internal magnetism Shield 103a: electron gun side opening 104: vertical space near vertical axis 105: barrel distortion of leaked vertical deflection magnetic field 106: long side inclined surface 107: arc-shaped notch 108: magnetic plate Inclined side surface 109: Magnetic material plate Inclined side surface 110: Vertical space near vertical axis 111: Barrel distortion of leaked vertical deflection magnetic field 112: Isomagnetic field line having barrel distortion 113: Shape formed by normal line of isomagnetic field line 121: Cross hatch pattern 122: Horizontal line at a position inward toward the center of the screen surface 124: Horizontal space near the horizontal axis 125: Barrel distortion of leakage horizontal deflection magnetic field 126: Long side Inclined surface 127: Arc-shaped notch 130: Left and right space near horizontal axis 131: Barrel distortion of leaked horizontal deflection magnetic field 132: Equal magnetic force line having barrel distortion 133: Shape formed by normal line of equal magnetic force line a: V-shaped notch Notch depth of part b: Height of trapezoidal partition c: Total length of trapezoidal partition part Δ: Left and right inner xen distortion ：: Upper and lower inner Sen distortion

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kenichi Sato 1-1, Komachi, Takatsuki-shi, Osaka Matsushita Electronic Industrial Co., Ltd. (56) References JP-A-49-88467 (JP, A) JP-A Hei 4-188543 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 29/02

Claims (7)

(57) [Claims] 1. A long-side inclined surface and a short-side inclined surface each having a long fluorescent screen-side terminal edge and a short electron-gun-side terminal edge, and the long-side inclined surface having the electron gun-side terminal edge as a base. A cathode ray tube comprising: a notch provided in each of the first and second portions; and an internal magnetic shield provided on each of two sides connected to the bottom side of the notch and protruding toward the inner wall of the funnel. 2. An electron gun-side terminal edge is longer and an electron gun-side terminal edge is shorter, and the electron gun-side terminal edge is shorter, and the electron gun-side terminal edge is a bottom side. A cathode ray tube comprising: a notch provided in each of the first and second portions; and an internal magnetic shield provided on each of two sides connected to the bottom side of the notch and protruding toward the inner wall of the funnel. 3. The shape of the notch is any one selected from a V-shape, an arc shape, and a trapezoidal shape.
A cathode ray tube as described. 4. The cathode ray tube according to claim 1, wherein the partition is trapezoidal. 5. The cathode ray tube according to claim 1, wherein the partition portion projects substantially perpendicularly to the long side inclined surface or the short side inclined surface. 6. The cathode ray tube according to claim 1, wherein the partition portion is formed by bending a long side inclined surface or a short side inclined surface. 7. The cathode ray tube according to claim 1, wherein the partition portion is formed by welding a magnetic plate to a long side inclined surface or a short side inclined surface.