JPH0541177A - Color cathode-ray tube - Google Patents

Abstract

PURPOSE:To avoid deterioration of color purity by composing an inner magnetism shielding body of a magnetic material having predetermined characteristics. CONSTITUTION:A color sorting means 3 is provided with an inner magnetism shielding body 11 enclosing a passage of an electron beam extending from this means 3 on the opposite side to the side facing a color phosphor surface 2. This shield body 11 have a pair of long side walls 11A, 11B extending along a frame side 4B of the color sorting means 3 facing each other, and short side walls 11C, 11D extending along an arm part to form a head-cut rectangular cone having a head part by the side walls 11A, 11B, 11C, 11D on the opposite side to the phosphor surface. A total of 4-8 rectangular apertures 12 are bored only in the long side walls 11A, 11B along the depth of the long side walls 11A, 11B, setting the rectangular apertures 12 to have a surface of 10-20% the total surface of the long side walls 11A, 11B. The inner part magnetism shielding body 11 is composed of a magnetic material having a property of a residual flux density Br of 8 kilogauss or more. Displacement of a landing position of an electron beam on the color phosphor surface 2 can be reduced, thereby deterioration of color purity can be avoided.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube, and more particularly to a Trinitron (registered trademark) type color cathode ray tube.

[0001]

2. Description of the Related Art In a color cathode ray tube such as a color television picture tube, as shown in FIG. 13, a color selecting means is opposed to a color fluorescent screen 2 formed on an inner surface of a panel 1P of a cathode ray tube tube body 1. 3 is arranged.

In a Trinitron (registered trademark) type color cathode ray tube, as shown in the pattern diagram of FIG. 14, the color phosphor screen 2 is, for example, a stripe-shaped red, green and blue light emitting phosphor R, which extends in the vertical direction. G and B are separately coated via a guard band GB made of a striped carbon coating film.

On the other hand, the color selecting means 3 has a structure called an aperture grill. As shown in FIG. 13, for example, the frame sides 4A and 4B facing each other and extending in the horizontal direction having an L-shaped cross section, and the U-shape provided across both ends of the frame sides 4A and 4B. It has a frame 4 consisting of arms 4C and 4D. Then, between the front end faces of the frame sides 4A and 4B of the frame 4, a large number of electron beam transmission slits 5 extending along the frame sides 4A and 4, that is, for example, extending in the vertical direction are arranged side by side as shown in FIG. The shield 6 made of, for example, an iron thin plate is formed on the frame side 4A.
And 4B with the required tension provided by the arms 4C and 4D welded to the front end faces thereof.

Then, for example, three electron beams corresponding to red, green, and blue emitted from the electron gun 7 arranged in the neck portion 1n of the tube body 1 enter the slit 5 of the color selecting means 3 at different angles. Incident on the color phosphor screen 2 to land on the corresponding red, green and blue phosphors R, G and B of the color phosphor screen 2, and the impact of this electron beam causes the phosphors R, G and B of each color to land. The color reproduction image can be obtained by obtaining the light emission from.

In a general color cathode ray tube including such a Trinitron (registered trademark) type color cathode ray tube, an electron beam is landed on a phosphor of a predetermined color by a so-called shadow mask as a color selecting means. In other words, since each color is selected, the electron beam is emitted from the center of its horizontal and vertical deflection to the fluorescent screen 2.
When the orbit changes due to an external magnetic field such as geomagnetism on the way to, the misalignment occurs due to a change in the angle of incidence on the color selection means, resulting in a decrease in color purity such as color shift.

Therefore, in the color cathode ray tube, an external magnetic shield (hereinafter referred to as OMS) is provided on the outer periphery of the funnel portion of the cathode ray tube body, and an internal magnetic element is attached inside the funnel portion so as to extend rearward from the color selecting means. A shield (hereinafter referred to as IMS) is provided, and a degaussing coil (not shown) is provided outside the tube to provide OMS and IMS.
By degaussing, a method of cutting off the influence of a magnetic field from the outside such as geomagnetism during the flight of the electron beam is adopted.

However, in recent years, the screen size of color cathode ray tubes has been further increased. Under these circumstances, the provision of the OMS not only inevitably increases the size and weight of the entire electron beam, but also increases the electron beam passage. There is a problem that the effect of shielding the external magnetic field with respect to is inferior to the IMS provided near the electron beam passage.

On the other hand, however, the demagnetizing power of the IMS is increased.

Further, in a general shadow mask type color cathode ray tube, a shadow mask in which circular electron beam transmitting holes are formed in a thin metal plate on a spherical surface which bulges forward is used as a color selecting means. Although the IMS is attached to this, the impact area of the electron beam on the shadow mask during operation of the cathode ray tube is considerably larger than that in the case of the aperture grill, so that the temperature rise is remarkable,
Due to this, the thermal expansion of the IMS is also large, and the resulting deformation of
There is a problem of influence on the shadow mask, that is, mislanding of the electron beam on the phosphor screen.

In this shadow mask type color cathode ray tube, as a cathode ray tube which uses the IMS and copes with the above-mentioned problems, for example, as disclosed in Japanese Utility Model Publication No. 55-27957, a shadow mask is provided behind the cathode ray tube. Of the truncated pyramidal magnetic metal plate having a small diameter toward the side, that is, the side where the electron gun 7 is disposed, the long side wall plate extending in the horizontal direction and the short side wall plate extending in the vertical direction are provided. 40-50% of the surface area of the IMS with multiple openings
It is proposed that the structure be drilled in the range of.

Also, in the IMS disclosed in JP-A-54-25157 and JP-B-63-67307, in the shadow mask type cathode ray tube, the position, area, etc. of the hole formed in the above-mentioned side wall of the IMS. Is being considered.

However, the above-mentioned Trinitron (registered trademark) type color cathode ray tube shows a property different from that of the above-mentioned IMS in the shadow mask type cathode ray tube, and a reasonable magnetic shield may be obtained depending on the already proposed IMS. If this is not done, it is not possible to adopt a configuration that excludes OMS. Therefore, for example, 34 of 25 inches or more
In the inch type color cathode ray tube, the OMS type structure is inevitably adopted, which causes problems of weight, size, and cost.

[0013]

In particular, the present invention relates to a trinitron (registered form) in which the color selecting means has a so-called aperture grill in which electron beam transmitting slits extending in one direction, specifically, the vertical direction are arranged. In a trademark type color cathode ray tube, without using OMS, it is possible to reliably avoid the unstable influence of the electron beam due to an external magnetic field such as the earth's magnetic field without using OMS, and to change the landing position of the electron beam on the color fluorescent screen. It is possible to reduce the deviation and to avoid a decrease in color purity due to the deviation.

[0014]

The present invention is shown in FIG. 1, FIG. 2 and FIG. 3, in which a plane stripe, a rear view and a side view of a front portion of an example of a Trinitron type color cathode ray tube according to the present invention are shown. As shown in FIG.
Opposed to the color fluorescent screen 2 formed on the inner surface of the P, color selecting means 3 is provided for selecting and arriving the electron beam corresponding to each color on the phosphor region of each color of the color fluorescent screen 2, and The selecting means 3 is provided with frame sides 4A and 4B which extend in the long side direction of the effective screen of the cathode ray tube and are opposed to each other, and a pair extending across both ends of the frame sides and extending in the short side direction of the effective screen. A collar having a structure in which a shield 6 in which a large number of electron beam transmission slits 5 extending along the short side direction are arranged side by side is stretched between frame sides 4A and 4B formed of the arm portions of A cathode ray tube is used.

Then, the color selecting means 3 is provided with an internal magnetic shield (I) which extends from the color selecting means 3 to the side opposite to the side facing the color fluorescent screen 2 and which surrounds the passage of the electron beam.
MS) 11 is provided.

The IMS 11 is provided with a frame side 4 of the color selecting means 3.
It has a pair of long side sidewalls 11A and 11B facing each other extending in the A and 4B directions and a pair of short side sidewalls 11C and 11D facing each other extending in the arm portions 4C and 4D,
These long side walls 11A and 11B and short side walls 11C and 11D form a rectangular truncated pyramidal body having a top on the side opposite to the phosphor screen 2.

The shape and size of the IMS 11 have a distance of 10 to 15 mm from the electron beam trajectory b extending from the deflection center P of the electron beam to the corner of the effective screen, and about 60 to 80% of this electron beam trajectory length. Select to cover.

Then, a total of 4 to 8 rectangular openings 12 are formed only on the pair of long side walls 11A and 11B.
Drill along the depth direction of A and 11B. These rectangular openings 12 are selected to have an area of 10 to 20% of the total area of both long side walls.

Further, the long side walls 11A and 11B are the inner side surfaces 11C1 of the pair of arm portions 11C and 11D which face each other.
The length is selected so as to extend across the region from S to the inner surface 11D1S.

Further, the IMS 11 has a residual magnetic flux density B
It is made of a magnetic material having r of 8 kilogauss or more.

[0021]

According to the above-described structure of the present invention, the influence of the external magnetic field on the electron beam trajectory can be surely reduced without providing the OMS, and the landing deviation on the fluorescent screen can be effectively reduced. This will be described in detail in the description of the embodiments of the present invention below.

[0022]

EXAMPLE An example of a color cathode ray tube according to the present invention will be described.

The present invention adopts a trinitron type color cathode ray tube (TR tube) structure as shown in FIG.

This color cathode ray tube is a cathode ray tube body 1.
, The inner surface of the panel 1P having a long side in the horizontal direction (Y direction), a short side in the vertical direction (X direction), and a long side in a circular shape bulging forward in a front view when viewed from the front. A color selection unit 3 is provided so as to face the color fluorescent screen 2 formed in the above.

The color selecting means 3 comprises a shield 6 in which a large number of electron beam transmitting slits 5 extending along the short side direction (Y direction) of the effective screen by the phosphor screen 2 are arranged side by side.

The shield 6 is supported by the frame 4. The frame 4 is frame sides 4A and 4B made of, for example, a steel material having an L-shaped cross section, which is curved along the long side direction of the effective screen described above along the arc of the cylindrical surface of the panel 1P, that is, the phosphor screen 2.
And an arm portion 4C made of, for example, a steel material, which is bent in a U shape so as to project rearward on the rear surface of each end of these frame sides 4A and 4B, that is, the surface opposite to the side facing the fluorescent surface 2.
And 4D are welded together.

The frame sides 4A and 4 of the frame 4
The shield 6 is stretched across the arcuate front end face of B.

The shield 6 is formed of, for example, an iron thin plate having slits 5 formed by selective etching by photolithography, and its upper and lower ends are welded to the front end faces of the frame sides 4A and 4B, for example. on the other hand,
As described in FIGS. 14 and 15, the color phosphor screen 2 has
Striped red, green, and blue phosphor regions R, G, and B extending along the extension direction of the slit 5 are arranged via a guard band GB made of, for example, a carbon layer.

In the color selecting means 3, a leaf spring 21 attached to the outer surface of the frame 4 is engaged with a support pin (not shown) attached to the inner peripheral surface of the panel 1P so as to have a predetermined position in the panel 1P. Mounted on.

The frame 4 of the color selecting means 3
Then, the IMS 11 is attached.

The IMS 11 is arranged along the frame sides 4A and 4B of the frame 4, respectively, and has long side walls 11A and 11B facing each other, and short side walls 11C extending in the directions along the arms 4C and 4D and facing each other. And 11
D, and the side walls 11A to 11D enclose an electron beam passage extending from the deflection center P of horizontal and vertical scanning of the electron beam toward the phosphor screen 2, and a rectangular truncated pyramid whose apex is on the deflection center P side. Form a body.

The long side walls 11A and 11B extend forward along the Z-axis direction on the opposite sides of the frame sides 4A and 4B, that is, on the upper surface of the frame side 11A and the lower surface of the frame side 11B. Flange portions 11AF and 11BF, which are abutted against each other and attached by welding, for example, are provided. The length 1 of the front portion of the long side wall portion in the X direction is defined by the inner side surfaces 4 of the arm portions 4C and 4D of the frame 4 which face each other.
One of C1 and 4C2 has a length from a position close to one to a position close to the inner side surface of the other.

The short side walls 11C and 11D abut against the rear surfaces of the arm portions 4C and 4D of the frame 4, and are attached to the flange portions 11CF and 1D by welding, for example.
1DF.

The size and shape of the IMS 11 are such that the side walls 11A to 11A from the trajectory b of the electron beam from the horizontal / vertical deflection center P of the electron beam toward the corner of the effective screen of the phosphor screen 2.
The distance a between D is 10 to 15 mm, preferably 10 to 1
The depth is selected to be 3 mm and covers 60 to 80% of the orbital length of the electron beam.

Then, a rectangular opening 12 having a major axis direction is formed only in the long side walls 11A and 11B of the IMS 11 in the depth direction thereof, that is, in the direction along the axis Z of the IMS.

A total of four to eight openings 12 are provided, for example, two openings 12 on each long side wall 11A and 11B as shown in the drawing.
Provide a total of four. These openings 12 include a plane including the axis Z and the Y direction intersecting the axis Z, and the axis Z and the X intersecting the axis Z.
The layout is selected to be symmetrical with respect to the plane including the direction.

The total area of these openings 12 is 10 to 20% of the total area of the side walls 11A and 11B.

Further, the short sides sidewalls 11C and 11D, the central portion of the rear end, the 0.7 to 0.9 of the depth r _D of required depth r _D for example of the short side sidewall depth length r Forming V-shaped notches 11VC and 11VD having.

Further, the 1MS11 having the above-mentioned structure is made of a steel plate having a residual magnetic flux density Br of 7 KG (kilogauss) or more, for example, SIS-HT and SIS-CR (both are trade names of Toyo Steel Co., Ltd.). The magnetic characteristics of these SIS-HT and SIS-CR are as shown in Table 1 below.

[0040]

[Table 1] Where Bm is the maximum magnetic flux density, Br is the residual magnetic flux density, and Hc
Is the coercive force, and m is the magnetic permeability.

The thickness of the ferromagnetic plate that constitutes the IMS is 0.3 mm or more when Br ≧ 8 KG.

According to the cathode ray tube having the IMS 11 having the above-described structure, it is possible to improve landing deviation by obtaining good demagnetization without providing an OMS and a shield effect of an external magnetic field such as geomagnetism with respect to an electron beam. did it.

Now, as shown in FIG. 2, each width W _PS of the striped phosphors R, G, B is 147 μm, the width W _GB of the striped guard band is 160 μm, the phosphor pitch is about 920 μm, and the slit 5 is formed. The deviation of the landing was measured when the width of the electron beam arriving therethrough, that is, the bright line width W _T was 240 μm.

In the color cathode ray tube, it is ideal that the emission line width W _T originally matches the phosphor width W _PS and there is no deviation of the electron beam landing.
Actually, the deviation of the electron beam occurs due to factors such as geomagnetism and temperature change. Therefore, the normal emission line width W _T is the phosphor width W _PS
Even when the landing of the electron beam is slightly increased, the stripe width W _PS of the phosphor can be bombarded with the electron beam over the entire width. However, even if the emission line width is made too large, if the landing of the electron beam is significantly deviated, it will land on the phosphors of other colors adjacent to each other beyond the guard band GB, and thus the emission line width W _T will be Generally, the stripe width W _PS of the phosphor is 1.6 to 2.
It is 0 times.

From the relationship between the emission line width W _T and the phosphor width W _PS , the electron beam impacts the entire width W _PS even if the landing of the electron beam deviates. The electron beam is (W _T -W _PS ).
It is when it is just off. Generally the W _T -W _PS is called beam missing allowances, the ratio of the deviation amount of the W _T -W _PS size and electron beam is desirable 100% or less. Below, K on the vertical axis of the measurement results in FIGS.
In the beam missing allowances ratio is obtained by taking K = a {shift of the electron beam quantity _{/ (W T -W PS)}} × 100 (%). The geomagnetic conditions were 0.3 G for the horizontal component and 0.35 G for the vertical component.

First, in the above-described structure, K is measured by changing the distance a between the electron beam trajectory b from the deflection center P of the electron beam toward the corner of the effective screen of the phosphor screen 2 and the inner surface of the IMS 11. The results shown in 5 were obtained. From this, it can be seen that the distance a in the present invention can be reduced by setting the distance a to 10 to 15 mm, preferably 10 to 13 mm. In this case, as described above, K ≦ 10
It is desirable that the value be 0%, but actually, when considering the current K, if the value is less than 100%, it means that the improvement has been observed.

Now, with this distance a kept constant, the electron beam shielding rate covering the orbital length of the electron beam toward the above-mentioned corner portion, specifically, the orbital length d of the electron beam in FIG. FIG. 6 shows the measurement results of the relationship between the ratio c / d with the length c covering the same and the ratio K described above. According to this, the smallest deviation is shown at the shielding rate of 66%, but as described above, even if K slightly exceeds 100%, that is, the shielding rate of the present invention is 60 to 80%. K ≦
Numeral 102 is provided with sufficient prevention of displacement. From the viewpoint of increasing the magnetic shield effect, it is considered that the larger the shield ratio, the more the influence of the external magnetic field can be reduced. However, in reality, the outer periphery of the funnel portion of the tubular body 1 on the base side is not affected by the electron beam. Since the horizontal and vertical deflection yokes are arranged, if the depth of the IMS becomes too long, it interferes with the magnetic field of this deflection yoke, which adversely affects the electron beam. Is 80% or less.

Further, in the present invention, a rectangular vertically long opening 12 is formed in the side wall of the long side of the IMS 11. First, the shape of the opening 12 is selected, and the same number (4 pieces in total) are formed at the same position. The result shown in FIG. 7 is obtained by measuring K in ()), and it can be seen that the beam deviation can be minimized in the case of the vertically long rectangle according to the present invention.

The relationship between the number of vertically elongated rectangular openings 12 and K is as shown in FIG.
It can be seen that although K <100% is obtained, four is more preferable. This tendency can be explained as follows.

That is, although not shown, the demagnetization coil provided on the outer periphery of the funnel portion of the tube body 1 degausses the IMS 11 and the color selection means 3. However, the color of the trinitron type color cathode ray tube (abbreviated as TR hereinafter) Sorting means 3
Then, the shield 6 has slits 5 extending in the vertical Y direction.
Since the magnetic resistance in the horizontal X direction is significantly larger than that in the Y direction due to the arrangement of., The magnetic flux flowing during degaussing is limited to the vertical Y direction. Therefore, the magnetic flux generated from the degaussing coil is shielded by the shield 6.
In order to allow more flow, the opening 12 is optimally a rectangle having the largest aspect ratio.

Incidentally, in the IMS proposed in Japanese Utility Model Publication No. 55-27957, openings are provided on all side walls of the long side and the short side. In this case, the color selection means is a shadow mask type, that is, a circular hole electron. The effect of the publication is to reduce the degaussing power and to dissipate the heat of the shadow mask, which is different from the object of the invention to prevent the deviation of the electron beam. It Further, it should be noted that the present invention adopts a different configuration as compared with the IMS disclosed in Japanese Examined Patent Publication No. 63-67307 in specifying the opening shape and area.

That is, in the present invention, it is specified that the vertically long rectangular opening 12 is formed.
2 with respect to the axis Z of the IMS and the X axis and the Y axis passing therethrough,
By arranging them so that they are symmetrical,
Four is better than four because the passage of the magnetic flux from the degaussing coil should be divided into two at the corner and both ends in the Y-axis direction. Increase the number and pass to the middle. Even if an attempt is made to form a path, only the amount of magnetic flux that reaches the corner portion or the Y-axis end portion is reduced, and even if the corner portion is most likely to cause landing deviation of the electron beam, the effect is rather small. ..

On the other hand, FIG. 9 shows the relationship between the total area of the openings 12 and K, which shows that K ≦ 82% at 10 to 24% of the total area of the long side walls. Indicates a value. This is also the actual public Sho 55-27957
It is significantly different from the value of 40 to 50% indicated in the No. This clearly shows that the TR tube and the shadow mask type cathode ray tube (hereinafter abbreviated as SM tube) exhibit different properties. One of them is that the TR tube is
Due to its structure, as described above, the bulging due to the thermal expansion of the mask found in the SM tube is strengthened, so that it is less susceptible to the electron beam shift due to the so-called doming effect, so it is necessary to radiate the radiant heat inside the IMS. The other is that the SM tube has a structure in which the magnetic flux from the degaussing coil flows in from the end portion in the X direction, so that openings are formed not only in the long side wall but also in the short side wall. In consideration of the fact that the magnetic flux is evenly distributed in the X direction and the Y direction, the opening area is large in the middle part, and the X direction and the Y direction are arranged.
An appropriate amount of magnetic flux is distributed to the end portions and corner portions in the direction. However, in the TR tube, as described above, the flow direction of the magnetic flux in the shield 6 is restricted,
It is pointed out that this consideration is meaningless.

With respect to the positions where the openings are formed, the closer the openings are, the larger the deviation of the electron beam at the end of the Y end of the TR tube and the smaller the deviation at the corners. Actually, selection is made in consideration of these. This is because the shield 6 of the TR tube is regulated in the direction of the magnetic flux passage as described above, but at the same time, it is stretched between the frame sides 4A and 4B with a required tension. On the other hand, since the thickness is formed to be less than 1/2 or less, there is a problem how much the magnetic flux for demagnetization flows from the IMS to the shield 6, and the opening is near the center of each side wall. If so, this is because the amount of magnetic flux flowing into the Y end is reduced.

Further, the long side wall 11A indicated by reference numeral 1 in FIG.
Since the frame 4 is made of a ferrous material, that is, a magnetic material, the arms 4C and 4D also have a magnetic shield effect, and the lengths 1 and 11B are close to the inner wall surfaces 4C ₁ and 4C ₂ of the arms 4C and 4D, respectively. Side wall 11A and 1
1B has an extended shape and size.

Further, the constituent material of the IMS 11 is Br ≧
Although it is set to 7.0 KG, it is generally important for a magnetic shield material to have a high magnetic permeability μ in order to obtain its magnetic shield effect, and it is actually used as the conventional IMS 11. Steel materials such as OCA-H
As shown in Table 2, T (manufactured by Toyo Steel Co., Ltd., trade name) has a magnetic permeability μ higher than that of SIS-HT and SIS-CR described above.

[0057]

[Table 2] Incidentally, these SIS-HT, SIS-CR, OCA-HT
The composition of (1) is mainly Fe, and electrolytic Cr acid treatment is performed, and is made of the additives of Table 3 below. For example, the annealing conditions are different.

[0058]

[Table 3] However, as compared with the case of using the OCA-HT steel material having the high magnetic permeability μm, Br ≦ 7K used in the present invention described above.
When the G steel material is used, its magnetic permeability μm is OCA-H.
Although it was smaller than T, its K value could be reduced by 30%. FIG. 10 shows the result of measurement of the relationship between Br and K value.

To devise this phenomenon, FIG.
A ferromagnetic B-H magnetization curve is shown, and Br is an intersection on the magnetic flux B when H = 0, and this is close to the final value Bre of the B-H loop during demagnetization shown in FIG. Have a relationship.

That is, as shown in FIG. 12, when a demagnetizing magnetic field is applied which attenuates the AC magnetic field by applying an alternating magnetic field, the hysteresis loop is gradually reduced, and the bias value H of the external magnetic field is increased.
It stays at the closing price Bre proportional to e. In this attenuation of the hysteresis loop, since the attenuation is performed while drawing a similar shape for each round, Bre and Br when H = He is set.
It should be proportional to o. From this, the larger the residual magnetic flux density Br in FIG. 11, the larger the residual magnetic flux after demagnetization, and the larger the amount of cancellation of the external magnetic field, and the smaller the amount of deviation of the electron beam.

On the other hand, the larger the film thickness of the constituent magnetic material of the IMS, the larger the cross-sectional area of the magnetic flux passage and the higher the magnetic shield effect and demagnetization effect, but the larger the residual magnetic flux density Br, the same. The K value decreases with the thickness. When Br ≧ 7KG, the thickness is 0.15.
Even in μm, the K value can be reduced.

As is clear from the above description, according to the present invention, the K value can be effectively reduced, that is, the landing deviation of the electron beam can be improved.

[0063]

As described above, according to the present invention, the OMS
It is possible to enhance the magnetic shield effect and demagnetization effect only by IMS in the TR tube without arranging
The electron beam landing deviation can be improved. Therefore, by omitting the OMS, it is possible to reduce the weight, simplify the manufacturing of the entire miniaturized composition, especially in a large-sized pipe, and further reduce the cost by about 44% as compared with the case where the conventional OMS is provided. You can Further, it has many advantages such as improvement of reliability due to improvement of demagnetization effect in IMS, miniaturization of degaussing coil and reduction of degaussing power.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of an example of a color cathode-ray tube according to the present invention viewed from the back.

FIG. 2 is a plan view of an example of a color cathode ray tube according to the present invention.

FIG. 3 is a side view of an example of a color cathode ray tube according to the present invention.

FIG. 4 is a rear view of an example of a color cathode ray tube according to the present invention.

FIG. 5 is a measurement curve diagram of K-distance a.

FIG. 6 is a measurement curve diagram of K-electron beam shielding rate.

FIG. 7 is a measurement table of the relationship between the aperture shape and K.

FIG. 8 is a measurement curve diagram of K-numerical aperture.

FIG. 9 is a measurement curve diagram of K-opening area.

FIG. 10 is a measurement curve diagram of K-Br.

FIG. 11 is a BH curve diagram of a ferromagnetic material.

FIG. 12 is a BH curve diagram at the time of demagnetization.

FIG. 13 is a perspective view of a main part of a conventional color cathode-ray tube viewed from the back.

FIG. 14 is a pattern diagram of a color fluorescent screen.

FIG. 15 is a cross-sectional view showing a relationship between a color fluorescent screen and a color selection unit.

[Explanation of symbols]

 1 Tube 1P Panel 2 Color Phosphor Screen 3 Color Selection Means 4 Frame 4A Frame Side 4B Frame Side 4C Arm 4D Arm 11 Internal Magnetic Shield (IMS) 11A Long Side Wall 11B Long Side Wall 11C Short Side Wall 11D Short Side Side wall 12 opening

[Procedure amendment]

[Submission date] February 18, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

On the other hand, the color selecting means 3 has a structure called an aperture grill. As shown in FIG. 13, for example, the frame sides 4A and 4B facing each other and extending in the horizontal direction having an L-shaped cross section, and the U-shape provided across both ends of the frame sides 4A and 4B. It has a frame 4 consisting of arms 4C and 4D. The juxtaposition between the front end surface of the side frame 4A and 4B of the frame 4, extends along between side frame 4A and 4 B, so that is for example a number of electron beam transmission slits 5 extending in the vertical direction shown in FIG. 15 The shield 6 made of, for example, an iron thin plate formed in an array is used as the frame side 4
It is stretched with the required tension given by the arms 4C and 4D welded to the front end faces of A and 4B.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004] Then, red emitted from the electron gun 7 arranged in the neck portion 1n of the tube 1, green and three electron beams that corresponds to blue, different angles to the slit 5 of the color selecting means 3 Incident on the color phosphor screen 2 to land on the corresponding red, green and blue phosphors R, G and B of the color phosphor screen 2, and the impact of this electron beam causes the phosphors R, G and B of each color to land. The color reproduction image can be obtained by obtaining the light emission from.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

Therefore, in the color cathode ray tube, an external magnetic shield (hereinafter referred to as OMS) is provided on the outer periphery of the funnel portion of the cathode ray tube body, and an internal magnetic element is attached inside the funnel portion so as to extend rearward from the color selecting means. A shield (hereinafter referred to as IMS) is provided, and a degaussing coil (not shown) is provided outside the tube to provide OMS and IMS.
Method of blocking the effects of an external magnetic field such as geomagnetism on the trajectory of the electron beam by degaussing is taken by.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

However, in recent years, the screen size of color cathode ray tubes has been further increased, and under these circumstances, providing an OMS not only inevitably increases the size and weight of the entire electron beam, but also increases the electron beam trajectory. There is a problem that the effect of shielding the external magnetic field with respect to is inferior to the IMS provided near the electron beam orbit .

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0019

[Correction method] Change

[Correction content]

Further, the long side walls 11A and 11B are selected to have a length which is arranged across a region from the inner side surface 4C1 of the pair of arm portions 4C and 4D facing each other to the inner side surface 4D1 .

[Procedure Amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction content]

This color cathode ray tube is a cathode ray tube body 1.
, For example, the inner surface of the panel 1P having long sides in the horizontal direction ( X direction) when viewed from the front, short sides in the vertical direction ( Y direction), and the long side direction bulging forward in a circular shape. A color selection unit 3 is provided so as to face the color fluorescent screen 2 formed in the above.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

The shield 6, for example by selective etching by the photolithography is formed of iron sheet forming the slit 5, the upper and lower end portions is stretched is welded to the front end surface of the side frame 4A and 4B. On the other hand, as described with reference to FIGS. 14 and 15, the color phosphor screen 2 has stripe-shaped red, green and blue phosphor regions R, G and B extending along the extension direction of the slit 5, respectively, made of, for example, a carbon layer. It is arranged through the guard band GB.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

In the color selection means 3, a plate spring (not shown) attached to the outer surface of the frame 4 is engaged with a support pin (not shown) attached to the inner peripheral surface of the panel 1P. It is mounted in place inside.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction content]

The IMS 11 is arranged along the frame sides 4A and 4B of the frame 4, respectively, and has long side walls 11A and 11B facing each other, and short side walls 11C extending in the directions along the arms 4C and 4D and facing each other. And 11
D and the side walls 11A to 11D enclose an electron beam trajectory from the deflection center P of horizontal and vertical scanning of the electron beam toward the phosphor screen 2, and a rectangular truncated pyramid with the deflection center P side as the apex. Form a body.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Name of item to be corrected] 0032

[Correction method] Change

[Correction content]

The long side walls 11A and 11B extend forward along the Z-axis direction on the opposite sides of the frame sides 4A and 4B, that is, on the upper surface of the frame side 11A and the lower surface of the frame side 11B. flanges 11AF and 11B which abuts
F is provided. The length 1 in the X direction of the front portion of the long side wall portion is close to one of the inner side surfaces 4C1 and 4C2 of the arm portions 4C and 4D of the frame 4, which face each other, from a position close to the other inner side surface. The length to the position.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Name of item to be corrected] 0033

[Correction method] Change

[Correction content]

Further, the short side walls 11C and 11D have flange portions 11CF and 11DF which abut against the rear surfaces of the arm portions 4C and 4D of the frame 4.

[Procedure Amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction content]

Further, the 1MS11 having the above-described structure is a steel plate having a residual magnetic flux density Br of 7 KG (kilogauss) or more, such as SIS-HT and SIS-CR (both Toyo Steel Co.
Constituted by 鈑 trade name). The magnetic characteristics of these SIS-HT and SIS-CR are as shown in Table 1 below.

[Procedure Amendment 13]

[Document name to be amended] Statement

[Item name to be corrected] 0040

[Correction method] Change

[Correction content]

[0040]

[Table 1] Where Bm is the maximum magnetic flux density, Br is the residual magnetic flux density, and Hc
Is the coercive force, and μm is the initial magnetic permeability.

[Procedure Amendment 14]

[Document name to be amended] Statement

[Correction target item name] 0042

[Correction method] Change

[Correction content]

[0042] According to the cathode ray tube having a IMS11 having the configuration described above, can be improved and good demagnetization without providing the OMS, the landing deviation in obtaining the shielding effect of the external magnetic field such as geomagnetism with respect to the electron beam It was

[Procedure Amendment 15]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction content]

As shown in FIG. 15 , each width W _PS of the striped phosphors R, G, B is 147 μm, the width W _GB of the striped guard band is 160 μm, the phosphor pitch is about 920 μm, and the slit 5 is formed. The deviation of the landing was measured when the width of the electron beam arriving therethrough, that is, the bright line width W _T was 240 μm.

[Procedure 16]

[Document name to be amended] Statement

[Correction target item name] 0050

[Correction method] Change

[Correction content]

In [0050] That is not shown and performs demagnetization of IMS11 and color selection means 3 with a degaussing coil which is provided in the funnel portion the outer periphery of the tube 1, (approximately referred to the following TR tube) Trinitron color cathode-ray tube In the color selecting unit 3, the shield 6 has slits 5 extending in the vertical Y direction, and therefore, the magnetic resistance in the horizontal X direction is significantly larger than that in the Y direction.
The direction of the magnetic flux flowing during degaussing is limited to the vertical Y direction. Therefore, the magnetic flux generated from the degaussing coil is shielded by the shield 6.
, The opening 12 in to flow more often, Ru rectangle optimum der the aspect ratio is largest.

[Procedure Amendment 17]

[Document name to be amended] Statement

[Correction target item name] 0058

[Correction method] Change

[Correction content]

[0058]

[Table 3] However, as compared with the case of using the OCA-HT steel material having the high magnetic permeability μm, Br ≧ 7K used in the present invention described above.
When the G steel material is used, its magnetic permeability μm is OCA-H.
Although it was smaller than T, its K value could be reduced by 30%. FIG. 10 shows the result of measurement of the relationship between Br and K value.

[Procedure 18]

[Document name to be amended] Statement

[Correction target item name] 0061

[Correction method] Delete

[Correction content]

[0061]

[Procedure Amendment 19]

[Document name to be amended] Statement

[Correction target item name] 0063

[Correction method] Change

[Correction content]

[0063]

As described above, according to the present invention, the OMS
It is possible to enhance the magnetic shield effect and demagnetization effect only by IMS in the TR tube without arranging
The electron beam landing deviation can be improved. Thus the omission of the OMS, in particular large pipes, lightweight, are worn is simplified to reduce the size of the entire Manufacturing, further considers only the degaussing system compared to the case of providing a conventional OMS
It is possible to perform a reduction in the of about 44% the cost. Further, it has many advantages such as improvement of reliability due to improvement of demagnetization effect in IMS, miniaturization of degaussing coil and reduction of degaussing power.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Kuwa ▼ Mountain Kiyoho 30 Ibarjima, Oya-cho, Inazawa-shi, Aichi Sony Inazawa Corporation

Claims (1)

[Claims] 1. A color selection means, which opposes a color phosphor screen formed on the inner surface of the panel of the tubular body, and selects and makes an electron beam corresponding to each color reach a phosphor region of each color of the color phosphor screen. The color selection means is provided so as to extend in the long side direction of the effective screen of the cathode ray tube and to face opposite frame sides, and to extend between both ends of these frame sides and extend in the short side direction of the effective screen. In a color cathode-ray tube having a configuration in which a shield composed of a plurality of electron beam transmitting slits extending in parallel along the short side direction between the frame sides of the pair of arm portions is juxtaposed on a frame composed of the pair of arm portions, The color selection means is provided with an internal magnetic shield body extending from the color selection means to the side opposite to the side facing the color phosphor screen and surrounding an electron beam passage, and the internal magnetic shield body is the color selection means. In the direction of the frame side of the means Having a pair of long side walls facing each other and a pair of short side walls extending along the arm direction, the pair of long side walls and the short side walls on the opposite side of the phosphor screen. It is a rectangular truncated pyramid shape having a top, and the shape and dimensions of the inner magnetic shield body are 10 to 15 mm from the trajectory of the electron beam from the deflection center of the electron beam to the corner of the effective screen, And, it is selected so as to cover about 60 to 80% of the electron beam orbital length, and a total of 4 to 8 rectangular openings are provided only on the long side wall of the pair.
The rectangular openings are formed along the depth direction of the long side walls, and the rectangular openings are selected to have an area of 10 to 20% of the total area of the long side walls. A color cathode ray tube, which is arranged across a region from the inner side surface to the inner side surface facing each other, and the inner magnetic shield body is made of a magnetic material having a residual magnetic flux density Br of 8 kilogauss or more.