JPH09147758A - Color cathode-ray tube and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display a high-density, high-definition image by forming an electron- beam reflecting film made of a thin film of bismuth oxide with a specific bulk density, on the surface of a color sorting electrode having a number of electron- beam through holes, which surface is collided with an electron beam. SOLUTION: This color cathode-ray tube comprises a panel part 1 where a phosphor film is formed over the inner surface of a faceplate 4; a neck part 2 enclosing an electron gun 9; and a funnel part 3 joining them together. The panel part 1 has a shadow mask (color sorting electrode) 6 arranged away from and opposite to the phosphor film 5 by a mask plate 7 located at the inner periphery of the panel part 1, the shadow mask having a number of electron-beam through holes. An electron-beam reflecting film 6R made of a thin film of bismuth oxide (Bi2 O3 ) with a bulk density of 4.0 to 9.3g/cm<3> is formed over the surface of the mask 6 against which an electron-beam 14 from the electron gun 9 collides. Therefore the beam through holes in the mask 6 become uniform in shape, making it possible to display a high-density, high- definition image.

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 a method for manufacturing the same, and more particularly to bismuth oxide (Bi ₂ O ₂₎ having a high bulk density on an electron beam collision surface of a color selection electrode.
₃ ) A color cathode ray tube having an electron beam reflecting film made of a thin film, and a method of manufacturing a color cathode ray tube including a step of depositing an electron beam reflecting film on one surface of a color selection electrode.

[0002]

2. Description of the Related Art Generally, in a color cathode ray tube, three electron beams emitted from an electron gun are formed on an inner surface of a panel through an electron beam passage hole of a color selection electrode such as a shadow mask. When projected onto the film, the pixel portion of the fluorescent film onto which the electron beam has been projected emits light, and a desired color image is displayed on the entire fluorescent film.

During such an image display operation, the electron beam transmittance of the color selection electrode, for example, a shadow mask is usually about 10 to 20%. Then, the electron beam that cannot pass through the color selection electrode and strikes the color selection electrode flows as a current in the color selection electrode, and the color selection electrode thermally expands due to Joule heat due to this current. As a result, the positional relationship between the color selection electrode and the fluorescent film formed on the inner surface of the panel part is slightly changed, and a landing error occurs in the electron beam projected on the fluorescent film. Such an electron beam landing error causes a color shift in a display image.
This phenomenon is called mask doming. When mask doming occurs in the display image of the color cathode ray tube, the color purity and whiteness uniformity of the display image are significantly deteriorated.

By the way, in the known mask doming suppression means used in the color cathode ray tube, the color selection electrode is made of a metal having a low coefficient of thermal expansion, for example, amber alloy, and the electron beam collision surface of the color selection electrode. By coating an electron beam reflection film on the surface of the color selection electrode, the electron beam energy input to the color selection electrode is reduced, thereby suppressing thermal expansion of the color selection electrode and reducing the mask doming amount.

In this case, as a method of forming the electron beam reflecting film on the color selection electrode, the first method disclosed in Japanese Patent Laid-Open No. 63-80438 and the Japanese Patent Laid-Open No. 63-80439 are disclosed. Second method, third method disclosed in JP-A-2-75132, JP-A-62-28352
A fourth method disclosed in Japanese Patent No. 6 is known.

In the first method, bismuth oxide (Bi ₂ O ₃ ) placed on a stainless steel evaporation dish is vacuum-deposited on one surface of a shadow mask (color selection electrode) by induction heating,
This is a method of forming an electron beam reflecting film.

In the second method, a tungsten boat is resistance-heated and bismuth oxide (Bi ₂ O ₃ ) is vacuum-deposited on one surface of a shadow mask (color selection electrode) to form an electron beam reflection film. Is.

In the third method, metal bismuth (Bi) is used.
This is a method in which a sintered pellet of powder is resistance-heated on a boat made of tungsten (W), and an electron beam reflective film of metal bismuth (Bi) is vacuum-deposited on one surface of a shadow mask (color selection electrode).

The fourth method uses a spray gun,
A suspension of bismuth oxide (Bi ₂ O ₃ ) powder was sprayed together with a slurry containing water glass as a binder, and bismuth oxide (Bi ₂ O ₃ ) oxide was used as an electron beam reflective film on one surface of a shadow mask (color selection electrode). This is a method of forming a coating film.

[0010]

However, in any of the first to fourth methods, as described below,
It has various problems.

First, in the first method, since the material to be vapor-deposited is a color selection electrode made of a conductor, the vapor deposition apparatus becomes complicated and the mass productivity is poor. In addition, since the stainless steel evaporation dish is induction-heated to a high temperature of about 900 ° C, a part of bismuth oxide (Bi ₂ O ₃ ) chemically reacts with the stainless steel of the evaporation dish, and the reaction product is simultaneously deposited on the color selection electrode. In an extreme case, bismuth oxide (Bi ₂ O
₃ ) is chemically reacted with the stainless steel of the evaporating dish to be reduced, and the reduced metal bismuth (Bi) is deposited on the color selection electrode. Since the vapor-deposited metal bismuth (Bi) has a relatively low melting point of about 270 ° C., when the heat treatment at about 400 to 450 ° C. is performed in the color cathode ray tube manufacturing process, the metal bismuth (Bi) small spheres, It becomes so-called bismuth ball and is formed on the color selection electrode,
After that, the bismuth balls are peeled off by vibration or the like, and the withstand voltage of the color cathode ray tube is deteriorated.

Next, in the second method, bismuth oxide (Bi ₂ O ₃ ) is formed by resistance heating of a boat made of tungsten.
In order to heat the bismuth oxide, a heating temperature higher than the heating temperature of the first method is required, and the heating causes the boat made of tungsten and bismuth oxide (Bi ₂ O ₃ ) to react with each other to raise the melting temperature and increase the bismuth oxide (Bi oxide). _A substance having a density lower than that of ₂ O ₃ ) is produced. Further, since the vapor deposition is performed in the low vacuum region of 10 to ² Torr, bismuth oxide (Bi
₂ O ₃ ) evaporates withdraw residual gas such as oxygen (O ₂ ) or nitrogen (N ₂ ), steam (H ₂ O),
It is deposited in a very porous state. Since the film obtained at this time is also vapor-deposited with impurities, the film composition becomes non-uniform, and it is difficult to form a high-density film. In particular, when the film thickness is on the order of μm or less, a uniform thin film cannot be obtained. The reflection effect of the electron beam becomes significantly worse. Further, as in the first method, since the boat made of tungsten is used for heating, part of bismuth oxide (Bi ₂ O ₃ ) evaporates and chemically reacts with tungsten in the boat, and the reaction product is also deposited on the color selection electrode. To be done. And in an extreme case, bismuth oxide (B
i ₂ O ₃ ) evaporates and chemically reacts with the tungsten of the boat to be reduced, and the reduced metal bismuth (Bi) is deposited on the color selection electrode to form bismuth balls on the color selection electrode. After that, the bismuth balls are peeled off by vibration or the like, and the withstand voltage of the color cathode ray tube is deteriorated.

Next, in the third method, the melting point of metal bismuth (Bi), which is the material of the deposited film, is usually around 270 ° C., and the temperature during the heat treatment in the manufacturing process of the color cathode ray tube is about 400 to 450 ° C. Therefore, during heat treatment in the manufacturing process, the vapor-deposited film of metal bismuth (Bi) formed on one surface of the color selection electrode is melted, and the surface tension causes the metal bismuth (Bi) to be spherical and form a bismuth ball. . When the bismuth ball adheres to the electron beam transmitting hole of the color selecting electrode, it blocks the electron beam transmitting hole and causes mask clogging of the color selecting electrode. This causes a fatal pixel defect for a fine pitch color cathode ray tube which requires a fine display image. Further, since the sintered pellet of metal bismuth (Bi) powder is expensive in itself, the cost becomes high when the electron beam reflecting film is formed.

In the fourth method, bismuth oxide (Bi) is used as a spray material for forming an electron beam reflecting film.
₂ O ₃ ) powder suspension is used, the particles of the formed bismuth oxide (Bi ₂ O ₃ ) coating film become coarse, and the thickness of the coating film becomes thick, so that it is formed on the color selection electrode. The electron beam transmission holes have different shapes. When the shapes of the electron beam transmission holes become irregular, the halation increases and the fidelity of the mask pattern decreases, and the color purity and the whiteness uniformity of the display image deteriorate. For a fine-pitch color cathode-ray tube that requires a high-density and high-definition display image, it causes fatal performance deterioration.

The present invention solves these problems, and a first object thereof is a color cathode ray tube in which an electron beam reflecting film capable of high-density and high-definition image display is formed on a color selection electrode. To provide.

A second object of the present invention is to provide a method of manufacturing a color cathode ray tube in which an electron beam reflecting film capable of high-density and high-definition image display can be formed on a color selection electrode. is there.

[0017]

In order to achieve the first object, the color cathode ray tube according to the present invention has a bulk density of 4.0 to 9.3 g on the surface of the color selection electrode on which the electron beam impinges. / Cm ³ of the bismuth oxide (Bi ₂ O ₃ ) thin film formed by the electron beam reflection film.

Further, in order to achieve the second object,
The method for manufacturing a color cathode ray tube according to the present invention includes a sample mounting part, a color selection electrode mounting part, a heating means, etc. in a vacuum container,
Using a vacuum vapor deposition apparatus having an evacuation means, a step of placing bismuth oxide (Bi ₂ O ₃ ) on the sample mounting portion, a step of mounting the color selection electrode on the color selection electrode mounting portion, and exhausting the inside of the vacuum container. _Second step of evaporating and forming an electron beam reflection film made of a bismuth oxide (Bi ₂ O ₃ ) thin film on the color selection electrode through a step of exhausting by a means and a step of heating and vaporizing bismuth oxide (Bi ₂ O ₃ ) by a heating means. It is equipped with means.

According to the first means, an electron beam reflecting film made of a dense bismuth oxide (Bi ₂ O ₃ ) thin film having a bulk density of 4.0 to 9.3 g / cm ³ is formed on one surface of the color selection electrode. Since there is no bismuth ball generated,
No mask clogging on the color selection electrode. Therefore, a fatal deterioration in performance such as a pixel defect does not occur, and a color cathode ray tube capable of high-density and high-definition image display can be obtained.

Further, the according to the second means, bismuth oxide (Bi ₂ O ₃₎ powder pellets or bismuth oxide (Bi ₂ O ₃₎ powder sample mounting portion (platinum or platinum alloy boat) above Evenly heated with bismuth oxide (Bi
₂ O ₃ ) vapor deposition rate is increased, and a chemical reaction does not occur between the platinum or platinum alloy boat and bismuth oxide (Bi ₂ O ₃ ). An electron beam reflection film made of a bismuth (Bi ₂ O ₃ ) thin film is formed by vapor deposition.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION In the first embodiment of the present invention, a color cathode ray tube includes a panel portion having a fluorescent film formed on the inner surface thereof, a neck portion having an electron gun accommodated therein, and a panel portion. A funnel part connecting the neck part and a color selection electrode having a large number of electron beam transmission holes, which are arranged in the panel part so as to be opposed to the fluorescent film with a space therebetween, for transmitting an electron beam projected from an electron gun. , The bulk density is 4.0 to 9.3 g / cm ³ on the surface of the color selection electrode where the electron beam collides.
Of the bismuth oxide (Bi ₂ O ₃ ) thin film of FIG.

One of the first embodiments of the present invention is a bismuth oxide (Bi ₂ O) film having a thickness of 5 to 700 nm.
₃ ) An electron beam reflection film consisting of a thin film is formed.

Another aspect of the first embodiment of the present invention is that
Weight per unit area is 2 × 10 ~ ^{6 to} 6.5 × 10 ~ ⁴ g
The electron beam reflection film made of a bismuth oxide (Bi ₂ O ₃ ) thin film having a thickness of / cm ² is formed.

Another aspect of the first embodiment of the present invention is that
The molar ratio of bismuth atom to oxygen atom is 0.5: 1 to 0.
An electron beam reflecting film made of a bismuth oxide (Bi ₂ O ₃ ) thin film in the range of 7: 1 is formed.

Another aspect of the first embodiment of the present invention is that
The film thickness of bismuth oxide (B
An electron beam reflection film made of i ₂ O ₃ ) is formed.

Further, in the second embodiment of the present invention, the method of manufacturing a color cathode ray tube includes a panel portion having a fluorescent film formed on an inner surface thereof, a neck portion accommodating an electron gun, a panel portion and a neck. A color including a funnel part connecting the parts and a color selection electrode having a large number of electron beam transmitting holes, which are arranged in the panel part so as to be opposed to the fluorescent film at a distance from each other and through which an electron beam projected from an electron gun is transmitted. A method of manufacturing a cathode ray tube, comprising: a vacuum container, an evacuation means for the vacuum container, a sample mounting part that is installed in the vacuum container, and has a sample mounting surface made of platinum or a platinum alloy, and a color selection electrode mounting part. And a step of placing bismuth oxide (Bi ₂ O ₃ ) on the sample placing part using a vacuum vapor deposition device comprising a heating means of the sample placing part, and placing a color selecting electrode on the color selecting electrode placing part. Exhaust the inside of the vacuum container with exhaust means That step bismuth oxide (Bi ₂ O
₃ ) is heated by a heating means to be vaporized, and an electron beam reflection film made of a bismuth oxide (Bi ₂ O ₃ ) thin film is vapor-deposited and formed on the color selection electrode.

One of the second embodiments of the present invention is an electron beam reflecting film made of a bismuth oxide (Bi ₂ O ₃ ) thin film so as to have a bulk density of 4.0 to 9.3 g / cm ^3. Are formed by vapor deposition.

Another embodiment of the second embodiment of the present invention is that
The sample mounting surface of the vacuum vapor deposition apparatus is provided with iridium (Ir), osmium (Os), palladium (Pd), rhodium (R).
h), a platinum alloy containing at least one of ruthenium (Ru).

Another embodiment of the second embodiment of the present invention is that
The sample mounting surface of the vacuum vapor deposition apparatus has a substantially trapezoidal shape and is configured to relieve mechanical stress due to thermal expansion and contraction.

Another embodiment of the second embodiment of the present invention is that
During the step of evacuating the inside of the vacuum container, the inside of the vacuum container is evacuated to a pressure of 10 to ⁴ Torr or less using an evacuation means.

Another embodiment of the second embodiment of the present invention is that
And vaporizing the bismuth oxide (Bi ₂ O ₃₎ by electrical heating of the sample mounting unit using a heating means during the step of vaporizing the bismuth oxide (Bi ₂ O _3).

According to the first embodiment of the present invention, the bulk density is 4.0 to 9.3 g / c on one surface of the color selection electrode.
Since the electron beam reflection film made of a dense bismuth oxide (Bi ₂ O ₃ ) thin film of m ³ is formed, the bismuth ball is not formed during the heat treatment in the manufacturing process of the color cathode ray tube, and the color due to the peeling of the bismuth ball is generated. Since the masking of the selection electrode mask does not occur, it is possible to obtain a fine-pitch color cathode-ray tube capable of high-density and high-definition image display without causing fatal deterioration of performance such as pixel defects. . In this case, preferably, the film thickness of the bismuth oxide (Bi ₂ O ₃ ) thin film is selected to be 5 to 700 nm, and the film thickness of the electron beam reflection film is 1% of the plate thickness of the color selection electrode.
With the following thickness, the shapes of the electron beam transmission holes of the color selection electrode will not be irregular.

According to the second embodiment of the present invention, when the electron beam reflecting film is formed, platinum (Pt) or platinum (Pt) is used as the sample mounting portion of the vacuum vapor deposition apparatus.
Alloy boat, preferably, iridium (Ir) - platinum (Pt) using the alloy boat, bismuth oxide to the boat (Bi ₂ O ₃₎ powder density-pressed pellets or bismuth oxide (Bi ₂ O ₃ ) A powder is placed, and an electron beam reflection film is vapor-deposited on the color selection electrode in a state where the inside of the vacuum container is evacuated to a pressure of 10 to ⁴ Torr or less. At this time, the pellets of bismuth oxide (Bi ₂ O ₃ ) powder or the bismuth oxide (Bi ₂ O ₃ ) powder are uniformly heated on the boat, and the deposition rate of bismuth oxide (Bi ₂ O ₃ ) can be increased. Since a boat made of platinum (Pt) alloy and bismuth oxide (Bi ₂ O ₃ ) do not chemically react with each other, a uniform bismuth oxide (Bi ₂ O ₃ ) thin film having a high bulk density is formed on the color selection electrode. The electron beam reflection film can be formed by vapor deposition. In addition, the color cathode ray tube manufactured according to the second embodiment of the present invention does not cause halation and prevents the deterioration of the shape of the electron beam transmitting hole of the color selection electrode, and thus suppresses the occurrence of mask doming. You can Further, the pellet obtained by high-density pressing the bismuth oxide (Bi ₂ O ₃ ) powder used in the second embodiment of the present invention is cheaper than the sintered pellet of the metal bismuth (Bi) powder. The manufacturing method according to the second embodiment can manufacture the electron beam reflecting film at a lower cost than the manufacturing method of the electron beam reflecting film made of metal bismuth (Bi).

[0034]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the overall construction of a color cathode ray tube, which is an embodiment of the color cathode ray tube according to the present invention.

In FIG. 1, 1 is a panel portion, 2 is a neck portion, 3 is a funnel portion, 4 is a face plate, 5 is a fluorescent film, 6 is a shadow mask constituting a color selection electrode, and 6R
Is an electron beam reflecting film, 7 is a mask frame, 8 is a deflection yoke, 9 is an electron gun, 10 is a purity adjusting magnet,
11 is a center beam static convergence adjustment magnet, 12 is a side beam static convergence adjustment magnet, 13 is an internal magnetic shield,
14 is an electron beam.

The tubular body constituting the color cathode ray tube comprises a large-diameter panel portion 1 arranged on the front side, an elongated neck portion 2 which houses an electron gun 9 therein, a panel portion 1 and a neck portion 2. It is composed of a funnel-shaped funnel portion 3 connected to each other.
The panel portion 1 is provided with a face plate 4 on the front surface, and a fluorescent film 5 is formed on the inner surface of the face plate 4 by adhesion. A mask frame 7 is fixedly arranged on the inner peripheral edge of the panel unit 1, and the shadow mask 6 is attached by the mask frame 7 so as to face the fluorescent film 5. Bismuth oxide (Bi ₂ O ₃ ) is formed on the surface of the shadow mask 6 on which the electron beam 14 projected from the electron gun 9 collides.
An electron beam reflecting film 6R made of a thin film is formed.
An internal magnetic shield 13 is provided inside the coupling portion between the panel portion 1 and the funnel portion 3, and a deflection yoke 8 is provided outside the coupling portion between the funnel portion 3 and the neck portion 2. The three electron beams 14 (only one is shown) projected from the electron gun 9 are deflected in a predetermined direction by the deflection yoke 8 and then projected onto the fluorescent film 5 through the shadow mask 6 so that the neck portion is formed. A purity adjusting magnet 10, a center beam static convergence adjusting magnet 11 and a side beam static convergence adjusting magnet 12 are arranged side by side on the outside of 2.

[0038] Figure 2, the color cathode ray tube of the shadow mask 6 of the embodiment shown in FIG. 1, bismuth oxide (Bi ₂
FIG. 3 is a cross-sectional configuration diagram of a vacuum vapor deposition device that forms an electron beam reflection film 6R made of an O ₃ ) thin film.

In FIG. 2, 15 is a vacuum vapor deposition device, and 16
Is a vacuum container, 17 is a color selection electrode (shadow mask) mount, 18 is a support, 19 is an iridium (Ir) -platinum (Pt) alloy boat, 19D is a substantially trapezoidal deposition sample mount, Reference numeral 20 is a pellet obtained by high-density pressing bismuth oxide (Bi ₂ O ₃ ) powder, reference numeral 21 is a power source, and other components that are the same as those shown in FIG.

Inside the vacuum vessel 16, the color selection electrode mounting portion 17, the support 18, the iridium (Ir) -platinum (P
t) The boats 19 made of alloy are respectively arranged, and the vacuum vapor deposition device 15 is configured in its entirety. In this vacuum vapor deposition device 15, the shadow mask 6 is placed on the color selection electrode placement part 17 with the surface on which the electron beam is projected facing down, and the color selection electrode placement part 17 is placed on the support base 18. Will be placed. The boat 19 made of iridium (Ir) -platinum (Pt) alloy is
A substantially trapezoidal vapor deposition sample mounting portion 19D is provided in the center, and bismuth oxide (Bi ₂
A pellet 20 obtained by high-density pressing O ₃ ) powder is placed. Both ends of the boat 19 made of an iridium (Ir) -platinum (Pt) alloy are connected to a power source 21, and the vapor deposition sample mounting portion 19D is heated by the energization from the power source 21.

In this embodiment, the electron beam reflecting film of the color cathode ray tube is manufactured as follows.

First, the vacuum vessel 16 is released to maintain the inside at atmospheric pressure, and the iridium (I
r) - platinum (Pt) bismuth oxide deposition sample mounting portion 19D of the alloy of the boat 19 (Bi ₂ O ₃₎ pellet 20 and the powder was high density pressed, for example, bismuth oxide having an average particle diameter of 1 [mu] m (Bi ₂ The O ₃ ) powder is pressed densely and pellets 20 weighing about 500 mg are placed.

Next, the shadow mask 6 made of iron (Fe) -nickel (Ni) alloy having a thickness of 50 to 300 μm and having a blackened surface is placed on the color selection electrode placement portion 17.

Then, a vacuum pump (not shown) connected to the vacuum container 16 is operated to evacuate the vacuum container 1.
The residual gas pressure in 6 is set to 2 × 10 ⁴ Torr or less.
After that, power of 800 W from the power source 21 is supplied to the iridium (I
r) -platinum (Pt) alloy boat 19 is added for 10 seconds, the vapor deposition sample mounting portion 19D is preheated and bismuth oxide (B
i ₂ O ₃ ) is melted.

Then, iridium (Ir) -platinum (P
t) The electric power applied to the alloy boat 19 is increased to 2.3 KW, and the vapor deposition sample mounting portion 19D is heated for 10 seconds to vaporize bismuth oxide (Bi ₂ O ₃ ). At this time, for example, a film thickness of 3 is formed on the electron beam projection surface of the shadow mask 6.
At 0 nm, the bulk density is about 8.6 g / cm ^3. Bismuth oxide (Bi ₂ O ₃ ) thin film 6R is deposited.

FIG. 3 shows the shadow mask (color selection electrode) formed of bismuth oxide (B) using the vacuum deposition apparatus shown in FIG.
i ₂ O ₃ ) It is an explanatory view showing an example of measurement points of the film thickness of the thin film 6R when the thin film 6R is formed, and the film thickness was measured using an M100 type optical interference film thickness meter manufactured by Sloan Co., USA. It is a thing.

In FIG. 3, the shadow mask 6 has a length-to-width ratio of 3: 4 and a diagonal length of 51 cm, and points O, A, and B in the figure represent measurement points of the film thickness. Show. In this case, the point O is the central portion of the shadow mask 6, and the point A is a distance I from the point O along the long side direction (XX direction).
It is a point separated by (17 cm), and point B is a point separated by a distance m (23 cm) from the point O along the diagonal direction.

The film thickness of the bismuth oxide (Bi ₂ O ₃ ) thin film 6R is measured by measuring the film thickness at each of point O, point A and point B, and obtaining the average value of the measured values. , The film thickness of the bismuth oxide (Bi ₂ O ₃ ) thin film 6R is measured.

In this case, the film thickness of the bismuth oxide (Bi ₂ O ₃ ) thin film 6R can be measured by the measuring means as described above.
Measurement using an optical microscope, scanning electron microscope (SE
Measurement by cross-section observation according to M) may be performed.

The bismuth oxide (Bi ₂ O ₃ ) thin film 6
The bulk density of R is a value obtained by measuring the mass of a bismuth oxide (Bi ₂ O ₃ ) vapor-deposited film vapor-deposited on a fixed area, the measured film thickness, and the formation area of the bismuth oxide (Bi ₂ O ₃ ) vapor-deposited film. And the volume of the bismuth oxide (Bi ₂ O ₃ ) vapor-deposited film obtained from the above.

Next, FIG. 5 is a characteristic diagram showing the relationship between the film thickness of the electron beam reflection film 6R formed on the shadow mask (color selection electrode) and the halation level (display image deterioration degree) of the color cathode ray tube. Yes, bismuth oxide (Bi
The color cathode ray tube of the present embodiment provided with an electron beam reflective film having a bulk density of ₂ O ₃ ) thin film of 7 g / cm ³ ,
2 shows the halation level of a known color cathode ray tube provided with an electron beam reflective film having a bulk density of 0.1 g / cm ³ formed by the powder spray method disclosed in JP-A-2-123635.

Here, the halation level (display image deterioration degree) of the color cathode ray tube is obtained by measuring the chromaticity value of the monochromatic red, and the monochromatic red is displayed on the color cathode ray tube fluorescent film, and the spectrophotometer is used. CIE (Commission)
International de l'Eclai
Rage) x, y chromaticity values are measured, and the z value is calculated by the following equation (1).
Ask by.

Z = 1- (x + y) ... (1) Further, in a color cathode ray tube provided with a shadow mask (color selection electrode) on which an electron beam reflection film is not formed,
Using the value z ₀ calculated in the same manner, the value of the halation level H is calculated by the following equation (2).

H = {(z−z ₀ ) / z ₀ } × 100 ... (2) In the equation (2), the halation level H is smaller and better as the value is closer to 0.

As shown in FIG. 5, bismuth oxide (B
The color cathode ray tube of this embodiment in which the thickness of the i ₂ O ₃ ) thin film, that is, the thickness of the electron beam reflecting film 6R is 5 to 700 nm, has a halation level (display image deterioration degree) of 0. The known color cathode ray tube in which the film thickness of the electron beam reflecting film cannot be set to 1 μm or less, while the level is almost constant at a near level, has a halation level H of at least 10 or more, and the color of the present embodiment is the same. It can be seen that the cathode ray tube has a very good halation level (display image deterioration degree).

In this case, in the color cathode ray tube of this embodiment, the electron beam reflecting film, that is, bismuth oxide (Bi) is used.
₂ O ₃ ) Since the thin film 6R is formed by vapor deposition,
The film thickness can be easily adjusted within the range of 5 to 700 nm, and a very good color cathode ray tube with a reduced halation level (display image deterioration degree) can be obtained. The color cathode-ray tube of No. ₂ has a bismuth oxide (Bi ₂
Since the powder spray method of spraying O ₃ ) powder is used, the bulk density of the obtained electron beam reflecting film is 0.1.
When the film thickness is as low as g / cm ³ and the film thickness is 1 μm or less, it becomes a porous film, and the incident electron beam is not reflected by the electron beam reflecting film, and bismuth oxide (B
i ₂ O ₃₎ becomes penetrate between the particles. For this reason, the known color cathode ray tube has a poor halation level (deterioration degree of display image), and the doming suppression rate also becomes poor as described later.

FIG. 6 is a characteristic diagram showing the relationship between the bulk density of the electron beam reflection film formed on the shadow mask (color selection electrode) and the doming suppression rate. It is expressed as a parameter.

In order to obtain the characteristic diagram shown in FIG. 6, the bulk density of the electron beam reflecting film is changed by changing the deposition rate during bismuth oxide (Bi ₂ O ₃ ) deposition and the residual gas pressure of the vacuum deposition apparatus. ing. In this case, the deposition rate is slow,
When the residual gas pressure is high, the bulk density is low.

The doming suppression rate is determined by the amount of movement of the electron beam on the fluorescent film 5 in the color cathode ray tube (the former) provided with a shadow mask (color selection electrode) having no electron beam reflecting film, and the electron beam reflecting film 6R. The amount of electron beam movement on the fluorescent film 5 in the color cathode-ray tube (latter) provided with the shadow mask (color selection electrode) having the above was measured by a microscope and obtained from the measurement result. That is,
The amount of electron beam movement after the fluorescent films in the former and latter two color cathode ray tubes were excited with a constant current for a certain period of time with a microscope, and the measured values of the latter were used to measure the latter ( The reduction amount of the former measured value (electron beam movement amount) with respect to the electron beam movement amount) is expressed as a percentage to obtain the doming suppression rate. The higher the doming suppression rate, the better.

As shown in the characteristic diagram of FIG. 6, the doming suppression rate gradually increases as the bulk density of the electron beam reflecting film increases, but as in the color cathode ray tube of this embodiment, the shadowing rate is reduced. Mask (color selection electrode) 6
When the film thickness of the electron beam reflection film 6R formed on the substrate, that is, the bismuth oxide (Bi ₂ O ₃ ) thin film is set to 5 to 700 nm, its bulk density is in the range of 4 to 9.3 g / cm ³ (electron beam The mass per unit area of the reflective film is 2 x 1
0 to ^{6 to} 6.5 × 10 ⁴ g / cm ³ ), whereby the color cathode ray tube of the present embodiment can have a doming suppression rate of at least 30% or more.

Further, in the color cathode ray tube of this example, the molar ratio of bismuth to oxygen in the vapor-deposited bismuth oxide (Bi ₂ O ₃ ) thin film was determined by SEM-WDX (Scannin).
gElectron Microscope-Wave
length Dispersive X-ray S
analysis method (Hitachi SEM-W
According to the analysis by DX650 type), bismuth was in the range of 0.5 to 0.7 mol with respect to 1 mol of oxygen, which was close to the theoretical value (0.67 mol). Incidentally, the known color cathode ray tube has a bulk density of the electron beam reflecting film formed by the powder spray method of 0.1 g.
Since it is not possible to make it above / cm ³ , it is not possible to make the doming suppression rate above 30%, as is clear from the characteristic diagram of FIG. Further, in the color cathode ray tube of the present embodiment, impurities contained in the vapor-deposited bismuth oxide (Bi ₂ O ₃ ) thin film were subjected to SEM-EDX (Scannin).
gElectron Microscope-Ener
gy Dispersive X-ray Spect
The metal component contained in the boat 19 on which the vapor deposition sample is placed was below the detection limit value (1 ppm) of the analyzer.

Next, FIG. 7 shows a case where a shadow mask (color selection electrode) 6 is formed with a bismuth oxide (Bi ₂ O ₃ ) thin film 6R having a bulk density of 7 g / cm ³ in the color cathode ray tube of this embodiment. FIG. 5 is a characteristic diagram showing a relationship among a film thickness, a halation level (display image deterioration degree), and a doming suppression rate.

As shown in the characteristic diagram of FIG. 7, when the bismuth oxide (Bi ₂ O ₃ ) thin film 6R according to the present embodiment is formed, the halation level (display image deterioration) in the thickness range of 5 to 500 nm. Degree) is almost 0,
The halation level (display image deterioration degree) is 5 or less even when the film thickness is in the range of 500 nm to 700 nm. Further, the doming suppression rate is at least 30% or more in the film thickness range of 5 to 100 nm, but becomes about 55% of the constant value in the film thickness range of 100 to 700 nm.

On the basis of these results, the color cathode ray tube of the present embodiment shows that the electron beam reflection film 6R formed on the shadow mask (color selection electrode) 6, that is, bismuth oxide (B).
i ₂ O ₃ ) thin film with a thickness of 5 to 700 nm
Since the selection is made within the range, as shown in FIG. 7, the doming suppression rate can be set to 30% or more, and the halation level (display image deterioration degree) does not form the electron beam reflection film. It is possible to obtain a very good color cathode ray tube which is almost the same as the above.

In the color cathode ray tube of this embodiment, the shadow mask (color selection electrode) 6 has bismuth oxide (Bi ₂ O).
₃ ) Since the electron beam reflecting film 6R made of a thin film is formed, a color cathode line capable of high-density and high-definition image display without fatal pixel defects without causing mask clogging or deformation of electron beam transmission holes. A tube is obtained.

According to the method of manufacturing a color cathode ray tube of this embodiment, the electron beam reflecting film 6R made of a bismuth oxide (Bi ₂ O ₃ ) thin film is formed on the electron beam projection surface of the shadow mask (color selection electrode) 6. Iridium (I
r) -Platinum (Pt) alloy boat 19 and pellets 20 obtained by high-density pressing bismuth oxide (Bi ₂ O ₃ ) powder
Since the pellets 20 are uniformly heated on the boat 19 by using, the deposition rate of the bismuth oxide (Bi ₂ O ₃ ) thin film is increased and the pellets 20 do not chemically react with the boat 19. On the shadow mask (color selection electrode) 6, it is possible to form the electron beam reflection film 6R made of a homogeneous bismuth oxide (Bi ₂ O ₃ ) thin film having a high bulk density.

In this embodiment, the case where the color selection electrode is the shadow mask 6 has been described as an example.
The color selection electrode according to the present invention is not limited to being a shadow mask, but can be similarly applied to other similar ones, for example, an aperture grill.

Further, in the present embodiment, the boat 19 on which the vapor deposition sample is placed is iridium (Ir) -platinum (Pt).
Although the case where the boat is made of an alloy is described as an example, the constituent material of the boat 19 according to the present invention is iridium (I).
r) -platinum (Pt) alloy is not the only one, and platinum (Pt) alone may be used.
s), palladium (Pd), rhodium (Rh), or ruthenium (Ru) and a platinum (Pt) alloy made of an alloy of platinum (Pt) or the like. In this case, at least the surface of the boat 19 on which the vapor deposition sample is placed should be covered with platinum (Pt) or the platinum (Pt) alloy. For heating, it is possible to use not only resistance heating but also heating means such as high frequency heating, infrared heating, and electron beam heating.

Further, in the present embodiment, the case where the pellet 20 obtained by high-density pressing bismuth oxide (Bi ₂ O ₃ ) powder, which has good workability and can be automated, is used as the vapor deposition sample. As described above, the vapor deposition sample according to the present invention is not limited to such a pellet sample, and bismuth oxide (Bi ₂ O ₃ ) powder may be used as it is.

Further, in the case of constructing the boat 19 in this embodiment, as shown in FIG. 4, the portion of the substantially trapezoidal vapor deposition sample placing portion 19D on which the vapor deposition sample is not placed is formed into a waveform. By providing the thermal expansion absorbing portion 22 that absorbs the mechanical stress of expansion and contraction due to heat, the mechanical stress of the boat 19 that expands and contracts with heating can be absorbed.

[0071]

As described above, according to the color cathode ray tube of the present invention, the electron beam reflection film formed on the electron beam projection surface of the color selection electrode has a bulk density of 4 to 9.3 g / cm.
^Three Since it was composed of the bismuth oxide (Bi ₂ O ₃ ) thin film of
Bismuth balls are formed during the heat treatment in the manufacturing process of the color cathode ray tube, and the bismuth balls are peeled off to cause clogging of the mask on the color selection electrode, or the particles forming the electron beam reflecting film are coarse and the film thickness is large. This makes it possible to obtain a fine-pitch color cathode-ray tube capable of displaying a high-density and high-definition image without causing a fatal performance deterioration without causing irregular shapes of the beam transmission holes in the color selection electrode. There is an effect that can be done.

According to the color cathode ray tube of the present invention,
Since the pellet obtained by high-density pressing bismuth oxide (Bi ₂ O ₃ ) powder is cheaper than the sintered pellet of metal bismuth (Bi) powder, it is possible to manufacture the electron beam reflection film at low cost. There is also.

Further, according to the method of manufacturing a color cathode ray tube of the present invention, as a vacuum vapor deposition apparatus for vapor deposition forming an electron beam reflecting film on the electron beam projection surface of the color selection electrode,
A boat made of iridium (Ir) -platinum (Pt) alloy;
Using the pellets high density pressed bismuth oxide (Bi ₂ O ₃₎ powder, when depositing form an electron beam reflecting film on the color selection electrode, bismuth oxide (Bi ₂ O ₃₎ powder pellets, on a boat Since it is heated uniformly and does not cause a chemical reaction with the boat, it accelerates the deposition rate of the electron beam reflection film, and the color selection electrode is made of a homogeneous bismuth oxide (Bi ₂ O ₃ ) thin film with high bulk density. There is an effect that an electron beam reflecting film can be formed.

Further, according to the method of manufacturing a color cathode ray tube of the present invention, the color cathode ray tube in which the electron beam reflecting film is vapor-deposited and formed on the color selection electrode by using the vacuum vapor deposition apparatus causes halation and electron beam transmission of the mask. There is also an effect that the deterioration of the hole shape is prevented and the occurrence of mask doming can be suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an overall configuration of a color cathode ray tube, which is an embodiment of the color cathode ray tube according to the present invention.

FIG. 2 shows a color selection electrode of the color cathode ray tube shown in FIG.
It is a sectional view of a vacuum deposition apparatus for forming an electron beam reflecting film made of bismuth oxide (Bi ₂ O ₃₎ thin film.

FIG. 3 is an explanatory diagram showing an example of measurement points of the film thickness of a bismuth oxide (Bi ₂ O ₃ ) thin film formed on a color selection electrode using the vacuum vapor deposition apparatus shown in FIG. .

FIG. 4 is a perspective view showing an example of a configuration of a vapor deposition sample mounting portion in the vacuum vapor deposition apparatus shown in FIG.

FIG. 5 is a characteristic diagram showing a relationship between a film thickness of an electron beam reflective film formed on a color selection electrode and a halation level (display image deterioration degree) of a color cathode ray tube.

FIG. 6 is a characteristic diagram showing the relationship between the bulk density of an electron beam reflective film formed on a color selection electrode and the doming suppression rate.

FIG. 7 shows the relationship between film thickness, halation level (display image deterioration degree) and doming suppression rate when a bismuth oxide (Bi ₂ O ₃ ) thin film is formed on a color selection electrode in the color cathode ray tube of the present embodiment. FIG.

[Explanation of symbols]

1 Panel Part 2 Funnel Part 3 Neck Part 4 Face Plate 5 Fluorescent Film 6 Color Selection Electrode (Shadow Mask) 6R Electron Beam Reflective Film 7 Mask Frame 8 Deflection Yoke 9 Electron Gun 10 Purity Adjustment Magnet 11 Center Beam Static Convergence Adjustment Magnet 12 Side Beam Static Convergence Adjustment Magnet 13 Inner Magnetic Shield 14 Electron Beam 15 Vacuum Evaporator 16 Vacuum Container 17 Color Selection Electrode (Shadow Mask) Placement 18 Supporting Base 19 Boat 19D Evaporation Sample Placement 20 Bismuth Oxide (Bi ₂₎ O ₃ ) Pellets obtained by pressing powder with high density 21 Power supply 22 Thermal expansion absorption part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Muto 3300 Hayano, Mobara-shi, Chiba Electronic device division, Hitachi, Ltd. (72) Politics Kumata Kumada 3300 Hayano, Mobara-shi, Chiba Hitachi, Ltd. Electronic device Within the business unit

Claims (13)

[Claims] 1. A panel section having a fluorescent film formed on an inner surface thereof, a neck section having an electron gun housed therein, a funnel section connecting the panel section and the neck section, and the inside of the panel section. In a color cathode ray tube provided with a color selection electrode having a large number of electron beam transmission holes for transmitting an electron beam projected from the electron gun, the electron beam of the color selection electrode. A color cathode ray tube, characterized in that an electron beam reflection film made of a bismuth oxide (Bi ₂ O ₃ ) thin film having a bulk density of 4.0 to 9.3 g / cm ³ is formed on the surface which collides with. 2. The color cathode ray tube according to claim 1, wherein the electron beam reflecting film made of the bismuth oxide (Bi ₂ O ₃ ) thin film has a film thickness of 5 to 700 nm. 3. The electron beam reflection film made of the bismuth oxide (Bi ₂ O ₃ ) thin film has a weight per unit area of 2 × 1.
The color cathode ray tube according to claim 1, wherein the color cathode ray tube has a weight of 0 to ^{6 to} 6.5 × 10 to ⁴ g / cm ² . 4. The electron beam reflective film comprising the bismuth oxide (Bi ₂ O ₃ ) thin film has a molar ratio of bismuth atoms to oxygen atoms in the range of 0.5: 1 to 0.7: 1. The color cathode ray tube according to claim 1, which is characterized in that. 5. The electron beam reflection film made of the bismuth oxide (Bi ₂ O ₃ ) thin film has a film thickness of 1% or less of a plate thickness of the color selection electrode. Color cathode ray tube. 6. A panel section having a fluorescent film formed on an inner surface thereof, a neck section accommodating an electron gun, a funnel section connecting the panel section and the neck section, and the fluorescent section inside the panel section. A method of manufacturing a color cathode ray tube, comprising: a color selection electrode having a number of electron beam transmitting holes, which are arranged to face each other and are spaced apart from each other, for transmitting an electron beam projected from the electron gun; From the evacuation means of the vacuum container, the sample mounting part installed in the vacuum container, the sample mounting surface is platinum or platinum alloy, the color selection electrode mounting part, and the heating means of the sample mounting part. Using the vacuum vapor deposition apparatus described above, placing bismuth oxide (Bi ₂ O ₃ ) on the sample placing part, placing a color selecting electrode on the color selecting electrode placing part, and Exhausting the gas by the exhaust means, And a process of vaporizing serial bismuth oxide (Bi ₂ O ₃₎ is heated by the heating means, bismuth oxide on the color selection electrode (Bi ₂ O ₃₎ that is deposited an electron beam reflecting film formed of a thin film And a method for manufacturing a color cathode ray tube. 7. The electron beam reflective film comprises a bismuth oxide (Bi ₂ O ₃ ) thin film having a bulk density of 4.0 to 9.3 g.
The method for producing a color cathode ray tube according to claim 6, wherein the vapor deposition is performed so that the color cathode ray tube has a thickness of / cm ³ . 8. The sample mounting surface in the vacuum vapor deposition apparatus is
The color according to claim 6, which is formed of a platinum alloy containing at least one of iridium (Ir), osmium (Os), palladium (Pd), rhodium (Rh), and ruthenium (Ru). Method for manufacturing cathode ray tube. 9. The sample mounting surface of the vacuum vapor deposition apparatus is
7. The method of manufacturing a color cathode ray tube according to claim 6, wherein the color cathode ray tube has a substantially trapezoidal shape and has a shape that relieves mechanical stress caused by thermal expansion and contraction. 10. The exhaust means in the vacuum vapor deposition apparatus comprises:
7. The method of manufacturing a color cathode ray tube according to claim 6, wherein the vacuum container is evacuated to a pressure of 10 to ⁴ Torr or less during the process of evacuating the vacuum container. 11. The heating means in the vacuum vapor deposition apparatus comprises:
During the process of vaporizing the bismuth oxide (Bi ₂ O ₃ ), the bismuth oxide (B 2
The color cathode ray tube according to claim 6, wherein i ₂ O ₃ ) is vaporized. 12. The heating means in the vacuum vapor deposition apparatus comprises:
The method for manufacturing a color cathode ray tube according to claim 6, wherein the bismuth oxide (Bi ₂ O ₃ ) is vaporized by infrared heating during the step of vaporizing the bismuth oxide (Bi ₂ O ₃ ). 13. The heating means in the vacuum vapor deposition apparatus comprises:
The bismuth oxide by electron beam heating during a process of vaporizing the bismuth oxide _{(Bi 2 O 3) (Bi} 2 O 3)
7. The method for manufacturing a color cathode ray tube according to claim 6, wherein the method is for vaporizing