JPS58189290A - Cathode ray tube for display - Google Patents

Abstract

PURPOSE:The titled cathode ray tube with high luminance having a toxic material-free fluorescent face, which is made by forming a fluorescent film of a specified long afterglowing, green to greenish yellow light emitting fluorescent material on a face plate opposing an electron gun. CONSTITUTION:Zns as a matrix is activated with 10<-4>-10<-1>wt% Cu and/or Au as an activator, 10<-6>-10<-1>wt% Ga and/or In as a first activator and 5X 10<-6>-5X10<-2>wt% at least one second activator selected from Cl, Br, I, F and Al to obtain a long atterglowing, green to greenish yellow light emitting fluorescent material of a particle size of several mu to several tens of mu. Then the neck portion 2 of a funnel 1 is provided with an electron gun 3 radiating a cathode ray with a beam diameter on a fluorescent face fo 0.05-0.4mm. and frame frequency of 20-50Hz, a fluorescent film 5 primarily composed of said fluorescent material is provided on the entire surface of a face plate 4 opposing the electron gun 3, and a deposit Al film is provided on the back surface of the face plate 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cathode ray tube for displays that emit green light, and more particularly to a cathode ray tube for displays that does not contain any harmful substances and has a high brightness, long afterglow green emitting fluorescent film.

In recent years, high-resolution display cathode ray tubes have been desired to be used in computer terminal display devices, aircraft control system display devices, etc. that display detailed characters and graphics.

The phosphor film of such a cathode ray tube for high-resolution displays needs to be composed of a phosphor with long afterglow properties. this is,
When the phosphor film of a cathode ray tube is composed of a short afterglow phosphor,
This is because flickering occurs on the screen due to the slow scanning speed of the fluorescent film. In general, the phosphor constituting the phosphor film of such a high-resolution display cathode ray tube has an afterglow time (herein, the time required for the luminance to drop to 10% of the excitation level after excitation is stopped, or " 10% afterglow time) is required to be several tens to hundreds of times longer than that of the short afterglow phosphor that constitutes the phosphor film of an ordinary cathode ray tube. In particular, cathode ray tubes for green-emitting high-resolution displays (
Cathode ray tubes (hereinafter abbreviated as cathode ray tubes) have visibility in the green range for the human eye, so even with the same emission energy, they can be perceived as having higher brightness than other emission colors, and even when viewed for long periods of time, there is less visual fatigue. Therefore, it is used in many of these applications.

Conventionally, manganese and arsenic-activated zinc silicate phosphors (P39 phosphors) and the like have been known as long-afterglow green-emitting phosphors used in such cathode ray tubes. This phosphor is the only long-afterglow green-emitting phosphor currently in practical use in terms of both emission brightness and afterglow time, and is used in large quantities. However, as the practical use of cathode ray tubes has progressed in recent years, the arsenic contained in this P39 phosphor has become a pollution problem, and cathode ray tubes using long-afterglow green-emitting phosphors that do not contain any pollutants have become a problem. It was hoped that it would appear. In addition, the P39 phosphor is a fine particle with an average particle size of 2 to 3μ, and even large particles are 5μ or less. The particle size distribution is also wide. On the other hand, at present, the particle size of the phosphor applied to the fluorescent surface is generally one having a median value of about 6 to 12 microns and a narrow particle size distribution from the viewpoint of coating characteristics, luminous efficiency, etc. Due to this point and the crystal shape, the P39 phosphor has poor coating characteristics. Furthermore, when classification is performed to obtain phosphors with uniform particle size, the yield decreases significantly;
Furthermore, when mixed with other phosphors, there are drawbacks such as uneven coating due to the difference in particle size.

An object of the present invention is to provide a green-emitting cathode ray tube having a fluorescent surface that is free of pollutants.

Another object of the present invention is to provide a cathode ray tube that emits green light with higher brightness than conventional cathode ray tubes.

In order to achieve the above object, the present inventors have conducted various studies on green-emitting cathode ray tubes that do not contain pollutants and have a good fluorescent surface. The inventors discovered that the above problems could be solved by a cathode ray tube consisting of a zinc sulfide phosphor activated with a specific amount of an activator, a phosphor film, and an electron gun having a specific beam diameter and frame frequency, and completed the present invention. reached.

The cathode ray tube of the present invention that emits a single color has a beam diameter of 0.05 to 0.41 RIK at the fluorescent surface and includes an electron gun that emits cathode rays with a frame frequency of 20 to 501 (z). On the face plate facing the electron gun, zinc sulfide is used as a matrix, copper or copper and gold is used as an activator, at least one of gallium or indium is used as a first co-activator, chlorine, bromine, One or more of iodine, fluorine and aluminum is used as the second co-activator, and the amounts of the first co-activator and the second co-activator are respectively adjusted to the base material. 10-4 to 10-1% by weight,
10-6 to 10-1 heavy plate% and 5 X 10'-' to
It is characterized by forming a phosphor film whose main component is a long-afterglow green to yellow-green emitting phosphor of 5 x 10 -2% by weight.

Here, exhibiting a single luminescent color means exhibiting a green luminescent color, and it is also possible to use a mixture of a single luminescent phosphor or a green luminescent phosphor.

The cathode ray tube of the present invention does not contain any pollutants such as arsenic in its fluorescent film, emits high-intensity light, and can emit light of any color from green to yellow-green by selecting the type and amount of activator. Long afterglow emission can also be obtained. Further, the afterglow time can be selectively obtained from several milliseconds to several hundred milliseconds by adjusting the activation amounts of the first coactivator and the second coactivator. Unlike the conventional long afterglow phosphor mentioned above, the coating properties are good and a good fluorescent film can be obtained.Furthermore, in combination with the electron gun, excellent image quality (resolution, gradation, etc.) for display use can be obtained. A cathode ray tube with high brightness, etc. is obtained.

The sulfide phosphor of the present invention has the same matrix as the conventionally known activator of copper or copper and gold, and the second co-activator and the co-activator. The afterglow time after excitation by electron beams, ultraviolet rays, etc. is stopped is several tens to hundreds of times longer than that of sulfide phosphors. The phosphor used in the present invention has a cubic or hexagonal crystal phase as its main crystal phase depending on the composition and firing temperature during production, but it is better to use a phosphor with a cubic system as its main crystal phase. The first co-activator (Ga, In) provides a phosphor that exhibits higher luminance than a phosphor having a hexagonal system as a main crystal phase, and also exhibits higher luminance and color purity.
Within the activation amount range, the former has a longer afterglow time than the latter. From this point of view, among the phosphors of the present invention, phosphors having a cubic system as a main crystal phase are more preferable than phosphors having a hexagonal system as a main crystal phase.

Note that the values of afterglow time mentioned in this invention are based on the assumption that the current density of the stimulating electron beam emitted from the electron gun is 0.4 μA.
/, is the value when .

The phosphor used in the present invention has a characteristic that conventional long-afterglow phosphors do not have, in that the afterglow time varies greatly depending on the current density of the stimulating electron beam, and generally, this tendency tends to change as the current density decreases. Afterglow time becomes longer.

The present invention will be explained in detail below.

As shown in FIG. 1, the structure of the cathode ray tube of the present invention is almost the same as that of a conventional monochromatic cathode ray tube such as a cathode ray tube for black and white television, except for the electron gun and fluorescent film components. That is, in the cathode ray tube of the present invention, an electron gun 3 is provided in the neck portion 2 of the funnel 1, and a face plate 4 facing the electron gun 3 is provided.
A fluorescent film 5 is formed on the entire upper surface. Generally, an aluminum vapor deposited film 6 is provided on the back surface of the fluorescent film 5 to prevent charge-up during excitation. The cathode ray tube constructed in this manner is characterized by comprising a phosphor film 5 made of a phosphor that emits a specific long afterglow green to yellowish green, and an electron gun 3 having a specific beam diameter and frequency. .

Regarding the manufacturing method of the long afterglow green to yellow-green emitting phosphor used in the present invention, a patent application previously filed by the applicant in 1973
Please refer to No. 7 25545 for a detailed explanation.

The long-afterglow green to yellow-green emitting phosphor thus obtained uses 11F lead sulfide as the host, copper or one of copper and gold as the active agent, and at least one of gallium or indium as the primary active agent. As a co-activator for chlorine, bromine, iodine,
At least one of fluorine and aluminum is added as a second
as a co-activator, and the amounts of the activator, the first co-activator, and the second co-activator are 10-4 to 10-4 relative to the base material, respectively.
10-1% by weight, 10-6 to 10-1% by weight and 5
X 10"-' to 5XIO" weight percent. Further, the amount of each of the activators is 10 to 5 x 10% by weight, 5 x 10' to 5% by weight, respectively, based on the base material.
X ], O-2 wt% and 5×10-2
], O-2% by weight is more preferable. (In addition,
This phosphor has 10-5 to 8
The case where sulfur of XlO' weight % is contained is also included. ).

The emission color of this phosphor varies from green to yellow-green depending on the type of activator and its activation amount. Generally, the activator is copper (
Cu ), it emits green light, and when the activator is copper and gold (Au) and the amount of AuO activation is increased, the color changes from green to yellow-green.The afterglow characteristics (afterglow time, etc.) ) is mainly determined by the selected type and activation amount of the first co-activator and the selected type and activation amount of the second co-activator.

Further, the electron gun used in the present invention emits cathode rays having a beam diameter of 0.05 to 0.4 mm at the fluorescent surface and a frame frequency of 20 to 501 (z).

An example of the emission spectrum of the cathode ray tube of the present invention is shown in FIG.
The afterglow characteristics are shown in Figure 3. Here, we will show a case of a green-emitting cathode ray tube using a cubic copper, gallium, and aluminum old zinc sulfide phosphor as the phosphor.

As shown in FIG. 2, the cathode ray tube of the present invention exhibits good green light emission similar to that used for the green light emission component of conventional color cathode ray tubes. In addition, as shown in curve ia in Fig. 3, it shows an afterglow time of about 40 milliseconds, and as shown in curve 1) (when conventional ZnS Cu, A/! phosphor is used as a phosphor film) The afterglow time is about 200 microseconds, which is sufficient for display purposes.

1st! The figure shows the relationship with the afterglow time of a cathode ray tube obtained when the activity M of the first co-activator of the Jl filter phosphor used in the present invention is changed. In this figure, curve 1 is the case where gallium (Ga) is selected as the first co-activator, and curve 1) is the case where indium (4n) is selected.

Point A in FIG. 5 indicates the emission color (green) of the cathode ray tube of the present invention.
shows.

In the present invention, a part of Co is used instead of the activator Cu.
When substituting u (0 to 5 X ], O'' weight % range), the luminescent color changes to the yellow-green color shown at point B.

The emitted light color shown at point C is when a conventional P39 phosphor is used. Compared to this, the cathode ray tube of the present invention has a brighter screen because it is closer to the yellow-green color for which the human eye has the highest visibility. is obtained. Further, when using a P39 phosphor, the emission color cannot be changed at all, but in the case of the present invention, a cathode ray tube with a desired emission color between approximately point B and point B can be provided.

Further, since the phosphor used in the present invention has a matrix of zinc sulfide, the particle size can be easily obtained from several microns to more than ten microns depending on the manufacturing method. In addition, since P39 phosphor is a flat particle, it is difficult to obtain a good phosphor film (but
Since the phosphor used in the present invention has a substantially spherical shape, a good phosphor film can be obtained.

As described above, the cathode ray tube of the present invention has a luminescent color closer to human visibility and a good phosphor film, so that it can emit light with higher brightness than conventional cathode ray tubes.

Incidentally, a small amount of a conventionally known green-emitting or yellow-green emitting phosphor may be mixed with the phosphor used in the present invention to adjust the emission color and afterglow characteristics. Further, in the phosphor used in the present invention, a part of the first coactivator may be replaced with scandium. Further, the phosphor of the present invention includes divalent europium,
It may be further activated with an activator such as bismuth or antimony. Furthermore, in the phosphor of the present invention, part of the sulfur may be replaced with selenium in order to shift the emission wavelength to a slightly longer wavelength side.

Additionally, pigments can be attached to or mixed with the phosphors used in the present invention to improve the contrast of the phosphors. As a pigment described in the previous publication, there is a pigment that has a green body color that is almost the same as the luminescent color of the phosphor.
A ZnO--CoO--NiO-based oxide green pigment or black pigment (iron oxide, tungsten, etc.) is used, and the pigment is used in an amount of 05 to 40 parts by weight per 100 parts by weight of the phosphor of the present invention.

The sulfide phosphor of the present invention can be subjected to any of the surface treatments and particle size selections used for conventionally known sulfide phosphors.

As described above, the cathode ray tube of the present invention does not contain any pollutants and emits high-intensity green light due to its good fluorescent surface, and has extremely high industrial utility value.

Next, the present invention will be explained by examples.

Example 1 Zinc sulfide raw powder ZnS 1000. j9 Copper sulfuric acid CuSO4-58200,4729 Nitric acid Ga+) Lamb Ga (NO3) a-81-1200,0
86g aluminum sulfate Al2(SO4)3.18
820 3.709 After thoroughly mixing these phosphor raw materials using a ball mill, appropriate amounts of sulfur and carbon were added and the mixture was charged into a quartz crucible. After covering the quartz crucible, the crucible was placed in an electric furnace and fired at a temperature of 9500C for 3 hours. During this firing, the inside of the crucible was in a carbon disulfide atmosphere. The fired product obtained after firing was taken out from the crucible, washed with water, dried, and passed through a sieve. In this way, the activation amounts of copper, gallium, and aluminum are 1.2 x 1, 0-2% by weight, and 1.5% by weight of the zinc sulfide matrix, respectively.
, X 10-” heavy phase % and 3
7.% of the cubic system. nS: Cu, Ga.

A/A phosphor was obtained.

This phosphor is a particle with a medium flame value of 8 microns and a sharp particle size distribution, showing an almost spherical shape.
A fluorescent film was formed by applying the coating to give rY.

Tore, beam radial force O, 1 mm, frame frequency 40
The cathode ray tube of the present invention shown in FIG. 1 was obtained by using an electron gun set at 11z.

The emission spectrum of this cathode ray tube is shown in FIG. 2, and its afterglow time was about 55 milliseconds, so a good display was obtained.

The color of the emitted light was as shown at point A in FIG. This cathode ray tube has an 8% improvement in brightness compared to a cathode ray tube using a conventional P39 phosphor.

Example 2 Indium nitrate (In(N03)) instead of gallium nitrate
3.3H20) was used in the same manner as in Example 1, except that 0.062.9 was used, and the activation amounts of copper, indium, and aluminum were 1.2 x 10'' weight% and 2 x 10-3 of the zinc sulfide matrix, respectively. % by weight and 3X10-2% by weight of ZnS:Cu, In.

An A4 phosphor was obtained.

A cathode ray tube of the present invention was produced in the same manner as in Example 1 after a 5% by weight black iron oxide pigment was adhered to the surface of this phosphor. The afterglow time was about 35 milliseconds, and a cathode ray tube with high brightness and high contrast was obtained.

Example 3 In Example 1, I-IAu (J4.
In the same manner except that 41h00.25 g was added, the fluorescent film was made such that copper, gold, gallium oxide, and aluminum alloy were 1.2 x 10-2% by weight and 1.2% by weight of the zinc sulfide matrix, respectively.
X1n'-"weight%, 1.5x1, 0-"weightIth%t
Cubic system 7 which is 2% by weight of V
．． nS: A cathode ray tube consisting of Co, An, C+r+, and Ae fireflies is YF). Its afterglow time was 40 milliseconds. This cathode ray tube emits yellow-green light, and has a brightness that is 1/2 higher than that of a cathode ray tube that uses a conventional P39 phosphor.
4%) Improvement 1~.

Example 4 Zinc sulfide was precipitated by adding ammonium sulfide to an aqueous zinc sulfate solution while constantly maintaining the pH value of the aqueous solution at 5 by adding sulfuric acid.

The raw zinc sulfide powder prepared in this way contained 7% by weight of zinc sulfide of non-stoichiometric sulfur. "Kono Kagakushuronko": Raw zinc sulfide powder containing a large amount of sulfur 101
07O i.e. zinc sulfide], 000 g-1-sulfur 7
0, '9), copper sulfate (CuSO4-5820) 0
．． 4729, gallium nitrate (Ga(NO3)3.8H2
0) 0.086 g, aluminum sulfate (A/2(S
Example 1 using 3.70 g of O4)a・18H20)
Similarly, copper, gallium, aluminum activation amount and sulfur content are respectively 1.2X10 of zinc sulfide matrix.
-2wt%, 1.5X10”wt%, 3X10”wt%
A ZnS:Cu,Ga,AAi phosphor was obtained containing an excess of sulfur above the stoichiometric amount of 10-4% by weight.

This phosphor has an almost spherical shape with a median particle size of 9 microns and a sharp particle size distribution. This phosphor is coated onto a face plate by a sedimentation method to a concentration of 5 mg ZcIl, and a phosphor film is formed. was formed (a good fluorescent film was obtained).

In addition to this, the beam diameter is 0.2 mm, and the frame frequency is 4 or 5.
The cathode ray tube of the present invention shown in FIG. 1 was obtained by using an electron gun set at Hz. This cathode ray tube emits green light,
Moreover, the afterglow time after the electron beam excitation stopped was about 55 milliseconds. In addition, this cathode ray tube is a cathode ray tube manufactured in exactly the same way except that it uses ZnS:CII, G, I, AJ phosphors (however, the activation amount is the same as above) that does not contain more than the stoichiometric amount of sulfur. The brightness was 10% higher than that of a tube.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the cathode ray tube of the invention, FIG. 2 is a diagram showing the emission spectrum of the cathode ray tube of the invention, FIG. 3 is a diagram showing the afterglow characteristics of the cathode ray tube of the invention, and FIG. A diagram showing the relationship between the activation amount of the first co-activator of the phosphor used in the present invention and the afterglow waiting time of the cathode ray tube. It is a diagram showing chromaticity points of a color system. 1...Funnel 2...Neck part 3...
x Child gun 4...Face plate 5.
...Fluorescent film 6...Aluminum evaporation BM (Voluntary) Procedural amendment Letter to the Commissioner of the Japan Patent Office 1 Indication of case Patent application No. 74007 of 1982 3, Person making the amendment Relationship to the case No patent applicant 6 Number of inventions increased by amendment None Claims (1) Beam diameter applied to fluorescent surface is 0.05 to 0.4 m
m, equipped with an electron gun that emits cathode rays with a frequency of 20 to 50H2,
1) On a spray mill, zinc sulfide is made into the R1 form, and copper; 1. Or use either copper or gold as an activator,
At least one of gallium or indium is used as a first coactivator; at least one of chlorine, bromine, iodine, fluorine, and aluminum is used as a second coactivator; The ratio of the co-activator and the second co-activator is 10-4 to 10-1% by weight and 1% by weight, respectively, with respect to the base material.
0-6~1O-1jli amount% and 5x10-6~5X
A cathode ray tube for a display that emits a single color, characterized by forming a phosphor film mainly composed of a long-afterglow green to yellow-green emitting phosphor of 10-"% by weight. (2) ) The cathode ray tube for display according to claim 1, wherein the electron gun has a beam diameter of 0.01 to 0.3n+m and a frame frequency of 30 to 45H7. an activator, a first co-activator and a second co-activator;
The activation amount of the j activator is 10-3 to 5X10-2% by weight, 5X10-5 to 5XiQ-2% by weight, and 5X1, respectively.
The cathode ray tube for display according to claim 1 or 2, characterized in that the content is 0-5 to 2X10-2% by weight. (/I) A patent characterized in that the phosphor contains 0.5 to 40% by weight of a pigment having a green or glancing body color based on the long afterglow green to yellow-green emitting phosphor. A cathode ray tube for display according to any one of claims 1 to 3. 2- (white light) door [continued m, 1-E book 1, matter f1 Patent application No. 107-7/I (No. 107 2, title of the invention: cathode ray tube for display 3, amended matter f1) Relationship with Patent applicant: Tokyo ?14 r!!fit Matsumachi 2-7-18 Name: Kasei A Ptonics Co., Ltd. 4, Agent 6, Number of inventions increased by amendment None 7,
The following sentence is inserted between lines 4 and 5 on page 9 of the description of the contents of the amendment in column 8 of "Detailed Description of the Invention" of the description to be amended. [Also, in the present invention, the beam diameter at the fluorescent surface refers to the luminous spot emitted at the just focus area when the cathode ray beam is irradiated onto the fluorescent surface, since the diameter of the cathode ray beam cannot be directly measured. It corresponds to the value φ1o (spot diameter defined at a position of 10% of the peak brightness on the brightness distribution) of the emission intensity distribution. ”-58:

Claims (4)

[Claims] (1) Equipped with an electron gun that emits cathode rays with a beam diameter of 005 to 0.4 mm at the fluorescent surface and a frame frequency of 20 to 501-1z, and a sulfide plate on the face plate facing the electron gun. Zinc is used as a matrix, copper or copper and gold is used as an activator, at least one of gallium or indium is used as a first co-activator, chlorine, bromine,
At least one of iodine, fluorine, and aluminum is used as a second coactivator, and the amounts of the activator, first coactivator, and second coactivator are each 10% of the base material.
Formation of a phosphor film mainly composed of a long-afterglow green to yellow-green emitting phosphor that is -4 to 10-1% by weight, 10-6 to 10-1% by weight, and 5X10' to 5X10'' by weight. A cathode ray tube for display use that emits a single color. (2) The cathode ray tube for display according to claim 1, wherein the electron gun has a beam diameter of 001 to 0.3 mm and a frame frequency of 30 to 45 fiz. (3) The activation amount of the inactivator, the first coactivator, and the second coactivator is 10-3 to 5 x 10-2% by weight, respectively;
5 X], 0' to 5 X 1. 3. The cathode ray tube for display according to claim 1 or 2, characterized in that the content is 5X10' to 2X10'' by weight. (4) A patent characterized in that the fluorescent film contains a pigment having a green or black body color in an amount of t, o, 5 to 40% by weight based on the long afterglow green to yellow-green emitting phosphor. A cathode ray tube for display according to any one of claims 1 to 3.