JPS5933154B2 - Green luminescent composition and slow electron beam excitation fluorescent display tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel luminescent composition that emits green light and a low-speed electron beam excited fluorescent display tube using the luminescent composition.

More specifically, the present invention relates to a green light-emitting composition prepared by mixing an appropriate amount of tin oxide (SnO2) and a specific green light-emitting phosphor, and a low-speed electron beam-excited fluorescent display using the light-emitting composition as a fluorescent film. Regarding pipes. As is well known, a low-speed electron beam-excited fluorescent display tube (hereinafter abbreviated as a "fluorescent display tube") has an anode plate having a fluorescent film on one side, and a cathode facing the fluorescent film. The device essentially has a structure in which it is sealed in a vacuum container, and the fluorescent film on the anode plate is excited by the low-speed electron beam emitted from the cathode, causing it to emit light.

1 and 2 are schematic diagrams of typical examples of fluorescent display tubes, with FIG. 1 showing a diode tube and FIG. 2 a triode tube. As shown in FIGS. 1 and 2, a fluorescent film 12 is provided on one side of an anode plate 11 made of an aluminum plate or the like. Anode plate 11 is supported by ceramic substrate 13. A cathode 14 is provided opposite the fluorescent film 12 provided on one side of the anode plate 11,
The fluorescent film 12 is excited by the low-speed electron beam emitted from the cathode 14 and emits light. In particular, in the triode shown in FIG. 2, a grid electrode 15 is provided in the gap between the four intelligence poles 14 and the fluorescent film 12 for controlling or diffusing the low-speed electron beam emitted from the cathode 14. In addition, Figures 1 and 2
In the fluorescent display tube shown in the figure, one cathode 14 is used, but if the fluorescent film 12 has a wide area, two or more cathodes may be provided. There are no restrictions. the anode plate 11 having a fluorescent film 12 on one side;
A ceramic substrate 13 and a cathode 14 (FIG. 1) or an anode plate 11 having a fluorescent film 12 on one side, a ceramic substrate 13, a cathode 14, and a grid electrode 15 (FIG. 2) are enclosed in a transparent container 16 made of glass or the like. The interior 17 is maintained at a high vacuum of 10-5 to 10-9T0rr. Conventionally, zinc-activated zinc oxide phosphor (ZnO:Zn) has been used as a phosphor that emits high-intensity light by slow electron beam excitation.
It has been known.

This phosphor emits high-intensity green-white light when excited by a slow electron beam with an accelerating voltage of several +V to several hundred volts at most.
Fluorescent display tubes having the above-mentioned structure and having a fluorescent film made of ZnO2Zn are widely used industrially as display elements for, for example, desktop computers and various measuring instruments. In this way, fluorescent display tubes with ZnO:Zn as a fluorescent film are in practical use, but the phosphor that emits light by slow electron beam excitation is Zn.
O: Little is known about anything other than Zn, so ZnO:
Fluorescent display tubes in which a fluorescent film is made of a phosphor other than Zn have hardly been known in the past. An object of the present invention is to provide a novel phosphor that emits high-intensity green light by excitation with a slow electron beam.

Another object of the present invention is to provide a novel fluorescent display tube that emits green light.

The inventors of the present invention have conducted various studies with the aim of obtaining a phosphor that emits high-intensity light through slow electron beam excitation and a fluorescent display tube using the phosphor. Ta.
As a result, copper-activated zinc sulfide phosphor (ZnS:Cu), copper and aluminum emit high-brightness green light under electron beam excitation at an accelerating voltage of several KV, but hardly emit light under slow electron beam excitation. Activated zinc sulfide phosphor (ZnS:Cu
．． Al), gold and aluminum activated zinc sulfide phosphor (
ZnS:Au. Al), copper, gold and aluminum activated zinc sulfide phosphors (ZnS:Cu,.Au,.Al), europium activated strontium gallium sulfide phosphors (
SrGa2S4:Eu2+), a manganese-activated zinc silicate phosphor (Zn2SiO4:Mn), whose general formula is (However, Ln is one or more of Y..Gd.Lu and La. The same applies hereinafter.) The phosphor contained in the terbium-activated rare earth oxysulfide phosphor and the general formula represented by (where Ln has the same definition as above, and X satisfies O≦X≦0.
This is a number that satisfies the condition of 5.

The same applies hereafter). A composition obtained by mixing an appropriate amount of a green-emitting phosphor, which is at least one of the phosphors contained in the cerium-activated rare earth aluminate-based phosphor, and tin oxide (SnO2). It has been discovered that this material exhibits high-intensity green light emission under slow electron beam excitation accelerated at an accelerating voltage of several +V to several hundred V at most, and furthermore, a fluorescent display of green light emission using this luminescent composition as a fluorescent film has been developed. This led to the invention of the tube.

That is, the green light-emitting composition of the present invention contains SnO2 and Zn
S: Cu. ZnS:Cu,. Al. ZnS: Au. Al
, Zns:Cu. AulAl. SrGa2S4:Eu2
+, phosphor contained in Zn2SiO4:Mn, Ln2O2S:Tb and Ln3(All-0.GaX)501
2: A mixed composition obtained by mixing Ce with at least one green-emitting phosphor, which is at least one of the phosphors contained in Ce, in which the mixing weight ratio of SnO2 and the green-emitting phosphor is 1:4. It is characterized by being in a range of 9:1 or less. Further, the fluorescent display tube of the present invention has an essential structure in which an anode plate having a fluorescent film on one side and a cathode facing the fluorescent film are enclosed in a container having a vacuum inside. In the tube, the fluorescent film is made of SnO2 and Zns:
Cu. zns:CulAl, ZnS:Au, . Al. Z
nS:Cu,. Au. Al. SrGa2S4:Eu2+
, Zn2siO4:Mn, Ln2O2S:Tb and Ln3(All-0,.GaX),01
A green light-emitting composition formed by mixing at least one of the phosphors contained in 22Ce with a green light-emitting phosphor in a weight ratio of more than 1:4 and less than 9:1. It is characterized by this. SnO2, which is a component of the luminescent composition of the present invention, is a general reagent SnO2 (hereinafter Sn
(referred to as O2 raw powder) or the above-mentioned SnO2 raw powder or sulfate, nitrate, chloride, hydroxide, etc.
SnO obtained by firing a tin compound that can be converted into O2 in air, a neutral atmosphere, or a weakly reducing atmosphere
2 (hereinafter referred to as calcined SnO2) is used.

The firing temperature for obtaining fired SnO2 may be any temperature below the melting point of SnO2 (approximately 1127°C). Note that SnO2 raw powder contains S such as SnO.
Although tin oxides other than nO2 may be mixed in, the presence of these tin oxides other than SnO2 will not adversely affect the light-emitting characteristics as long as it is present in a small amount. On the other hand, ZnS:Cu, ZnS:Cu. Al. ZnS:A
u. Al. ZnS:Cu,. Au,. Al, SrGa2
S4: Eu2+, Zn2SiO4:Mn. Ln2O2S
:Tb and Ln3(Al,-0.Gax)5012:
Ce was manufactured by a conventionally known manufacturing method.

The luminescent composition of the present invention comprises the above-mentioned SnO2 and ZnS:Cu.
、． ZnS:Cu,. Al,. ZnS:Au,. Al,
ZnS:Cu,. Au,. Al, SrGa2S4:Eu
2+, Zn2SiO4:Mn. Ln2O2S: Fluorescent substance contained in Tb and Ln3(All-0.GaX)50
It can be obtained by thoroughly mixing 12:Ce with at least one green-emitting phosphor in a mortar, ball mill, mixer mill, etc. Both have SnO2/green luminescent phosphor values of 1/4 to 9.
/1 (but not including 1/4) by weight. When the value of SnO2/green-emitting phosphor is 1/4 or less, the resulting composition has properties close to those of a green-emitting phosphor and does not emit light with sufficient brightness under slow electron beam excitation. On the other hand, when the value of SnO2/green-emitting phosphor is greater than 9/1, the resulting composition has a small amount of green-emitting phosphor, resulting in very weak luminescence. From the viewpoint of brightness, a more preferable value of SnO2/rare earth phosphor is 1/4 to 4/
1, more preferably 3/7 to 7/3. There are various possible reasons why a composition obtained by adding and mixing SnO2 to a green-emitting phosphor that hardly emits light under slow electron beam excitation exhibits light emission under slow electron beam excitation. Mainly by adding and mixing SnO2, which has better conductivity than these green-emitting phosphors, the conductivity of the entire composition is improved, and as a result, the charge up phenomenon during excitation is eliminated, and the excitation efficiency is improved. It seems that this is for the purpose. The fluorescent display tube of the present invention is manufactured by the method described below.

First, the green light emitting composition described above is coated by precipitation coating onto an anode plate, usually supported by a ceramic substrate, to form a phosphor film. That is, an anode plate is placed in a suspension in which the composition is dispersed in water, and the composition is applied by settling on one side of the anode plate by the weight of the composition.
The water is then removed and the coating is dried. In order to improve the adhesion of the fluorescent film obtained in this case to the anode plate, a small amount (0.01 to 0.1%) of water glass may be added to the suspension. Also, the coating density is 5711fi! /Cd~3
0/Cd is appropriate. Note that although the method of forming a fluorescent film is generally the sedimentation coating method described in Dojo and is widely practiced, the method of forming the fluorescent film in the fluorescent display tube of the present invention is not limited to this sedimentation coating method. . Next, the linear heater is Ba
O. A cathode coated with an oxide such as SrO or CaO is placed facing the fluorescent film on the anode plate with a spacing of approximately 1 mm to 5 m, and this pair of electrodes is placed in a transparent container such as glass. After installing inside the container, exhaust the inside of the container. After the inside of the container reaches a degree of vacuum of at least 10 -5 T0rr or more, the exhaust is stopped and the container is sealed. After sealing, the getter is removed to further increase the degree of vacuum inside the container. In this manner, the fluorescent display tube of the present invention can be obtained. The phosphor film on the anode plate is flat, and the cathode is linear. In order to diffuse the low-velocity electron beam emitted from the electrode, a phosphor film is placed between the cathode and the phosphor film as shown in Figure 2. It is desirable to install a mesh-like grid electrode as a diffusion electrode. In this case, better results can be obtained if the mesh is as narrow as possible so that the loss of the amount of light emitted by the fluorescent film is small and the low-velocity electron beam is well diffused. Specifically, it is desirable that the diameter of the mesh is 500 microns or less, and the aperture ratio (the area of the holes through which the low-speed electron beam passes, relative to the total area of the grid electrode) is 50% or more. The anode plate can display arbitrary characters and figures by dividing the electrode form into the required character and figure shapes and making it possible to selectively apply the required voltage to each electrode. I can do it. In addition, the anode plate is divided into dots or lines, and a fluorescent film of a green light-emitting composition made of a mixture of SnO2 and a green light-emitting phosphor is formed on some of the electrodes, and a fluorescent film of a green light-emitting composition made of a mixture of SnO2 and a green light-emitting phosphor is formed on the other electrodes. A fluorescent display tube capable of displaying multiple colors can be obtained by forming a fluorescent film made of a phosphor for slow electron beam excitation whose emission color is different from that of the composition. FIGS. 3A, B, and C are Sn fluorescent films of the fluorescent display tube of the present invention, respectively.
O2 raw powder and ZnS:Cu, ZnS:Cu, . Al and ZnS: Au. SnO2/ZnS:Cu, . SnO2/Zn
S: Cu. Al and SnO2/ZnS:Au. Al value (weight ratio) and anode plate voltage (acceleration voltage) are 60V
The relationship with luminescence brightness in the case of (curve a) and SnO2/
Zns:Cu,. ZnO2/ZnS:Cu,. Al and SnO2/ZnS:Au. The relationship between the value of Al and the acceleration voltage at which the luminescent composition starts to glow, that is, the threshold voltage (curve b
).

As is clear from curve a in Figure 3 A, B and C, SnO
2/Zns:CulSnO2/ZnS:Cu. Al and SnO2/Zns:Au,. Al value is 1/4 to 4
Fluorescent display tubes with a fluorescent film made of a luminescent composition in the range of /1 have particularly high brightness, especially fluorescent display tubes with a fluorescent film made of a luminescent composition in the range of 3/7 to 7/3. has even higher brightness. Furthermore, as is clear from curves b in FIG. 3-A, B, and C, it can be seen that the greater the amount of SnO2 mixed, the lower the threshold voltage becomes. As mentioned above, Fig. 3 A, B, and C show SnO2/Zns when using SnO2 raw powder, respectively.
:Cu,. snO2/Zns: CulAl and SnO
2/ZnS:Au. Relationship between Al value and luminance and SnO2/Zns:Cu. snO2/ZnS:Cu,.
Al and SnO2/Zns: This is a graph showing the relationship between the values of Au and Al and the threshold voltage, and when calcined SnO2 is used instead of SnO2 raw powder, the results are almost the same as in Figure 3-A, B and C. Get results. Also, ZnS:Cu. Z
nS: Cu. Al or ZnS: Au. Zns:CulAu.instead of Al. Al. SrGa2S4:Eu2
+, Zn2siO4:Mn,. Ln2O2S: Fluorescent substance contained in Tb and Ln3 (All-e, GaX)50
12: Figure 3-A also when using a phosphor contained in Ce.
, B and C were confirmed. FIG. 4 illustrates the emission spectrum of the fluorescent display tube of the present invention, and A shows the emission spectrum of the fluorescent display tube whose fluorescent film is a luminescent composition made by mixing SnO2 and ZnS:Cu. , B is SnO2 and ZnS:CU. In the emission spectrum of a fluorescent display tube whose fluorescent film is a luminescent composition formed by mixing Al with SnO2 and ZnS:Au. D is the emission spectrum of a fluorescent display tube whose fluorescent film is a luminescent composition formed by mixing Al with SnO2 and ZnS:Cu, . Au,
．． The emission spectrum of a fluorescent display tube whose fluorescent film is a luminescent composition formed by mixing Al with E is SnO2 and SrGa2S.
4: Emission spectrum of a fluorescent display tube whose fluorescent film is a luminescent composition formed by mixing EU2+, F is SnO2 and Zn2
Emission spectrum of a fluorescent display tube whose fluorescent film is a luminescent composition formed by mixing SiO4:Mn, G is SnO2 and Y2
Emission spectrum of a fluorescent display tube whose fluorescent film is a luminescent composition formed by mixing O2S:Tb, H is SnO2 and La2
Emission spectrum of a fluorescent display tube whose fluorescent film is a luminescent composition formed by mixing O2S:Tb, I is SnO2 and Y3A
The emission spectrum of a fluorescent display tube whose fluorescent film is a luminescent composition formed by mixing l5Ol2:Ce and J is SnO2.
This is an emission spectrum of a fluorescent display tube whose fluorescent film is a luminescent composition formed by mixing Y3(AlO.6, GaO.4)5012:Ce and Y3(AlO.6, GaO.4)5012:Ce.

It can be seen from FIG. 4 that the fluorescent display tube of the present invention emits green light. Note that SnO2, Y2O2S:Tb and La
2O2S:Ln other than Tb phosphor contained in 2O2S:Tb, Y3Al5Ol2:Ce and Y3(AlO.6
, GaO・4) 5012: Ln3 other than Ce (All-
x) GaX) 5012:Although the emission spectrum of a fluorescent display tube whose fluorescent film is made of a luminescent composition formed by mixing a phosphor contained in Ce is not shown, these fluorescent display tubes also have It was confirmed that its emission spectrum showed green light emission similar to the fluorescent display tubes shown in FIG.

The fluorescent display tube of the present invention emits green light with better color purity than conventional fluorescent display tubes using ZnO:Zn as a fluorescent film. It is more practical than a fluorescent display tube that uses a fluorescent film.

FIG. 5 shows the emission chromaticity points of the fluorescent display tube of the present invention and the fluorescent display tube whose fluorescent film is ZnO:Zn on the CIE color system chromaticity coordinates, and points A, B, C, D, E, F, G
, H, I and J have the emission spectra of the fourth
Figure - Emission chromaticity points of the fluorescent display tube of the present invention shown as A, B, C, D, E, F, G, H, I and J, point K is ZnO
: Emission chromaticity point of a fluorescent display tube whose fluorescent film is Zn.
As is clear from FIG. 5, the fluorescent display tube of the present invention is made of Zn.
It has a green color and better color purity than conventional fluorescent display tubes that use O:Zn as a fluorescent film. In addition, SnO2 and Y
Ln2 other than 2O2S:Tb and La2O2S:Tb
Fluorescent substance contained in O2S:Tb, Y3Al5Ol2:C
e and Y3 (AlO.6, GaO.4) 5012:C
Ln3 other than e (All-0,.GaX) 5012:C
Although the emission chromaticity points of fluorescent display tubes whose fluorescent film is made of a luminescent composition formed by mixing each of the phosphors contained in e.g. The fifth point is
Like each of the fluorescent display tubes shown in the figure, it was confirmed that the fluorescent display tubes emit green light with better color purity than conventional fluorescent display tubes using ZnO:Zn as a fluorescent film. As described above, the present invention provides a luminescent composition that emits high-intensity green light by slow electron beam excitation, and a fluorescent display tube having a fluorescent film made of the luminescent composition. The luminescent compositions and fluorescent display tubes of the present invention are composed of conventional ZnO:Zn and ZnO:Zn.
It exhibits green light emission with better color purity than conventional fluorescent display tubes using nO:Zn as a fluorescent film, and has great industrial utility value.

Next, the present invention will be explained with reference to Examples.

Example 1 1 part by weight of sn02 raw powder (reagent manufactured by Shuzuihikotabe Shoten) and Cu
Parts by weight of ZnS:Cul having an activation amount of 4 x 10-4 y/y were thoroughly mixed using a mortar.

A suspension of the obtained composition 1'00~ in 100 cc of distilled water containing 0.01% water glass was used to support a ceramic substrate by a sedimentation coating method. X
1. A fluorescent film with a coating density of approximately 5η/Cd was formed on a 7n aluminum anode plate. Next, a cathode made of a tungsten wire heater coated with an oxide was placed opposite to the fluorescent film on the anode plate. After installing this pair of electrodes in a hard glass container with an interval of approximately 5 mm, the container was evacuated.The degree of vacuum in the container was 10-
After reaching a vacuum level of about 5T0rr, the evacuation was stopped and the container was sealed, and then the getter was removed to further increase the vacuum level inside the container. In this way, a fluorescent display tube having the structure shown in FIG. 1 was obtained. This fluorescent display tube has an anode plate voltage of 60
V, cathode voltage 1.2V and anode plate current 2mA
Then, green light was emitted with a luminance of 240 ft-L. Example 2 Sn(NO3)4 (reagent manufactured by Shuzuihikotabe Shoten) was packed in an alumina crucible and fired in air at 500°C for 1 hour.

After sufficiently pulverizing the obtained calcined SnO2 using a ball mill, 3 parts by weight of this calcined SnO2 and Cu and Al activation amounts were 1.3×10-37/7 and 3.8×, respectively.
ZnS:Cu.10-47/7. 7 parts by weight of Al were sufficiently mixed using a mortar. A fluorescent display tube was produced in the same manner as in Example 1 except that the composition thus obtained was used. This fluorescent display tube has an anode plate voltage of 60V. When the cathode voltage was 1.2 V and the anode plate current was 1.4 mA, green light was emitted with a luminance of 120 ft-L. Example 3 Sn(NO3)4 (reagent manufactured by Shuzuihikotabe Shoten) was packed in an aluminium crucible and fired in air at 500°C for 1 hour.

After sufficiently pulverizing the obtained calcined SnO2 using a ball mill, the weight part of this calcined SnO2 and the Cu and Al activation amounts were 1.3×10-37/7 and 3.8×1, respectively.
ZnS:Cu.0-47/7. Parts by weight of All were sufficiently mixed using a mortar. A fluorescent display tube was produced in the same manner as in Example 1 except that the composition thus obtained was used. This fluorescent display tube emitted green light with a luminance of 240 ft-L when the anode plate voltage was 60 V, the cathode voltage was 1.2 V, and the anode plate current was 2.8 mA. Example 4 Sn(NO3)4 (reagent manufactured by Shuzuihikotabe Shoten) was packed in an alumina crucible and fired in air at 500°C for 1 hour.

After sufficiently pulverizing the obtained calcined SnO2 using a ball mill, 7 parts by weight of this calcined SnO2 and Cu and Al activation amounts were 1.3×10-37/7 and 3.8X, respectively.
10-4y/f of ZnS:Cu. 3 parts by weight of Al were thoroughly mixed using a mortar. A fluorescent display tube was produced in the same manner as in Example 1 except that the composition thus obtained was used. This fluorescent display tube emitted green light with a luminance of 210 ft-L when the anode plate voltage was 60 V, the cathode voltage was 1.2 V, and the anode plate current was 3.3 mA.
Example 5 3 parts by weight of sn02 raw powder (reagent manufactured by Shuzuihikotabe Shoten) and Au
and ZnS:AU. Al
7 parts by weight were thoroughly mixed using a mortar.

A fluorescent display tube was produced in the same manner as in Example 1 except that the composition thus obtained was used. This fluorescent display tube has a luminance of 400 ft- when the anode plate voltage is 60V, the cathode voltage is 1.2V, and the anode plate current is 2.3mA.
It showed green luminescence of L. Example 6 1 part by weight of sn02 raw powder (reagent manufactured by Shuzuihikotabe Shoten) and A
u and A1 activation amount are each 1.3×10-37/7
and 3.8X10-47/7 ZnS:Au. A
1 parts by weight were thoroughly mixed using a mortar.

A fluorescent display tube was produced in the same manner as in Example 1 except that the composition thus obtained was used. This fluorescent display tube has a luminance of 420 ft-L when the anode plate voltage is 60V, the cathode voltage is 1.2, and the anode plate current is 3.2mA.
It showed green light emission. Example 7 7 parts by weight of sn02 raw powder (reagent manufactured by Shuzuihikotabe Shoten) and A
u and Al activation amount are each 1.3×10-37/7
and ZnS:Au. which is 3.8 x 10-47/7. A
13 parts by weight were thoroughly mixed using a mortar.

A fluorescent display tube was produced in the same manner as in Example 1 except that the composition thus obtained was used. This fluorescent display tube has a luminance of 240 ft- when the anode plate voltage is 60V, the cathode voltage is 1.2V, and the anode plate current is 3.3mA.
The green light emission of L was reduced. Example 8 7 parts by weight of sn02 raw powder (reagent manufactured by Shuzuihikotabe Shoten) and C
u. Au and Al activation amounts are each 10-4V/7,
Z being 2 x 10-47/y and 2 x 10-47/7
nS: Cu. Au. 3 parts by weight of Al were thoroughly mixed using a mortar.

A fluorescent display tube was produced in the same manner as in Example 1 except that the composition thus obtained was used. This fluorescent display tube has a luminance of 230 ft- when the anode plate voltage is 60V, the cathode voltage is 1.2V, and the anode plate current is 2.0mA.
It showed green luminescence of L. Example 9 1 part by weight of sn02 raw powder (reagent manufactured by Shuzuihikotabe Shoten) and Mn
Zn2SiO4:M with an activation amount of 2×10-27/7
nl parts by weight were thoroughly mixed using a mortar.

A fluorescent display tube was produced in the same manner as in Example 1 except that the composition thus obtained was used. This fluorescent display tube has a luminance of 10ft-L when the anode plate voltage is 90V, the cathode voltage is 1.2V, and the anode plate current is 2.5mA.
It showed green light emission. Example 10 Sn(NO3)4 (reagent manufactured by Shuzuhikotabe Shoten) was packed in an alumina crucible and fired at 600° C. for 1 hour in a weakly reducing atmosphere consisting of 98% nitrogen and 2% hydrogen.

After sufficiently pulverizing the obtained calcined SnO2 using a ball mill, 7 parts by weight of this calcined SnO2 and a Tb activation amount of 1.6
3 parts by weight of Gd2O2S:Tb, which is X10-1y/7, was thoroughly mixed using a mortar. A fluorescent display tube was produced in the same manner as in Example 1 except that the composition thus obtained was used. This fluorescent display tube emitted green light with a luminance of 80 ft-L when the anode plate voltage was 90V, the cathode voltage was 1.2V, and the anode plate current was 6.0mA.

[Brief explanation of drawings]

1 and 2 are schematic diagrams of typical examples of fluorescent display tubes, with FIG. 1 showing a diode and FIG. 2 showing a triode. 17... Inside the display tube kept in high vacuum, 11.
... Anode plate, 12 ... Fluorescent film, 1
3... ... Ceramic substrate, 14 ... Cathode, 15 ... Grid electrode, 16 ... Container. Figure 3-A, B and C are the fluorescent films of the fluorescent display tube of the present invention, SnO2 raw powder and Zns:CulZnS.
Cu. Al and ZnS: Au. SnO2/ZnS:Cu.
SnO2/ZnS: CusAl and SnO2/ZnS
:Au. Relationship between the value of Al and the emission brightness when the anode plate voltage is 60 V (curve a) and SnO2/Zns:C
u. snO2/Zns: Cu, Al and SnO2/Z
nS:Au. It is a graph showing the relationship (curve b) between the value of Al and the threshold voltage.

Claims (1)

[Claims] 1. Tin oxide (SnO_2) and copper-activated zinc sulfide phosphor (
ZnS:Cu), copper and aluminum activated zinc sulfide phosphor (ZnS:Cu,Al), gold and aluminum activated zinc sulfide phosphor (ZnS:Au,Al), copper, gold and aluminum activated zinc sulfide phosphor Fluorescent material (ZnS: Cu, A
u, Al), europium-activated strontium gallium sulfide phosphor (SrGa_2S_4:Eu^2^+),
Manganese-activated zinc silicate phosphor (Zn_2SiO_4:M
n), the general formula is Ln_2O_2S:Tb (Ln is Y
, Gd, Lu, and La) contained in the terbium-activated rare earth oxysulfide phosphor and whose general formula is Ln_3 (Al_1_-
_x, Ga_x)_5O_1_2:Ce (However, Ln has the same definition as above, and x is a number satisfying the condition 0≦x≦0.5) Cerium-activated rare earth aluminate-based phosphor and a green-emitting phosphor, which is at least one of the phosphors contained in the composition, in a weight ratio of more than 1:4 and less than 9:1. 2. The green light-emitting composition according to claim 1, wherein the mixing weight ratio of the SnO_2 and the green light-emitting phosphor is in the range of more than 1:4 and less than 4:1. 3. The green light-emitting composition according to claim 2, wherein the mixing weight ratio is in the range of 3:7 to 7:3. 4. A fluorescent display tube having a structure in which an anode plate having a fluorescent film on one side and a cathode facing the fluorescent film are enclosed in a vacuum container, in which the fluorescent film is made of tin oxide. (SnO_2) and copper-activated zinc sulfide phosphor (Zn
S: Cu), copper and aluminum activated zinc sulfide phosphor (ZnS: Cu, Al), copper, gold and aluminum activated zinc sulfide phosphor (ZnS: Cu, Au, Al), europium activated strontium sulfide・Gallium phosphor (S
rGa_2S_4:Eu^2^+) Manganese-activated zinc silicate phosphor (Zn_2SiO_4:Mn) The general formula is Ln_
2O_2S:Tb (However, Ln is Y, Gd, Lu and L
The phosphor contained in the terbium-activated rare earth oxysulfide phosphor represented by one or more of a) and the general formula Ln_3(Al_1_-_x, Ga_x)_5
O_1_2: Ce (however, Ln has the same definition as above,
x is a number that satisfies the condition 0≦x≦0.5). , a green light-emitting composition mixed in a weight ratio of greater than 1:4 and less than 9:1. 5. The slow electron beam excitation fluorescent display according to claim 4, wherein the mixing weight ratio of the SnO_2 and the green light-emitting phosphor is in the range of more than 1:4 and less than 4:1. tube. 6. The low-speed electron beam excited fluorescent display tube according to claim 5, wherein the mixing weight ratio is in the range of 3:7 to 7:3.