JP2944596B2 - Method for manufacturing fluorescent display device excited by slow electron beam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hot cathode type or a cold cathode type electron gun provided inside a device kept in a vacuum, and an accelerating voltage of 5 or more is provided by the electron gun.
A fluorescent film (a film formed by mixing and heating a phosphor and a conductive material) provided at a plurality of anode sites is irradiated with a low-speed electron beam emitted at about 00 V or less, and high-luminance light is emitted from the fluorescent film. Accordingly, the present invention relates to a method for manufacturing a low-speed electron-beam-excited fluorescent display device that displays characters, designs, moving images, and the like in a single color or in multiple colors (several colors to full colors) with good luminance balance.

[0002]

2. Description of the Related Art In recent years, various display devices for displaying the state and information of a device using images such as characters, designs and moving images have been put to practical use. As this display device, for example, a high definition television (high definition,
Cathode ray tube (CRT) widely used as TV and personal computer display terminal including HDTV), liquid crystal display (LCD) used for notebook personal computer, etc. In recent years, a fluorescent display tube (FIP) for displaying an image, a plasma display panel (PDP) that has been color-displayed in recent years as a wall-mounted television, and the like are widely known. In recent years, as a new display device,
It is also well known that a field emission display (FED) has been proposed and is being actively developed for practical use.

[0003] These display devices are excellent in that they can instantaneously and visually display and transmit states and information that change every moment by electrical control, and their demands are increasing as transmission means in the information society. ing. In addition, CRTs have been widely used as televisions and personal computer display devices as excellent display devices since ancient times, and are still widely used today.

Since a CRT requires a depth dimension on the order of the screen dimension, the depth dimension increases as the screen size increases, the installation area increases, the weight increases, and the screen brightness increases due to the large screen size. Is reduced. In order to prevent these problems, various display devices have been required in place of CRTs, which require higher voltage and higher power and have problems such as lack of portability. I have. Such display devices include LCDs, FIPs, PDPs, and FDPs that can display with a small depth dimension.
So-called flat panel displays such as ED have been proposed and put into practical use (or under development)
This is also well known.

[0005] Among these known display devices, display devices (CRT, FI
P, FED), and the prior art will be further described below.

The CRT has a structure in which an electron gun, a phosphor film containing a phosphor, a shadow mask, and the like are provided in a vacuum-maintained state. Electrons accelerated at a high voltage of 1 kV or more (high speed) from the electron gun. This is a display device that irradiates a phosphor with a line to cause the phosphor to emit light. The fluorescent film in the color display CRT has three phosphors corresponding to the three primary colors (R, G, B).
It has a structure in which different kinds of phosphors are separately applied to a panel portion serving as a display screen in a pattern of minute stripes or dots. Then, the irradiation direction of the beam of the high-speed electron beam is electrically deflected by a shadow mask, a deflection yoke, and the like provided inside the apparatus, and the beam is irradiated to a desired fluorescent film portion.
(Red), G (Green), and B (Blue) are emitted, and the emission luminance (brightness / darkness) is changed by the beam intensity of the electron beam to mix colors to produce a full-color display. It is used in practical applications such as televisions and HDTVs.

The reason why CRTs are widely used at present is that the ratio of display quality to price (cost effect) is high.
d / m ² or more), the color reproducibility is good, the luminance balance is not lost even after long-term use (for example, 20,000 to 30,000 hours or more), and the color shift is small. C
The development of high-luminance phosphors and the development and improvement of manufacturing processes have played a major role in the development of RT technology that has led to the present excellent display quality. "Phosphor Handbook", edited by the same Society of Phosphors, Ohmsha, published in 1987). According to this document, there was once a time when (Zn, Cd) S was used in the base composition as a green or red phosphor, but as a result of many attempts to develop a phosphor, cadmium was not included. Phosphors having the same or better emission characteristics have been developed and have been used up to the present time. As the current phosphors for CRT, for example, a blue light-emitting phosphor is ZnS: Ag (base composition is ZnS, and a desired emission color is ZnS: Ag). Phosphor to which Ag is added as an activator for obtaining: the same notation below), and ZnS: Au, Cu, Al or Z as a green light-emitting phosphor
nS: Cu, Al, Y ₂ O ₂ S:
It is stated that Eu is used.

As described above, CRTs are widely used in practice, but as described above, they are heavy and lack portability, or require a high voltage because they use high-speed electron beams.
Problems such as the necessity of high-withstand-voltage electrical components and the difficulty of reducing the size and weight are becoming noticeable, and FIPs have been put into practical use or FEDs are being developed to solve these problems.

Both the FIP and the FED are so-called flat panel displays having a small depth dimension, and are electron-beam-excited fluorescent display devices that do not require a high voltage. Since they do not deflect the beam irradiation direction of the electron beam, they are necessary for beam deflection. This eliminates the need for a depth space, and enables a thin structure.
In addition, the development and improvement of phosphors and phosphor films that emit light with high brightness even for electron beams with low acceleration voltage and low energy compared to electron beams on CRTs eliminate the need for electrical high-voltage design, and are compact and lightweight. For example, the above-mentioned documents (1) and (2); (“Electro-Ceramics”, Vol. 24, No. 123, 1993: published by Gakudensha), document (3); (Takao Kishino, "Fluorescent Display Tube", Sangyo Tosho, 1990), Reference (4); (Nikkei Electronics, January 29, 1996, pp. 85-p. 10).
2), Reference (5); (M. Urayama et al .: Inte
rational Electron Device
s Meeting, Technical Diges
tp. 16-7-1, 1995).

The FIP or FED issuance display mechanism is briefly described. A cathode (electron gun), an anode, and the like are arranged in a display device which is kept in a vacuum so that an electron beam can fly. A voltage (acceleration voltage) is applied between the anode and the anode, and an electron beam emitted from an electron gun (hot cathode type or cold cathode type) is caused to collide with the anode. A fluorescent film is fixed on the surface of the anode, and the electron beam flying toward the anode hits the fluorescent film and causes the fluorescent film to emit light. By partially controlling the flight of the electron beam, 2. Description of the Related Art Light emission of only a fluorescent film is controlled to display characters, designs, and the like. The fluorescent film and the anode are fixed so as to be in an electrically conductive state, and are fixed by a heat treatment at about 400 to 500 ° C. in a display device manufacturing process, as is well known.

As described above, the low-speed electron-beam-excited fluorescent display device having the appearance of a flat panel display is:
It is widely used as a FIP. Specifically, it emits light with a low-speed electron beam accelerated at a low acceleration voltage of about several tens of volts (in other words, has a small energy) and emits light, and is used as a display device incorporated in a home appliance such as a video or a car. As a display device such as a speed meter, FIP is widely used in practice as a display device for characters and designs. Also,
As a display device that displays fine images like a television,
Practical research on the practical use of EDs is currently being actively conducted. As described in the above-mentioned literature and the like, the conventional techniques relating to the slow electron beam excitation fluorescent display have the following problems (A) and (B) peculiar to the slow electron beam excitation. That is also true.

(A) Because of the low-speed electron beam, the energy of the irradiated electron beam is small, and the depth of penetration of the electron beam into the phosphor is limited to the very near surface of the phosphor, and depends on the acceleration voltage. At most, the penetration depth is about 10 nm or less, and only light emission from this penetration depth region can be obtained, and the entire amount of the activator contained in the phosphor cannot be excited to emit light. Is inherently difficult to obtain.

(B) The lower the acceleration voltage of the irradiated electron beam,
Phosphors are more susceptible to (negative) charging, and even if the emission electron dose is increased to obtain high-luminance emission,
Due to the negatively charged phosphor, the irradiated electron beam receives a repulsive force, and the electron beam cannot reach the phosphor. As a result, the brightness cannot be increased despite the increase in the electron dose.

Since the above-mentioned phenomenon peculiar to the low-speed electron beam occurs, it is not easy to obtain high-luminance light emission with the low-speed electron beam, and not only the development and manufacturing method of the phosphor but also the manufacturing method of the display device as FIP or FED. Various developments and improvements, such as those described below, are still being actively conducted.

Speaking of phosphors, they are limited to those practically used for low-speed electron beams.
In the above-mentioned documents (2) and (3), ZnO: Z
n, blue for ZnS: Cl, green yellow for ZnS: Au, A
(1) It is stated that (Zn, Cd) S: Ag, Cl is practically used in red.

In particular, with respect to the red-based phosphor, there is a high demand for red light emission because of its high visibility and excellent color for display. Phosphors that are widely used for high-luminance light emission are (Zn, Cd) S: Ag, Cl,
As described in Japanese Patent Application Laid-Open No. 1-104684 and the like, luminance stabilization and the like have been improved. However, this phosphor contains cadmium specified as a specific chemical substance and contains cadmium. It is also well-known that a red phosphor that emits light of the same high brightness without containing the same is desired. As a cadmium-free red phosphor, a phosphor Y ₂ O ₂ S widely used in the above-mentioned CRT using a high-speed electron beam:
It is also well-known that even if Eu is used for a low-speed electron beam, a luminance sufficient for practical use cannot be obtained, and a phosphor containing cadmium has been put to practical use, as described in the above-mentioned documents. However, cadmium-free phosphors are still being developed (Y ₂ O ₂ S: Eu · aY ₂ O ₃ : 1 ×
10 ⁻⁴ ≦ a ≦ 2 × 10 ⁻³ ), or a composition in which the element Y, which is one of the main components of Y ₂ O ₂ S: Eu, is partially replaced with the element La. Japanese Patent Application Laid-Open No. Hei 7-310074; a red light-emitting composition is disclosed.

As described above, in addition to the development and improvement of a phosphor suitable for a low-speed electron beam, a conductive substance is added and mixed in order to reduce the charging of the phosphor which is a problem peculiar to the low-speed electron beam. For example, In ₂ O ₃ , ZnO or Sn
O ₂ or combinations thereof _{In (2-xy) Sn x} M y O
_z (where M is at least one of Sb, Cd, Zn, W, Ti, and Mo), etc.
No. 55172, Japanese Patent Publication No. 52-23912,
JP-A-6-168683, JP-A-3-33185
Gazette).

On the other hand, in the manufacture of a low-speed electron-beam-excited fluorescent display device, various measures for improving the brightness are taken according to the process. For example, an anode of a phosphor paste (a mixture of a phosphor, a conductive material and a binder) is used. In the step of screen printing on a portion, in order to prevent crystallinity deterioration of the phosphor surface caused by mechanical friction with the screen, another substance for buffering, ZnO particles, or the like is added (JP-A-6-16).
No. 8683), or in order to effectively attach fine particles of a conductive substance or the like to the phosphor surface, a binder to be added to the phosphor paste is added to a water-soluble polymer or a solvent-soluble polymer depending on the solvent used in another step. Polymers are properly used (Japanese Patent Publication No. 62-33266).

In a heating step (for example, about 400 to 500 ° C.) performed to decompose and remove the binder of the phosphor paste printed on the anode portion and fix the binder as a phosphor film, the phosphor (ZnS, (Zn) , Cd) sulfides such as S and oxysulfides such as Y ₂ O ₂ S) in order to prevent alteration and deterioration, firstly, pre-sintering is performed at a lower temperature in the air, and then main sintering is performed. A method performed in a non-oxidizing atmosphere (Japanese Patent Publication No. 1-58618) is disclosed. In addition, in the low-energy electron-beam-excited light emission of the oxide phosphor ZnO: Zn, which is widely used as a phosphor that emits high-intensity green light, the deterioration or variation in luminance can be reduced by adding a substance such as tungsten oxide. The reason may be that the added mixed substance such as tungsten oxide absorbed the luminance deteriorating substance (which is presumed to be a gas component such as H ₂ O and CO ₂ ). ,
(Japanese Patent Publication No. 3-9580). Further, in order to obtain the same effect more effectively, an additive mixed substance such as tungsten oxide is not simply added and mixed, but ZnO: Zn added and mixed with an unadded ZnO: Zn phosphor.
Disclosed in Japanese Patent Application Laid-Open No.
-106848) is also well known. Similarly, as another method of positively removing the factor of luminance degradation and improving the luminance, heat treatment is performed after treatment with active oxygen to gasify and remove contaminants on the phosphor surface that cause the luminance to decrease. (JP-A-3-35086) and various attempts have been disclosed.

It is also known that in a multi-color display, a plurality of types of phosphors having different emission colors are used, and if the luminance balance of each emission color is lost, it appears as a color shift and the display quality is significantly reduced. There are various manufacturing improvements to keep the luminance balance within a certain range (for example, Japanese Patent Application Laid-Open No. 55-152782), and the lifetime inherent to the phosphor (the phosphor has a Is usually referred to as "life" since the quality of the light emission deteriorates and the luminance decreases.
It is also well known that various attempts have been made to reduce the temperature to at least several thousand hours, for example, to provide a thin coating or a protective coating on the surface of the phosphor particles.

The prior art relating to the slow electron beam excited fluorescent display has been described in detail by taking FIP as an example. FEDs that are currently being actively developed also have a problem caused by low-speed electron beams. For example, in the above-mentioned reference (4), high-luminance display is achieved by developing and improving a phosphor.
Attempts to achieve low acceleration voltages (50 V, 350 V), or to avoid problems caused by low-speed electron beams, use phosphors for high-speed electron beams for CRTs and use relatively high acceleration voltages (4 to 6 kV). ) Describes the current FED-related technologies such as an attempt to realize it. Display of characters and designs (display colors are usually from several colors to at most ten colors)
Unlike the FIP, which performs FIP, which displays moving images and videos in full color similar to a television, a phosphor with a small color shift, in other words, a well-balanced luminance is particularly desired.

In short, in the prior art relating to the slow electron beam excited fluorescent display device, the number of phosphors that emit light with relatively high luminance is limited, and the display device is manufactured simply by using a phosphor having a desired composition. However, it is not possible to provide a display device that emits light with practical luminance and has less luminance unevenness,
Technical development and improvement of various manufacturing methods and manufacturing conditions according to the type of phosphor (for example, sulfide, oxysulfide, oxide) are still being actively carried out, as described above. This is the state of the art.

It is well known that the prior art relating to the low-speed electron-beam-excited fluorescent display device in FIP or FED has not reached the technical level of the high-speed electron-beam fluorescent display device such as a television. In terms of image quality, F
The IP is a degree for displaying characters or designs. Also,
FEDs aiming to display images as fine as televisions or HDTVs are currently being actively developed in various parts of the world, and have not been widely used. In terms of multi-color display, as described above, FIPs are usually only a few colors, at most only about ten colors, whereas FEDs under development aiming for similar full-color displays such as televisions have the aforementioned characteristics. As described in reference (4), the development of a phosphor has become a major technical problem.

With regard to the red-based prior art phosphor, (Zn, Cd) S, which is known as the phosphor having the highest luminance (of red emission), is used as a base composition and activated according to a desired emission color. Phosphors to which agents have been added are widely used practically, but there is a problem in that they contain cadmium which is a specific chemical substance. As described above, in recent years, (Zn, C
d) Proposals aimed at substituting the S phosphor (Japanese Patent Application Laid-Open Nos. 7-310073 and 7-310074).
Publication). Both the red phosphor Y ₂ O that there are well known has been considered that there is no brightness to practicality
₂ S: Eu is used as the main component, the former (JP-A-7-31
0073), a composition containing an oxide (Y ₂ O ₃ ) in a certain concentration range (1 × 10 ⁻⁴ to 2 × 10 ^{−3 in} moles) is preferable, and a phosphor having a composition outside this concentration range is preferred. The brightness is 1.5 times higher than that of. In addition, the latter (Japanese Unexamined Patent Publication No.
In JP) -310074, compositions obtained by replacing a part of the element Y _{La ((Y 1-xy La} x Ln y) 2 O 2 S: where Ln is Eu and / or Sm; O <x ≦ 0.035 ;
0.01 ≦ y ≦ 0.1), which is 1.5 times higher than the luminance of a composition containing no La. As is clear from the above-mentioned publication, all of these methods can change the mixing ratio of a plurality of raw materials necessary for synthesizing the phosphor, and can change the synthesizing conditions (specifically, the heating for synthesizing in the crucible. And the brightness and composition of the obtained phosphor were investigated by changing the firing temperature and the holding time, etc., and it was found that the phosphor exhibited relatively high brightness in a specific composition range. Phosphor that has been abandoned as
It is noteworthy that it has been clarified that the luminance can be increased by a slight composition change.

However, as described in the prior art, even if a low-energy electron-beam-excited fluorescent display device is manufactured using a phosphor having the above-described specific composition range, it often does not exhibit desired emission characteristics. That is what a person skilled in the art will experience. Also, if desired emission characteristics can be obtained by specifying a composition range, what kind of composition of a phosphor finally obtained as a display device through a manufacturing process is required to be the specific composition range described above. Whether to adopt a manufacturing method and manufacturing conditions is a big problem in practical use. The two publications do not describe the manufacture of the display device, and are problematic in the practical use of the display device. Each of them is novel in that it has a phosphor composition not containing cadmium, but is a conventional red phosphor (Zn,
Cd) There is no disclosure of a luminance comparison with S, and it must be said that sufficient light emission luminance has not been obtained so as to be substituted.

[0026]

The above-mentioned prior art has the following problems.

(A) In the prior art, (Zn, Cd) S is widely used as a yellow phosphor, and has a problem of environmental pollution as with the red phosphor. In addition, it manufactures a highly practical new phosphor capable of emitting high-brightness yellow light by mixing a single composition or a plurality of emission colors without cadmium, and a low-speed electron-beam-excited fluorescent display device using this new phosphor. A method for doing so has not yet been disclosed.

(B) The phosphor inherently has a so-called light emission lifetime (preferably several thousand hours or more, more preferably 20,000 to 30,000 hours or more) in which the emission luminance decreases with long-term lighting. Therefore, the lifespan of the different types of phosphors is not the same. This problem has been solved by the phosphor technology for high-speed electron beams such as televisions, but has not been solved by the phosphor technology for low-speed electron beams as described above.
According to the prior art, in a display device in which different phosphors are mixed to form a single luminescent color, the brightness balance of each phosphor in the mixed phosphor film is lost due to long-term use (for example, about several years), and color shift occurs. Inherently have the problem of causing In short, the prior art has a problem that the lifetime (generally, shorter than the lifetime of the phosphor) of the display device without color shift due to the luminance balance collapse is short.

In view of the above problems, an object of the present invention is to use a phosphor material containing no harmful substances such as cadmium,
Provided is a method for manufacturing a low-speed electron-beam-excited fluorescent display device using a yellow phosphor that can be driven at a low voltage, has a high luminance equal to or higher than that of a conventional device using cadmium, and has little color shift. It is in.

[0030]

According to the present invention, there is provided a method of manufacturing a fluorescent display device excited by a low-energy electron beam, comprising: an anode, a cathode opposed to the anode, and a general formula of Ln ₂ O ₂ S: R (where Ln is G
d, La, Y, Lu and at least one selected from the group consisting of Lu, and R is a rare earth element). Manufacturing method of low-energy electron-beam-excited light-emitting display device placed in a container
In law, the oxysulfide phosphor, Ln ₂ O ₂ S: E
u (where Ln is at least one selected from the group consisting of Gd, La, Y and Lu) red light-emitting phosphor and Ln ₂ O ₂
S: Tb (where Ln is at least one member selected from the group consisting of Gd, La, Y, and Lu, and the same applies hereinafter) characterized by being mixed with a green light-emitting phosphor to form a yellow light-emitting phosphor. .

The inventor uses a cadmium-free phosphor and mixes it so that the phosphor emits at least as high luminance as the (Zn, Cd) S-based yellow light-emitting phosphor containing cadmium. And found a method for producing a yellow phosphor with less color shift over a long period of use, leading to the present invention.

[0032]

Next, embodiments of the present invention will be described with reference to the drawings.

[0033] Figures 1 and 2, theory embodiments of the present invention
In a partially cutaway perspective view and a side cross-sectional view showing a slow electron beam excited fluorescent display device for clarifying, as one of the representative slow electron beam excited fluorescent display devices, a yellow fluorescent photofluorescent display device is shown. ing.

As shown in FIGS. 1 and 2, the fluorescent display device 10 for emitting yellow light is formed in a container comprising a substrate glass 1, a side plate 2 and a cover glass 3. The inside of this container is kept in a high vacuum. On the substrate glass 1, an anode conductor 6 on the insulating layer 5 connected to the lead wire 4A is formed. On this anode conductor 6, a phosphor film 7 whose oxidation has been suppressed in a non-oxidizing atmosphere using a phosphor from which oxide has been removed is formed. A grid 8 is disposed above the anode conductor 6, and a filament cathode 9 is disposed above the grid 8. It is obtained by sealing a container in which the filament cathode 9, the grid electrode 8, and the anode conductor 6 are mounted on the substrate glass 1 in a non-oxidizing atmosphere, and evacuating and sealing.

In FIG. 2, 4B denotes a power supply wiring layer and 4C
Is a connection conductor arranged in a through hole provided in the insulating layer 5 for connecting the power supply wiring layer 4B and the anode conductor, and 11 is a display surface.

Next, a method for forming the fluorescent film 7 will be described.

An ordinary manufacturing method (for example, Japanese Patent Application Laid-Open No. 7-310)
No. 073), the red phosphor of Ln ₂ O ₂ S: Eu and the green phosphor of Ln ₂ O ₂ S: Tb were etched with an acid as described in Japanese Patent Application No. 08-165542, and The oxide is removed by heat treatment in a non-oxidizing atmosphere and mixed. A phosphor paste obtained by mixing the mixed phosphor, a conductive substance, and a self-decomposition type binder,
Printing is performed on the anode portion on the substrate of the display device, followed by baking at 500 ° C. for 20 minutes in a non-oxidizing atmosphere to form the fluorescent film 7. Next, by using this anode substrate to produce a low-speed electron-beam-excited fluorescent display device, a high-brightness and practical yellow-light-emitting low-speed electron-beam-excited fluorescent display device that does not use cadmium is completed. (Example 1) A phosphor fired by a normal firing method is washed with water and dried, and a Y ₂ O ₂ S: Eu red light emitting phosphor and Y are dried.
500 g of each of the ₂ O ₂ S: Tb green light-emitting phosphors is suspended in 2 liters of pure water, and the pH is adjusted to 3.0 with hydrochloric acid (special grade reagent).
After adjusting to 0, stir for 30 minutes. After that, the eluate was sufficiently washed by decantation, dehydrated and dried,
An etched phosphor whose surface was slightly etched was obtained. Next, 7.6 g (20 mol% with respect to the etching phosphor) of sulfur (S) powder (purity 4N, # 200 pass) is added to 450 g of each of the etching phosphors, and mixed with a blender. The obtained mixture is placed in an alumina crucible, and the crucible is put into a larger crucible together with activated carbon, and then covered with a lid and heated in a firing furnace at 500 ° C. for 4 hours, thereby obtaining a non-oxidizing atmosphere in a carbon reducing atmosphere. Heat treatment was performed in a neutral atmosphere to remove oxides.

Next, the Y ₂ O subjected to the above oxide removing treatment
₂ S: Eu red-emitting phosphor and Y ₂ O ₂ S: Tb at a ratio of the green emitting phosphor a one-to-one, and stirred and mixed by a magnetic stirrer in ethyl alcohol, and the yellow light emitting phosphor and then dried.

Next, 15 parts by weight of indium oxide as a conductive agent, an organic vehicle (30 parts by weight of an acrylic resin, 40 parts by weight of butyl carbitol acetate, 15 parts by weight of terpineol, 30 parts by weight of a liquid mixture in which 15 parts by weight of butyl lactate were dissolved were added and mixed to prepare a phosphor paste.

After forming the above-mentioned paste on a normal fluorescent display substrate glass by a screen printing method to form a fluorescent film,
It dried at 0 degreeC for 60 minutes.

Thereafter, the substrate glass having the fluorescent film is placed in a non-oxidizing atmosphere furnace sufficiently substituted with nitrogen,
At 20 ° C. for 20 minutes, when the substrate temperature was 150 ° C. or higher, the furnace always kept a nitrogen atmosphere, and at 100 ° C. or lower, the substrate glass was taken out from the atmospheric furnace.

In the subsequent heating step, the fluorescent display device shown in FIGS. 1 and 2 was manufactured with the fluorescent film always kept in a non-oxidizing atmosphere. As described above, the fluorescent display device 10 encloses a container in which the filament cathode 9, the grid electrode 8, and the anode conductor 6 are mounted on the substrate glass 1 in a non-oxidizing atmosphere, and evacuates and seals the container. Is formed.

The fluorescent display device thus obtained was subjected to an anode voltage of 30 V, a cathode voltage of 1.5 V, and a grid voltage of 17 V.
Lit at room temperature as a luminance meter (BM-7
(Type). As a result, as shown in Example 1 of Table 1 below, the above-described fluorescent display device obtained a luminance of 1205 cd / m ₂ at CIE chromaticity coordinates (0.43, 0.50).

Further, (Zn, Cd) S: Au, Cu, A
l Using a yellow light emitting phosphor, the phosphor is not treated in a non-oxidizing atmosphere, and the phosphor film is treated in the air without performing the treatment. C
In IE chromaticity coordinates (0.43, 0.53), luminance 1220
cd / m ² .

Therefore, the luminance of the fluorescent display device according to the present invention is the same as that of the conventional phosphor (Zn, Cd) containing Cd.
S: Compared to Au, Cu, Al (Comparative Example 1), substantially the same chromaticity and emission luminance were obtained. (Example 2) A yellow light emitting fluorescent display device was prepared in the same manner as in Example 1 except that the phosphors to be mixed were changed to a Gd ₂ O ₂ S: Eu red light emitting phosphor and a Gd ₂ O ₂ S: Tb green light emitting phosphor. Was prepared.

As a result, the above-mentioned fluorescent display device is shown in Table 1 below.
As shown in Example 2, CIE chromaticity coordinates (0.43,
0.50), and an emission luminance of 1375 cd / m ² was obtained.

The fluorescent display device according to the present invention is shown in Table 2
As shown in FIG. 1, the conventional (Zn, Cd) S: Au,
It was equivalent to the Cu, Al yellow light emitting phosphor.

In addition to the above mixed phosphor, La ₂ O ₂
S: Eu + La ₂ O ₂ S: Tb, Lu ₂ O ₂ S: Eu +
Lu ₂ O ₂ S: Tb, Gd ₂ O ₂ S: Eu + Y ₂ O
₂ S: Tb, Y ₂ O ₂ S: Eu + Gd ₂ O ₂ S: Tb,
Has the same effect as the above embodiment.

[0049]

As described above, the present invention can provide a non-polluting, high-brightness, yellow-emitting, slow-electron-beam-excited fluorescent display device that does not contain harmful substances such as Cd.

Further, in the present invention, there is no need for capital investment for maintenance and disposal of harmful substances, which is conventionally required, and there is an effect that the production cost can be reduced as a result.

Even though the yellow light emitting phosphor in the present invention is a mixed phosphor, even if the phosphor is deteriorated due to lighting for a long period of time (for example, thousands of hours) of several thousand hours, the luminance is reduced. Since the main components are the same, the decrease in luminance of each luminescent color is almost the same, so that the luminance balance between each luminescent color does not collapse and has an effect of maintaining excellent color reproducibility for a long time. I have.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a slow electron beam excitation fluorescent display device for describing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a slow electron beam excited fluorescent display device for describing an embodiment of the present invention.

[Explanation of symbols]

 Substrate glass Side plate Cover glass 4A Lead wire 4B Power supply wiring layer 4C Connection conductor 5 Insulating layer 6 Anode conductor 7 Phosphor film 8 Grid 9 Filament cathode 10 Fluorescent display device 11 Display surface

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C09K 11/00-11/89 H01J 29/10-29/34 H01J 31/30-31/24

Claims (7)

(57) [Claims] An anode, a cathode opposed to the anode, and a general formula of Ln ₂ O ₂ S: R (where Ln is Gd, La,
At least one selected from the group consisting of Y and Lu;
Arrangement is a light emitting member formed with a fluorescent film containing oxysulfide phosphor represented by a rare earth element) on the substrate, in a vacuum chamber
Te manufacturing method smell <br/> the low voltage electron beam excitation light emitting display device that location, the oxysulfide _{phosphor, Ln 2 O 2 S: Eu} ( where, Ln is Gd, La, Y, from the group consisting of Lu Selected at least one) red-emitting phosphor and Ln ₂ O ₂ S: T
b (where Ln is at least one member selected from the group consisting of Gd, La, Y, and Lu) a low-speed electron beam-excited fluorescent display device characterized in that a yellow light-emitting phosphor is obtained by mixing a green light-emitting phosphor . Production method. 2. The method according to claim 1, wherein the yellow light-emitting phosphor is Gd ₂ O ₂ S:
_{2. The} method according to claim 1, wherein the phosphor is a mixed phosphor of Eu red light emitting phosphor and Gd ₂ O ₂ S: Tb green light emitting phosphor. 3. The method according to claim _2, wherein the yellow light-emitting phosphor is Y ₂ O ₂ S: Eu.
Red light-emitting phosphor and Y ₂ O ₂ S: production side of low voltage electron beam excitation phosphor display apparatus according to claim 1, wherein the Tb green-emitting phosphor
Law . 4. The method according to claim 1, wherein the yellow light-emitting phosphor is La ₂ O ₂ S: E.
u red light emitting phosphor and La ₂ O ₂ S: Made in low voltage electron beam excitation phosphor display apparatus according to claim 1, wherein the Tb green-emitting phosphor
Construction method . 5. The method according to claim 1, wherein the yellow light-emitting phosphor is Lu ₂ O ₂ S: E.
u red light emitting phosphor and Lu ₂ O ₂ S: Made in low voltage electron beam excitation phosphor display apparatus according to claim 1, wherein the Tb green-emitting phosphor
Construction method . 6. The method according to claim 1, wherein the yellow light-emitting phosphor is Gd ₂ O ₂ S: E.
u red light-emitting phosphor and Y ₂ O ₂ S: Production of low voltage electron beam excitation phosphor display apparatus according to claim 1, wherein the Tb green-emitting phosphor
How . 7. The method according to claim 1, wherein the yellow light-emitting phosphor is Y ₂ O ₂ S: Eu.
Red light-emitting phosphor and Gd ₂ O ₂ S: Production of low voltage electron beam excitation phosphor display apparatus according to claim 1, wherein the Tb green-emitting phosphor
How .