JP2003114632A - Method for displaying fluorescent image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for displaying a fluorescent image by which space saving is possible while high sensitivity is obtained and sufficient displaying performance of a fluorescent image can be obtained. SOLUTION: By the method for displaying a fluorescent image, a fluorescent image obtained by using fluorescent ink containing at least a phosphor is irradiated with excitation light from an excitation light source to generate fluorescent light emitting from the phosphor excited by the excitation light to display an image. In the method, organic electroluminescence is used for the excitation light source for the fluorescent image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention irradiates a fluorescent image having a phosphor with excitation light from an excitation light source, and displays an image based on the fluorescence emitted from the phosphor when excited by the excitation light. The present invention relates to a fluorescent image display method.

[0002]

2. Description of the Related Art In recent years, fluorescent images have been widely used for various purposes such as advertisements and store interiors. For example, in a fluorescent image expressed using only fluorescent ink, it is often desired to obtain a fluorescent image in which it is invisible that the ink is used when the excitation light of the contained phosphor is not irradiated. .

Heretofore, as an optimum device for displaying an image formed by using a fluorescent substance (phosphor), for example, Japanese Patent Laid-Open Nos. 6-228235 and 7-334103 are available.
Although those described in No. 1 are known, all of them use a black light or a UV lamp as an excitation light source for the phosphor.

[0004]

However, when a black light is used as the excitation light source, the distance from the excitation light source to the fluorescence image is at least a dozen cm in order to spread the ultraviolet rays as the excitation light to the fluorescence image. It is necessary to separate them by several meters, and it is not possible to meet the demand for space saving. Further, it has been difficult to uniformly emit an image having a large area by conventional black light irradiation.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fluorescent image display method capable of saving space even with high brightness and emitting an image uniformly. It is in.

[0006]

The above circumstances of the present invention have been achieved by the following configurations.

1. A fluorescent image obtained by irradiating an excitation light from an excitation light source to a fluorescent image obtained by using a fluorescent ink containing at least a phosphor, and performing image display based on the fluorescence emitted from the phosphor when excited by the excitation light. In the display method, an organic electroluminescence is used as an excitation light source of the fluorescence image, wherein the fluorescence image display method.

2. A fluorescent image obtained by irradiating an excitation light from an excitation light source to a fluorescent image obtained by using a fluorescent ink containing at least a phosphor, and performing image display based on the fluorescence emitted from the phosphor when excited by the excitation light. In the display method, inorganic electroluminescence is used as an excitation light source for the fluorescence image, wherein the fluorescence image display method.

3. 3. The fluorescent image display method according to 1 or 2, wherein the excitation light source is a light emitting panel and is superposed on a display panel having a fluorescent image.

4. A fluorescent image obtained by irradiating an excitation light from an excitation light source to a fluorescent image obtained by using a fluorescent ink containing at least a phosphor, and performing image display based on the fluorescence emitted from the phosphor when excited by the excitation light. In the display method, an LED is used as an excitation light source for the fluorescence image, and the fluorescence image display method is characterized.

5. 5. The fluorescent image display method according to 4, wherein a light guide plate is used. 6. The fluorescence image display method according to any one of 1 to 5, wherein the excitation light source is an ultraviolet light source.

7. 7. The fluorescent image display method according to any one of 1 to 6, wherein the fluorescent image is printed using an inkjet printer.

In order to solve the above-mentioned problems, the inventors of the present invention use any one of an organic EL, an inorganic EL and an LED as an excitation light source and have sufficient brightness as compared with the conventional fluorescent image display method. The present invention has been completed based on the finding that an overwhelming space saving can be realized and a fluorescent image can be uniformly emitted.

The excitation light used as the excitation light source for the fluorescence image is not particularly limited as long as the visibility of the fluorescence image is good,
It is preferable to use a light source having a wavelength of 365 nm, which is capable of irradiating a light ray containing abundant ultraviolet rays in the range of 220 to 405 nm, and particularly a relatively widely used light source having a wavelength of 365 nm. Blue may be applied to the excitation light. Such an ultraviolet light source may be capable of varying or flashing the irradiation ultraviolet light amount by a dimmer.

The present invention will be described in detail below. The present invention is characterized by using an organic electroluminescence (hereinafter, also abbreviated as organic EL) element as an excitation light source for a fluorescence image. The organic EL element is an ultraviolet light source (UV-
Organic EL) is preferable.

In the present invention, the organic EL device basically has a structure in which a light emitting layer is sandwiched between a pair of electrodes, and a hole injection layer or an electron injection layer is interposed if necessary. And any one or more of the compounds represented by formulas (I), (III), (IV) and (V) described in JP 2001-93670 A should be contained in any of the organic layers. Is preferred. Specifically, (i) anode / light emitting layer / cathode (ii) anode / hole injection layer / light emitting layer / cathode (iii) anode / light emitting layer / electron injection layer / cathode (iv) anode / hole injection layer There are structures such as / light emitting layer / electron injection layer / cathode.

The light emitting layer (1) has an injection function capable of injecting holes from the anode or the hole injection layer and injecting electrons from the cathode or the electron injection layer when an electric field is applied, (2) It has a transport function to move the injected charges (electrons and holes) by the force of the electric field, and (3) provides a field for recombination of electrons and holes inside the light-emitting layer and connects it to light emission. ing. However, there may be a difference between the ease with which holes are injected and the ease with which electrons are injected, and the transport function represented by the mobility of holes and electrons may be large or small. Those having a function of moving one of the charges are preferable. There is no particular limitation on the kind of the light emitting material used for the light emitting layer, and a known material as a light emitting material in the conventional organic EL element can be used. Such a light emitting material is mainly an organic compound, and depending on a desired color tone, for example, Macromol. Sym
p. The compounds described in Vol. 125, pages 17 to 26 are mentioned.

As a method for forming a light emitting layer using the above materials, for example, a vapor deposition method, a spin coating method, a casting method,
It can be formed by thinning it by a known method such as the LB method, but a molecular deposition film is particularly preferable. Here, the molecular deposition film is a thin film formed by depositing the compound in a vapor phase state, or a film formed by solidifying a molten state or a liquid phase state of the compound.
Usually, this molecular deposited film can be distinguished from a thin film (molecular cumulative film) formed by the LB method based on the difference in agglomeration structure and higher-order structure and the functional difference resulting therefrom.

Further, this light emitting layer is disclosed in JP-A-57-5178.
As described in No. 1, it can be formed by dissolving the above light emitting material together with a binder such as a resin in a solvent to form a solution, and then thinning the solution by a spin coating method or the like. The thickness of the light emitting layer thus formed is not particularly limited and can be appropriately selected depending on the situation, but is usually in the range of 5 nm to 5 μm (emission peak wavelength 405 nm).

As the anode in this EL element, a material having a high work function (4 eV or more) metal, alloy, electrically conductive compound or a mixture thereof as an electrode material is preferably used. Specific examples of such an electrode material include A
Metals such as u, CuI, indium tin oxide (IT
O), SnO ₂ , ZnO, and other electrically conductive transparent materials. This anode may be formed into a thin film by a method such as vapor deposition or sputtering of these electrode substances, and a pattern of a desired shape may be formed by a photolithography method, or if pattern accuracy is not required (100 μm). As above, the pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material. To take out light emission from this anode,
It is desirable that the transmittance is higher than 10%, and the sheet resistance as an anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 nm to 1 μm, preferably 10 to 200 nm.

On the other hand, as the cathode, a metal having a low work function (4 eV or less) (referred to as an electron injecting metal), an alloy, an electrically conductive compound, or a mixture thereof is used as an electrode material. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum /
Aluminum oxide (Al ₂ O ₃ ) mixture, indium, lithium / aluminum mixture, rare earth metal and the like can be mentioned. Among these, from the viewpoint of electron injecting property and durability against oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function value, for example, a magnesium / silver mixture or magnesium. Aluminium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) mixture, lithium / aluminum mixture and the like are suitable. The cathode can be produced by forming a thin film of these electrode substances by a method such as vapor deposition or sputtering. or,
The sheet resistance as the cathode is preferably several hundred Ω / □ or less,
The film thickness is usually 10 nm to 1 μm, preferably 50 to 200.
It is selected in the range of nm. In addition, in order to transmit the emitted light, it is convenient that either the anode or the cathode of the organic EL element is transparent or semi-transparent and the luminous efficiency is improved.

Next, the hole injection layer provided as necessary has a function of transmitting the holes injected from the anode to the light emitting layer, and the hole injection layer is interposed between the anode and the light emitting layer. By doing so, many holes are injected into the light emitting layer at a lower electric field, and the electrons injected from the cathode or the electron injection layer into the light emitting layer are the electrons present at the interface between the light emitting layer and the hole injection layer. The barrier makes it possible to obtain an element having excellent light emitting performance, such as being accumulated at the interface in the light emitting layer and improving the light emitting efficiency. The material for the hole injection layer (hereinafter referred to as the hole injection material) is not particularly limited as long as it has the above-described preferable properties, and is conventionally used as a hole charge injection / transport material in an optical transmission material. Any known material used for the hole injection layer of the EL element can be selected and used.

The hole injecting material has a hole injecting property or an electron blocking property, and may be an organic substance or an inorganic substance. Examples of the hole injection material include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives. , Fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers,
Examples thereof include conductive polymer oligomers, especially thiophene oligomers. As the hole injecting material, the above materials can be used, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

Typical examples of the aromatic tertiary amine compound and styrylamine compound are N, N, N ', N'.
-Tetraphenyl-4,4'-diaminophenyl; N,
N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine (TPD); 2,2-bis (4-di-p-tolyl) Aminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′,
N'-tetra-p-tolyl-4,4'-diaminobiphenyl; 1,1-bis (4-di-p-tolylaminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl ) Phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N'-di (4-methoxyphenyl) -4,4'-diaminobiphenyl; N,
N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- ( Di-p-tolylamino) -4'-
[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenyl Carbazoles, as well as those having two fused aromatic rings in the molecule described in U.S. Pat. No. 5,061,569, such as 4,4'-bis [N- (1-naphthyl) -N
-Phenylamino] biphenyl (NPD), JP-A-4-
No. 3,088,88, three triphenylamine units linked in a starburst type 4,4 ',
4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MTDATA) and the like can be mentioned.

Inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material. This hole injection layer can be formed by thinning the above hole injection material by a known method such as a vacuum vapor deposition method, a spin coating method, a casting method, and an LB method. The film thickness of the hole injection layer is not particularly limited, but is usually about 5 nm to 5 μm. The hole injection layer may have a single-layer structure composed of one or more of the above materials, or may have a laminated structure composed of a plurality of layers having the same composition or different compositions.

Further, the electron injecting layer used as necessary may have a function of transmitting the electrons injected from the cathode to the light emitting layer, and its material is any of conventionally known compounds. One can be selected and used.

Materials used for this electron injection layer (hereinafter, referred to as
Examples of electron injection materials) include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, heterocyclic tetracarboxylic acid anhydrides such as naphthaleneperylene, carbodiimides, phenylenylidene methane derivatives, anthraquinodimethane and Examples thereof include anthrone derivative and oxadiazole derivative. or,
A series of electron-transporting compounds described in JP-A-59-194393 are disclosed as materials for forming a light-emitting layer in this specification, but as a result of studies by the present inventors,
It has been found that it can be used as an electron injection material. Further, in the oxadiazole derivative, a thiadiazole derivative in which an oxygen atom of the oxadiazole ring is substituted with a sulfur atom, or a quinoxaline derivative having a quinoxaline ring known as an electron-withdrawing group can also be used as an electron injecting material.

Further, a metal complex of an 8-quinolinol derivative,
For example, tris (8-quinolinol) aluminum (Al
q), tris (5,7-dichloro-8-quinolinol)
Aluminum, tris (5,7-dibromo-8-quinolinol) aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol)
Zinc (Znq) and the like, and metal complexes in which the central metal of these metal complexes is replaced with In, Mg, Cu, Ca, Sn, Ga, or Pb can also be used as the electron injection material. In addition, metal-free or metal phthalocyanine, or those whose terminal is substituted with an alkyl group, a sulfonic acid group, or the like can be preferably used as the electron injection material. The distyrylpyrazine derivative exemplified as the material for the light emitting layer can also be used as the electron injecting material, and like the hole injecting layer, n-type-S
Inorganic semiconductors such as i-type and n-type-SiC can also be used as the electron injection material.

This electron injection layer can be formed by forming the above compound by a known thin film forming method such as a vacuum vapor deposition method, a spin coating method, a casting method and an LB method. The thickness of the electron injection layer is not particularly limited, but is usually selected in the range of 5 nm to 5 μm. The electron injection layer may have a single-layer structure composed of one or more of these electron injection materials, or may have a laminated structure composed of a plurality of layers having the same composition or different compositions.

Next, a suitable example for producing the organic EL device will be described. As an example, a method of manufacturing an EL device composed of the above-mentioned anode / hole injection layer / light-emitting layer / electron injection layer / cathode will be described. First, on a suitable substrate, a desired electrode material,
For example, a thin film made of a material for an anode is formed by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably in the range of 10 to 200 nm, to prepare an anode. Next, a thin film made of the material of the hole injection layer, the light emitting layer, and the electron injection layer, which are element materials, is formed on this.

As the thinning method, there are the spin coating method, the casting method, the vapor deposition method and the like as mentioned above. However, from the viewpoint that a uniform film is easily obtained and pinholes are hard to be formed, vacuum vapor deposition is performed. Method is preferred. When this vapor deposition method is used for this thinning, the vapor deposition conditions vary depending on the type of compound used, the target crystal structure of the molecular deposited film, the association structure, etc., but generally the boat heating temperature is 50 to 4
50 ° C., vacuum degree 10 ⁻⁶ to 10 ⁻³ Pa, vapor deposition rate 0.01
~ 50 nm / sec, substrate temperature -50 ~ 300 ° C, film thickness 5n
It is desirable to appropriately select in the range of m to 5 μm.

After the formation of these layers, a thin film made of the material for the cathode is formed thereon and has a thickness of 1 μm or less, preferably 50 to 200.
A desired EL element can be obtained by forming a film having a thickness in the range of nm by, for example, vapor deposition or sputtering and providing a cathode. In order to fabricate this organic EL element, it is preferable to consistently fabricate from the hole injecting layer to the cathode by one vacuum evacuation. It is also possible to fabricate the layers and the anode in this order. When a DC voltage is applied to the EL device thus obtained, light emission can be observed by applying a voltage of about 5 to 40 V with the anode having a positive polarity and the cathode having a negative polarity. Further, even if a voltage is applied with the opposite polarity, no current flows and no light emission occurs. Further, when an AC voltage is applied, light is emitted only when the anode is in the + state and the cathode is in the − state. The waveform of the alternating current applied may be arbitrary.

Further, in the present invention, inorganic electroluminescence (hereinafter, inorganic E) is used as an excitation light source for fluorescence images.
An element (also abbreviated as L) is used. The inorganic EL element is preferably an ultraviolet light source (UV-inorganic EL).

In the present invention, as the basic constitution of the inorganic EL element, two types can be considered as shown in FIGS. 1 (a) and 1 (b). FIG. 1A is a perspective view showing a first basic structure, and FIG. 1B is a perspective view showing a second basic structure.

As shown in FIG. 1A, the first element 1
The substrate-side electrode 3 is formed on the glass substrate 2, and the first insulating film 4 made of a-SiNx or the like, ZnF ₂ : Gd is formed thereon.
And the like, and the second insulating film 6 are formed in this order, and the transparent electrode 7 such as ITO is formed on the second insulating film 6. By applying a voltage between the transparent electrode 7 and the electrode 3 on the substrate side, the light emitting layer 5 emits ultraviolet rays, and the ultraviolet rays are irradiated as an excitation light source. In this structure, light emission is observed through the transparent electrode 7. Thus, the EL composite element using the ultraviolet emission of the EL element as the excitation light source is
It has a structure in which the ultraviolet light emitted by an EL element known in the related art is used as an excitation light source.

As shown in FIG. 1B, the second element 8
Is a structure in which light emission is observed through a glass substrate, a transparent electrode 7 is formed on the glass substrate 2, and a first insulating film 4 such as a-SiNx and ZnF ₂ : Gd light emission are formed on the transparent electrode 7. The body layer 5 and the second insulating film 6 are formed in this order, and the electrode 3 is formed on the second insulating film 6. Transparent electrode 7
By applying a voltage between the electrode 3 and the electrode 3
Emits ultraviolet rays, which are observed through the glass substrate 2.

In the present invention, the first basic structure is referred to as an anti-stack structure, but the anti-stack structure is more preferable than the second basic structure in terms of luminous efficiency. The reason is that in the case of the second basic structure, the ultraviolet light emitted from the light emitting layer 5 is absorbed by the glass substrate 2 by about 50%, and the light emission efficiency is poor. This is because the ultraviolet light emitted from the light emitting layer 5 is only slightly absorbed by the transparent electrode 7. Therefore, in the present invention, the above-mentioned reverse laminated structure is used as a basic structure.

The EL composite element used in the present invention comprises a substrate side electrode arranged on a substrate, a first insulating film formed on these substrate side electrodes, and a first insulating film formed on this first insulating film. A light emitting layer, a second insulating film formed on the light emitting layer, and a transparent electrode arranged on the second insulating film,
By applying a voltage between the transparent electrode and the substrate-side electrode, ultraviolet rays are emitted from the light emitting layer.

In this EL composite element, the light emitting layer is preferably made of ZnF ₂ : Gd (emission peak wavelength 311 nm), although not particularly limited thereto. This ZnF
₂ : Gd gives strong ultraviolet emission.

Another EL composite element is a substrate-side electrode formed on a substrate, a first insulating film formed on the substrate-side electrode, and a light-emitting body formed on the first insulating film. Layer, a second insulating film formed on the light emitting layer, a transparent electrode arranged on the second insulating film, and an ultraviolet reflection film formed on the transparent electrode. By applying a voltage between the substrate and the electrode on the substrate side, ultraviolet rays are emitted from the light emitting layer and the ultraviolet rays are emitted. Also in this case, it is preferable that the light emitting layer is made of ZnF ₂ : Gd because strong ultraviolet light emission can be obtained. The ultraviolet reflecting film improves the brightness and eliminates the influence of ultraviolet rays on the human body.

Further, in the present invention, any one of the above ELs
It is preferable to use an EL display (light emitting panel) equipped with a composite element. The display can be manufactured using an EL composite element by a method well known to those skilled in the art.

The EL composite element used in the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a plan view showing an outline of an example of the EL composite element, and FIG. 3 is a partial sectional view taken along the line I--I in FIG. 2 and 3, in the EL composite element 1
Is a substrate-side electrode 3 arranged on the glass substrate 2, a first insulating film 4 formed on these substrate-side electrodes 3, and a light-emitting layer 5 formed on this first insulating film 4. And a second insulating film 6 formed on the light emitting layer 5, and a transparent electrode 7 arranged on the second insulating film 6. A voltage can be applied between the transparent electrode 7 and the electrode 3 on the substrate side.

In this EL composite element 1, a metal electrode arranged as a substrate-side electrode 3 is formed on a glass substrate 2. As the metal electrode, for example, an Al electrode, an Au electrode, an Ag electrode, a Cu electrode, a Ni electrode or the like can be used. An Al electrode is preferable. These metal electrodes can be formed by, for example, a vacuum vapor deposition method, a sputtering method, or the like. When precision is not required, a conductive paste may be applied to form the layer.

The first insulating film 4 and the second insulating film 4 are formed on the electrode 3 on the substrate side.
The phosphor layer 5 sandwiched by the insulating film 6 is arranged
ing. The material of the light emitting layer 5 is not particularly limited.
However, for example, ZnF₂: Gd, ZnF₂: Nd etc.
Be done. Of these, ZnF ₂: UV emission with strong Gd
It is preferable because it can be obtained.

ZnF ₂ : Gd will be described in more detail. ZnF ₂ and a Gd compound (for example, GdF ₃ , Gd ₂
O ₃ , GdCl ₃ , Gd ₂ S _{3 and the} like) raw material pellets for electron beam evaporation are
For example, it can be obtained by sintering at 600 ° C. for about 2 hours. The concentration of the Gd compound in ZnF ₂ is, for example, 1.0 to
It is about 4.0 mol%, preferably about 2.5 mol%. The ZnF ₂ : Gd active layer can be obtained, for example, by keeping it in a vacuum chamber at 150 ° C. and then quenching it at 300 ° C. for about 1 hour. In this way, ZnF ₂
Zn with Gd ³⁺ incorporated as an emission center in the lattice
F ₂ : Gd is obtained.

Examples of the Gd compound include GdF ₃ , Gd ₂ O ₃ , GdCl ₃ and Gd ₂ S ₃ as mentioned above. Of these, the strongest ultraviolet emission can be obtained by using GdCl _3. To be

The thickness of the light emitting layer 5 is not particularly limited, but is usually about 300 to 900 nm, for example 600.
nm.

As materials for the first insulating film 4 and the second insulating film 6,
Are not particularly limited, but include, for example, a-SiNx, Y
₂O₃, Al₂O₃, Ta₂O_Five, SiO₂, BaTiO₃, P
bTiO₃, PbZrO₃, TiO₂, SrTiO₃Etc.
You can Of these, a-SiNx, Y₂O₃, Al
₂O₃, Ta₂O_Five, SiO₂Is generally high in breakdown voltage but dielectric
Low rate (10-20), BaTiO₃, PbTiO₃,
PbZrO₃, TiO₂, SrTiO₃Is generally the dielectric constant
Is high (up to 100), but the breakdown voltage is low. Also, Ta₂O _FiveAnd Si
O₂It is also possible to use a composite membrane or the like. These
Then, a-SiNx is preferable.

The first insulating film 4 and the second insulating film 6 can be formed by plasma CVD method, sputtering method, sol-gel or the like. In the case of plasma CVD method, NH ₃ , H ₂
And SiH ₄ as a gas source can be deposited at 150 ° C., for example. The thickness of the first insulating film 4 and the second insulating film 6 is not particularly limited, but is usually about 200 to 600 nm, for example 400 nm.

A transparent electrode 7 is arranged on the second insulating film 6. As the transparent electrode 7, for example, indium tin oxide ITO, SnO ₂ , ZnO, or a composite of ITO and ZnO can be used, but ITO is preferable. The transparent electrode 7 can be formed by a sputtering method, sol-gel or the like.

In the EL composite element having such a structure,
When a voltage is applied between the transparent electrode 7 and the substrate-side electrode 3, the light emitting layer 5 emits ultraviolet rays.

The fluorescent image in the present invention is preferably formed with fluorescent ink. The fluorescent ink may be organic or inorganic, but an inorganic fluorescent material is preferable in terms of light resistance and weather resistance.

The composition of the inorganic phosphor used in the fluorescent ink is not particularly limited, and any known inorganic phosphor composition can be used depending on the intended excitation light wavelength of the fluorescent image, the emission color, or the like. .

The composition of the inorganic phosphor is, for example, JP-A Nos. 50-6410, 61-65226 and 64-2.
2987, 64-60671, and JP-A-1-168.
Inorganic phosphors described in No. 911 and the like can be used as appropriate, but as the crystal matrix thereof, Y ₂ O ₂ S, Z
Metal oxides represented by n ₂ SiO ₄ , Ca ₅ (PO ₄ ) ₃ Cl, etc., sulfides represented by ZnS, SrS, CaS, etc., and Ce, Pr, Nd, Pm, Sm, Eu, Gd, T
A combination of rare earth metal ions such as b, Dy, Ho, Er, Tm, and Yb and metal ions such as Ag, Al, Mn, and Sb as an activator or coactivator is preferable. Preferred examples of the crystal matrix are listed below.

ZnS, SrS, GaS, (Zn, Cd)
S, SrGa ₂ S ₄ , YO ₃ , Y ₂ O ₂ S, Y ₂ O ₃ , Y ₂ Si
O ₃ , SnO ₂ , Y ₃ Al ₅ O ₁₂ , Zn ₂ SiO ₄ , Sr ₄ A
l ₁₄ O ₂₅ , CeMgAl ₁₀ O ₁₉ , BaAl ₁₂ O ₁₉ , Ba
MgAl ₁₀ O ₁₇ , BaMgAl ₁₄ O ₂₃ , Ba ₂ Mg ₂ Al
₁₂ O ₂₂ , Ba ₂ Mg ₄ Al ₈ O ₁₈ , Ba ₃ Mg ₅ Al
_{18 O 3 5, (Ba,} Sr, Mg) O · aAl 2 O 3, (B
a, Sr) (Mg, Mn ) Al 1 0 O 17, (Ba, Sr,
Ca) (Mg, Zn, Mn) Al ₁₀ O ₁₇ , Sr ₂ P
₂ O ₇ , (La, Ce) PO ₄ , Ca ₁₀ (PO ₄ ) ₆ (F,
Cl) ₂ , (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ C
l ₂ , GdMgB ₅ O ₁₀ , (Y, Gd) BO _{3, and the} like.

The crystal matrix and the activator or coactivator are not particularly limited in the composition of the elements, and those partially substituted with the elements of the same family can be used, and those which emit visible light by absorbing from the ultraviolet region to the blue region. Any combination can be used so long as it is preferable to use an inorganic oxide phosphor or an inorganic halide phosphor.

Inorganic phosphor materials used in the present invention are described below.
Examples of physical compounds are shown below, but the present invention is not limited to these compounds.
It is not fixed. [Blue emitting inorganic phosphor compound] (BL-1) Sr₂P₂O₇: Sn_Four ⁺ (BL-2) Sr_FourAl₁₄O_{twenty five}: Eu²⁺ (BL-3) BaMgAl_TenO₁₇: Eu²⁺ (BL-4) SrGa₂S_Four: Ce³⁺ (BL-5) CaGa₂S_Four: Ce³⁺ (BL-6) (Ba, Sr) (Mg, Mn) Al_TenO
₁₇: Eu²⁺ (BL-7) (Sr, Ca, Ba, Mg)_Ten(P
O_Four)₆Cl₂: Eu²⁺ (BL-8) ZnS: Ag (BL-9) CaWO_Four (BL-10) Y₂SiO_Five: Ce (BL-11) ZnS: Ag, Ga, Cl (BL-12) Ca₂B_FiveO₉Cl: Eu²⁺ (BL-13) BaMgAl₁₄O_{twenty three}: Eu²⁺ (BL-14) BaMgAl_TenO₁₇: Eu²⁺, T
b³⁺, Sm²⁺ (BL-15) BaMgAl₁₄O_{twenty three}: Eu²⁺ (BL-16) Ba₂Mg₂Al₁₂O_{twenty two}: Eu²⁺ (BL-17) Ba₂Mg_FourAl₈O₁₈: Eu²⁺ (BL-18) Ba₃Mg_FiveAl₁₈O₃₅: Eu²⁺ (BL-19) (Ba, Sr, Ca) (Mg, Zn,
Mn) Al_TenO₁₇: Eu ²⁺ [Green-emitting inorganic phosphor compound] (GF-1) (Ba, Mg) Al₁₆O₂₇: Eu²⁺, M
n²⁺ (GF-2) Sr_FourAl₁₄O_{twenty five}: Eu²⁺ (GF-3) (Sr, Ba) Al₂Si₂O₈: Eu²⁺ (GF-4) (Ba, Mg)₂SiO_Four: Eu²⁺ (GF-5) Y₂SiO_Five: Ce³⁺, Tb³⁺ (GF-6) Sr₂P₂O₇-Sr₂B₂O_Five: Eu²⁺ (GF-7) (Ba, Ca, Mg)_Five(PO_Four)₃C
l: Eu²⁺ (GF-8) Sr₂Si₃O₈-2SrCl₂: Eu²⁺ (GF-9) Zr₂SiO_Four, MgAl₁₁O₁₉: C
e³⁺, Tb³⁺ (GF-10) Ba₂SiO_Four: Eu²⁺ (GF-11) ZnS: Cu, Al (GF-12) (Zn, Cd) S: Cu, Al (GF-13) ZnS: Cu, Au, Al (GF-14) Zn₂SiO_Four: Mn (GF-15) ZnS: Ag, Cu (GF-16) (Zn, Cd) S: Cu (GF-17) ZnS: Cu (GF-18) Gd₂O₂S: Tb (GF-19) La₂O₂S: Tb (GF-20) Y₂SiO_Five: Ce, Tb (GF-21) Zn₂GeO_Four: Mn (GF-22) CeMgAl₁₁O₁₉: Tb (GF-23) SrGa₂S_Four: Eu²⁺ (GF-24) ZnS: Cu, Co (GF-25) MgO · nB₂O₃: Ce, Tb (GF-26) LaOBr: Tb, Tm (GF-27) La₂O₂S: Tb (GF-28) SrGa₂S_Four: Eu²⁺, Tb³⁺, Sm
²⁺ [Red emitting inorganic phosphor compound] (RL-1) Y₂O₂S: Eu³⁺ (RL-2) (Ba, Mg)₂SiO_Four: Eu³⁺ (RL-3) (Ba, Mg) Al₁₆O₂₇: Eu³⁺ (RL-4) (Ba, Ca, Mg)_Five(PO_Four)₃C
l: Eu³⁺ (RL-5) YVO_Four: Eu³⁺ (RL-6) YVO_Four: Eu³⁺, Bi³⁺ (RL-7) CaS: Eu³⁺ (RL-8) Y₂O₃: Eu (RL-9) 3.5MgO, 0.5MgF₂GeO₂:
Mn (RL-10) YBO₃: Eu In addition to the above compounds,
Examples include organic fluorescent substances and calcium halophosphate.

The method for producing the inorganic phosphor is not particularly limited,
As a method for synthesizing without lowering the luminous efficiency, various known production methods such as a method of synthesizing a composite metal oxide and a spray pyrolysis method can be applied.
As a method for synthesizing the composite metal oxide, a solid phase method in which powdery oxides of two or more kinds of metals are mixed and subjected to high temperature heat treatment
And a liquid phase method in which a precursor of the composite metal oxide is synthesized and separated from a solution in which the raw materials are dissolved, and the resulting precursor is oxidized.

The liquid phase method refers to a general reaction method in a liquid phase such as a coprecipitation method, a reaction crystallization method and a sol-gel method, and can be appropriately selected in the present invention. However, it is particularly preferable to synthesize the precursor by the sol-gel method.

Here, the method for producing the inorganic phosphor by the sol-gel method will be specifically described. The sol-gel method is, for example, an element (metal) used as a matrix or an activator or a co-activator, for example, a metal alkoxide (for example, Si (OCH ₃ ) ₄ etc.) or a metal complex (for example, Eu ³⁺
_{(CH 3 COCH = C (O-} ) CH 3) 3 , etc.) or their organic solvent solution to double alkoxide make the addition of elemental metal (e.g., Al (OBu) was added to metallic magnesium 2-butanol solution of ₃ Make Mg (Al (OBu)
₃ ) ₂ etc.), a metal halide, and a metal salt of an organic acid are mixed in a necessary amount in a reaction vessel, and thermally or chemically hydrolyzed and polycondensed to produce a synthetic method.

Any solvent may be used when the sol-gel method is applied as long as the reaction raw materials are dissolved, but ethanol is preferable from the viewpoint of environment. The reaction initiator may be an acid or a base, but a base is preferable from the viewpoint of hydrolysis rate. As the type of base, if the reaction starts, NaOH,
Although general one such as ammonia can be used, ammonia is preferable from the viewpoint of easy removal. As a method for mixing the reaction initiator, it may be added to the mother liquor in advance, may be added at the same time as the raw materials, or may be added to the raw materials in advance. The method of addition is preferred. When using a plurality of reaction raw materials, the order of addition of the raw materials may be the same or different, and a suitable order can be appropriately assembled depending on the activity, and in some cases, a double alkoxide may be formed.

Any solvent may be used when the coprecipitation method or the reaction crystallization method is applied as long as the reaction raw materials are dissolved, but water is preferable from the viewpoint of easy control of the degree of supersaturation. When a plurality of reaction raw materials are used, the addition order of the raw materials may be the same or different, and an appropriate order can be appropriately assembled depending on the activity.

When the precursor is synthesized by the liquid phase method, the temperature, the addition rate, the stirring rate, the pH, etc. may be controlled during the reaction and the ultrasonic wave may be irradiated during the reaction in any method. . A surfactant or a polymer may be added to control the particle size. It is also one of the preferred embodiments that the liquid is concentrated and / or aged if necessary after the addition of the raw materials.

After synthesizing the precursor by the liquid phase method, if necessary, various steps such as filtration, washing, drying, calcination and dispersion may be carried out, or classification may be carried out.

Although any known method may be used for the firing method, it is preferable to use a rotary kiln. The firing temperature and time may be adjusted so that each phosphor has the highest performance, and the atmosphere may be an oxidizing gas, a reducing gas, a sulfurizing gas, an inert gas, or the like depending on the composition.

The dispersing method is, for example, a high speed stirring impeller type dispersing machine, colloid mill, roller mill, ball mill, vibrating ball mill, attritor mill, planetary ball mill, sand mill, etc. ) And a shearing force, or a dry type disperser such as a cutter mill, a hammer mill and a jet mill, an ultrasonic disperser, a high pressure homogenizer and the like. Among these, in the present invention, it is particularly preferable to use a wet media type disperser that uses a medium, and it is further preferable to use a continuous type wet media type disperser capable of continuously performing dispersion treatment. A mode in which a plurality of continuous wet media type dispersers are connected in series is also applicable. As used herein, "continuously dispersible treatment" means that at least the inorganic phosphor and the dispersion medium are dispersed in the disperser while being continuously supplied to the disperser at a constant quantitative ratio per hour, and are produced in the disperser. It refers to a form in which the dispersed product is extruded into the supply and discharged continuously from the disperser. In the method for producing an inorganic phosphor of the present invention, when a wet media type disperser that uses a medium as a dispersion treatment step is used, the dispersion chamber container (vessel) can be appropriately selected from a vertical type and a horizontal type. Is.

Fluorescent ink is used for handwriting, printing, electrostatic printing,
It can be used in various forms such as a method of drawing a fluorescent image with a brush or a spray, a method of printing by applying it to various printers, and the like. Among them, application as an inkjet recording ink for printing using an inkjet printer is one of the preferred embodiments of the present invention.

The fluorescent ink may be applied as an ink for ink jet recording in any form as long as it contains an inorganic phosphor, and may further contain a coloring material in addition to the inorganic phosphor. Good. When including a coloring material,
Various forms that are practically used in known inks for ink jet recording can be applied, such as a form in which a pigment is dispersed and contained, a form in which a dye is dissolved and contained, and the like. When applying the fluorescent ink as an ink for inkjet recording,
An image may be formed by ejecting one type of fluorescent ink containing an inorganic phosphor, or an image may be formed by ejecting a plurality of types of ink using a plurality of inkjet heads. Particularly in the latter case, the other ink may have any form as long as at least one type of ink is a fluorescent ink containing an inorganic phosphor, and the ink containing only the inorganic phosphor, the inorganic phosphor and the coloring material may be used. Any combination of the ink containing the ink and the ink containing only the coloring material can be appropriately applied.

Next, the ink jet recording ink according to the present invention will be described. Water-Soluble Organic Solvent An aqueous liquid medium is preferably used as the solvent used in the inkjet recording ink according to the present invention, and a mixed solvent of water and a water-soluble organic solvent is more preferably used as the aqueous liquid medium. Examples of water-soluble organic solvent preferably used, alcohols, polyhydric alcohols, polyhydric alcohol ethers, amines, amides,
Heterocycles, sulfoxides and the like can be mentioned. Polymer Dispersant As the water-soluble polymer dispersant used in the inkjet recording ink according to the present invention, the following water-soluble resins can be used, which are preferable from the viewpoint of ejection stability.

Preferred water-soluble resins are styrene-acrylic acid-alkyl acrylate copolymers, styrene-acrylic acid copolymers, styrene-maleic acid copolymers, styrene-maleic acid-alkyl acrylates. Ester copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-maleic acid half ester copolymer, vinylnaphthalene-acrylic acid copolymer, vinylnaphthalene-maleic acid It is a water-soluble resin such as a copolymer. It is also possible to use two or more of these water-soluble resins in combination.

The content of the soluble resin in the total amount of the ink is preferably 0.1 to 10% by mass, more preferably 0.3 to 5% by mass.

The content of the coloring material dispersible or soluble in water used for the ink jet recording ink is preferably 1 to 10% by mass based on the total mass of the ink. Water-soluble dye A water-soluble dye is preferably used in the inkjet recording ink according to the present invention. Examples thereof include direct dyes, acid dyes, reactive dyes and basic dyes. Pigment As the pigment that can be used in the ink jet recording ink according to the present invention, conventionally known organic and inorganic pigments can be used. For example, many azo pigments such as azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, phthalocyanine pigments, perylene and perylene pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindolinone pigments, and quinophthaloni pigments. Examples thereof include cyclic pigments, dye lakes such as basic dye type lakes and acid dye type lakes, organic pigments such as nitro pigments, nitroso pigments, aniline black and daylight fluorescent pigments, and inorganic pigments such as carbon black.

As a method for dispersing the pigment, various types such as a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill and a paint shaker can be used.

It is also preferable to use a centrifugal separator or a filter for the purpose of removing coarse particles of the pigment dispersion. Surfactants Surfactants preferably used in the inkjet recording ink according to the present invention include alkyl sulfates, alkyl ester sulfates, dialkyl sulfosuccinates, alkylnaphthalene sulfonates, alkyl phosphates,
Anionic surfactants such as polyoxyalkylene alkyl ether phosphates and fatty acid salts, polyoxyethylene alkyl ethers, polyoxyalkylene alkyl phenyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene block copolymers, etc. Nonionic surfactant, glycerin ester, sorbitan ester, polyoxyethylene fatty acid amide,
Examples include activators such as amine oxides, and cationic surfactants such as alkylamine salts and quaternary ammonium salts.

These surfactants can also be used as a dispersant for pigments, and an anionic surfactant can be preferably used.

When the fluorescent ink is applied as the ink for ink jet recording, an image is formed while controlling the ejection amount and position by the printer driver. An additive color mixture color driver using an inorganic phosphor has not been known so far and plays a very important role in forming a fluorescent image in an inkjet printer. Until now, when trying to form a fluorescent image, in addition to forming it by hand while checking the fluorescent image emitted by illuminating with a black light, it is possible to print a certain number of images or to form by photolithography. Although there is only a method, it is possible to easily form various images by using an additive color mixture color driver.

Next, a fluorescent image obtained by using the fluorescent ink will be described. The fluorescent ink is used to form a fluorescent image, and the type of color of the emission color can be arbitrarily used, such as a fluorescent image used in a single color and a fluorescent image reproduced in full color. In addition, various known UV absorbers can be used as black ink for reproducing black, and as white ink for reproducing white, fluorescent ink of each color is used in appropriate amounts to express white. Alternatively, in order to prevent color misregistration, phosphors may be mixed in advance so that desired white can be expressed and used as one white ink.

The fluorescent image is obtained by using a fluorescent ink and an ink containing a coloring material, and by irradiating two or more kinds of light sources having different wavelengths, the image appears from a solid color and / or the color of the same image. And / or displaying two or more types of images on the same surface are particularly preferable.

A water-resistant and light-resistant protective film can be provided on these images according to the respective needs.

The substrate for forming a fluorescent image may be paper, cloth, resin, metal or any other material. In particular, it is preferable to use a material that does not contain unnecessary fluorescent material as the base material, but if the material has unnecessary light emission, apply an ultraviolet absorber or other non-luminous material to quench the light emission. Is possible.

The place where the fluorescence image is used can be used in any environment such as indoors, outdoors, and around water, but when there is a small amount of ambient light such as daylight, or when excitation light is actively emitted. An environment in which it is possible is preferred. For example, if it is indoors, underground or a place where external light is less incident, and if it is outdoors, safety display, road display, advertisement, fleet marking and the like can be mentioned.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a perspective view showing an embodiment in which an EL display (light emitting panel) including an organic EL element is used as an excitation light source for a fluorescent image.

In this figure, 10 is an EL display 17 equipped with an organic EL element and a fluorescent image display panel 1.
It is a fluorescence image device consisting of 1. When a voltage is applied between the anode and the cathode, the EL display 17 including the organic EL element emits ultraviolet rays from the light-emitting body contained in the EL display 17, and the ultraviolet rays are used as an excitation light source on the display panel 11. The formed fluorescent image is strongly excited to emit light, and the fluorescent substance in the image area emits fluorescent light.

Although not shown, when an inorganic EL element is used, an EL element including an inorganic EL element is used as an alternative to the EL display 17 including the organic EL element shown in FIG.
A display is installed so that the fluorescent image formed on the display panel 11 is strongly excited to emit light, and the fluorescent substance in the image area emits fluorescent light.

FIG. 5A is a perspective view showing an embodiment in which an LED is used as an excitation light source for a fluorescence image.
5B is a vertical cross-sectional view of the fluorescent display device taken along line II-II in FIG.

The LED is preferably an ultraviolet light source (UV-LED). As the UV-LED, those manufactured by Nichia Corporation (emission peak wavelength 385 nm) can be used.

In these figures, 10 is a fluorescent image device comprising a light guide plate 12 and a fluorescent image display panel 11, and 15 is a fluorescent image device.
Is an LED which is an ultraviolet light source arranged so as to face the end surface of the light guide plate 12, and 16 is arranged so as to cover the ultraviolet light source so that most of the ultraviolet rays from the LED 15 are incident on the end surface of the light guide plate 12. The reflection plate 14 is a pedestal part, which has a slit in the widthwise central part of the upper surface, and the lower end part of the display panel 11 is sandwiched by the slit part by an appropriate means, and the ultraviolet light source 15 is provided therein.
The reflecting plate 16 is housed and fixed by an appropriate supporting means. Further, 13 is a light guide plate 12 and a display panel 1.
1 is a reflective layer made of aluminum foil, which is provided by being attached to the upper surface and the left and right end surfaces.

The LED 15 as an ultraviolet light source is optimal if it is manufactured by Nichia Corporation (emission peak wavelength 385 nm). Further, the LED 15 may be made to be capable of varying the amount of ultraviolet rays to be irradiated or blinking it by a dimmer.

The reflecting plate 16 is made of, for example, a mirror surface plate having an aluminum vapor deposition layer formed on one surface of a resin plate, or a white synthetic resin plate, etc., so that the ultraviolet rays emitted from the LEDs 15 can be efficiently taken into the light guide plate. belongs to.

In the above, the light guide plate 12 and the display panel 1
The lower surface of 1 directly faces the LED 15 and therefore LE
Part of the ultraviolet ray emitted from D15 is directly or partly reflected by the reflection plate 16, and most of it is incident on the light guide plate 12 and the display panel 11 from the lower end surface. The ultraviolet ray incident on the light guide plate travels in the light guide plate while repeating total reflection, and reaches every corner of the light guide plate. Then, the light is scattered toward the display panel 11 to strongly excite the fluorescent image of the display panel 11 to emit light, thereby enhancing the visibility of the image portion.

A light guide plate may be combined with the LED as shown to serve as an excitation source. As such a light guide plate, a resin having a refractive index of more than 1 is used. As such a resin, a hard resin such as an acrylic resin can be used.

The light guide plate guides the ultraviolet light emitted from the ultraviolet light source in a predetermined position and direction.
8-46447, JP-A-2-126501 and 2-
221924, 4-145485, 9-804.
No. 29, No. 6-258501, No. 6-23084
Conventionally known light guide plates such as No. 6, No. 6-47984 and No. 7-19775 can be used.

As the shape of the light guide plate, various shapes such as a square plate shape, an arbitrary plate shape, and a rod shape can be used.

The light guide plate has a thickness of 0.1 to 100 mm, preferably about 2 to 20 mm, for example, glass that transmits ultraviolet rays, or has high transparency such as polymethylmethacrylate (PMMA) and contains an ultraviolet absorber. It is made of a synthetic resin plate. More specifically, the light guide plate is preferably made of a material having a high internal transmittance, and when manufactured by a molding method, acrylic resin (PMMA),
Plastic materials such as polystyrene (PS) and polycarbonate (PC) are preferable.

[0096]

EXAMPLES The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto. << Preparation of Inorganic Phosphor >> Preparation of Inorganic Phosphor (Ba ₂ SiO ₄ : Eu ²⁺ ) Tetraethoxysilane 1.34 × 10 ⁻¹ mol and Europium (trivalent) acetylacetonate complex 1.00 × 1
A solution obtained by dissolving 0 ^-2 mol in 300 ml of ethanol was used as solution A, and this solution A was added to ammonia 5.00 x 10 ^-2.
mol-added water-ethanol (1: 1, 400 ml)
A sol was prepared by dropping the solution into the solution at a rate of about 1 ml / min with stirring. The obtained sol is about 15 with an evaporator.
The solution was concentrated to a double concentration, and 500 ml of a 0.33 mol / l barium nitrate salt aqueous solution was added to the solution to cause gelation to obtain a wet gel (1).

The wet gel (1) obtained was placed in a closed container,
It was aged at 90 ° C. for 10 hours. After that, filter paper (Advant
It was separated by filtration using ec5A) and dried at 50 ° C. for 10 hours. A sintering inhibitor (aluminum oxide C, manufactured by Aerosil Co., Ltd.) was mixed with the precursor obtained by drying in an amount of 1% by mass based on the mass of the precursor, and a 2% H ₂ —N ₂ atmosphere was used.
Heat treatment is performed at 1000 ° C. for 2 hours and firing is performed. The fired phosphor was crushed with a crusher to obtain an inorganic phosphor. << Preparation of Fluorescent Ink for Inkjet Recording >> For the inorganic phosphor prepared above, the following respective components (dispersion medium containing water as a main component) so as to have the following "component composition of solid fine particle dispersion of inorganic phosphor" Were added and mixed to prepare respective inorganic phosphor-containing slurries. Next, the inorganic phosphor-containing slurry is subjected to a preliminary dispersion process using a dissolver to obtain a crude dispersion, and then a bead mill disperser (VMA-GETZ).
DISPERMATT SL-C5 manufactured by MANN was used to prepare solid fine particle dispersions of the inorganic phosphor. In the bead mill dispersion, zirconia beads having an average particle size of 0.3 mm were used, and the filling rate of the beads was 80%. <Inorganic phosphor solid fine particle dispersion component composition> Inorganic phosphor 20 g Amphiphilic compound Nonipol 400 (manufactured by Sanyo Kasei) 5 g Anionic dispersant Joncryl 62 (molecular weight 8500, manufactured by Johnson Polymer) 2 g Acetylene glycol 1 g Ion-exchanged water 50 g To 35 g of a solid fine particle dispersion (dispersion liquid) of the inorganic phosphor prepared above, 8 g of diethylene glycol was added with stirring.
7 g of 1,5-pentanediol and 50 g of ion-exchanged water were added dropwise over 30 minutes to prepare a fluorescent ink for inkjet recording. The concentration of the solid particles of the inorganic phosphor contained in the ink was 15% by mass. << Preparation of fluorescent image formation and fluorescent image display panel >> Using the fluorescent ink for inkjet recording prepared above,
Inkjet printer (Kon
SD-1044S manufactured by ica) was used to emit an inorganic fluorescent ink, and four fluorescent images were formed with the same A1 size.

The obtained fluorescent image was set as a panel for displaying a fluorescent image in patterns 1) to 4) of the fluorescent image display device described below. << Preparation of Fluorescent Image Display Device >> 1) As an ultraviolet light source, an EL light-emitting panel provided with the organic EL element described in Example 2 of JP 2001-93670 A was prepared, and as shown in FIG. A fluorescent image display device having a constitution in which it was superposed on the fluorescent image display panel thus obtained was produced.

2) As an ultraviolet light source, JP-A-11-19
An EL light emitting panel having the inorganic EL device described in [Embodiment 1] of No. 5488, in which the electrodes are changed as shown in FIG. 1, is prepared, and as shown in FIG. A fluorescent image display device having a structure in which the fluorescent image display panel thus obtained was overlaid was manufactured.

3) An LED manufactured by Nichia Corporation (emission peak wavelength 385 nm) was prepared as an ultraviolet light source, and an A1 size acrylic resin "SUMIPEX 010" (trade name) manufactured by Sumitomo Chemical Co., Ltd. was used as a light guide plate. And using the fluorescent image display panel obtained as described above, as shown in FIG.
A fluorescent image display device having a structure as shown in (b) was produced. The LED was installed in the base of the fluorescent image display device.

4) As an ultraviolet light source, "Fluorescent black light (FL40BL.B) (trade name) 40W (wavelength 365 nm)" manufactured by Matsushita Electric Works, Ltd. was prepared. As a comparative example, FIG. 6 shows the arrangement relationship between the fluorescent image display panel obtained as described above and the fluorescent black light. << Fluorescent image display test >><< Evaluation of fluorescent image formation and image visibility >> 1) to above
As a result of observing each of the fluorescent images obtained by the fluorescent image display device of 4), the fluorescent black light needs a sufficient installation space to illuminate the entire fluorescent image display panel, which is an improvement in terms of space saving. There is room for. On the other hand, when the LED, the organic EL element and the inorganic EL element were used, the installation space could be significantly reduced. Furthermore, when an organic EL element and an inorganic EL element were used, the entire fluorescent image surface could be made to emit light uniformly and with high brightness.

[0102]

According to the present invention, the installation space is much smaller than the case where a fluorescent black light is used as an ultraviolet light source, and it can be installed in a place where it could not be installed in the past, and a sufficient A remarkable effect such as the ability to display a fluorescent image can be ensured.

[Brief description of drawings]

FIG. 1A is a perspective view showing a first basic structure of an inorganic EL element, and FIG. 1B is a perspective view showing a second basic structure.

FIG. 2 is a plan view showing an outline of an example of an EL composite element.

FIG. 3 is a partial cross-sectional view taken along the line I-I in FIG.

FIG. 4 is a perspective view showing an embodiment in which an EL display including an organic EL element is used as an excitation light source for a fluorescence image.

5A is a perspective view showing an embodiment in which an LED is used as an excitation light source for a fluorescent image, and FIG. 5B is a vertical cross-sectional view of the fluorescent display device taken along line II-II in FIG. 5A. is there.

FIG. 6 is a fluorescent image display panel in a fluorescent image device;
It is a perspective view which shows the arrangement | positioning relationship with a fluorescent black light.

[Explanation of symbols]

1 First element (EL composite element) 2 glass substrates 3 electrodes 4 First insulating film 5 Luminescent layer 6 Second insulating film 10 Fluorescence imager 11 Display panel 12 Light guide plate 16 Reflector 18 black light 19 black light socket

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takayuki Suzuki             Konica Stock Market, 1 Sakura-cho, Hino City, Tokyo             In-house (72) Inventor Hideki Hoshino             Konica Stock Market, 1 Sakura-cho, Hino City, Tokyo             In-house (72) Inventor Tokiko Hoshino             Konica Stock Market, 1 Sakura-cho, Hino City, Tokyo             In-house F-term (reference) 2C056 FB01 FD07                 4J039 AD03 AD10 BA13 BA18 BA30                       BA32 BE01 BE02 BE12 BE22                       BE33 CA03 EA28 EA34 EA35                       EA38 GA24                 5C096 AA01 AA22 BA04 CA03 CC02                       CC06 CC07 CC36

Claims (7)

[Claims] 1. A fluorescent image obtained by using a fluorescent ink containing at least a phosphor is irradiated with excitation light from an excitation light source, and an image is obtained based on fluorescence emitted from the phosphor when excited by the excitation light. A fluorescent image display method for displaying, characterized in that organic electroluminescence is used as an excitation light source of the fluorescent image. 2. An image obtained by irradiating a fluorescent image obtained by using a fluorescent ink containing at least a fluorescent substance with an excitation light from an excitation light source, and being excited by the excitation light to emit light from the fluorescent substance. In a fluorescent image display method for displaying, an inorganic electroluminescence is used as an excitation light source for the fluorescent image, which is a fluorescent image display method. 3. The fluorescent image display method according to claim 1, wherein the excitation light source is a light emitting panel and is superposed on a display panel having a fluorescent image. 4. A fluorescent image obtained by using a fluorescent ink containing at least a phosphor is irradiated with excitation light from an excitation light source, and an image is obtained based on fluorescence emitted from the phosphor when excited by the excitation light. A fluorescent image display method for displaying, characterized in that an LED is used as an excitation light source for the fluorescent image. 5. The fluorescent image display method according to claim 4, wherein a light guide plate is used. 6. The fluorescent image display method according to claim 1, wherein the excitation light source is an ultraviolet light source. 7. The fluorescent image display method according to claim 1, wherein the fluorescent image is printed using an inkjet printer.