JPH10315605A - Fluorescent image forming material and fluorescent image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent image forming material having an identification pattern, e.g. a transparent fluorescent bar code, of enhanced security level requiring prevention of forgery in which an UV light source other than 365 nm can be employed and acquisition and production of material are difficult. SOLUTION: A fluorescent image forming layer F, substantially transparent to the visible, light, containing a first fluorescent material emitting fluorescence in first visible wavelength region upon irradiation with UV-rays of first wavelength and a second fluorescent material emitting fluorescence in second visible wavelength region different from the first visible wavelength region upon irradiation with UVrays of second wavelength and forming a recognition pattern-like fluorescent image upon irradiation with UV-rays of the first or second wavelength is provided on a substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent image forming product and a fluorescent image reading apparatus for irradiating a fluorescent image forming product with ultraviolet light to form and read a fluorescent image.

[0002]

2. Description of the Related Art There is known a method in which various information data is converted into a bar code and attached to a product, and the code information is read and input to a computer or the like. Typically, the barcode is a black bar printed on a white background. This utilizes the difference between the reflected light of the white and black bars.

Recently, various identification patterns such as a two-dimensional bar code represented by a Carla code have been used to increase the amount of information.

There is also a demand for making barcodes transparent in order to improve design and security, and transparent barcodes such as transparent infrared absorbing barcodes, transparent infrared emitting barcodes, and transparent fluorescent barcodes have been demanded. Barcodes are being developed.

[0005] A transparent infrared absorbing barcode is a barcode printed with an ink or the like using a material that is substantially transparent to visible light and absorbs infrared light. The difference in reflected light between the portion where the infrared absorbent is printed and the portion where the infrared absorber is not printed is used.

[0006] A transparent infrared-emitting bar code is an ink that uses a material that is substantially transparent to visible light and emits infrared light of another wavelength when irradiated with infrared light of one wavelength. The bar code is printed by using a difference between a portion that emits infrared light and a portion that does not emit infrared light.

A transparent fluorescent bar code is a bar code which is substantially transparent to visible light and is printed with an ink or the like using a material which emits visible light when irradiated with ultraviolet light of a certain wavelength. The difference between a portion that emits visible light and a portion that does not emit visible light is used.

As a bar code with improved security, a transparent bar code is printed on a part of the product in a confidential manner as a countermeasure against counterfeit products and counterfeit products. A method is used in which the authenticity is determined based on the fact that a transparent barcode is not printed on the imitation product.

[0009] Among the transparent barcodes, the fluorescent luminescent ink used for the transparent fluorescent barcode includes, in place of a colored organic pigment or an inorganic pigment having absorption in the visible light region used in ordinary printing inks, A fluorescent pigment is used. Other components of the fluorescent ink include vehicles and adjuvants. The above fluorescent light-emitting ink,
A fluorescent image forming layer can be formed on a substrate by offset printing, thermal transfer printing, or the like, similarly to a normal printing ink. Here, the fluorescent pigment is a phosphor that emits light of each color such as red, green, and blue.

The fluorescent substance is a substance which emits fluorescence when irradiated with ultraviolet light, and can be roughly classified into an inorganic fluorescent substance and an organic fluorescent substance. Colorless phosphors that absorb little or no visible light can be broadly classified into colored phosphors that have a certain absorption band in the visible light region.

In order to make a bar code image, which is a fluorescent image, appear on the transparent fluorescent bar code, ultraviolet light serving as excitation light is applied. Thus, the phosphor in the transparent fluorescent barcode absorbs ultraviolet light and emits fluorescent light in the visible light region. This fluorescence can be detected and confirmed using a camera or the like. As the wavelength of the ultraviolet light to be irradiated,
An appropriate wavelength is determined depending on the type of phosphor used, and various light sources can be selected depending on the type of phosphor. In particular, a small black light that emits ultraviolet light having a wavelength of 365 nm is widely used.

[0012]

However, as described above, 365 nm black light is commercially available,
Because transparent fluorescent barcodes that need to prevent counterfeiting as described above can be easily obtained by anyone, what kind of transparent fluorescent barcode is formed at any position on the product It is possible to visually check whether or not the bar code has been printed, and there has been a problem that the security level of the transparent fluorescent barcode using the fluorescent light emitting ink is becoming lower.

Further, in recent years, it has become relatively easy to obtain fluorescent light-emitting inks and the like, so that forgery has become easy. Thus, there has been a problem that the security level is further reduced.

The present invention has been made in view of the above problems, and therefore, it is necessary to prevent forgery,
It is also possible to use an ultraviolet light source other than 365 nm, it is difficult to obtain and manufacture the material, and the security level is increased, and a fluorescent image formed product capable of forming an identification pattern such as a transparent fluorescent bar code, and ,
It is an object of the present invention to provide a fluorescent image reading apparatus capable of easily performing reading such as image recognition of the fluorescent image formed product or the like.

[0015]

In order to achieve the above-mentioned object, at least one fluorescent image-forming product of the present invention is provided on a substrate.
A fluorescent image-forming product having a fluorescent image forming layer,
The fluorescent image forming layer includes a first phosphor that emits fluorescent light having a wavelength in a first visible light region when irradiated with ultraviolet light having a first wavelength, and a first visible light region that is irradiated with ultraviolet light having a second wavelength. A second phosphor that emits fluorescence having a wavelength in a second visible light region different from the wavelength of the second light, and is substantially transparent to visible light, and the first wavelength or the second wavelength Is irradiated with the ultraviolet rays to form a fluorescent image in the form of a pattern for identification.

The above-mentioned fluorescent image-formed product contains at least two kinds of fluorescent substances in the fluorescent image-forming layer. These phosphors may be contained in the same layer in the fluorescent image forming layer, or may be contained in different layers in the fluorescent image forming layer. As these phosphors, there are a phosphor excited by ultraviolet rays near 254 nm used as ultraviolet rays (germicidal lamps) of relatively short wavelength, an ultraviolet ray near 365 nm often used as ultraviolet rays of relatively long wavelength, and 254n.
Phosphors that are widely excited in both wavelength regions of ultraviolet light near m can be broadly classified.

Here, the phrase "the fluorescent image forming layer is substantially transparent to visible light" means that the fluorescent image forming layer has a property of transmitting visible light, and that the fluorescent image forming layer is partially or entirely over the entire visible light region. When the color is white (colorless) because of the property of reflecting visible light, and the color of the base on which the fluorescent image forming layer containing the fluorescent substance is formed is substantially the same as the color of the fluorescent substance. This includes the case where it is substantially difficult to visually confirm the presence or absence of the phosphor.

Since the phosphors used in the above-mentioned fluorescent image forming article of the present invention have different wavelength ranges of the fluorescent light emitted from the respective phosphors, ultraviolet light capable of simultaneously exciting the respective phosphors is used. Upon irradiation, the fluorescent light emitted from these phosphors is mixed and observed, whereby a fluorescent image forming layer that emits a color that has not been obtained conventionally can be obtained.

As the phosphor used in the fluorescent image formed article of the present invention, one or more phosphors can be selected from the two types of phosphors having different excitation wavelengths. By changing this, it is possible to obtain a fluorescent image forming layer in which the wavelength region of the emitted fluorescent light is different, that is, the color of the emitted fluorescent light is different.

For example, assume that only the first phosphor emits fluorescence with 365 nm ultraviolet light and emits blue fluorescence.
When ultraviolet light of 254 nm, both the first phosphor and the second phosphor emit fluorescent light, and a fluorescent image formed using an ink that emits red fluorescent light that is a mixed color of the fluorescent light of both fluorescent substances, Even if the counterfeiter forges using a phosphor that emits blue light by irradiating ultraviolet rays of 365 nm, the authenticity determiner can confirm the fluorescence image using ultraviolet rays of both 365 nm and 254 nm. It is possible to determine the authenticity. In the above case, since the forgery is imitated with respect to the fluorescence with respect to the 365 nm ultraviolet ray, it is possible to determine the authenticity by examining whether the forged article emits red fluorescence by irradiating the 254 nm ultraviolet ray.

Therefore, it is necessary for a forger to forge not only the fluorescence characteristics of the ultraviolet ray of 365 nm but also the ultraviolet ray of 254 nm, so that the forgery is very difficult and the security level can be increased. In addition, by mixing a combination of a plurality of patterns by the fluorescent image forming layer in one fluorescent image formed product, the forgery prevention effect can be further enhanced.

Also, the wavelength range of the emitted fluorescent light is different.
It is also possible to change the color of the fluorescent light by changing the mixing ratio of the kinds of phosphors, and it is possible to emit light of a plurality of colors simply by using two kinds of phosphors.
Forgery can be made extremely difficult by combining these fluorescent image forming layers that emit fluorescence of a plurality of colors.

Also, by including the two kinds of phosphors having different emission wavelengths in different layers in the fluorescent image forming layer, it is possible to form different identification patterns in each layer. For example, a first fluorescent image forming layer for forming a first identification pattern using a first phosphor and a second fluorescent image forming layer for forming a second identification pattern using a second phosphor are formed. I do. This makes it possible to increase the total amount of information to be given to the identification pattern.

In the above-mentioned fluorescent image formed article of the present invention, preferably, the first wavelength is shorter than the second wavelength, and the second phosphor is the first wavelength and the second wavelength. Fluorescence is emitted by ultraviolet light of a wavelength. When the first phosphor and the second phosphor are irradiated with ultraviolet light having a wavelength that can be excited,
The color of the fluorescent light emitted by the first phosphor and the color of the second phosphor are mixed to obtain a fluorescent image formed product that emits a color that has not been obtained conventionally.

In the above-described fluorescent image-formed product of the present invention, preferably, the first wavelength is longer than the second wavelength, and the second phosphor is substantially exposed to ultraviolet light of the first wavelength. Does not emit fluorescence. When one of the first phosphor and the second phosphor is irradiated with an ultraviolet ray having a wavelength that can excite one of the phosphors and does not substantially excite the other, only the fluorescence of one of the phosphors is emitted, and the color of the fluorescence at that time is emitted. Can be different from the color of the fluorescence when the other phosphor is irradiated with ultraviolet light having a wavelength that can be excited. As described above, by changing the excitation wavelength, it is possible to obtain a fluorescent image formed product having a different wavelength region of the emitted fluorescent light, that is, a fluorescent image having a different color of the emitted fluorescent light.

In the above-mentioned fluorescent image formed article of the present invention, preferably, the first phosphor is an oxide or an oxyacid salt-based inorganic phosphor, and the second phosphor is an oxide or an oxygen. It is a salt-based inorganic phosphor. More preferably, the first phosphor is Sr ₃ (PO ₂ ) ₃ Cl: Eu, ZnO: Zn, Zn ₂ SiO ₄ : Mn,
Inorganic phosphor selected from Zn ₂ GeO ₄ : Mn, Y ₂ O ₃ : Eu, Y (P, V) O ₄ : Eu, Y ₂ O ₂ S: Eu, and ZnS: Cu (Mn) And the second phosphor is Sr ₃ (PO ₂ ) ₃ Cl: Eu, ZnO: Zn, Zn ₂ SiO ₄ : M
n, Zn ₂ GeO ₄ : Mn, Y ₂ O ₃ : Eu, Y (P, V) O ₄ : Eu, Y ₂ O ₂ S: Eu,
And ZnS: Cu (Mn).
It is excellent in heat resistance, humidity resistance and other weather resistance, aging characteristics (durability), and light resistance. It is a stable material with a relatively large particle size and high brightness. Can be planned.

Further, in order to achieve the above object, the fluorescent image reading apparatus of the present invention contains a phosphor which emits fluorescent light having a wavelength in the visible light region by irradiating ultraviolet rays on a substrate, and substantially emits visible light. An apparatus for reading an image of a fluorescent image-forming product having at least one fluorescent image-forming layer that is electrically transparent, a first ultraviolet irradiating unit that irradiates the fluorescent image-forming product with ultraviolet light of a first wavelength, and An ultraviolet irradiating unit having a second ultraviolet irradiating unit for irradiating ultraviolet light of a second wavelength, and detecting fluorescence emitted from the fluorescent image forming layer when irradiated by the ultraviolet irradiating unit, and converting the fluorescence into a read signal. The apparatus includes a fluorescence sensing unit, a signal processing unit that processes the read signal to generate read information, and an output unit that outputs the read information.

The above-described fluorescence image reading apparatus of the present invention comprises:
An ultraviolet irradiation means capable of irradiating a fluorescent image formed product having a fluorescent image forming layer with ultraviolet light of a first wavelength and ultraviolet light of a second wavelength. This makes it possible to irradiate the fluorescent image formed article with ultraviolet rays having different wavelengths. Further, the fluorescence sensing means senses the fluorescence emitted from the fluorescent image formed product in response to the irradiated ultraviolet light, and converts the fluorescence into a read signal. Further, the signal processing means processes the read signal and converts it into read information. further,
Output means outputs read information.

The ultraviolet irradiating means capable of irradiating the ultraviolet light of the first wavelength and the ultraviolet light of the second wavelength forms a fluorescent image according to the excitation wavelength dependency of the phosphor contained in the fluorescent image formed product. to enable. When the fluorescent image-formed product contains a phosphor having different fluorescent characteristics with respect to the ultraviolet light of the first wavelength and the ultraviolet light of the second wavelength, it is possible to read different fluorescent images depending on the ultraviolet light wavelength.

The fluorescence image reading apparatus of the present invention described above
Preferably, there is provided information comparing means for receiving the read information from the output means, comparing the read information with standard information stored in advance, and outputting predetermined information according to a result of the comparison. Thus, the read information can be compared with the standard information, and a process set in advance according to the read information can be performed.

The above-described fluorescent image reading apparatus of the present invention
Preferably, the fluorescent image forming layer is a first phosphor that emits fluorescent light of a wavelength in a first visible light region by irradiation of ultraviolet light of the first wavelength, and the fluorescent material is irradiated with ultraviolet light of the second wavelength. A second phosphor that emits fluorescence having a wavelength in a second visible light region different from the wavelength in the first visible light region; The wavelength and the second wavelength of the second ultraviolet irradiation unit are configured to be different from each other, and the ultraviolet irradiation unit emits the ultraviolet light of the first wavelength or the second wavelength to the fluorescent image-formed product. Irradiate to form a fluorescent image in the form of a pattern for identification. Fluorescence can be emitted in the first visible light region and the second visible light region, and when two types of phosphors having different emission wavelengths are contained in different layers in the fluorescent image forming layer, the respective phosphors are emitted. Different identification patterns can be formed in the layers. For example, a first fluorescent image forming layer for forming a first identification pattern using a first phosphor and a second fluorescent image forming layer for forming a second identification pattern using a second phosphor are formed. I do. This makes it possible to increase the total amount of information to be given to the identification pattern.

[0032]

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

[0033]First embodiment FIG. 1 is a sectional view of a fluorescent image formed product according to the first embodiment of the present invention.
It is. Fluorescence is emitted in the first visible light region on the upper layer of the base 1
Fluorescent image forming layer F containing first phosphor_aBut
And an intermediate layer 2 is formed by covering the upper layer.
And a layer different from the first phosphor can be
A second phosphor containing a second phosphor that emits fluorescence in a viewing light region;
Fluorescent image forming layer F_bIs formed, and the upper layer is
Bar coat 3 covers. First fluorescent image forming layer F
_aAnd the second fluorescent image forming layer F _bAnd from the fluorescent image form
A layer F is formed.

The fluorescent image forming layer F can form a fluorescent image in the form of a pattern for identification by being irradiated with ultraviolet rays. As the style of the identification pattern,
For example, a bar code, a color code, an area code, or the like can be used. The first fluorescent image forming layer _Fa is the first fluorescent image forming layer Fa.
The of identification pattern, the second fluorescent image forming layer F _b second
Can be formed. The first identification pattern and the second identification pattern may be the same pattern or different patterns, but by making them different, it is possible to increase the amount of information possessed by the identification pattern than before.

The fluorescent ink for forming the fluorescent image forming layer F contains, as its components, a fluorescent pigment, a vehicle, an auxiliary agent, and the like, like the ordinary printing ink. Here, the fluorescent pigment is a phosphor that emits light of each color such as red, green, and blue, and contains two types of phosphors that emit light of different wavelengths.

The phosphor is a substance that emits fluorescence when irradiated with ultraviolet light, and can be roughly classified into an inorganic phosphor and an organic phosphor. Colorless phosphors that absorb little or no visible light can be broadly classified into colored phosphors that have a certain absorption band in the visible region. In the present invention, a colorless phosphor that absorbs little or no visible light is used. In addition, in order to ensure transparency in the visible light region, in the present invention, a transparent phosphor in the visible light region is used, or when the transparency of the phosphor is low, the same color as the color of the phosphor in the visible light region is used. By providing a phosphor on the lower ground of the, it can be made pseudo transparent.

As the colorless inorganic phosphor, Ca, Ba,
Mg, Zn, Cd and other oxides, sulfides, silicates, phosphates, tungstates, and other crystals as main components;
A pigment obtained by adding a metal element such as g, Ag, Cu, Sb, or Pb or a rare earth element such as a lanthanoid as an activator and calcining the same can be used.

Examples of the inorganic phosphor that emits red light include Y ₂ O ₃ : Eu, YVO ₄ : Eu, Y ₂ O ₂ S: Eu, 3.5 MgO, 0.5 MgF
₂ GeO ₂ : Mn, (Y, Gd) BO ₃ : Eu, Y (P, V) O ₄ : Eu or the like can be used.

Examples of inorganic phosphors that emit green light include ZnO: Zn, Zn ₃ SiO ₂ : Mn, Zn ₃ S: Cu, Al, (Zn, Cd) S: Cu,
Al, ZnS: Cu, Au, Al, Zn ₂ SiO ₄ : Mn, ZnS: Ag, Cu, (Zn, Cd)
S: Cu, ZnS: Cu, Gd ₂ O ₂ S: Tb, La ₂ O ₂ S: Tb, Y ₂ SiO ₅ : Ce, T
b, Zn ₂ GeO ₄ : Mn, CeMgAl ₁₁ O ₁₃ : Tb, SrGa ₂ S ₄ : Eu ²⁺ , ZnS: C
u, Co, MgO ・ nB ₂ O ₃ : Ce, Tb, LaOBr: Tb, Tm, La ₂ O ₂ S: Tb
, ZnS: Cu (Mn) or the like can be used.

Examples of inorganic phosphors that emit blue light include ZnS: Ag, CaWO ₄ , Y ₂ SiO ₅ : Ce, ZnS: Ag, Ga, Cl, Ca ₂
B ₅ O ₃ Cl: Eu ²⁺ , BaMgAl ₁₄ O ₂₃ : Eu ²⁺ , Sr ₃ (PO ₂ ) ₃ Cl: Eu, or the like can be used.

Examples of the organic phosphor include diaminostilbene disulfonic acid derivatives, imidazole derivatives, coumarin derivatives, triazoles, carbazoles, pyridines, and the like.
Derivatives such as naphthalic acid and imidazolone, dyes such as fluorescein and eosin, and compounds having a benzene ring such as anthracene can be used.

Two kinds of phosphors having different fluorescence wavelength ranges are selected from the above compounds and the like, and the first phosphor is formed in the fluorescent image forming layer F.
The fluorescent image-forming product of the present invention can be obtained by incorporating the phosphor as a second phosphor and a second phosphor. Three or more kinds of phosphors can be contained, but at least two kinds of phosphors having different fluorescence wavelength regions are required. Here, in order to have different fluorescence wavelength regions, it is sufficient that there is a wavelength region in which only one of them emits fluorescence, and preferably, there is no overlapping portion between the fluorescence emission wavelength regions.

In terms of weather resistance such as heat resistance and moisture resistance, and aging characteristics (durability), inorganic phosphors are excellent. On the other hand, organic phosphors have good wettability of the ink vehicle, and therefore have excellent suitability for producing inks without any particular surface treatment. Among the above-mentioned phosphors, in order to improve durability, weather resistance, especially light resistance or printability, a stable oxide or oxyacid salt-based inorganic phosphor having a relatively large particle size and high luminance. Is preferred. For example, Sr ₃ (PO ₂ ) ₃ Cl: Eu (blue), ZnO: Zn (green), Zn ₂ S
iO ₄ : Mn (green), Zn ₂ GeO ₄ : Mn (green), Y ₂ O ₃ : Eu (red), Y (P, V) O ₄ : Eu (red), Y ₂ O ₂ S: Eu ( Red), ZnS:
Cu (Mn) (green) can be preferably used.

It is preferable to adjust the particle size of the phosphor particles in order to improve the suitability for fluorescence such as luminance and the printability of ink. As the phosphor particles, those composed of particles having an average particle diameter of 0.7 to 4 μm are preferably used, and more preferably, an average particle diameter of 0.7 to 2 μm.
m, most preferably from 1 to 2 μm. In general, it is expected that the smaller the particle size of the pigment particles, the better the ink properties will be. However, when the particle size of the phosphor particles is less than 0.7 μm, a phenomenon in which the brightness of the fluorescence is significantly reduced is observed. Therefore,
It is preferable to use phosphor particles having a particle size of 0.7 μm or more. On the other hand, when the particle size exceeds 4 μm, the transparency of the obtained fluorescence image may be reduced.

The content of the phosphor relative to the entire composition excluding the solvent constituting the fluorescent light-emitting ink is preferably from 15 to 80% by weight in order to improve both luminance and transferability (adhesion) to a printing substrate. And a more preferable range is 20 to 50% by weight. When the content of the phosphor is less than 15% by weight, the fluorescent brightness in the ink composition state is extremely lowered depending on the type of the fluorescent material. It may decrease to about 10.

Further, the properties of the phosphor (hiding power, coloring power,
It is preferable to perform a surface treatment to improve oil absorption, durability, etc.). In particular, when an inorganic phosphor is used, its surface is hydrophilic and has poor affinity for an oily polymer. Therefore, it is preferable to perform a surface treatment to improve the affinity for the polymer. For example, the following method is available.

(A) Coating: The coating acts as a surfactant. For example, there are dispersants for low-molecular or high-molecular fatty acids, fatty acid salts and wax.

(B) Coupling agent: The coupling agent binds firmly to the phosphor and reacts with the polymer. For example, there are a silane compound, a titanium compound, a metal chelate compound and the like.

(C) Polymerizable monomer: A low molecular weight monomer or oligomer is reacted with the phosphor surface to form an irreversible layer. For example, there are polymerizable organic acids and reactive oligomers.

The vehicle of the fluorescent light-emitting ink forming the fluorescent image forming layer F of the present invention has substantially no absorption band in the wavelength region of ultraviolet light for exciting the phosphor and the wavelength region of visible light. Is preferred. Examples of the binder resin which is a main component of the vehicle include polyethylene [polyethylene (PE), ethylene-vinyl acetate copolymer (EVA), vinyl chloride-vinyl acetate copolymer], polypropylene (PP), vinyl [ Polyvinyl chloride (P
VC), polyvinyl butyral (PVB), polyvinyl alcohol (PVA), polyvinylidene chloride (PVd)
C), polyvinyl acetate (PVAc), polyvinyl formal (PVF)], polystyrene [polystyrene (P
S), styrene-acrylonitrile copolymer (AS),
Acrylonitrile-butadiene-styrene copolymer (A
BS)], acrylic [polymethyl methacrylate (P
MMA), MMA-styrene copolymer], polycarbonate (PC), cellulosic [ethyl cellulose (E
C), cellulose acetate (CA), propylcellulose (CP), acetic acid / cellulose acetate (CAB), cellulose nitrate (CN)], fluorine type (polychlorofluoroethylene (PCTFE), polytetrafluoroethylene (P
TFE), tetrafluoroethylene-hexafluoroethylene copolymer (FEP), polyvinylidene fluoride (PVdF)], urethane (PU), nylon (type 6, type 66, type 610, type 1)
1], polyester (alkyd) type [polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycyclohexane terephthalate (PC
T)], and a thermoplastic resin such as a novolak type phenol resin. It is also possible to use thermosetting resins such as resol type phenolic resins, urea resins, melamine resins, polyurethane resins, epoxies, unsaturated polyesters, and natural resins such as proteins, rubber, shellac, copal, starch, and rosin. it can.

Furthermore, these resins can be emulsions for aqueous coatings. Examples of emulsions for aqueous paints include vinyl acetate (homo) emulsion, vinyl acetate-acrylate copolymer emulsion, and vinyl acetate-ethylene copolymer resin emulsion (E).
VA emulsion), vinyl acetate-vinyl versatate copolymer resin emulsion, vinyl acetate-polyvinyl alcohol copolymer resin emulsion, vinyl acetate-vinyl chloride copolymer resin emulsion, acrylic emulsion, acrylic silicone emulsion, styrene-acryl copolymer resin emulsion, Polystyrene emulsion, urethane emulsion, chlorinated polyolefin emulsion,
Epoxy-acryl dispersion, SBR latex, or the like can be used.

Further, if necessary, a plasticizer for stabilizing the flexibility and strength of the print film and a solvent for adjusting the viscosity and drying may be added to the vehicle. The solvent includes a low-boiling solvent having a boiling point of about 100 ° C. and a high-boiling petroleum solvent having a boiling point of 250 ° C. or more, depending on the printing method.
As a solvent having a low boiling point, for example, alkylbenzene or the like can be used.

Further, auxiliary agents such as various reactants for improving drying, viscosity and dispersibility can be appropriately added.
The auxiliary agent is used to adjust the performance of the ink. For example, a compound that improves the friction resistance of the ink surface after drying, a dryer that promotes the drying of the ink, and the like can be used.

A photopolymerization-curable or electron beam-curable resin that does not use a solvent can also be used as a binder resin that is a main component of the vehicle. For example, there are acrylic resins, and specifically, the following are commercially available as acrylic monomers.

Examples of the monofunctional acrylate include 2-ethylhexyl acrylate, 2-ethylhexyl EO adduct acrylate, ethoxydiethylene glycol acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and caprolactone adduct of 2-hydroxyethyl acrylate. Phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, nonylphenol EO adduct acrylate,
Acrylate obtained by adding caprolactone to nonylphenol EO adduct, 2-hydroxy-3-phenoxypropyl acrylate, tetrahydrofurfuryl acrylate, caprolactone adduct of furfuryl alcohol, acryloylmorpholine, dicyclopentenyl acrylate, dicyclopentanyl acrylate, dicyclopentyl acrylate Cyclopentenyloxyethyl acrylate, isobornia acrylate, acrylate of caprolactone adduct of 4,4-dimethyl-1,3-dioxane, acrylate of caprolactone adduct of 3-methyl-5,5-dimethyl-1,3-dioxane, etc. Can be used.

Examples of polyfunctional acrylates include hexanediol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, tripropylene glycol diacrylate, neopentyl glycol hydroxypivalate diacrylate, and neopentyl glycol hydroxypivalate. A caprolactone adduct diacrylate of
Acrylic acid adduct of 1,6-hexanediol diglycidyl ether, diacrylate of acetal compound of hydroxypivalaldehyde and trimethylolpropane, 2,2-bis [4- (acryloyloxydiethoxy) phenyl] propane, 2,2-bis [4- (acryloyloxydiethoxy) phenyl] methane, diacrylate of hydrogenated bisphenol A ethylene oxide adduct, tricyclodecane dimethanol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, Trimethylolpropane propylene oxide adduct triacrylate, glycerin propylene oxide adduct triacrylate, dipentaerythritol hexaacrylate / pentaacrylate mixture, dipenta Lower fatty acids and esters of acrylic acid Risuritoru, acrylate caprolactone adduct of dipentaerythritol, tris (acryloyloxyethyl) isocyanurate, and the like can be used 2-acryloyloxyethyl phosphate.

The inks made of these resins are solventless and have a composition that causes a chain polymerization reaction by irradiation of electromagnetic waves or electron beams. Among them, those of the ultraviolet irradiation type require a photopolymerization initiator, A polymerization inhibitor, a chain transfer agent and the like may be added as a sensitizer and an auxiliary depending on the above.

Examples of the photopolymerization initiator include: 1) direct photolysis type such as arylalkyl ketone, oxime ketone, and acylphosphine oxide; 2) radical polymerization reaction type such as benzophenone derivative and thioxanthone derivative; 3) cationic polymerization reaction Examples of the type include an aryldiazonium salt, an aryliodonium salt, an arylsulfonium salt, an arylacetophenone salt, and others, such as 4) an energy transfer type, 5) a photo redox type, and 6) an electron transfer type. For the electron beam curing type, a resin similar to that of the above-described ultraviolet irradiation type may be used, and a photopolymerization initiator may not be required, and various assistants may be added as needed.

The fluorescent light-emitting ink comprising the above-mentioned fluorescent pigment, vehicle and auxiliary agent may further contain an irreversible decolorizable colorant. The decolorizable colorant in this case has an absorption in the visible region before the operation for decoloring, that is, it is colored, but by the operation for decolorization, for example, irradiation with near infrared rays A colorant that has almost no absorption in the visible region irreversibly, that is, changes to a state transparent to visible light. When printing with a fluorescent light-emitting ink containing such a decolorizable colorant,
The printed image can be identified with the naked eye without performing ultraviolet irradiation, and the printing accuracy can be improved.
After that, it can be made transparent to visible light by performing a decoloring operation.

The fluorescent image-forming product of the present invention containing a fluorescent substance can be obtained by forming a fluorescent image-forming layer on a substrate by various conventionally known methods using the above-mentioned fluorescent luminescent ink. be able to. For example, there are an intaglio printing method such as a relief printing method and a gravure method, a lithographic printing method of an offset method, and a screen stencil (stencil). In addition, a thermal transfer method (for example, JP-A-61-2131)
No. 95, 59-54598, 62-11
1800, JP-A-3-187786), an ink jet system (for example, JP-A-3-8137).
No. 6) can also be used. Further, it is also possible to form a fluorescent light emitting image comprising a fluorescent image forming layer containing a phosphor by the method described in JP-A-4-338598. When the thermal transfer method is used, it is preferable that the thickness of the fluorescent image forming layer is at least 6 μm or more to secure the amount of light. Therefore, it is preferable to add a binder or wax such as carnauba wax to the image forming layer. Further, since it is preferable that the ink surface is thermally melted, it is preferable to use a thermoplastic resin as a binder resin which is a main component of the vehicle.

The thickness of the fluorescent image forming layer formed by the fluorescent light-emitting ink can be appropriately determined depending on the required fluorescent luminance and the content of the fluorescent substance.
It can be 1 to 10 μm. In the present invention, from the viewpoint of ensuring transparency, the phosphor particles having a relatively small particle size are used as described above. However, the insufficient fluorescent intensity due to the small particle size increases the thickness of the fluorescent image forming layer. This can be compensated for.

According to the above method, a fluorescent image forming layer F which forms a fluorescent image in the form of a pattern for identification by irradiating ultraviolet rays is formed on the substrate 1. At this time, as a format of the identification pattern, for example, a bar code, a color code, an area code, or the like can be used.

In the above method, except that the fluorescent image forming layer F containing two kinds of phosphors having different wavelength ranges of the emitted fluorescent light is formed on the substrate 1, the substrate 1 used in the present invention, the underprinting, etc. Conventionally known materials can be used for the visible image forming layer, the intermediate layer 2 and the protective layer 3.

In order to make it more difficult to visually recognize an image formed as a fluorescent image under visible light, it is also preferable to print a camouflage pattern or a tint block with visible ink in the fluorescent image forming area as a base print. The camouflage pattern is preferably a random pattern as much as possible, and its color is preferably a light color that does not affect the color of the fluorescent light emitted by the phosphor as much as possible.

The visible image forming layer such as the underprinting described above is
It can be formed by a known printing method using a known coloring paint or ink. For example, a coloring paint or ink can be obtained by adding various pigments to a binder according to the color to be colored. As the binder, those exemplified as the resin constituting the vehicle component of the above-mentioned fluorescent light emitting ink for the fluorescent image forming layer can be used. The coloring paint or ink may further include a plasticizer, a stabilizer, a wax, a desiccant, a drying aid, a curing agent,
Thickeners, dispersants, solvents or diluents can be added. Examples of the printing method include a printing method such as a usual gravure method, a roll method, a knife edge method, and an offset method, and a transfer method.
When the transfer method is used, it is preferable to smooth the transfer surface by coating a suitable resin in advance and forming a smooth layer in order to improve the adhesiveness of the transfer pattern.

As the intermediate layer 2, a layer having high transmittance with respect to visible light is preferable. As the constituent components, those exemplified as the resin constituting the vehicle component of the above-mentioned fluorescent light emitting ink for the fluorescent image forming layer can be used. In particular, a photopolymerization-curing type or an electron beam-curing type without using a solvent is preferable, and examples thereof include an acrylic resin. This can be formed using the above-mentioned acrylic monomer. In addition, you may add a solvent and an auxiliary agent as needed.

The intermediate layer 2 is not particularly limited, but the intermediate layer below the fluorescent image forming layer can be an ultraviolet absorbing layer in which an ultraviolet absorbing agent is substantially fixed. This can be, for example, at least an ultraviolet absorber and a resin. By selecting the ultraviolet absorber from the group consisting of particles having an ultraviolet absorbing ability or a resin having an ultraviolet absorbing functional group, the ultraviolet absorber is substantially It is possible to form a fixed ultraviolet absorbing layer.

As the particulate matter having an ultraviolet absorbing ability,
For example, an ultraviolet absorbing inorganic pigment can be used, and for example, zinc oxide, titanium oxide, and the like can be used.
From the viewpoint that these particles are substantially transparent to visible light and do not substantially migrate to the fluorescent image forming layer, the particle diameter is suitably in the range of 0.1 to 1 μm.

As the organic ultraviolet absorber, a benzophenone-based, benzotriazole-based, acrylate-based or salicylate-based ultraviolet absorber can be used. As the benzophenone-based ultraviolet absorber, for example, 2-hydroxy-4-methoxybenzophenone,
2,2′-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone,
2,4-dihydroxybenzophenone, resorcyol monobenzoate, 2,4-di-t-butylphenyl-
3,5-di-t-butyl-4-hydroxybenzoate, 2-hydroxy-4-n-octylbenzophenone and the like. Examples of the benzotriazole-based ultraviolet absorber include, for example, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole (Tinuvin P, manufactured by Ciba-Geigy), 2- (2′-hydroxy-3′-t) −
Butyl-5'-methylphenyl) -5-chlorobenzotriazole (Tinuvin 326, manufactured by Ciba-Geigy), 2
-[2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole (Tinuvin 234, Ciba-Geigy) and the like. Also,
Examples of the acrylate UV absorber include 2-ethylhexyl-2-cyano-3, 3-diphenyl acrylate, ethyl-2-cyano-3, and 3-diphenyl acrylate. As the salicylate-based ultraviolet absorber, for example, phenyl salicylate, 4-t-butylphenyl salicylate, p-octylphenyl salicylate and the like can be used.

It is appropriate to select the thickness of the ultraviolet absorbing layer so that the reflectance of the ultraviolet light from the ultraviolet absorbing layer becomes substantially “0”. For example, when the ultraviolet absorber is emulsion tinuvin and the wavelength of the ultraviolet light of the light source is 2
In the case of 54 nm, the thickness of the ultraviolet absorbing layer is sufficient to be 1 μm or less, for example, suitably in the range of 0.1 to 1 μm.

The above ultraviolet absorbing layer can be formed as an excitation light blocking layer on the fluorescent image forming layer. In the region where the excitation light blocking layer is formed, even if irradiated with ultraviolet light, it is absorbed by the excitation light blocking layer and cannot reach the fluorescent image forming layer, so that no fluorescence is emitted. Therefore, by forming a region where the excitation light blocking layer is not formed and a region where the excitation light blocking layer is not formed, it is possible to form a region that does not emit fluorescent light and a region that does not emit fluorescent light, thereby forming a fluorescent image. In this case, a fluorescent image may be formed by forming an excitation light blocking layer formed along a pattern or the like on a fluorescent image layer formed to emit uniform fluorescence, and
Further, a fluorescent image may be formed by forming an excitation light blocking layer along another pattern or the like on a fluorescent image layer formed along a certain image pattern.

The protective layer 3 preferably has high transparency to visible light and ultraviolet light, and can be formed by overlamination or overcoating. The overlaminate can be formed by laminating a transparent film such as polyethylene terephthalate, polyvinyl chloride, polyethylene, or polypropylene by a conventional method.

As the overcoat, those exemplified as the resin constituting the vehicle component of the fluorescent light emitting ink of the fluorescent image forming layer described above can be used. In particular, a photopolymerization-curing type or an electron beam-curing type without using a solvent is preferable, and examples thereof include an acrylic resin. This can be formed using the above-mentioned acrylic monomer.
As described above, additives such as a polymerization initiator are contained, and those additives having high transparency to visible light and ultraviolet light are appropriately selected. Further, an OP layer may be formed on the outermost surface by offset printing of a medium or the like.

Examples of the substrate 1 include plastics such as vinyl chloride, nylon, cellulose diacetate, cellulose triacetate, polystyrene, polyethylene, polypropylene, polyester, polyimide and polycarbonate; metals such as copper and aluminum; paper;
Impregnated paper or the like can be used alone or in combination as a composite. The material can be appropriately selected from the above materials in consideration of physical properties required for the substrate, for example, strength, rigidity, concealing property, light opacity and the like. The thickness of the substrate is usually about 0.005 to 5 mm.

When a white high-quality paper is used as the substrate 1, a fluorescent whitening agent is usually added to the white high-quality paper to increase the whiteness. Irradiates blue. Therefore, when ultraviolet light is applied to visually recognize a fluorescent image by the phosphor contained in the fluorescent image forming layer formed on the paper substrate, the fluorescent whitening agent in the paper substrate also emits fluorescence,
There is a disadvantage that it is difficult to confirm the image. Therefore, it is desirable to select a paper substrate to which no fluorescent whitening agent is added or a paper substrate to which the addition amount is as small as possible. It is also effective to form an ultraviolet absorbing layer containing 10% by weight of tinuvin (manufactured by Ciba Geigy) on a paper substrate as a base print for suppressing the influence of the fluorescent whitening agent.

As a means for irradiating ultraviolet light serving as excitation light for causing a fluorescent image to emerge, various light sources can be selected according to the type of the fluorescent substance. Light emitting black lights are commercially available in small sizes and are easy to use. Further, a germicidal lamp that emits ultraviolet light having a wavelength of 254 nm can be used. In addition, it is preferable to select the type of the phosphor in accordance with the two wavelength ranges because the embodiment of the present invention is easily performed. Table 1 below illustrates the relationship between the phosphor and the wavelength of the excitation light.

[0077]

[Table 1]

As shown in Table 1, depending on the type of the fluorescent substance, the fluorescent substance emits fluorescent light by irradiation with ultraviolet light of 254 nm,
phosphor that does not emit fluorescent light with ultraviolet light of 254 nm,
And phosphors that emit fluorescence when irradiated with both ultraviolet rays at 365 nm. In the present invention, two or more kinds of phosphors having different wavelength ranges of emitted fluorescent light are contained, and at least one of the phosphors has a wavelength of 365 nm.
It is preferable to use a phosphor that can be excited by ultraviolet light having a wavelength other than the above. Further, by selecting these phosphors having different wavelengths of excitable ultraviolet light, the color of the fluorescent image obtained by the wavelength of the ultraviolet light to be irradiated can be made different. For example, the fluorescent image obtained by the irradiation of ultraviolet light of 254 nm can be obtained. And a fluorescent image formed by irradiating a 365 nm ultraviolet ray can form a fluorescent image forming layer having a different color.

For example, the first fluorescent light is not emitted by irradiation of ultraviolet light of 254 nm and emitted by ultraviolet light of 365 nm.
The phosphor in the first phosphor imaging layer F _a, 254 nm and 3
When the second phosphor emits fluorescence by ultraviolet irradiation of both 65nm to be contained in the second fluorescent image forming layer F _b, 36
When irradiated with 5nm UV can form a first identification pattern according to the second fluorescence image forming layer F _b. In the ultraviolet irradiation of 254 nm, the by the first fluorescent image forming layer F _a and the second fluorescent image forming layer F _b 1
And the second identification pattern can be formed by fluorescence of different wavelengths. Examples of such a combination of the first phosphor and the second phosphor include, for example, a combination of a Sr ₃ (PO ₂ ) ₃ Cl: Eu-based fluorescent pigment and a Y ₂ O ₃ : Eu-based fluorescent pigment, Sr ₃ (PO ₂ ) A combination of a ₃ Cl: Eu fluorescent pigment and a Zn ₂ SiO ₄ : Mn fluorescent pigment can be used.

Second Embodiment FIG. 2 is a sectional view of a fluorescent image formed product according to a second embodiment of the present invention. A fluorescent image containing a first phosphor that emits fluorescence in a first visible light region and a second phosphor that emits fluorescence in a visible light region in a region different from the first phosphor in an upper layer of the base 1 The formation layer _Fc is formed, and the upper layer is covered with the overcoat 3. Fluorescent imaging layer F is formed by a fluorescent imaging layer F _c.

In the above-mentioned fluorescent image formed product, the first fluorescent material and the second fluorescent material are the same layer, that is, the fluorescent image forming layer F _c.
Is formed in the same manner as the fluorescent image-formed product of the first embodiment, except that it is contained. At this time, the identification pattern by the first phosphor and the identification pattern by the second phosphor are the same.

When the first phosphor and the second phosphor are irradiated with ultraviolet rays capable of simultaneously exciting both phosphors,
Fluorescence from both phosphors is mixed to emit light. Further, by selecting phosphors having different wavelengths of excitable ultraviolet light, the color of the obtained fluorescent image can be made different by making the wavelength of the irradiated ultraviolet light different.

[0083]Third embodiment FIG. 3 is a sectional view of a fluorescent image formed product according to a third embodiment of the present invention.
It is. Fluorescence is emitted in the first visible light region on the upper layer of the base 1
Image forming layer F containing first phosphor _aAnd the second
Emits fluorescence in a visible light region different from that of the first phosphor
Image forming layer F containing second phosphor_bAnd the first
Image forming layer F containing the first phosphor and the second phosphor_c
And an overcoat 3 covers the upper layer.
Overturned. Fluorescent image forming layer F_a, F_b, F_cFireflies
An optical image forming layer F is formed.

[0084] Fluorescence imaging of the above, the fluorescent image forming layer F _a by fluorescence ink containing a first fluorescent material,
The fluorescent image forming layer _Fb is formed by the fluorescent light emitting ink containing the second phosphor, and the fluorescent image forming layer _Fc is formed by the fluorescent light emitting ink containing the first phosphor and the second phosphor. , Formed in the same manner as the fluorescent image formed product of the first embodiment. At this time, a pattern different from the identification pattern using the first phosphor and the identification pattern using the second phosphor can be formed.

[0085] Fluorescence image forming layer F _c containing the first phosphor and the second phosphor, when irradiated simultaneously excitable UV both phosphors, fluorescence is mixed from both the phosphor To emit light. Further, by selecting phosphors having different wavelengths of ultraviolet light which can be excited for the first phosphor and the second phosphor, the wavelengths of the ultraviolet rays to be irradiated are made different, so that the colors of the obtained fluorescent images are made different. In addition, since different identification patterns can be formed, it is possible to increase the information amount of the identification patterns.

Fourth Embodiment FIG. 4 is a diagram schematically showing the configuration of a fluorescence image reading apparatus according to this embodiment. An apparatus for reading an image of a fluorescent image formed article 10, comprising an ultraviolet light source 20, a fluorescent sensor 30
, A signal processing unit 40, an output unit 40a, and an information comparison unit 5
0 and an output unit 50a.

The fluorescent image-forming product 10 contains a phosphor which emits fluorescent light having a wavelength in the visible light range upon irradiation with ultraviolet light on a substrate, and at least one fluorescent material which is substantially transparent to visible light.
A fluorescent image forming layer.

[0088] ultraviolet light source 20, a second ultraviolet irradiation unit for irradiating the first ultraviolet irradiation unit and the second ultraviolet [nu _uv2 wavelengths is irradiated with ultraviolet rays [nu _uv1 the first wavelength fluorescence imaging was 10 Have. For example, ultraviolet ν of the first wavelength
The black light is irradiated with ultraviolet rays of 365nm wavelength as the first ultraviolet irradiation unit for irradiating _uv1, a second ultraviolet irradiation unit for irradiating ultraviolet light [nu _uv2 the second wavelength,
A germicidal lamp that emits ultraviolet light having a wavelength of 254 nm can be used. The first ultraviolet irradiation section and the second ultraviolet irradiation section can be switched by a switch or the like. Also, using a light source that emits light widely in the ultraviolet region, two types of ultraviolet filters that select and transmit wavelengths with different transmission wavelength characteristics are installed, and the irradiation wavelength can be changed by switching the filter so that the ultraviolet light source can be used. It can also be 20.

The fluorescent sensor 30 senses the fluorescent light v _fl emitted from the fluorescent image forming material 10 when irradiated with ultraviolet light from the ultraviolet light source 20, and converts it into a read signal S30 which is an electric signal. For example, a monochrome CCD sensor having a wide sensitivity in the entire visible light region or a color CCD sensor having a sensitivity to three colors of red, green, and blue can be used. For monochrome CCD sensors, attach a color filter to the surface of the sensor,
It is also possible to have sensitivity by spectrally separating each color such as red, green and blue.

The signal processing section 40 performs arithmetic processing such as analysis and computerization of the read signal S30 read by the fluorescent sensor 30, and converts it into read information S40. The read information is output by the output unit 40a.

The information comparing section 50 receives the read information S40, compares it with the standard information stored in the information comparing section 50 in advance, and outputs predetermined information from the output section 50a according to the result of the comparison. The signal processing unit 40 and the information comparison unit 50 may be configured to perform processing in one computer. From the output unit 50a, a desired output device such as a CRT or a printer, or a higher-level device such as a computer can be connected. When comparison with standard information or the like is not performed, the information comparing unit 50 may not be provided, and the output unit 40a can be connected to a desired output device such as a CRT or a higher-level device such as a computer.

According to the fluorescent image reading apparatus of the present embodiment described above, the fluorescent image can be read by irradiating the fluorescent image formed article with ultraviolet rays of two different wavelengths. When the fluorescent image formed product forms different fluorescent images by irradiation with the above two types of ultraviolet wavelengths, the fluorescent images corresponding to the respective ultraviolet wavelengths can be read.

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

Embodiment 1 FIG. 5 shows a credit card 10 created in this embodiment.
a. In addition to the credit card name and member name on the base, it is hard to see because it is transparent under visible light,
A fluorescent light-emitting barcode area A in which a barcode-shaped fluorescent image shown in FIG. 6 is formed by irradiating ultraviolet rays is formed.

A method for manufacturing the above card will be described. First, a fluorescent light-emitting ink D1 having the composition shown in the following table was produced. An Sr ₃ (PO ₂ ) ₃ Cl: Eu fluorescent pigment emitting blue-violet fluorescence and a Y ₂ O ₃ : Eu fluorescent pigment emitting red fluorescence were contained.

[0096]

[Table 2]

Further, a fluorescent light-emitting ink S1 using only the Sr ₃ (PO ₂ ) ₃ Cl: Eu-based fluorescent pigment as the fluorescent material and a Y ₂ O ₃ : Eu-based fluorescent material as the fluorescent light-emitting ink D1 were used. A fluorescent light-emitting ink S2 containing only a pigment was produced.

PET (188 μm thick) was used as a substrate, and the above-mentioned fluorescent luminescent inks D1, S1,
Using S2 and S2, printing was performed by offset printing in a barcode shape shown in FIG. Offset printing was performed using ordinary ink except for the above-mentioned character portions.

Embodiment 2 FIG. 7 is a perspective view schematically showing a fluorescence image reading apparatus according to this embodiment. Hereinafter, the operation of the present apparatus will be described. Credit card 1 created in Example 1
0a, the fluorescent lamp 20
a irradiates an ultraviolet ray having a wavelength of 365 nm, or an ultraviolet lamp 20b irradiates an ultraviolet ray having a wavelength of 254 nm.

When the fluorescent light-emitting barcode area A is irradiated with ultraviolet light, the phosphor in the fluorescent light-emitting barcode area A absorbs ultraviolet light and emits fluorescent light, thereby forming a barcode-like fluorescent image.

The above-mentioned barcode-shaped fluorescent image is sensed by the monochrome type CCD sensors 30a and 30b provided with color filters and read signals S30a and S3.
0b. Here, the monochrome CCD sensor 3
0a and 30b indicate that the number of CCD pixels is n as shown in FIG.
The spectral sensitivity characteristic has a wide sensitivity in the visible light region, as shown in FIG. 8B. A blue filter having spectral characteristics shown in FIG. 9 is attached to the pixel surface of the monochrome CCD sensor to provide a blue sensor 30a having sensitivity to blue, and a red filter is attached to obtain a red sensor 30b having sensitivity to red.

The decoder 40 receives the read signals S30a and S30b, performs arithmetic processing such as analysis and computerization, converts the read information into read information S40, outputs the read information to the result display unit 60, and displays it.

FIG. 10 shows the decoder input waveform obtained by the above method. FIG. 10A shows the output waveform of the red sensor when ultraviolet light having a wavelength of 254 nm is irradiated, and FIG.
Is the output waveform of the blue sensor when irradiating ultraviolet light with a wavelength of 254 nm, (c) is the output waveform of the red sensor when irradiating ultraviolet light with a wavelength of 365 nm, and (d) is 365n.
The output waveforms of the blue sensor when ultraviolet light having a wavelength of m is irradiated are shown. Different waveforms were obtained depending on the wavelength of the ultraviolet light to be irradiated and the spectral sensitivity of the sensor, and more information could be obtained than before.

Also, the standard information is stored in the decoder 40 in advance, and the function of comparing the above four kinds of output waveforms with the standard information is given to the decoder 40. The authenticity of the attached credit card was confirmed. For example, the bar code incorporates a bar that emits blue light by UV irradiation at 365 nm wavelength and a bar that emits red light by UV irradiation at 254 nm wavelength in the bar code. A barcode pattern different from the real barcode was exhibited by the irradiation of the ultraviolet rays, and it could be determined that the barcode was fake.

Also, the authenticity of a conventional fluorescent image-forming product containing only one kind of phosphor is determined by examining a fluorescent image using ultraviolet light having a wavelength of 254 nm in addition to ultraviolet light having a wavelength of 365 nm. It became possible.

Embodiment 3 FIG. 11 is a perspective view schematically showing a fluorescence image reading apparatus according to this embodiment. Blue sensor 30 in the second embodiment
a and the red sensor 30b are replaced with a color CCD sensor 30c, and the rest is the same as the second embodiment.

The above color CCD sensor is similar to that shown in FIG.
As shown in (a), each of n (R), green (G), and blue (B) pixels having spectral sensitivities in red, green, and blue is arranged alternately by n each. The spectral sensitivity characteristics are as shown in FIG. For example,
When the red light strikes, a signal is generated only in the red pixel, and a read signal for the red light is transmitted to the decoder 40. Similarly, the signals for the green and blue lights are separately transmitted.

The result of outputting a fluorescent image as a waveform when the fluorescent barcode attached to the credit card of the first embodiment was read by the above apparatus was the same as that of the second embodiment. In this way, different waveforms are obtained depending on the wavelength of the ultraviolet light to be irradiated and the spectral sensitivity of the color CCD sensor,
More information could be obtained than before. In addition, by using a color CCD sensor, the size of the fluorescent image reading device could be reduced.

Further, the standard information is stored in the decoder 40 in advance, and a function of comparing the above four kinds of output waveforms with the standard information is given to the decoder 40. The authenticity of the attached credit card was confirmed.

The fluorescent image formed product and the fluorescent image reading device of the present invention are not limited to the above-described embodiment. For example, the ultraviolet light source is black light (emission of 365 nm)
The light source is not limited to a germicidal lamp (254 nm), but may be anything that emits ultraviolet light. However, in this case, it is necessary to check in advance whether the wavelength of the ultraviolet light to be used can sufficiently excite the phosphor in the fluorescent image formed product, and to select the phosphor. The fluorescent sensor only needs to be able to sense light, and is not limited to a device using a CCD element. Functions such as a signal processing unit such as a decoder, an output unit, and a result display unit can be housed in a computer such as one personal computer. In addition, various changes can be made without departing from the spirit of the present invention.

[0111]

According to the present invention, it is possible to use an ultraviolet light source other than 365 nm, which is required to prevent forgery, and it is difficult to obtain and manufacture it, and the security level is increased. It is possible to provide a fluorescent image formed product on which an identification pattern such as a fluorescent barcode is formed.
By selecting the wavelengths that can be excited by the two kinds of phosphors, different colors of fluorescent light are emitted by the irradiation of the first wavelength and the irradiation of the second wavelength, and different identification patterns are formed. Therefore, the amount of information of the identification pattern can be increased.

Further, according to the present invention, it is possible to provide a fluorescent image reading apparatus capable of easily performing reading such as image recognition of the above-mentioned fluorescent image formed product or the like.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a fluorescent image formed product according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a fluorescent image formed product according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of a fluorescent image formed product according to a third embodiment of the present invention.

FIG. 4 is a schematic diagram of a fluorescence image reading device according to a fourth embodiment of the present invention.

FIG. 5 is a schematic diagram of a fluorescent image formed product (credit card) created in Example 1 of the present invention.

FIG. 6 is a diagram showing a fluorescent light-emitting barcode attached to a fluorescent image formed product (credit card) created in Example 1 of the present invention.

FIG. 7 is a perspective view schematically illustrating a fluorescence image reading apparatus according to a second embodiment of the present invention.

FIG. 8A is a pixel arrangement diagram of a CCD sensor used in a fluorescence image reading device according to a second embodiment of the present invention, and FIG. 8B is a diagram showing a spectral sensitivity characteristic thereof.

FIG. 9 is a diagram illustrating a spectral characteristic of a color filter attached to a CCD sensor used in the fluorescence image reading device according to the second embodiment of the present invention.

FIG. 10 is a diagram in which a fluorescent image formed on the fluorescent image forming product according to the first embodiment of the present invention is read by the fluorescent image reading device according to the second embodiment, and a read waveform is output; (A) shows the output waveform of the red sensor when ultraviolet light having a wavelength of 254 nm is irradiated, and (b) shows the output waveform of the red sensor.
The output waveform of the blue sensor when irradiating ultraviolet light with a wavelength of 54 nm, (c) the output waveform of the red sensor when irradiating ultraviolet light with a wavelength of 365 nm, and (d) are irradiated with ultraviolet light of a wavelength of 365 nm. The output waveforms of the blue sensor are shown below.

FIG. 11 is a perspective view schematically illustrating a fluorescence image reading apparatus according to a third embodiment of the present invention.

FIG. 12A is a pixel arrangement diagram of a color CCD sensor used in a fluorescence image reading device according to a third embodiment of the present invention, and FIG. 12B is a diagram showing a spectral sensitivity characteristic thereof.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base | substrate, 2 ... Intermediate layer, 3 ... Protective layer, F ... Fluorescent image forming layer, 10 ... Fluorescent image formed matter, 20 ... Ultraviolet light source, 30 ...
Fluorescent sensor, 40: signal processing unit, 50: information comparison unit, 4
0a, 50a ... output unit.

Claims (10)

[Claims] 1. A fluorescent image forming product having at least one fluorescent image forming layer on a substrate, wherein the fluorescent image forming layer has a wavelength in a first visible light region by irradiation with ultraviolet light of a first wavelength. A first phosphor that emits fluorescence and a second phosphor that emits fluorescence having a wavelength in a second visible light region different from the wavelength in the first visible light region by irradiation with ultraviolet light having a second wavelength. A fluorescent image-forming product, which is substantially transparent to visible light and forms a fluorescent image in the form of an identification pattern when irradiated with ultraviolet light of the first wavelength or the second wavelength. 2. The method according to claim 1, wherein said first wavelength is shorter than said second wavelength, and said second phosphor emits fluorescence by ultraviolet rays of said first wavelength and said second wavelength. Fluorescent image formation. 3. The fluorescent image forming apparatus according to claim 1, wherein said first wavelength is longer than said second wavelength, and said second phosphor does not substantially emit fluorescence by ultraviolet light of said first wavelength. Stuff. 4. The method according to claim 1, wherein the first phosphor is an oxide or oxyacid salt inorganic phosphor, and the second phosphor is an oxide or oxyacid salt inorganic phosphor. 4. The fluorescent image-formed product according to any one of 3. 5. The method according to claim 1, wherein the first phosphor is Sr._Three(PO_Two)_ThreeCl: Eu, Zn
O: Zn, Zn_TwoSiO_Four: Mn, Zn_TwoGeO_Four: Mn, Y_TwoO_Three: Eu, Y (P, V) O_Four: E
u, Y_TwoO_TwoInorganic selected from S: Eu and ZnS: Cu (Mn)
A phosphor, wherein the second phosphor is Sr_Three(PO_Two)_ThreeCl: Eu,
ZnO: Zn, Zn_TwoSiO_Four: Mn, Zn_TwoGeO _Four: Mn, Y_TwoO_Three: Eu, Y (P, V)
O_Four: Eu, Y_TwoO_TwoSelected from S: Eu and ZnS: Cu (Mn)
The fluorescent image formed product according to claim 4, which is an inorganic phosphor. 6. A fluorescent image comprising at least one fluorescent image forming layer which contains a phosphor which emits fluorescent light having a wavelength in the visible light region upon irradiation with ultraviolet light and is substantially transparent to visible light. An apparatus for reading an image of a formed product, comprising: a first ultraviolet irradiating unit that irradiates the fluorescent image formed product with ultraviolet light of a first wavelength; and a second ultraviolet irradiating unit that irradiates ultraviolet light of a second wavelength. An ultraviolet light irradiating means, a fluorescent light sensing means for sensing fluorescence emitted from the fluorescent image forming layer when irradiated with the ultraviolet light irradiating means and converting the fluorescent light into a read signal, and a signal for processing the read signal to obtain read information A fluorescent image reading device comprising: a processing unit; and an output unit that outputs the read information. 7. The fluorescent image reading apparatus according to claim 6, further comprising information comparing means for receiving the read information from the output means, comparing the read information with standard information stored in advance, and outputting predetermined information according to a result of the comparison. apparatus. 8. A fluorescent image forming layer, comprising: a first phosphor that emits fluorescent light having a wavelength in a first visible light region by irradiation with ultraviolet light of the first wavelength; and a fluorescent material that is irradiated with ultraviolet light of the second wavelength. A second phosphor that emits fluorescence having a wavelength of a second visible light region different from the wavelength of the first visible light region, and the second ultraviolet light irradiation unit of the first ultraviolet irradiation unit of the ultraviolet irradiation unit. 1 is different from the second wavelength of the second ultraviolet irradiation unit, and the first wavelength or the second wavelength is supplied from the ultraviolet irradiation unit.
The fluorescent image reading apparatus according to claim 6, wherein the fluorescent image-forming product is irradiated with ultraviolet light having a wavelength of to form a fluorescent image in a pattern for identification. 9. The second fluorescent light, wherein the first wavelength of the first ultraviolet irradiator of the ultraviolet light irradiator is shorter than the second wavelength of the second ultraviolet irradiator. The fluorescence image reader according to any one of claims 6 to 8, wherein the body emits fluorescence by ultraviolet light of the first wavelength and the second wavelength. 10. The second fluorescent light, wherein the first wavelength of the first ultraviolet irradiator of the ultraviolet irradiator is longer than the second wavelength of the second ultraviolet irradiator. 9. The fluorescence image reading apparatus according to claim 6, wherein the body does not substantially emit fluorescence by the ultraviolet light having the first wavelength.