JPWO2016084843A1 - Luminescent medium and inspection method thereof - Google Patents

Abstract

Provided is a light emitting medium that more reliably prevents forgery, prevents duplication, and improves confidentiality. A light emitting medium (1) is arranged on a base material (2) and a first light source that emits light in a visible light wavelength region when irradiated with light in a first wavelength region longer than the visible light wavelength region. The light emitter 3 and a second light emitter 4 that is disposed on the substrate and emits light in the visible light wavelength region when irradiated with light in the second wavelength region shorter than the visible light wavelength region.

Description

  The present invention relates to a light-emitting medium that emits light in the visible wavelength region by wavelength conversion of light, and an inspection method thereof.

  When light in a certain wavelength range is irradiated, the electrons are excited, and when the electrons return to the original ground state, the light that emits light according to the energy of the electrons is used. Materials having a wavelength conversion function for emitting light in the region are known. A typical example of such a material is a phosphor that converts ultraviolet light into visible light.

  In Patent Document 1, a pattern such as a fluorescent material is formed on a printable material such as a banknote or a securities certificate, or an ID card or an identification card such as a passport, and light from a light source such as a copying machine is used. When irradiated, it hides hidden characters and images and prevents counterfeiting of printed matter.

JP 2005-88546 A

  If a pattern such as the above-mentioned phosphor is formed on printed matter such as banknotes, if you investigate in advance in which wavelength band the pattern will appear, use a copier that does not use a light source in the same wavelength band. May cause illegal duplication of printed matter.

  In addition, the phosphor described above can be used for the purpose of storing secret information because information such as specific characters is not visually recognized unless specific light is irradiated. However, as described above, it is not so difficult to grasp which wavelength band light is irradiated to reveal information. For example, if the wavelength of light applied to the printed material is continuously changed, the wavelength at which information is visually recognized can be easily detected.

As described above, in the conventional technique, even if a phosphor is used for the purpose of storing secret information, it cannot be said that the secrecy is high.
Patent Document 1 uses a material that converts the wavelength of light from a light source into a wavelength in the visible light band so that information can be visually recognized. However, if information is recorded using a material that emits light in a wavelength band that cannot be visually recognized, and information is automatically grasped using a device that senses this light, the information is not visible, so it is confidential. Therefore, the determination process can be speeded up and accurate.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a light emitting medium and an inspection method thereof that can more reliably prevent forgery, prevent duplication, and improve confidentiality. It is.

In order to solve the above problems, in one embodiment of the present invention, a base material;
A first light emitter that is disposed on the substrate and emits light in a visible light wavelength region when irradiated with light in a first wavelength region longer than the visible light wavelength region;
There is provided a light emitting medium comprising: a second light emitter that is disposed on the substrate and emits light in a visible light wavelength region when irradiated with light in a second wavelength region shorter than the visible light wavelength region.

  The emission color when the first light emitter is irradiated with light in the first wavelength range may be the same color as the emission color when the second light emitter is irradiated with light in the second wavelength range. .

  The first light emitter and the second light emitter may be disposed so as not to overlap the base material.

  The first light emitter and the second light emitter are visible when the first light emitter is irradiated with light in the first wavelength range and the second light emitter is irradiated with light in the second wavelength range. It may include at least one piece of specific pattern, picture, character, symbol, and number that can be used.

The first light emitter may be a first coating material that emits light in a visible light wavelength region when irradiated with light in the first wavelength region,
The second light emitter may be a second coating material that emits light in a visible light wavelength region when irradiated with light in the second wavelength region,
The first coating material and the second coating material may be coated on the substrate in accordance with the contour of the information.

In another embodiment of the present invention, a substrate;
A first light emitter that is disposed on the substrate and emits light in the second wavelength region when irradiated with light in the first wavelength region; and
A second light emitter that is disposed on the substrate and emits light in the second wavelength range when irradiated with light in a third wavelength range different from the first wavelength range, and
The first wavelength range is a wavelength range shorter than the visible light wavelength range,
The second wavelength region is an infrared light wavelength region,
The light emitting medium in which the third wavelength range is shorter or longer than the visible wavelength range is provided.

  The first wavelength region may be an ultraviolet light wavelength region.

  The third wavelength range may be an ultraviolet wavelength range or an infrared wavelength range.

The first light emitter emits light in the second wavelength region having a wavelength longer than that of the first wavelength region,
The second light emitter may emit light in the second wavelength range having a shorter wavelength than the third wavelength range.

The first light emitter emits light in the second wavelength region having a wavelength longer than that of the first wavelength region,
The second light emitter may emit light in the second wavelength band having a longer wavelength than the third wavelength band.

In another aspect of the present invention, a first light emitter that is disposed on a substrate and emits light in a second wavelength region when irradiated with light in the first wavelength region, and the first light emitter disposed on the substrate and the first light emitter. The first light emission on the substrate with respect to a light emitting medium comprising: a second light emitter that emits light in the second wavelength range when irradiated with light in a third wavelength range different from the first wavelength range Irradiating the second light emitter with light in the third wavelength range while irradiating the body with light in the first wavelength range;
While irradiating the first light emitter on the substrate with the light of the first wavelength region, and irradiating the second light emitter with the light of the third wavelength region, the first light emitter and the And a step of inspecting the surface of the second light emitter.

The first wavelength region is a wavelength region longer than the visible light wavelength region,
The second wavelength range is a visible light wavelength range,
The third wavelength range may be shorter than the visible wavelength range.

The first wavelength range is a wavelength range shorter than the visible light wavelength range,
The second wavelength region is an infrared light wavelength region,
The third wavelength region may be a wavelength region shorter or longer than the visible light wavelength region.

  According to the present invention, forgery prevention, duplication prevention, and confidentiality can be improved more reliably.

FIG. 2 is a longitudinal sectional view of the light emitting medium 1. FIG. 3 is a plan view of the light emitting medium 1. The figure which shows an example which specifies the place of the 1st light-emitting body 3 and the 2nd light-emitting body 4. FIG. The figure which shows another example which specifies the place of the 1st light-emitting body 3 and the 2nd light-emitting body 4. FIG. The figure which shows an example of the information represented by the 1st light-emitting body 3 and the 2nd light-emitting body 4. FIG. The figure which shows another example of the information represented by the 1st light-emitting body 3 and the 2nd light-emitting body 4. FIG. 1 is a diagram showing a schematic configuration of a light emitting medium inspection apparatus 10 according to an embodiment of the present invention. The figure explaining the optical wavelength conversion of 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail. In the drawings attached to the present specification, for convenience of illustration and understanding, the scale, the vertical / horizontal dimensional ratio, and the like are appropriately changed or exaggerated from those of the actual ones.

(First embodiment)
FIG. 1A is a longitudinal sectional view of the light emitting medium 1, and shows a sectional structure in the AA line direction of the plan view shown in FIG. 1B. As shown in FIGS. 1A and 1B, the light emitting medium 1 includes a first light emitter 3 and a second light emitter 4 disposed on a substrate 2.

  The base material 2 should just be a material excellent in adhesiveness with the 1st light-emitting body 3 and the 2nd light-emitting body 4, and a specific material is not ask | required in particular. For example, it may be a transparent or opaque resin material, an inorganic material such as glass, or a fiber material such as paper.

  The first light emitter 3 and the second light emitter 4 are visible when the second light emitter 4 is irradiated with light in the second wavelength region while the first light emitter 3 is irradiated with light in the first wavelength region. Information of at least one of a specific pattern, pattern, character, symbol and number.

  More specifically, the first light emitter 3 emits light in the visible light wavelength region when irradiated with light in the first wavelength region longer than the visible light wavelength region. Thus, the first light emitter 3 is an up-conversion light emitter that converts light having a long wavelength into visible light having a short wavelength.

  Further, the second light emitter 4 emits light in the visible light wavelength region when irradiated with light in the second wavelength region shorter than the visible light wavelength region. Thus, the second light emitter 4 is a fluorescent light emitter that converts light having a short wavelength into visible light having a long wavelength.

  The first wavelength range is, for example, a wavelength longer than 0.8 μm, and is typically an infrared wavelength range (0.8 μm to 1 mm). Since the first light emitter 3 only needs to emit light in the visible wavelength range, the first wavelength range may be a wavelength range longer than the infrared wavelength range (for example, a terahertz wave or a millimeter wave).

  The second wavelength range is a wavelength shorter than 0.4 μm, for example, and is typically an ultraviolet wavelength range (0.01 μm to 0.4 μm). Since the second light emitter 4 only needs to emit light in the visible light wavelength region, the second wavelength region may be a shorter wavelength region (for example, X-rays) than the ultraviolet wavelength region.

  The visible light wavelength range in which the first light emitter 3 and the second light emitter 4 emit light is, for example, 0.4 μm to 0.8 μm.

  The emission color in the visible light wavelength region emitted by the first light emitter 3 and the emission color in the visible light wavelength region emitted by the second light emitter 4 may be any color that can be visually recognized by the human eye. Then, it is not particularly intended to distinguish between the emission color in the visible light wavelength range emitted by the first light emitter 3 and the emission color in the visible light wavelength range emitted by the second light emitter 4. Therefore, the emission color in the visible light wavelength region emitted by the first light emitter 3 and the emission color in the visible light wavelength region emitted by the second light emitter 4 are preferably similar colors. Here, the similar color refers to, for example, that the emission color of the second light emitter 4 is within a range of 1/6 centering on the emission color of the first light emitter 3 in the hue ring.

  Note that the emission color in the visible light wavelength region emitted by the first light emitter 3 and the emission color in the visible light wavelength region emitted by the second light emitter 4 do not have to be similar colors. That is, the light emission color of the first light emitter 3 and the light emission color of the second light emitter 4 may be different from each other to such an extent that the color difference can be identified by human eyes.

  In the first light emitter 3, when the light in the first wavelength region is irradiated, the electrons in the first light emitter 3 are excited, and extra energy is emitted as visible light when the excited electrons return to the ground state. . Specific materials of the first light emitter 3 include, for example, erbium (Er), holmium (Ho), praseodymium (Pr), thulium (Tm), neodymium (Nd), gadolinium (Gd), europium (Eu), It contains at least one or more rare earth elements selected from the group consisting of samarium (Sm), terbium (Tb), dysprosium (Dy) and cerium (Ce), and the base material of the phosphor particles includes a halide and the like. It is done.

  In the second light emitter 4, electrons in the second light emitter 4 are excited when irradiated with light in the second wavelength region, and extra energy is emitted as visible light when the excited electrons return to the ground state. . Specific materials of the second luminous body 4 include, for example, fluorescein fluorescent dyes, coumarin fluorescent dyes, rhodamine fluorescent dyes as dyes, europium / manganese activated barium magnesium aluminate, Examples thereof include zinc silicate activated with manganese, europium activated yttrium oxide, europium activated yttrium sulfide, zinc oxide, zinc germanate activated with manganese, europium activated yttrium phosphovanadate, and the like.

  Some illuminants start to emit light when irradiated with light in a certain wavelength range and continue to emit light for a while even when light irradiation is stopped, so-called phosphorescence is generated, In the present embodiment, it is desirable to select a material that emits light only while irradiating light in a predetermined wavelength range. The reason is that the light emission according to the present embodiment is performed for the purpose of obtaining the secret information recorded in the light emitting medium 1 only when light of two kinds of wavelength ranges is simultaneously irradiated, as will be described later. This is because the medium 1 can be used.

  The first light emitter 3 is a first coating material (for example, ink) that emits light in the visible light wavelength region when irradiated with light in the first wavelength region. The second light emitter 4 is a second coating material (for example, ink) that emits light in the visible light wavelength region when irradiated with light in the second wavelength region. The first coating material and the second coating material are coated on the substrate 2 in accordance with the contour of information.

  The first light emitter 3 and the second light emitter 4 are, for example, colorless or nearly colorless materials, and it is impossible to visually recognize where the first light emitter 3 and the second light emitter 4 are arranged in the light emitting medium 1. There is a fear. Therefore, the first light emitter 3 and the second light emitter 4 may be colored with a predetermined pigment. However, it is necessary that the content of information represented by the first light emitter 3 and the second light emitter 4 cannot be specified by the color of the pigment. For example, as shown in FIG. 2A, instead of mixing the first light emitter 3 and the second light emitter 4 with a pigment, the base material 2 is formed on the base 2 according to the formation range of the first light emitter 3 and the second light emitter 4. You may apply | coat a pigment to. In FIG. 2A, the color on the base material 2 showing the formation range 5a of the first light emitter 3 is different from the color on the base material 2 showing the formation range 5b of the second light emitter 4, thereby coloring each color. This makes it possible to grasp that it is necessary to make the wavelengths of the light to be irradiated to the areas 5a and 5b different.

  Alternatively, as shown in FIG. 2B, the frames 6a and 6b indicating the arrangement locations of the first light emitter 3 and the second light emitter 4 are printed on the base material 2, and the colorless and transparent first inside the frames 6a and 6b. The light emitter 3 and the second light emitter 4 may be disposed. In this case, the presence of the colorless and transparent first light emitter 3 and the second light emitter 4 cannot be visually recognized, but by providing the frames 6a and 6b on the substrate 2, the first light emission is provided inside the frames 6a and 6b. It can be easily recognized that the body 3 and the second light emitter 4 are arranged. In FIG. 2B, it is necessary to change the wavelength of the light to be irradiated by setting the frame line 6a surrounding the formation range of the first light emitter 3 as a solid line and the frame line 6b surrounding the formation range of the second light emitter 4 as a broken line. It helps to understand what is happening.

  In addition, when the light for the first light emitter 3 and the light for the second light emitter 4 are irradiated on the entire surface of the light emitting medium 1, these lights are also applied to the first light emitter 3 and the second light emitter 4. Therefore, even if both the first light emitter 3 and the second light emitter 4 are colorless and transparent, the first light emitter 3 and the second light emitter 4 can emit light without any trouble. Therefore, it is not essential to add a color to the first light emitter 3 and the second light emitter 4 by mixing pigments.

  However, when the light for the first light emitter 3 and the light for the second light emitter 4 are irradiated on the entire surface of the light emitting medium 1, the second light emitter 4 emits light by the light for the first light emitter 3. On the contrary, the frequency range in which each of the first light emitter 3 and the second light emitter 4 emits light is set as much as possible so that the first light emitter 3 does not emit light due to the light for the second light emitter 4. It needs to be narrow so that the frequency ranges do not overlap.

  3A and 3B show information that is visible when the first light emitter 3 is irradiated with light in the first wavelength region, and information that is visible when the second light emitter 4 is irradiated with light in the second wavelength region. It is a figure which shows an example.

  As shown in these drawings, the first light emitter 3 and the second light emitter 4 are arranged at different locations on the substrate 2. There are mainly two reasons for arranging them at different locations. The first reason is that when the first light emitter 3 and the second light emitter 4 are arranged in the same position on the base material 2, the light in one of the first wavelength region and the second wavelength region is light. This is because it becomes difficult to specify whether the information visually recognized when the light is irradiated is formed on the first light emitter 3 or the second light emitter 4. The second reason is that when light in both the first wavelength region and the second wavelength region is irradiated simultaneously, information on the first light emitter 3 and information on the second light emitter 4 are obtained. This is because the information is visually recognized by being overlapped, and information cannot be separated and extracted in the overlapped area. Further, when the line of the first light emitter 3 and the line of the second light emitter 4 intersect, or when at least a part of the first light emitter 3 and the second light emitter 4 are in contact, the first light emitter 3. And the second illuminant 4 are visually recognized in similar colors, it is not possible to know which illuminant is a line or region. Therefore, it is desirable to arrange the first light emitter 3 and the second light emitter 4 at some distance from each other.

  In the example of FIG. 3A and FIG. 3B, the first light emitter 3 and the second light emitter 4 that are the same size and the same rectangular shape are arranged adjacent to each other, but the sizes of the first light emitter 3 and the second light emitter 4 are the same. There is no particular limitation on the shape. In FIG. 3A, the plurality of first light emitters 3 are arranged in a distributed manner, and the plurality of second light emitters 4 are also arranged in a dispersed manner, but the first light emitter 3 and the second light emitter 4 are arranged. There are no particular restrictions on the number or arrangement. For example, as shown in FIG. 3B, a plurality of first light emitters 3 may be arranged together in one region, and a plurality of second light emitters 4 may be arranged together in another region.

  In FIG. 3A and FIG. 3B, the information visually recognized by the light emission by the first light emitter 3 and the information visually recognized by the light emission by the second light emitter 4 are combined to complete one meaningful information for the first time. I am doing so. For example, in the case of FIG. 3A, the character “A” is visually recognized by combining information visually recognized by light emission by the first light emitter 3 and information visually recognized by light emission by the second light emitter 4. I am doing so. Further, in the case of FIG. 3B, the pattern representing the house is visually recognized by combining the information visually recognized by the light emission by the first light emitter 3 and the information visually recognized by the light emission by the second light emitter 4. I have to.

  As described above, the light emitting medium 1 according to the present embodiment is meaningful only when the first light emitter 3 is irradiated with light in the first wavelength region and the second light emitter 4 is irradiated with light in the second wavelength region. Some information is visible. Accordingly, if the second light emitter 4 is not irradiated with light in the second wavelength region while the first light emitter 3 is irradiated with light in the first wavelength region, meaningful information is output from the light emitting medium 1. It becomes impossible to obtain information, and the confidentiality of information can be improved.

  Although there is a possibility that the emission wavelength is specified by continuously changing the emission wavelength of the irradiation light, in the present embodiment, the first light emitter 3 and the second light emitter 4 emit light in separate wavelength ranges. Therefore, the possibility that information is acquired by irradiating light in the wavelength regions respectively corresponding to the first light emitter 3 and the second light emitter 4 at the same timing becomes very low.

  Further, even if an attempt is made to replicate the light emitting medium 1 according to the present embodiment, the first light emitter 3 is not visible unless it emits light in the first wavelength range, and the second light emitter 4 does not emit light in the second wavelength range. Since it cannot be visually recognized as much as possible, there is less possibility that both the emission wavelength region of the first light emitter 3 and the emission wavelength region of the second light emitter 4 will be noticed, and the possibility of duplication is reduced.

  Further, when the light emitting medium 1 according to the present embodiment is used for authenticity determination, when the first light emitter 3 is irradiated with light in the first wavelength region and the second light emitter 4 is irradiated with light in the second wavelength region. Since it suffices to check whether or not the meaningful information that was originally planned is visually recognized, it is possible to determine the authenticity only with the first light emitter 3 and the second light emitter 4, and the authentication determination process. Can be simplified, and authenticity can be easily determined visually by human eyes.

  FIG. 4 is a diagram showing a schematic configuration of the luminescent medium inspection apparatus 10 according to one embodiment of the present invention. The light emitting medium inspection apparatus 10 of FIG. 4 includes an infrared light irradiation unit 11 that irradiates the light emitting medium 1 with infrared light, an ultraviolet light irradiation unit 12 that irradiates the light emitting medium 1 with ultraviolet light, and the light emitting medium 1. An imaging unit 13 that images the surface and a display unit 14 that displays the captured image are provided.

  The infrared light irradiation unit 11 irradiates the first light emitter 3 on the light emitting medium 1 with light in the first wavelength region (for example, infrared wavelength region), and the ultraviolet light irradiation unit 12 emits the second light emission on the light emitting medium 1. The body 4 is irradiated with light in a second wavelength region (for example, an ultraviolet wavelength region).

  As described above, in the present embodiment, the second light emitter 4 is irradiated with light in the second wavelength region while the first light emitter 3 is irradiated with light in the first wavelength region. That is, the timing at which the infrared light irradiation unit 11 irradiates light to the first light emitter 3 and the timing at which the ultraviolet light irradiation unit 12 irradiates light to the second light emitter 4 are the same.

  For example, when the beam diameter of the light emitted from the infrared light irradiation unit 11 is smaller than the surface area of the first light emitter 3, the light emitted from the infrared light irradiation unit 11 is reflected on the first light emitter 3. By scanning at high speed, it may appear to the human eye as if the entire surface of the first light emitter 3 is irradiated at the same timing. The same applies to the ultraviolet light irradiation unit 12.

  When the first light emitter 3 and the second light emitter 4 are identified by different colors by pigments or the like, the infrared light irradiation unit 11 irradiates light according to the position of the first light emitter 3. It is desirable to irradiate light from the ultraviolet light irradiation unit 12 in accordance with the position of the second light emitter 4. In this case, first, the entire surface of the light emitting medium 1 is imaged, the positions of the first light emitter 3 and the second light emitter 4 are automatically detected, and the infrared light irradiation unit 11 is matched with the detected positions. The irradiation direction of light from the ultraviolet light irradiation unit 12 may be automatically switched.

  Further, as described above, when the first light emitter 3 and the second light emitter 4 are colorless and transparent, and the positions of the first light emitter 3 and the second light emitter 4 cannot be specified by appearance, the infrared light irradiation unit 11 and the ultraviolet light irradiation unit 12 may be applied to the entire surface of the light emitting medium 1. In this case, when the beam diameter of the light from the infrared light irradiation unit 11 and the ultraviolet light irradiation unit 12 is smaller than the surface area on the light emitting medium 1, the light from the infrared light irradiation unit 11 and the ultraviolet light irradiation unit 12 is used. May be scanned on the light emitting medium 1 at high speed. Alternatively, an optical system is provided on the rear side of the optical axis with respect to the infrared light irradiation unit 11 and the ultraviolet light irradiation unit 12, and the entire surface on the light emitting medium 1 is irradiated by expanding the beam diameter of light from each irradiation unit. Also good.

  The display unit 14 in FIG. 4 is a luminescent medium in a state where the infrared light irradiation unit 11 irradiates the first light emitter 3 with light and the ultraviolet light irradiation unit 12 irradiates the second light emitter 4 with light. The entire surface on 1 is imaged and displayed.

  The light emitting medium inspection apparatus 10 of FIG. 4 is used for at least one of inspection of whether the light emitting medium 1 is authentic, detection of specific information embedded in the light emitting medium 1, and prevention of duplication of the light emitting medium 1. be able to.

  For example, if the originally intended information is visually recognized by both the first light emitter 3 and the second light emitter 4 in the surface image on the light emitting medium 1 displayed on the display unit 14 in FIG. Can be determined to be genuine. Since this information is visible only when the first light emitter 3 is irradiated with light in the first wavelength region and the second light emitter 4 is irradiated with light in the second wavelength region, secret information is emitted. Even if the information is recorded on the medium 1, there is a low possibility that the information can be read without permission.

  In addition, since a third party cannot easily recognize that information is visually recognized when the first light emitter 3 and the second light emitter 4 are each irradiated with light in a specific wavelength range, the light emitting medium according to the present embodiment. The possibility of copying 1 is also reduced.

  As described above, in this embodiment, the first light emitter 3 that emits light in the visible wavelength region when irradiated with light in the first wavelength region, and the visible light wavelength when irradiated in the second wavelength region. In order to arrange the second light emitter 4 that emits light in the region on the light emitting medium 1, the first light emitter 3 and the second light emitter 4 are irradiated with light in the corresponding wavelength ranges respectively. Both the body 3 and the second light emitter 4 emit light so that specific information can be visually recognized. Since this information is not visible unless light in the wavelength region corresponding to each of the first light emitter 3 and the second light emitter 4 is irradiated, secret information that cannot be easily read is recorded on the light emitting medium 1. be able to. Accordingly, it is possible to check whether or not the light emitting medium 1 is authentic, use the light emitting medium 1 as a secret information storage place, or prevent the light emitting medium 1 from being duplicated.

(Second Embodiment)
In the first embodiment described above, the example in which the first light emitter 3 and the second light emitter 4 emit light in the visible wavelength range has been described. However, the second embodiment described below is the first light emission. The body 3 and the second light emitter 4 emit light in the infrared wavelength region.

  The cross-sectional structure of the luminescent medium according to the second embodiment is the same as that shown in FIGS. 1A and 1B. The first light emitter 3 according to the second embodiment emits light in the second wavelength region when irradiated with light in the first wavelength region. The second light emitter 4 emits light in the second wavelength region when irradiated with light in a third wavelength region different from the first wavelength region.

  The first wavelength range is a shorter wavelength range than the visible light wavelength range. As a more specific example, the first wavelength range is an ultraviolet wavelength range or an infrared wavelength range.

  The second wavelength region is an infrared light wavelength region. The third wavelength range is a wavelength range shorter or longer than the visible light wavelength range. More specifically, the third wavelength range is an infrared wavelength range.

  FIG. 5 is a diagram for explaining optical wavelength conversion according to the second embodiment. That is, FIG. 5A and FIG. 5B are diagrams schematically illustrating wavelength conversion of light of the first light emitter 3 and the second light emitter 4. The first light emitter 3 and the second light emitter 4 may perform wavelength conversion as shown in FIG. 5A or may perform wavelength conversion as shown in FIG.

  In the example of FIG. 5A, the first light emitter 3 performs down conversion by emitting light in the ultraviolet wavelength region and emitting light in the infrared wavelength region. Moreover, the 2nd light-emitting body 4 irradiates the light of an infrared-light wavelength range, and performs the up-conversion which light-emits the light of the infrared-light wavelength range shorter than the light.

  In the example of FIG. 5B, the first light emitter 3 performs down conversion by emitting light in the ultraviolet wavelength region and emitting light in the infrared wavelength region. Moreover, the 2nd light-emitting body 4 irradiates the light of an infrared-light wavelength range, and performs the down conversion which light-emits the light of the infrared-light wavelength range longer than the light.

A material that emits light in the infrared wavelength region by irradiating light in the ultraviolet wavelength region and a material that emits light in another infrared wavelength region by irradiating light in the infrared wavelength region The specific type is not particularly limited. For example, an inorganic phosphor such as YVO ₄ : Nd or Y ₂ O ₂ S: Nd is applicable as a specific material that emits light in the infrared wavelength region by irradiating light in the ultraviolet wavelength region. is there. Alternatively, an organic light conversion material such as nanodiamond may be applied. Alternatively, phosphor fine particles having a perovskite structure represented by BaSnO ₃ may be applied. Or you may apply rare earth metals, such as Eu and Ce.

  The first light emitter 3 and the second light emitter 4 according to the second embodiment emit light in the infrared wavelength region when irradiated with light in the ultraviolet wavelength region or the infrared wavelength region. It is not possible to visually recognize the light. Therefore, a dedicated device for detecting the light emitted from the first light emitter 3 and the second light emitter 4 is required. The luminescent medium inspection apparatus 10 incorporating such a dedicated apparatus can be configured in the same manner as in FIG. In the case of the first embodiment, the imaging unit 13 in the luminescent medium inspection apparatus 10 in FIG. 4 detects visible light, whereas the imaging unit 13 according to the second embodiment uses infrared light. Is detected. More specifically, the imaging unit 13 according to the second embodiment detects infrared light emitted from the light emitting medium 1 and converts it into an image signal. This image signal is displayed on the display unit 14.

  Thus, in the second embodiment, when the light in the ultraviolet light wavelength region is irradiated, the light in the infrared light wavelength region is emitted, or when the light in the infrared light wavelength region is irradiated, the wavelength region is shifted. Emits light in the infrared wavelength region. It is not possible to visually determine whether or not the light is shining in a desired wavelength range, and since it can be determined only by using a dedicated device, the security performance is improved. Therefore, the light emitting medium according to the present embodiment is suitable for uses where security is important, such as forgery prevention purposes. In addition, by applying the light emitting medium of the present embodiment to the light emitting medium inspection apparatus 10 in FIG. 4, it is possible to determine whether the emission wavelength range is regular or not more accurately and faster than relying on visual observation.

  The aspect of the present invention is not limited to the individual embodiments described above, and includes various modifications that can be conceived by those skilled in the art, and the effects of the present invention are not limited to the contents described above. That is, various additions, modifications, and partial deletions can be made without departing from the concept and spirit of the present invention derived from the contents defined in the claims and equivalents thereof.

    DESCRIPTION OF SYMBOLS 1 Light emitting medium, 2 Base material, 3 1st light emitter, 4 2nd light emitter, 10 Light emitting medium inspection apparatus, 11 Infrared light irradiation part, 12 Ultraviolet light irradiation part, 13 Imaging part, 14 Display part

Claims (13)

A substrate;
A first light emitter that is disposed on the substrate and emits light in a visible light wavelength region when irradiated with light in a first wavelength region longer than the visible light wavelength region;
And a second light emitter that emits light in the visible light wavelength region when irradiated with light in the second wavelength region shorter than the visible light wavelength region.   The emission color when the first light emitter is irradiated with light in the first wavelength band is similar to the emission color when the second light emitter is irradiated with light in the second wavelength band. The luminescent medium described in 1.   The light emitting medium according to claim 1, wherein the first light emitter and the second light emitter are arranged separately from each other on the base material.   The first light emitter and the second light emitter are visible when the first light emitter is irradiated with light in the first wavelength range and the second light emitter is irradiated with light in the second wavelength range. The luminescent medium according to claim 1, comprising at least one information of a specific pattern, a pattern, a character, a symbol, and a number that can be made. The first light emitter is a first coating material that emits light in a visible light wavelength region when irradiated with light in the first wavelength region,
The second light emitter is a second coating material that emits light in a visible light wavelength region when irradiated with light in the second wavelength region,
The light emitting medium according to claim 4, wherein the first coating material and the second coating material are coated on the substrate in accordance with an outline of the information. A substrate;
A first light emitter that is disposed on the substrate and emits light in the second wavelength region when irradiated with light in the first wavelength region; and
A second light emitter that is disposed on the substrate and emits light in the second wavelength range when irradiated with light in a third wavelength range different from the first wavelength range, and
The first wavelength range is a wavelength range shorter than the visible light wavelength range,
The second wavelength region is an infrared light wavelength region,
The light emitting medium, wherein the third wavelength range is shorter or longer than the visible wavelength range.   The luminescent medium according to claim 6, wherein the first wavelength range is an ultraviolet wavelength range.   The light emitting medium according to claim 6, wherein the third wavelength range is an ultraviolet wavelength range or an infrared wavelength range. The first light emitter emits light in the second wavelength region having a wavelength longer than that of the first wavelength region,
The light emitting medium according to claim 6, wherein the second light emitter emits light in the second wavelength range having a shorter wavelength than the third wavelength range. The first light emitter emits light in the second wavelength region having a wavelength longer than that of the first wavelength region,
The light emitting medium according to claim 6, wherein the second light emitter emits light in the second wavelength region having a wavelength longer than that of the third wavelength region. A first light emitter that emits light in the second wavelength region when irradiated with light in the first wavelength region disposed on the substrate, and a third wavelength that is disposed on the substrate and different from the first wavelength region A light emitting medium comprising: a second light emitter that emits light in the second wavelength region when irradiated with light in the region; and the light in the first wavelength region on the first light emitter on the substrate. Irradiating the second light emitter with light in the third wavelength range,
While irradiating the first light emitter on the substrate with the light of the first wavelength region, and irradiating the second light emitter with the light of the third wavelength region, the first light emitter and the And a step of inspecting a surface of the second light emitter. The first wavelength region is a wavelength region longer than the visible light wavelength region,
The second wavelength range is a visible light wavelength range,
The luminescent medium inspection method according to claim 11, wherein the third wavelength range is shorter than the visible wavelength range. The first wavelength range is a wavelength range shorter than the visible light wavelength range,
The second wavelength region is an infrared light wavelength region,
The method for inspecting a luminescent medium according to claim 11, wherein the third wavelength range is a wavelength range shorter or longer than a visible light wavelength range.