JPH11212436A - Hologram laminated body and hologram copy method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hologram laminated body and a hologram copy method which stably copies a hologram having less noise and high quality. SOLUTION: The hologram laminated body includes an original plate 1 for copy to be used for hologram copy, and an internal reflection light intensity reduction member 6 which reduces the intensity of internal reflective light on the layer surface other than the original plate 1 for hologram copy to <=1/100 of incident light intensity is provided to reduce the stray light due to internal reflection. The internal reflective light intensity reduction member 6 is a black absorption body which has 38% transmittance to the light wavelength for copy and can be arranged on the side opposite to the side irradiated with light for copy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hologram duplication, and more particularly to a laminate including a hologram duplication master and a hologram duplication method using the same.

[0002]

2. Description of the Related Art In order to produce a hologram having desired characteristics (diffraction wavelength, diffraction angle, focal length, etc.), a relative position between a hologram photosensitive material and a laser light source is determined, and precisely fixed at that position. Must be exposed. And
In order to produce a large number of holograms identical to this hologram, this time-consuming positioning had to be repeated many times, which required a lot of time and trouble.

Therefore, there has been proposed a method in which a hologram duplication master is first prepared, a film-shaped hologram photosensitive material is brought into close contact with the master, and light is irradiated from the photosensitive material side to duplicate the hologram (Japanese Patent Laid-Open No. Hei. No. 9-90857). According to this method, there is an advantage that the same hologram can be continuously manufactured in a large number without performing complicated positioning many times.

[0004] Here, in preparing the hologram duplication master, first, light of a predetermined wavelength is separately applied to the front and back surfaces of a transparent substrate (eg, glass) having a photosensitive material for hologram recording adhered to one surface. It is arranged so as to be irradiated at a predetermined angle, exposure is performed, and predetermined optical characteristics are given to the photosensitive material. The wavelength, irradiation angle and the like are set in accordance with the required hologram specifications. Next, the hologram provided to the photosensitive material is subjected to a fixing process according to the characteristics of the photosensitive material. Finally, especially when the hologram is made of a resin material, a heating step is performed in order to make interference fringes clearer.

[0005] Next, in the production of a duplicate hologram, a photosensitive material is adhered to an original produced as described in the above-mentioned publication,
Exposure is performed from one side with light of the same wavelength using the same optical system as the original. By doing so, the hologram is recorded on the copying photosensitive material by interference between the incident light and the diffracted light from the hologram. After that, the photosensitive material on the copy side is peeled off from the original plate, and a product is obtained by the same steps as in the production of the original plate.

[0006]

Generally, the hologram duplication master used in the conventional duplication has a layer structure as it is when it is produced, but a colored substrate glass is used. Is also shown.

[0007] In the former case, at the time of duplication, the irradiation light can be transmitted through the hologram duplication master. In other words, when a photosensitive material for duplication is attached to an original having such a layer structure and exposure for duplication is performed, for example, stray light due to internal reflection light at the interface between the original and the air becomes stronger, and the resulting duplicate is obtained. The hologram will be very noisy.

In the latter case, the transmitted light from the original plate is absorbed to some extent by the substrate glass, but it is required to more strictly suppress the internally reflected light.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide a hologram laminate including a hologram duplication master capable of obtaining a low-noise copy by suppressing internal reflection light, and a hologram using the same. It is to provide a duplication method.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a hologram laminate having a hologram duplication master used to be superimposed on a hologram photosensitive material at the time of hologram duplication, wherein a layer interface other than the hologram duplication master is used. This is achieved by a configuration in which an internal reflected light intensity attenuating member for reducing the internal reflected light intensity at 1/100 or less to the incident light intensity is laminated at least.

That is, by using an internal reflection light intensity attenuating member that reduces the internal reflection light intensity to 1/100 or less of the incident light intensity inside the superimposed hologram duplication master and duplication photosensitive material, The stray light is reduced by suppressing the internal reflection light intensity and reducing the number of internal reflections.

Further, the internal reflection light intensity attenuating member is a black absorber having a transmittance of 38% or less with respect to the wavelength of the light for duplication, and is disposed at a position opposite to a side irradiated with light at the time of duplication. It can be configured.

By using the black absorber under such conditions, the transmitted light can be surely absorbed in a wide applicable range value for the incident angle of the irradiation light for duplication, the stray light intensity, the diffraction efficiency, etc., and the internal reflection is suppressed. be able to.

Further, the internal reflection light intensity attenuating member may be a low reflection (AR) coated glass, and may be arranged on a side opposite to a side irradiated with light at the time of duplicating a hologram.

The reflectance of the low reflection (AR) coated glass is preferably 2.3% or less at a light incident angle of 70 °. Thus, when the required incident angle is about 70 °, stray light can be suppressed to a very small value.

Further, the object of the present invention is to provide a hologram duplication method in which a hologram laminate having a hologram duplication master is superimposed on a hologram photosensitive material, and light is irradiated from the hologram photosensitive material side to produce a duplicate hologram. As the hologram laminate, the internal reflected light intensity at the layer interface other than the hologram duplication master is 1/1 of the incident high intensity.
A hologram laminate is formed on the hologram photosensitive material so that the internal reflection light intensity attenuation member to be reduced to 00 or less is at least laminated, and the internal reflection light intensity attenuation member is arranged on the side opposite to the hologram photosensitive material side. This is achieved by creating a duplicate hologram by superimposing.

According to the present invention, a high-quality duplicate hologram with less noise can be stably obtained by providing the internal reflection light intensity attenuating member as described above in replicating a hologram.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a basic configuration of a hologram laminate according to an embodiment of the present invention. In FIG. 1, the hologram duplication master 1 is stuck on a substrate glass 5, and the opposite surface is protected by a protective layer 4. Further, on the outer surface of the protective layer 4, a UV-curable adhesive 3
Is provided on the outer surface of the substrate glass 5 via the UV-curable adhesive 3.
And has a plurality of layer configurations as a whole.

FIG. 3 is a schematic view showing a process of performing hologram duplication using the hologram duplication master 1. As shown in FIG.

Among them, the photosensitive material film for duplication 11
Has a three-layer structure (not shown) in which the photosensitive material 12 is sandwiched between support films 13 and 14. The photosensitive material film 11 sent out from the unwinding roller 31 on which the copying photosensitive material film 11 is set is cleaned through a cleaning unit 44 composed of an adhesive roller, and is cleaned by a peeling roller 45 in the sticking / peeling head 32. The support film 13 on one side is peeled off. The separated support film 13 is taken up by a take-up roller 33. On the other hand, the photosensitive material film 11 with the exposed surface of the photosensitive material 12 is moved from right to left in FIG.
Is laminated on the surface of the hologram duplication master 1. The reason why the support film on the hologram duplication master side is peeled off is to prevent dust or the like from being caught between the hologram duplication master 1 and the hologram duplication master 1 and the duplication photosensitive material. The purpose of this is to minimize the number of layers existing between the layers 12 and 12 and to eliminate the influence of internal reflection and the like.

Next, an anti-reflection coated glass 34 is placed on the hologram duplication master 1 on which the photosensitive material film 11 is laminated, with a refractive index matching liquid interposed therebetween. After trimming by ultraviolet light, exposure is performed by irradiation with an Ar laser or the like, and a diffraction image similar to that of the hologram duplication master 1 is recorded on the duplication photosensitive material 12. At this time, a black absorber 6 is provided on the side of the hologram duplication master 1 on which the photosensitive material film 11 is not laminated, and the incident light reaching the black body absorber 6 is reduced to a level that does not become stray light due to internal reflected light. The light is absorbed and the reflection is weakened to such an extent that it hardly reaches the photosensitive material film 11. Therefore, the reflected light at the interface with the black body absorber 6 hardly causes a diffracting action with the incident light at the photosensitive material film 11.

After such duplication recording, the photosensitive material film 11 is peeled off from the hologram duplication master 1, and the protective film 50 is bonded to the exposed surface of the photosensitive material 12 by the laminating roller 38. In order to form a sufficient diffraction image on the photosensitive material, ultraviolet light exposure is performed by an ultraviolet irradiation device 42, and the photosensitive material is wound by a winding roller 43.

Here, the light intensity of stray light due to internal reflection is:
The light intensity used for the replication includes the transmittance A% of the hologram photosensitive material 11, the diffraction efficiency η% of the hologram replication master 1, the transmittance X% of the black absorber 6, and the reflectance R _{s at the} interface between the black absorber 6 and the air. , Again multiplied by the transmittance X% of the black absorber 6. Here, the transmittance is the vertical transmittance T ₁ , and the transmittance T ₂ at oblique incidence (incident angle θ ₁ ) changes according to the internal incident angle θ ₂ according to the following equation.

[0024]

(Equation 1)

Therefore, if replication is performed with S-polarized light having an incident angle θ ₁ , the stray light intensity can be obtained by the following equation.

[0026]

(Equation 2)

Here, the intensity of the stray light is 1/1 of the intensity of the incident light.
When the value is less than 00 (preferably 1/1000), stray light becomes difficult to be recorded as a hologram, and a high-quality duplicate hologram can be obtained.

Here, usually, many hologram photosensitive materials have a transmittance A of 30 to 90% with respect to the wavelength of incident light. In general, the diffraction efficiency η% of the hologram duplication master is determined by the intensity ratio of the incident light and the diffracted light (RO
In consideration of the ratio, it is desirable that the incident angle θ _{1 in} replication be 70% or less. The refractive index n of the black absorber is set to around 1.5 in accordance with the refractive index of glass or a hologram photosensitive material. Then, the stray light intensity can be calculated by the above equation using the transmittance A of the hologram photosensitive material, the diffraction efficiency η of the hologram duplication master, the incident angle θ ₁ in the duplication, and the transmittance X of the black absorber as variables.

FIG. 4 shows the relationship among the diffraction efficiency η of the master for hologram duplication, the transmittance X of the black absorber, and the intensity of stray light when duplicated with 70 ° incident light. FIG. 5 shows the relationship among the incident angle θ ₁ of the duplicated light, the transmittance X of the black absorber, and the intensity of the stray light when using a hologram duplication master having a diffraction efficiency of 50%. 4 and 5, the stray light intensity is such that the transmittance A of the hologram photosensitive material is 90%, the diffraction efficiency η of the hologram duplication master is 50%, and the incident angle θ ₁ in the duplication is 70 °.
It becomes maximum when.

Therefore, the stray light intensity is set to 1/10 of the incident light intensity.
It can be seen from FIGS. 4 and 5 that the transmittance of the black absorber may be reduced to about 38% or less in order to reduce the value to 0 or less.

As an example, using a black absorber (privacy glass) having a transmittance of 20%, a dye having an oscillation wavelength of 555 nm was added to a photopolymer with a polyvinyl alcohol (PVA) cover sheet having a spectral sensitivity curve shown in FIG. Copying was performed by irradiating a laser beam at 70 °. As a result, a high-quality duplicate hologram having almost no noise was obtained.

In the embodiment shown in FIG. 1, the substrate glass 5 is the substrate glass at the time of exposing the hologram duplication master 1, and can be omitted. When the substrate glass 5 is omitted, the surface of the substrate glass 5 is subjected to mold release processing in advance,
After the exposure, the hologram duplication master 1 should be easily peeled off. FIG. 2 is a sectional view of the basic configuration of the hologram laminate without the substrate glass 5. In this case, the hologram duplication master is directly attached to the black absorber 6.

FIG. 7 shows a basic configuration diagram of a hologram according to another embodiment of the present invention. In FIG. 7, a hologram duplication master 1, a cover glass 2, a UV-curable adhesive 3,
Since the protective layer 4 and the substrate glass 5 have the same layer configuration as in FIG. 1, the same components are denoted by the same reference numerals. A low reflection (AR) coated glass 9 is attached to the substrate glass 5.

FIG. 3 shows a process for producing a duplicate hologram.
The same steps as described above can be used. When light is incident on the hologram duplication master 1 and the photosensitive material film 11 superposed thereon, the low reflection (AR) coated glass 9 is formed on the side of the hologram duplication master 1 on which the photosensitive material film 11 is not laminated. Is provided. At this time, the incident light reaching the low reflection (AR) coated glass 9 is transmitted to such an extent that it does not become stray light due to the internally reflected light, and its reflection is weakened to such an extent that it hardly reaches the photosensitive material film 11. Therefore, the light reflected at the interface with the low-reflection (AR) coated glass 9 hardly causes a diffraction effect on the incident light at the portion of the photosensitive material film 11.

As described above, in the embodiment of FIG. 7, the low reflection (AR) coated glass 9 reduces stray light due to internal reflection at the interface between the substrate glass 5 and the air on the side opposite to the hologram duplication master 1. effective.

The light intensity of the stray light due to the internal reflection is equal to the light intensity used for duplication and the transmittance A of the hologram photosensitive material for duplication.
%, Diffraction efficiency η% of the hologram duplication master, low reflection (A
R) It is obtained by multiplying the reflectance R% of the coated glass.

Assuming that replication is performed with S-polarized light at an incident angle θ ₁ , the stray light intensity is obtained by the following equation.

[0038]

(Equation 3)

Regarding the hologram duplication using the hologram duplication master on which the low reflection (AR) coated glass is laminated, if the intensity of the stray light becomes 1/100 (preferably 1/1000) or less of the intensity of the incident light, the stray light It becomes difficult to record on a photosensitive material, and a high-quality duplicate hologram can be obtained.

Here, as described above, a general hologram photosensitive material has a transmittance A of 30 to the wavelength of incident light.
It has a numerical value of ９０90%. The diffraction efficiency η% of the hologram duplication master is desirably 50% or more in consideration of the intensity ratio (RO ratio) between the incident light and the diffracted light at the time of duplication, and the incident angle θ ₁ in the duplication is 70 °. The following is desirable. The refractive index n of the low reflection (AR) coated glass is adjusted according to the refractive index of the glass or the hologram photosensitive material.
It should be around 1.5. From the above equation, the intensity of the stray light is calculated by using the transmittance A of the hologram photosensitive material, the diffraction efficiency η of the hologram duplication master, the incident angle θ ₁ in the duplication, and the reflectance R of the low reflection (AR) coated glass as variables. Can be.

FIG. 8 shows a graph obtained by copying with 70 ° incident light.
The relationship between the diffraction efficiency η of the hologram replica master, the reflectance R of the low reflection (AR) coated glass, and the intensity of stray light is shown. From FIG. 7, the intensity of the stray light becomes maximum when the transmittance A of the hologram photosensitive material is 90% and the diffraction efficiency η of the hologram of the master is 50%. Therefore, the stray light intensity is set to 1/10 of the incident light intensity.
It can be seen from FIG. 8 that the reflectance of the low-reflection (AR) coated glass should be about 2.3% or less at 70 ° incidence in order to make it 0 or less.

In this embodiment, a low-reflection (AR) coated glass having a reflectance of 0.2% is used, and the spectral sensitivity curve of FIG.
Oscillation wavelength 55 to photopolymer with VA cover sheet
Duplication was performed by injecting 5 nm dye laser light at 70 °. As a result, as in the case of using the black absorber, a high-quality duplicate hologram with almost no noise was obtained.

As the hologram material, in addition to the above, various photosensitive materials such as a photopolymer such as a polyvinyl carbazole type, gelatin dichromate, a photo resist, and a silver salt can be used. As a recording light source, a dye laser whose oscillation wavelength can be freely changed is particularly effective.

Although not used in the above embodiment,
A black absorber that is further provided with a low reflection (AR) coat may be used.

The thickness from the outermost surface of the cover glass 2 to the surface of the hologram duplication master 1 on the substrate glass side depends on the coherence length of an exposure light source (usually a laser) used for duplication. Specifically, it is necessary to set the coherence distance of the light source to 以下 or less. However, if the thickness is too small, a problem occurs in mechanical strength. This thickness is preferably about 1 to 10 mm. As an exposure light source at the time of duplication, a monochromatic light source transmitted through an interference filter can be used, but a laser having a long coherence distance is preferable. In particular, a laser whose oscillation line width is narrowed by an etalon is preferable.

In the hologram duplication master 1,
It is desirable that the adhesive 3 has high transparency and small light scattering (low haze). Further, it is preferable to use a material having a small amount of embedment of bubbles and having a viscosity that can easily fill the uneven surface.
At the time of bonding, it is preferable to place a weight and allow to stand for several hours in order to remove bubbles and make the adhesive layer uniform. The curing method of the adhesive 3 is preferably a thermosetting type, an ultraviolet curing type, a two-component mixed curing type, a hot melt curing type (hot melt), or the like.
The material of the adhesive 3 may be rubber-based, acrylic-based,
Silicone type, hot melt type and the like can be mentioned. In this embodiment, the cover glass 2 is a glass having a thickness of 1.1 mm,
The protective layer 4 used PVA, and the adhesive used was an ultraviolet-curable optical adhesive (NOA-61, manufactured by Norland Corporation in the United States).

The component of the adhesive 3 is a hologram duplication master 1
The protective layer 4 is interposed at the interface between the hologram duplication master 1 and the adhesive 3 in order to prevent any adverse effect on the adhesive. As the protective layer 4, PVA, EVAL film, P
An ET film or the like can be used, but it is preferable that the film has as little birefringence as possible and has a refractive index of around 1.5.

[0048]

According to the present invention, an internal reflection light intensity attenuating member for reducing the internal reflection light intensity to 1/100 or less of the incident light intensity for a hologram duplication original plate to which a hologram photosensitive material is adhered at the time of hologram duplication. With the stacked configuration, a high-quality duplicate hologram with little noise can be stably obtained.

Further, by making the internal reflection light intensity attenuating member a black absorber or a low reflection (AR) coated glass having a transmittance of 38% or less with respect to the wavelength of the light for duplication, the incident angle of the irradiation light for duplication and the stray light Transmitted light can be reliably absorbed in a wide range of application values such as intensity and diffraction efficiency, and internal reflection can be suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a basic configuration of a hologram duplication master according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a basic configuration of a hologram duplication master according to another embodiment of the present invention.

FIG. 3 is a schematic view showing a step of performing hologram duplication.

FIG. 4 is a diagram showing a relationship between transmittance of a black absorber, diffraction efficiency of a hologram duplication master, and stray light intensity.

FIG. 5 is a diagram showing a relationship between transmittance, incident angle, and stray light intensity of a black absorber.

FIG. 6 is a diagram showing a spectral sensitivity curve of a photopolymer.

FIG. 7 is a sectional view of a basic configuration of a hologram duplication master according to still another embodiment of the present invention.

FIG. 8 is a graph showing the relationship between the reflectance of Ar-coated glass, the diffraction efficiency of a hologram duplication master, and the intensity of stray light.

[Explanation of symbols]

 1: Original for hologram duplication 2: Cover glass 3: Adhesive 4: Protective layer 5: Substrate glass 6: Black absorber 9: Low reflection (AR) coated glass 11: Photosensitive material film for duplication 12: Photosensitive material 13, 14 : Support film 31: Unwind roller 32: Adhering / peeling head 33: Winding roller 34: Non-reflective coated glass 38: Laminating roller 42: Ultraviolet irradiation device 43: Winding roller 44: Cleaning unit 45: Peeling roller 47 : Laser beam 50: Protective film

Claims (5)

[Claims] 1. A hologram laminate having a hologram duplication master used by being superimposed on a hologram photosensitive material at the time of hologram duplication, wherein an internal reflected light intensity at a layer interface other than the hologram duplication original is measured as an incident light intensity. A hologram laminate comprising at least an internal reflection light intensity attenuating member reduced to 1/100 or less. 2. The internal reflection light intensity attenuating member is a black absorber having a transmittance of 38% or less with respect to a duplication light wavelength, and is disposed at a position opposite to a side irradiated with light at the time of duplication. The hologram laminate according to claim 1, wherein: 3. The internal reflection light intensity attenuating member has a low reflection (A
3. The hologram laminate according to claim 1, wherein the hologram laminate is R) coated glass, and is disposed on a side opposite to a side on which light at the time of hologram replication is irradiated. 4. 4. The hologram laminate according to claim 3, wherein the reflectance of the low reflection (AR) coated glass is 2.3% or less at a light incident angle of 70 ° or less. 5. A hologram duplicating method for producing a duplicate hologram by superimposing a hologram laminate having a hologram duplication master on a hologram photosensitive material and irradiating light from the hologram photosensitive material side. The internal reflected light intensity at the layer interface other than the hologram duplication master is 1/100 of the incident high intensity.
A hologram laminated body is superimposed on the hologram photosensitive material so that the internal reflected light intensity attenuation member to be reduced below is at least laminated, and the internal reflected light intensity attenuation member is arranged on the side opposite to the hologram photosensitive material side. And producing a duplicate hologram.