JP3224595B2 - Hologram duplication method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hologram contact copying method.

[0002]

2. Description of the Related Art As a hologram duplication method, it is well known to irradiate an original hologram and a duplication photosensitive material which is in close contact with the hologram from a direction almost perpendicular. However, when the light is incident on the original hologram and the photosensitive material for copying in close contact with the original hologram at a small angle, the ratio of reflection due to the difference in refractive index between the air and the material increases, and the amount of transmitted light incident on the photosensitive material decreases. Would. Therefore, the energy of the light beam incident into the hologram dry plate per unit time becomes small, and the exposure time becomes long.
When irradiating a light beam at a small angle to the original hologram and the surface of the photosensitive material for duplication in close contact with the original hologram, the light beam may be incident through a transparent body having a surface substantially perpendicular to the light beam. Therefore, a method using a glass block or a prism is known.

FIG. 6 shows an example in which a glass block is used. A photosensitive material 1 for copying is brought into close contact with a reflection original hologram 3 and a glass block 2 having the same refractive index as the photosensitive material.
When the light beam 4 is incident from a surface substantially perpendicular to the light beam, the reproduced light from the original hologram 3 and the incident light interfere with each other in the photosensitive material, and the hologram image is copied. At this time, since the angle of incidence on the glass block is almost perpendicular, reflection is reduced, and the amount of energy incident per unit time is increased, so that the hologram can be copied efficiently. When a transmission type hologram is used as an original, the same is true except that the positional relationship between the original and the photosensitive material for duplication is reversed.

FIG. 7 shows an example in which a prism is used. Similarly, a photosensitive material 1 for copying is brought into close contact with a reflection type original hologram 3, and
By causing the light beam 4 to enter through the prism 5 having the same refractive index as the photosensitive material, the reproduced light from the original hologram 3 and the incident light interfere with each other in the photosensitive material, and the hologram image is copied. Although not shown, there has also been proposed an apparatus in which the glass block is rotated so that the surface of the glass block is always perpendicular to the incident light beam (Japanese Patent Laid-Open No. 3-237481).

[0005]

However, in a conventional hologram duplication method in which a transparent body is brought into close contact with an original hologram and a duplication photosensitive material which is in close contact with the original hologram, a very large number of exposures are required, especially when large-area exposure is performed. There is a problem that a transparent body material is required, and as a result, it becomes expensive and bulky and heavy. An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a hologram duplication method capable of reducing the amount of a transparent material, being inexpensive and lightweight, and performing large-area exposure.

[0006]

FIG. 1 is a diagram for explaining a hologram duplication method according to the present invention. A transparent body 11 having a saw-tooth-shaped cross section is brought into close contact with one surface of the copying photosensitive material 10. As the transparent body 11, a material having a refractive index close to the refractive index of the photosensitive material is preferable.
Since the refractive index of the photosensitive material is 1.3 to 1.7, glass, plastic, an inorganic substance, or the like can be used as the transparent body, and glass or plastic is preferable in view of easiness of processing and the like. . Further, glass is preferable because the influence of vibration is likely to occur when the irradiation time of the light beam is long.

[0007] A reflection type original hologram is brought into close contact with the surface on the opposite side of the photosensitive material 10, and a light beam 13 is made incident through a transparent body 11. The slope 11a of the transparent body 11 is substantially perpendicular to the light flux 13, and the slope 11b is substantially parallel to the light flux or has a slightly larger angle. Such a transparent body,
If the incident angle of the light beam is determined, it can be created correspondingly.

In such a configuration, when a light beam is incident through the transparent body 11, the light is diffracted by the original hologram 12 to generate reproduction light toward the photosensitive material, and the image of the original hologram is formed by interference between the incident light beam and the reproduction light. Be replicated. Since the transparent body having the saw blade-shaped cross section is used, the amount of the material of the transparent body is small, the cost is low, and the transparent body is thin and lightweight, and can cope with a large area. In particular, when copying on a large area, it can be easily created by using a method for creating a Fresnel lens or the like.

In FIG. 1, there is a possibility that the reflected light on the surface of the photosensitive material, or the light diffracted by the original hologram and transmitted through the photosensitive material is irregularly reflected on the inclined surface 11b of the transparent body 11 to disturb the duplicate image. Therefore, as shown in FIG.
It is desirable to perform a light absorption process on the surface and absorb the light flux 15 incident on the inclined surface 11b to prevent irregular reflection at the interface between air and the transparent body. In each of the above-described examples, it is desirable that a liquid (index matching liquid) having a refractive index close to the liquid (index matching liquid) is interposed between the transparent body and the recording material. Examples of the index matching liquid include xylene (refractive index: 1.50), Isopar L (Exxon: refractive index: 1.42), Cargill oil (refractive index: 1.59), and the like. What is necessary is just to adjust and use it.

When recording a hologram of a larger area, the transparent body and the mirror are intermittently moved while moving.
By recording, a larger area can be recorded than a transparent body. That is, as shown in FIGS. 3 (a) to 3 (d), a transparent body 11 having a sawtooth shape in cross section is brought into close contact with one surface of a large-area copying photosensitive material 10, and an original hologram 12 is brought into close contact with the other surface. , The transparent body 1 while irradiating the light flux 13
1. Large-area hologram duplication can be performed by sequentially moving the original hologram 12. FIG.
It is also possible to supply the photosensitive material 10 continuously and sequentially, and mass-produce it by a winding method. In the above description, a reflection type hologram was used as an original. However, the present invention is not limited to this, and a transmission type hologram can be used as an original. In this case, a photosensitive material for duplication and an original are used. May be reversed.

[0011]

According to the present invention, the transparent material having a saw-toothed cross section is brought into close contact with the photosensitive material and the original hologram which are brought into close contact with each other, so that the material of the transparent material is reduced, the weight and size are reduced, and the hologram is copied at low cost. The hologram can be duplicated at an arbitrary incident angle by forming the angle of the saw blade shape of the transparent body in accordance with the incident angle of the incident light beam. In addition, the hologram of a large area can be easily copied by relatively moving the transparent body, the original hologram, and the photosensitive material and sequentially copying.

[0012]

Embodiments of the present invention will be described below. Example 1 As shown in FIGS. 4 (a) and 4 (b), the width θ = 50 cm, the height b = 2 cm, the length c = 50 cm, and the angle θ of the slope of the transparent body having a saw-tooth shape in cross section. ₁ = 15 °,
A mold was formed by cutting so that θ ₂ = 75 ° and the incident angle of light flux θ ₃ = 15 °, and a transparent PMMA body was formed by a press method. Next, this transparent body was brought into close contact with a photosensitive material (Omnidex 352: manufactured by DuPont) via an index matching solution of xylene. Further, an original hologram having interference fringes having a pitch of 1.4 μm in a direction parallel to the film surface was also adhered to the opposite surface of the photosensitive material via an index matching liquid of xylene. This was placed in the holder on the seismic isolation table and left for 2 minutes. And 48 of Ar laser
Light emitted from 8 nm was diffused by a spatial filter, and parallelized light by a parabolic mirror was incident from the transparent body side at an angle of θ ₃ = 15 °. When exposed at an exposure dose of 20 mJ / cm ² , the interference fringes of the original hologram were duplicated on the photosensitive material. After that, baking is performed at 120 ° C for 2 hours, and the diffraction efficiency is 7
A duplicate hologram of 0% was obtained. However, an unnecessary rainbow was observed from reflection at the interface between the transparent body and the air.

[Example 2] In the transparent body of Example 1, when the slope 11b shown in FIG. 2 was subjected to anti-reflection treatment, the same diffraction efficiency was obtained, and unnecessary rainbows were not observed.

[Embodiment 3] The photosensitive material in the embodiment 1 is made into a film having a width of 110 cm and a length of 550 cm as shown in FIG.
0, 11, 12,..., 18, 19, and 20 were exposed and copied in this order. As a result, interference fringes were formed on the whole, and when this film was affixed to a window glass, reflection characteristics of infrared light of about 1.4 μm with respect to infrared rays were improved, and a decrease in room temperature was observed.

[0015]

As described above, according to the present invention, the material of the transparent body is reduced, the weight and size of the transparent body are reduced, the hologram can be duplicated at low cost, and the angle of the saw blade shape of the transparent body can be reduced. The hologram can be duplicated at an arbitrary incident angle by creating the hologram according to the incident angle of the incident light beam. At this time, irregular reflection can be prevented by applying light absorption processing to the surface where the transparent body does not enter. Stripe disturbance can be eliminated. In addition, it is possible to easily copy a large-area hologram by moving the transparent body, the original hologram and the photosensitive material relative to each other and copying them sequentially.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a hologram duplication method of the present invention.

FIG. 2 is a diagram illustrating an example in which a light absorption process is performed on a slope of a saw blade on which a light beam does not enter.

FIG. 3 is a diagram illustrating a large area hologram duplication method.

FIG. 4 is a diagram illustrating an embodiment of the present invention.

FIG. 5 is a diagram illustrating another embodiment of the present invention.

FIG. 6 is a diagram illustrating a conventional hologram duplication method using a glass block.

FIG. 7 is a diagram illustrating a conventional hologram duplication method using a prism.

[Explanation of symbols]

Reference Signs List 10: photosensitive material, 11: transparent body, 11a, 11b: slope (non-reflection treated surface), 12: original hologram, 13: incident light beam, 15: light beam.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03H 1/00-1/32 G02B 5/18

Claims (3)

(57) [Claims] 1. A method of replicating a hologram by bringing a duplication photosensitive material and an original hologram into close contact with each other and illuminating the original hologram, wherein a transparent body having a saw blade shape in cross section is brought into close contact with the duplication photosensitive material and the original hologram that are brought into close contact with each other. Let
A hologram duplication method, wherein a hologram is duplicated by causing a light beam to enter through a surface of a transparent body substantially perpendicular to the light beam. 2. A hologram method of replication according to claim 1, characterized in that applied to the other inclined surface of the saw blade is not applying a light beam to light-absorbing processing. 3. A process according to claim 1 or 2, wherein,
A hologram duplication method, wherein a large-area hologram is duplicated by successively duplicating a transparent material and an original hologram and a photosensitive material while moving them relatively.