JPH11202742A - Original plate for hologram duplication and duplication method for hologram - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hologram of which valid part is at a prescribed position, has a prescribed shape and dimension by a method with excellent mass produc tivity by setting the position, shape and dimension of the valid area formed on an original plate for duplication so as to correct the deviation of the valid area of a duplicated hologram and the valid area of the original plate for the duplication generated in the duplication. SOLUTION: The valid area 30 of the original plate 21 for hologram duplication is corrected so as to obtain the valid area 32 at a prescribed position, having a prescribed shape and dimension in the duplicated hologram. Light cast on such an original plate 21 from a divergence point is diffracted by the hologram and spread as divergence light from a pseudo divergence point. Since cover glass and an optical adhesive material are interposed between the original plate 21 and a photosensitive material 1 and both are distanced, points corresponding to the valid areas A'-C' of the original plate 21 become A-C on the photosensitive material 1 by the spread of diffracted light and the valid area 32 of the prescribed shape and dimension is obtained at the prescribed position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hologram duplication master and a method of manufacturing a hologram, and more particularly to a hologram duplication master and a method of manufacturing a hologram in which an effective portion has a predetermined position, shape and size. .

[0002]

2. Description of the Related Art With the recent development of hologram materials and laser technology, products using holograms are increasing. For example, a hologram is used as an optical element in a holographic display device that diffracts light containing information and displays the information to an observer, an optical scanner of a barcode reading device, and the like. For example, there is a head-up display (hereinafter, referred to as HUD) as a display device for displaying information to a driver of a vehicle such as an automobile. In this method, optical information projected from an information projection unit such as a liquid crystal display device is projected onto a combiner including a hologram and a half mirror incorporated in a windshield of an automobile or the like, and a driver almost moves a viewpoint from a driving state. This allows information to be read without the need. In addition, forgery prevention marks on ID cards and credit cards, decorative holograms, hologram calendars, and the like use holograms on which images are recorded.

In order to produce a single hologram having certain desired characteristics (diffraction wavelength, diffraction angle, focal length, etc.), the relative positions of the hologram photosensitive material and the laser light source are determined, and the positions are precisely determined. Exposure must be fixed. In order to produce a large number of holograms identical to this hologram, this time-consuming positioning must be repeated many times, which is a time-consuming and time-consuming operation.

In Japanese Patent Application Laid-Open No. 9-90857, a hologram duplication master (hereinafter simply referred to as an original) is prepared, a hologram photosensitive material is brought into close contact with the master, and light is irradiated from the photosensitive material side to duplicate the hologram. A method has been proposed. 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.

[0005]

By the way, an original plate is usually provided with an exposed portion (hereinafter referred to as an effective area) having a predetermined shape and size functioning as a hologram, at a predetermined position on the entire surface of the hologram photosensitive material, and a coherent light source. And a portion in which the material is exposed to light having no light. According to the above replication method,
A duplicate hologram having an effective area substantially similar to the effective portion recorded on the master is obtained. "Almost the same" means that an effective area can be formed with a predetermined shape and dimensions at a predetermined position of the hologram photosensitive material for duplication, but at a predetermined position to be obtained, the effective shape and dimensions are exactly the same. Means not to be.

When the copied hologram is used as graphic art by drawing a three-dimensional image or the like, even if the position, shape, dimensions, and the like of the effective area are slightly shifted, it does not cause a serious problem. However, when the copied hologram is used as an optical element, a serious problem arises when the position, shape, dimensions, and the like of the effective area are shifted. That is, when a hologram is used as an optical element,
In the use state, the optical arrangement of the hologram and the light source used when reproducing the hologram is strictly determined. If the optical arrangement is shifted, a reproduced image cannot be observed by a viewer at a predetermined wavelength in a predetermined direction. Therefore, in the duplicated hologram, if the position, shape, and dimensions of the effective area are not sufficiently accurate, a reproduced image cannot be observed by a viewer at a predetermined wavelength in a predetermined direction.

An outline of the above-mentioned duplication method will be described with reference to FIG. The original 21 has an effective area 30 of a predetermined shape and size recorded at a predetermined position, and nothing is recorded in the other non-effective area 31. The light emitted from the divergence point 12 ′ is diffracted by the original 21 and the pseudo divergence point 1
It spreads as divergent light from 1 '. In the drawing, the light is not refracted by a hologram or glass, and is drawn. The cover glass 25 and the optical adhesive 23 are interposed between the master 21 and the duplication hologram photosensitive material 1, and the distance between them is large. Therefore, points corresponding to the effective areas A, B, and C of the hologram 21 are different on the photosensitive material 1, such as A ", B", and C ", due to the spread of the diffracted light. As shown in FIGS. 8A and 8B, the effective area 30 having a predetermined position,
Is provided, the position, the shape, and the size of the effective area 32 on the hologram photosensitive material 1 exposed by the copy are changed.

The problem of the change in the position, shape, and size of the effective area has not been recognized when a hologram is used in conventional graphic arts, but is serious when a hologram is used as an optical element. It is a problem. In order to solve such a problem, the present invention has found a hologram duplication master plate and a hologram duplication method which have not been known so far, and newly provides them.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is a hologram duplication master used by being superimposed on a duplication hologram photosensitive material during hologram duplication. In the hologram duplication master, an effective area having a hologram optical function of a predetermined shape and dimensions and a non-effective area having no hologram optical function are formed at a predetermined position on the entire surface thereof, The effective area corrects a difference between at least one of the position, shape, and size of the effective area of the duplicate hologram formed at the time of the duplication and at least one of the effective area position, shape, and dimension of the hologram duplication master. A hologram duplication master, characterized in that it is formed differently from a desired effective area of a duplication hologram to be obtained. .

The present invention also provides a hologram duplication method in which a hologram duplication master is superimposed on a duplication hologram photosensitive material and light is irradiated from the duplication hologram photosensitive material side or the hologram duplication master side to produce a duplicate hologram. Wherein the hologram duplication master has an effective area having an optical function of a hologram having a predetermined shape and dimensions and a non-effective area having no optical function of a hologram formed at a predetermined position on the entire surface thereof. In forming an effective area in the duplicate hologram, the effective area of the hologram duplication master is at least one of a position, a shape, and a size of a desired effective area formed in the duplicate hologram to be obtained. And to correct the difference between at least one of the position, shape and size of the effective area of the hologram duplication master Formed by changing the effective region formed in duplicate hologram, it provides a method for duplicating a hologram, which comprises using for the production of duplicate hologram.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is an enlarged view of an essential part showing an example of the hologram duplication method of the present invention, and FIG. 2 is a conceptual diagram of the entire hologram duplication method of the present invention. Basically, the light from the laser 5 is irradiated as the divergent light from the divergence point 12 'in a state where the hologram photosensitive material for duplication 1 is brought into close contact with the hologram for duplication laminate 20 on which the original plate 21 is laminated. Duplicate

The copy hologram laminate 20 holds a hologram on a transparent substrate, and preferably has a structure in which the surface is covered with thin glass or the like in order to secure mechanical strength. It is also effective to provide a member that absorbs unnecessary light or prevents its reflection to prevent noise at the time of duplicate exposure. Specifically, as shown in FIG. 1, an original 21 is held on a glass substrate 22, which is sealed between a cover glass 25 and a stray light absorbing glass 24 by an optical adhesive 23.

The original 21 has an effective area 30 corrected so that the effective area 32 of the hologram to be copied has a predetermined shape and size at a predetermined position.

The original plate 21 can be manufactured, for example, as follows. As shown in FIG. 4, a mask 40 in which a portion 41 corresponding to the corrected effective area is shielded from light and the other portion 42 is transparent, is used as a stack 20 (the original photosensitive material 21 ′ is held on the glass substrate 22). UV light from the mask exposure light source 50 is irradiated thereon. Thereby, the photosensitive material 2
Exposure of the portion 33 of 1 'other than the effective region 32 is lost. Next, the stacked body 20, as shown in FIG. 3, the distance r _1,
Exposure is performed by causing light from a divergence point 11 having an incident angle θ ₁ and light from a divergence point 12 having a distance r ₂ and an incident angle θ ₂ to interfere with each other. The divergence point can be obtained by using a spatial filter combining an objective lens and a pinhole.

Although not shown, the divergence point 12 and the laminate 2
If necessary, an optical element such as a mirror or a lens may be introduced between zero. For example, if a collimator lens is inserted, light diverging from the same diverging point can be made into parallel light. Also, the position of the divergence point can be changed pseudo using a lens, or convergent light can be used. If an aspheric lens is used, an aspheric wave can be obtained instead of a simple spherical wave. The optical path can be changed by a mirror, or the same effect as a lens can be obtained by using a curved mirror. It is also effective to further laminate the glass with an antireflection film on the laminate 20 in order to reduce noise at the time of duplicate exposure.
It is more preferable to add a refractive index matching liquid to the interface between the photosensitive material and the glass with the antireflection film.

As shown in FIG. 5A, the effective area 30 of the master 21 is located at a predetermined position on the hologram to be copied.
The correction is performed so that the effective area 32 of the shape and size is obtained as shown in FIG. Divergence point 12 '
Is diffracted by the hologram 21 and spreads as divergent light from the pseudo divergence point 11 '. Since the cover glass 25 and the optical adhesive 23 are interposed between the original 21 and the photosensitive material 1 and the distance between them is large, the effective areas A ', B', and C 'of the original 21 due to the spread of the diffracted light. Are formed on the photosensitive material 1 as A, B, and C, and an effective area 32 having a predetermined shape and size is obtained at a predetermined position.

The correction of the effective area may be performed based on the following principle. As shown in FIG. 6, the angle in the medium (glass, hologram) of the diffracted light at an arbitrary point P on the effective area 32 of the hologram to be copied is φ, and the total thickness of the cover glass 25 and the optical adhesive 23 is d. The position of the point P ′ on the master corresponding to P may be shifted by δ calculated by δ = d × tanφ.

More generally, the shape of the effective area of the duplicate hologram to be produced may be a shape projected onto the surface of the original 21 with reference to the divergence point 11 '. This principle can be applied not only to the case where the diffracted light is the diverging light described above, but also to the case where the diffracted light is a parallel light or a convergent light. Strictly speaking, it is necessary to consider the refraction due to the medium as described above. However, when the thickness of the original is sufficiently small compared to the distance to the divergence point of exposure, there is no practical problem even if the refraction effect is ignored. .

The effective area in the present invention is a portion where a hologram is recorded, and includes not only a main area used as an optical element but also a mark and a reference line for positioning and shape processing. Therefore, it is called an effective area.

The hologram in the present invention usually has several tens.
mm to several 100 mm square area, several μm to several 1
One having a thickness of about 0 μm is exemplified. This hologram is desirable in that a volume / phase hologram such as a Lippmann type can obtain a high diffraction efficiency,
A hologram such as an emboss type or a rainbow type can be widely used. The type of the hologram is not particularly limited, such as a transmission type and a reflection type.
As the hologram photosensitive material, various photosensitive materials such as photopolymers such as acrylic and polyvinyl carbazole, gelatin dichromate, photo resist and silver salt can be used. The hologram photosensitive material may be in the form of a single sheet, but is preferably in the form of a roll film in consideration of mass productivity.

The base material of the hologram in the present invention is appropriately selected according to the use and the state of use. It goes without saying that the incident side of the reproduction light and the exit side of the diffracted light with respect to the hologram are transparent substrates, but this may be one that partially transmits light. For example, not only a transparent glass plate but also a glass plate colored with bronze or green can be used as the base material. Further, a portion through which the reproduction light or the diffracted light does not pass may be opaque. As a material of the base material, besides glass, a resin substrate such as acryl, polycarbonate, polyvinyl chloride, polyolefin, or the like, or a transparent crystal may be used. In addition, the thickness of the substrate is not only a plate having a thickness of several mm, but also a thickness of 1 mm.
The following film may be used, or a block having a thickness of several cm may be used. Further, the surface of these substrates may be provided with an antireflection coating, a hard coating, or a water-repellent coating as necessary.

[0022]

Embodiments of the present invention will be described below. The distance between the divergence point 11 on the reference light side and the photosensitive material is 100 mm, and the distance between the divergence point 12 on the object light side and the photosensitive material is 1000 mm.
An example of producing a hologram having the following configuration will be described. As shown in FIG. 4, the laminate 20 is masked after correcting the effective area,
In the exposure system of FIG. 3, r ₁ = 100 mm, θ ₁ = 25
Exposure was performed under the conditions of °, r ₂ = 1000 mm, and θ ₂ = 25 °. The original plate 21 produced in this manner was sealed between the cover glass 25 and the stray light absorbing glass 24 with the optical adhesive 23 to produce the duplication hologram laminate 2. The thickness of the cover glass is 1.1 mm, and the thickness of the adhesive layer is about 0.05.
mm (50 μm).

The correction of the effective area is as follows. The effective area of the duplicate hologram to be produced is 50 as shown in FIG.
It is a square of mm square. At this time, the vertical line including the point A ′ on the original 21 corresponding to the point A is shifted to the left by 0.22 mm,
The point B ′ corresponding to the center point B is shifted to the left by 0.54 mm,
The vertical line including the point C ′ corresponding to the point C is shifted to the left by 0.85 mm. The upper and lower horizontal lines were narrowed by 0.31 mm on the A 'side and 0.26 mm on the B' side. That is, the center is shifted to the left by 0.54 mm, the width is 49.37 mm, and the length is 49.3.
A trapezoidal effective area of 8 (A 'side) mm and 49.48 (B' side) mm was provided on the master.

The duplication hologram photosensitive material 1 was brought into close contact with the duplication hologram laminate 20 having the original plate 21 thus corrected, and the hologram was duplicated as shown in FIG. In this case, a roll-shaped acrylic photopolymer film was used as the hologram photosensitive material for duplication, and a dye laser beam having a wavelength of 545 nm was used as the laser beam. By exposing the photopolymer film while intermittently moving forward, a large number of holograms having an effective area of a predetermined shape and size (50 mm square) at a predetermined position could be easily copied in large quantities.

[0025]

According to the hologram duplication master and the method of manufacturing a hologram of the present invention, a hologram having an effective portion having a predetermined position, shape and size can be provided by a method excellent in mass productivity. .

[Brief description of the drawings]

FIG. 1 is an enlarged view of a main part showing an example of a hologram duplication method of the present invention.

FIG. 2 is a conceptual diagram showing an example of a hologram duplication method according to the present invention.

FIG. 3 is a conceptual diagram showing an example of a method for producing an original plate.

FIG. 4 is a conceptual diagram showing an example of a method for providing an effective area on an original.

FIG. 5 is an enlarged view of a main part of an original explaining an effective area (a),
Enlarged view of main part of duplicate hologram (b)

FIG. 6 is a conceptual diagram showing an example of a method of correcting an effective area of an original.

FIG. 7 is an enlarged view of a main part showing an example of a conventional hologram duplication method.

FIG. 8 is an enlarged view of a main part of an original explaining an effective area (a),
Enlarged view of main part of duplicate hologram (b)

[Explanation of symbols]

 1: Holographic photosensitive material for duplication 11, 11 ': Reference light divergence point 12, 12': Object light divergence point 21: Original plate 23: Optical adhesive 24: Stray light absorbing glass 25: Cover glass 30: Effective area of original plate 31: Non-effective area of original 32: Effective area of duplicate hologram 33: Non-effective area of duplicate hologram

Claims (3)

[Claims] 1. A hologram duplication master used to be superimposed on a duplication hologram photosensitive material at the time of duplication of a hologram, wherein the hologram duplication master has a predetermined shape and size at a predetermined position on the entire surface thereof. An effective area having an optical function of the hologram and a non-effective area having no optical function of the hologram are formed, and the effective area has a position, a shape, and a size of an effective area of a duplicate hologram formed at the time of duplication. It is formed so as to be different from a desired effective area of a duplicate hologram to be obtained so as to correct a difference between at least any one of them and at least any one of an effective area position, a shape and a dimension of the hologram duplication master. A hologram duplication master, characterized in that: 2. The hologram duplication method, wherein a hologram duplication master is superimposed on a duplication hologram photosensitive material and light is irradiated from the duplication hologram photosensitive material side or the hologram duplication master side to produce a duplicate hologram. The duplication master has an effective area having an optical function of a hologram having a predetermined shape and dimensions and a non-effective area having no optical function of the hologram formed at a predetermined position on the entire surface thereof. The effective area of the original for hologram duplication, the position, shape and / or size of the desired effective area to be formed on the duplicate hologram to be obtained and the hologram duplication. Duplicate hologram so as to correct the difference from the position, shape and / or size of the effective area of the original By changing the effective formed region is formed, a hologram method replication, which comprises using for the production of duplicate hologram. 3. The method according to claim 1, wherein the correction is performed by using a distance between the hologram duplication material and the hologram duplication master, a position and an incident angle of a diverging point of irradiated light, a spread of diffracted light by the hologram duplication master, and a duplication. The position, shape and size of the effective portion of the hologram duplication master and the effective region of the duplicate hologram determined by at least one of the refractive indices of the optical member to be set. A method for duplicating a hologram according to claim 2.