JP4433351B2 - Hologram replication method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hologram duplicating method, and more particularly to a hologram duplicating method that requires illumination with an incident angle larger than the critical angle of a hologram or a medium supporting the hologram.
[0002]
[Prior art]
The present applicant has filed many applications regarding an image display device comprising a liquid crystal display element and a hologram color filter in Japanese Patent Application Laid-Open No. 6-308332 and the like.
[0003]
This hologram color filter, for example, makes the illumination light parallel to the interference fringes recorded on the hologram photosensitive layer such as a photopolymer provided on the transparent substrate incident from the transparent substrate side, and diffracts the illumination light by the interference fringes to generate the hologram photosensitive layer. The wavelength is dispersed and condensed on the side of the transparent medium superimposed on the surface, but the polarization separation function that hardly diffracts the S-polarized light component and hardly diffracts the P-polarized light component by the interference fringe is developed. The illumination light may be incident at an incident angle larger than the critical angle θ _C of the transparent substrate of the hologram color filter for reasons such as obtaining optimum wavelength selectivity.
[0004]
In other holograms, it may be necessary to make the reproduction illumination light or illumination light incident at an incident angle larger than the critical angle θ _{C of the} hologram substrate or the hologram photosensitive layer.
[0005]
[Problems to be solved by the invention]
In order to produce a hologram having similar characteristics from a hologram master in which the incident angle of the reproduction illumination light is set to be larger than the critical angle θ _{C at} the interface between air and the hologram substrate, the hologram entrance surface of the hologram master has conventionally been used. A prism having an appropriate shape is closely attached to the refractive index matching liquid, and illumination light for duplication is incident on the interference fringe of the hologram master through the prism at an incident angle larger than the critical angle θ _C. A method has been used in which the first-order diffracted light diffracted in step 1 and the zero-order transmitted light transmitted without being diffracted by the interference fringes are caused to interfere with each other in a hologram photosensitive material in close contact with the hologram master.
[0006]
However, this conventional method requires a prism for making the illumination light for duplication incident on the hologram master, which is troublesome and costly. Also, compared with the case of direct incidence on the hologram master, the interface reflection at the prism is increased. If the prism is not bonded to the hologram master, the prism may move during use. Conversely, if the prism is bonded, remove the prism. An extra process is required.
[0007]
The present invention has been made in view of such problems of the prior art, and the object thereof is from a hologram master set to illuminate at an incident angle larger than the critical angle of the hologram medium or a medium supporting the hologram medium. It is an object of the present invention to provide a method of easily replicating a hologram having the same characteristics by the hologram replication method.
[0008]
[Means for Solving the Problems]
The hologram duplication method of the present invention that achieves the above object is a method for duplicating a hologram from a hologram original plate in which the incident angle of the reproduction illumination light is larger than the critical angle θ _{C at} the interface between air and the hologram medium or a medium supporting the hologram In
Duplicate illumination light is incident from the side of the hologram medium of the hologram master or the medium that supports it, and the duplicate illumination light is guided to the hologram diffraction region by repeated reflection in the hologram medium or the medium that supports it. In this method, the first-order diffracted light and the zero-order transmitted light that have exited the hologram master from the region are incident on the hologram photosensitive layer of the hologram photosensitive material to cause interference. However, the critical angle θ _C is θ _C = sin ⁻¹ (1 / n); n is the refractive index of the hologram medium of the hologram master or the medium supporting it.
[0009]
In this case, it is desirable that the side surface of the hologram master is a tapered surface inclined with respect to the hologram surface.
[0010]
Further, as the hologram original plate, one in which an amplitude diffraction grating corresponding to hologram interference fringes is provided on one surface of a transparent substrate can be mentioned.
[0011]
In that case, it is desirable that a reflection layer is provided on at least one side surface of the hologram original plate from the region where the amplitude diffraction grating is provided.
[0012]
In addition, the hologram master may be duplicated from the hologram as a base.
[0013]
A hologram to be duplicated includes a hologram color filter.
[0014]
In the hologram master of the present invention, an amplitude diffraction grating corresponding to the interference fringes of the hologram is provided on one surface of the transparent substrate, and is a hologram master used for replicating a hologram. In the hologram master whose angle is larger than the critical angle θ _{C at} the interface between air and its transparent substrate,
The side surface shape is formed so that the duplicate illumination light can be introduced from a side surface of the transparent substrate, and the duplicate illumination light introduced from the side surface is guided to the region of the amplitude diffraction grating by repeated reflection in the transparent substrate. It is characterized by being comprised so that it may be.
[0015]
In this case, it is desirable that the reflective layer is provided on any one side of the side of the transparent substrate from the region where the amplitude diffraction grating is provided.
[0016]
The hologram master is used for a hologram master for a hologram color filter, for example.
[0017]
In the present invention, duplicate illumination light is incident from the side of the hologram medium of the hologram master or the medium that supports it, and the duplicate illumination light is incident on the hologram diffraction region by repeated reflection in the hologram medium or the medium that supports it. Since the first-order diffracted light and the 0th-order transmitted light that have been guided out of the hologram master from the hologram diffraction area are incident on the hologram photosensitive layer of the hologram photosensitive material to interfere with each other, a prism for allowing the illumination light for replication to enter Is not required, and it does not require time and cost for hologram replication, and can perform hologram replication efficiently and stably, and does not require special post-processing.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the hologram duplication method of the present invention will be described based on examples.
[0019]
FIG. 1 shows the configuration of one embodiment of a hologram master. The hologram master 20 is a hologram master for a hologram color filter, and a diffraction grating 2 as an interference fringe of the hologram color filter is provided on one surface of the transparent substrate 1 as an amplitude diffraction grating. The side surface 3 of the transparent substrate 1 is tapered, and the taper angle is set to such an angle that the illumination light 7 for duplication described later enters the taper surface 3 substantially perpendicularly. A reflective metal film 5 such as Cr is provided on the side 3 side half of the surface opposite to the surface on which the diffraction grating 2 of the transparent substrate 1 is provided, and the other half of the surface is a water-soluble resin to which a dye is added. An antireflection layer 6 made of a light absorbing film such as a film (Japanese Patent Application No. 11-17262) and a light absorbing adhesive film (Japanese Patent Application No. 11-60209) is provided. A reflective metal film 4 such as Cr is provided on the side surface 3 side portion of the surface of the transparent substrate 1 on which the diffraction grating 2 is provided.
[0020]
With such a configuration, when the duplication illumination light 7 is incident substantially perpendicularly to the tapered surface of the side surface 3 of the hologram master 20, the light 8 entering the transparent substrate 1 is reflected into the reflective metal film 4 and the reflective metal film. 5 is repeated at least once and guided to the region of the diffraction grating 2. The guided light 8 is incident on the diffraction grating 2 at an incident angle θ larger than the critical angle θ _{C at} the interface between air and the transparent substrate 1, and the first-order diffracted light 9 and the zero-order transmitted light 10 are separated from the hologram master 20. And the light 11 reflected by the region of the diffraction grating 2 reaches the antireflection layer 6 and is absorbed.
[0021]
Note that the side surface 3 of the transparent substrate 1 is not necessarily tapered, and may be a surface perpendicular to the surface of the transparent substrate 1. In short, the thickness of the transparent substrate 1 is selected so that the light 8 repeatedly guided through the transparent substrate 1 is incident on the entire region of the diffraction grating 2 at a predetermined incident angle θ, and the position of the side surface 3 The angle may be selected so as to satisfy the condition.
[0022]
Further, it is not always necessary to provide the reflective metal films 4 and 5 on the surfaces (both surfaces of the transparent substrate 1) for guiding the illumination light 8 by repeated reflection, and may be guided by total reflection at the interface between the transparent substrate 1 and air. . Further, although the antireflection layer 6 is not necessarily provided, it is necessary to prevent the reflected light 11 from being reflected or scattered on the side surface opposite to the side surface 3 of the transparent substrate 1 and returning to the diffraction grating 2. is there.
[0023]
In order to produce a hologram color filter having the same characteristics as the hologram master 20 by using the hologram master 20 having the configuration as shown in FIG. 1 by the hologram replication method, as shown in FIG. The hologram photosensitive material 30 is brought into close contact with the surface side via the refractive index matching liquid 21.
[0024]
Here, the hologram photosensitive material 30 is configured by sequentially applying a hologram photosensitive layer 32 such as a photopolymer and a protective layer 33 on a glass substrate 31 and adding a dye to the opposite surface. An antireflection layer 34 made of a light absorbing film such as an adhesive resin film (Japanese Patent Application No. 11-17262) and a light absorbing adhesive film (Japanese Patent Application No. 11-60209) is provided. Adhere to the hologram master 20.
[0025]
In this arrangement, when the duplication illumination light 7 is incident on the tapered surface of the side surface 3 of the hologram master 20 substantially perpendicularly, the first-order diffracted light 9 and the zeroth-order light from the diffraction grating 2 of the hologram master 20 as described above. The transmitted light 10 exits from the hologram master 20, enters the hologram photosensitive layer 32 of the hologram photosensitive material 30 through the refractive index matching liquid 21 and the protective layer 33, and then interferes with each other to form interference fringes similar to those of the diffraction grating 2. Recording is performed in the hologram photosensitive layer 32. Further, the lights 9 and 10 transmitted through the hologram photosensitive layer 32 are absorbed by the antireflection layer 34 provided on the back surface of the hologram photosensitive material 30. Accordingly, in the hologram photosensitive material 30, as in the hologram original plate 20, a hologram color filter that needs to make the illumination light incident at an incident angle θ larger than the critical angle θ _{C at} the interface between air and the transparent substrate is duplicated. .
[0026]
The antireflection layer 34 of the hologram photosensitive material 30 is not necessarily provided.
[0027]
As described above, the hologram duplication method of the present invention and the hologram original plate therefor have been described based on the embodiments. However, the present invention is not limited to these embodiments, and various modifications are possible.
[0028]
【The invention's effect】
As is apparent from the above description, according to the hologram duplication method of the present invention, the duplication illumination light is incident from the side of the hologram medium of the hologram master or the medium that supports the hologram medium, and the hologram medium or the medium that supports the hologram medium. The duplicate illumination light is guided to the hologram diffraction area by repetitive reflection inside, and the first-order diffracted light and the 0th-order transmitted light that have exited the hologram master from the hologram diffraction area are incident on the hologram photosensitive layer of the hologram photosensitive material to interfere with each other. Therefore, there is no need for a prism or the like for making the illumination light for duplication incident, the duplication of the hologram does not take time and cost, and the hologram duplication can be performed stably and efficiently. It is not necessary.
[Brief description of the drawings]
FIG. 1 is a diagram showing the configuration of one embodiment of a hologram master according to the present invention.
FIG. 2 is a diagram showing an arrangement for replicating a hologram by a hologram replication method using the hologram master in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Transparent substrate 2 ... Amplitude diffraction grating 3 ... Side surface (taper surface) of a transparent substrate
4, 5 ... Reflective metal film 6 ... Antireflection layer 7 ... Illumination light for duplication 8 ... Illumination light for duplication 9 in transparent substrate ... 1st order diffracted light 10 ... 0th order transmitted light 11 ... Reflected light 20 ... Hologram original plate 21 ... Refraction Rate matching liquid 30 ... Hologram photosensitive material 31 ... Glass substrate 32 ... Hologram photosensitive layer 33 ... Protective layer 34 ... Antireflection layer

Claims (5)

In a method for replicating a hologram from a hologram original plate in which the incident angle of the reproduction illumination light is larger than the critical angle θ _{C at} the interface between air and the hologram medium or the medium supporting it,
Duplicate illumination light is incident from the side of the hologram medium of the hologram master or the medium that supports it, and the duplicate illumination light is guided to the hologram diffraction region by repeated reflection in the hologram medium or the medium that supports it. A hologram duplication method, characterized in that first-order diffracted light and zero-order transmitted light that have exited from a hologram original plate from an area are incident on and interfere with a hologram photosensitive layer of a hologram photosensitive material. However, the critical angle θ _C is θ _C = sin ⁻¹ (1 / n); n is the refractive index of the hologram medium of the hologram master or the medium supporting it.   2. The hologram duplication method according to claim 1, wherein the side surface of the hologram original plate is a tapered surface inclined with respect to the hologram surface.   3. The hologram duplication method according to claim 1, wherein the hologram master is provided with an amplitude diffraction grating corresponding to a hologram interference fringe on one surface of a transparent substrate.   4. The method for replicating a hologram according to claim 3, wherein a reflection layer is provided on any one surface of the hologram original plate on the side surface side from at least a region where the amplitude diffraction grating is provided.   5. The hologram duplication method according to claim 1, wherein the hologram is a hologram color filter.

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