JP2000330460A - Transparent relief hologram - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent hologram with a more simple structure and equivalent quality. SOLUTION: The transparent relief hologram is produced by laminating a transparent base overcoat layer 4 with a metal compd. thin film layer 5 having thickness to maintain translucent property and having a different refractive index than that of the base overcoat layer. A relief part 6 where the optical interference wave fronts are recorded is formed on the opposite face of the thin film layer to the base overcoat layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a relief hologram, and more particularly to an improvement of a so-called transparent relief hologram which is a reflection hologram and has transparency.

[0002]

2. Description of the Related Art Holograms in which a three-dimensional image is reproduced by recording an interference wavefront of light have been successively developed since the first proposal was made in the 1940's, and many types of holograms have been provided.

[0003] Among these holograms, a metal compound is used as a material of a light reflecting layer in a relief hologram of a surface irregularity type, and the thickness of the metal reflecting layer is set to a thickness that allows light to pass therethrough, so that an original hologram is formed. There is provided a so-called transparent hologram in which not only a reconstructed image can be seen but also what is behind the hologram can be seen through the hologram. For example, Japanese Patent Publication No. 7-62784,
JP-A-168516 discloses those holograms.

In these conventional holograms, as shown in FIG. 1, an ordinary resin sheet is used as a hologram forming layer 1 and an interference wavefront 2 of light is recorded on the surface thereof, and a metal surface is formed on the relief forming surface. It has a two-layer structure in which a compound thin film 3 is formed. (The above publication, Asakura Shoten Publishing, Toshihiro Kubota "Introduction to holography" Figure 7.17,
And "Holographic Display", published by Sangyo Tosho, edited by Junpei Tsujiuchi, p.187, see Figures 2.35 and 2.36)

[0005]

The hologram having such a configuration has an advantage that a suitable hologram reconstructed image can be obtained by making the refractive indexes of the hologram forming layer and the metal reflection layer different by a certain range. Since the metal reflection layer must be formed after the hologram relief layer is formed on the hologram forming layer in advance, the manufacturing process is complicated and advanced technology is required in combination with the special technical field of the hologram. You. In addition, in actual use, it is necessary to provide, for example, a protective layer, an adhesive layer, an anchor layer for enhancing the adhesive effect, etc., in addition to the two-layer structure. I've been working. Therefore, it is needless to say that the structure is preferably as simple as possible, and also from the viewpoint of ensuring transparency, it is desirable that the number of constituent elements is smaller. An object of the present invention is to provide a transparent hologram having a simpler configuration.

[0006]

In order to achieve the above object, in the present invention, a transparent hologram is formed by forming a transparent hologram with a transparent substrate oversheet layer having a thickness capable of maintaining light transmittance. A thin film layer of a metal compound having a refractive index different from the refractive index of the layer was laminated, and a relief portion on which an optical interference wave surface was recorded was formed on the surface of the thin film layer opposite to the substrate oversheet layer.

The substrate oversheet layer is for protecting the thin film layer of the metal compound and for reproducing the hologram in cooperation with the thin film layer of the metal compound. The material is, for example, polyester, polyolefin, etc. There is no particular limitation as long as it has been conventionally used for this type of application and has appropriate strength, surface smoothness, and transparency. The thickness may be any thickness that does not hinder hologram reproduction, and may be hard or soft.

The metal compound may be conventional, for example
Titanium dioxide, zirconium dioxide, zinc sulfide, zinc oxide, indium oxide, cerium dioxide, tantalum oxide,
Magnesium oxide, silicon dioxide, magnesium fluoride, aluminum oxide, and the like can be used. The thickness of the thin film layer of the metal compound may be any range as long as transparency can be maintained, but if it is too thick, cracking occurs or if it is too thin, a sufficient relief portion cannot be formed to obtain a good hologram reconstructed image. 50 to 10,000 is preferred.

As a means for forming a relief in the metal compound thin film layer, conventional thin film forming means such as a vacuum evaporation method, a sputtering method, a reactive sputtering method, and an ion plating method may be used. Alternatively, the relief portion may be formed after the metal compound thin film layer is laminated on the base material oversheet layer in advance, or may be laminated on the substrate oversheet layer after forming the relief portion on the metal compound thin film layer in advance. Good.

The transparent hologram of the present invention may be provided with a suitable protective sheet of a commonly used synthetic resin on the substrate oversheet layer. In the transparent hologram of the present invention, an appropriate pattern layer can be provided at an arbitrary position. For example, it can be provided on the surface of the thin film, the surface of the substrate oversheet layer, or on both surfaces. The transparent hologram of the present invention includes those provided with additional constituent parts for any purpose such as an adhesive layer and a protective layer in a range that does not hinder hologram reproduction in addition to the basic structure and the above-mentioned picture layer. . The present invention will be described in detail with reference to the drawings.

[0011]

FIG. 2 is a longitudinal sectional view of one embodiment of the hologram of the present invention. 4 is a substrate oversheet layer of a transparent 50 μm thick polyester resin sheet, 5 is a thin film layer obtained by vapor-depositing zinc oxide on the polyester resin sheet to a thickness of 600 °,
Reference numeral 6 denotes a relief portion formed on the outer surface of the metal compound thin film layer.

A full-color rainbow hologram was continuously produced by a roll pressure press method using a hologram stamper roll, which was previously prepared by laminating a sheet in which a thin film layer of a metal compound and a base material oversheet layer were separately formed by a conventional method.

The produced full-color rainbow hologram produced a hologram reconstructed image which was not inferior to the conventional hologram forming layer provided separately. In addition, the pattern behind the hologram could be seen through the hologram in the angle range where the hologram was not reproduced, not to mention the portion other than the relief portion.

FIG. 3 shows the use of the above-mentioned hologram, in which a transparent adhesive 7 is applied to the relief portion side of the metal compound thin film layer for about 10 minutes.
The transparent hologram sheet is formed by providing a 75 μm thick polyester film having a thickness of μ and further coating a silicon film 8 on the outside thereof as a release layer 9. Although the transparent hologram of this embodiment is configured to be used as a decorative body for retrofitting, it is an excellent one that can be used for a wide range of applications.

[0015]

The transparent hologram of the present invention has a simpler structure by positively eliminating the hologram forming layer which has been considered to be indispensable and forming a relief portion directly on the thin film layer of the metal compound. It can be easily manufactured at low cost, and can be used without change even in actual use.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a conventional transparent hologram.

FIG. 2 is a longitudinal sectional view of the transparent hologram of the present invention.

FIG. 3 is a longitudinal sectional view of a hologram seal using the transparent hologram of the present invention.

Claims (1)

[Claims] 1. A laminate comprising a transparent substrate oversheet layer and a thin film layer of a metal compound having a refractive index different from the refractive index of the substrate oversheet layer in a thickness capable of retaining light transmittance,
A transparent relief hologram, wherein a relief portion on which an optical interference wave surface is recorded is formed on a surface of the thin film layer opposite to the substrate oversheet layer.