Dai Nippon Printing Co., Ltd.

Konica Minolta Opto, Inc.

Dia Nippon Printing Co., Ltd.

Tomoko Kumasawa

Masachika Watanabe

Tsuyoshi Yamauchi

Kenji Ueda

Makio Kurashige

Mitsuru Kitamura

Masanori Umeya

Akiko Kitamura

Kenji Michiue

Tomonobu Moriya

Masashi Iwasaki

Toshihiro Kubota

A process by which a multi-image type hologram, wherein one 3D image changes over to another depending on a viewing direction, can be fabricated in a simple construction, and a multi-image type hologram fabricated by that process. According to the process for the fabrication of a multi-image type hologram wherein one image changes over to another depending on a viewing direction, the area of a hologram recording material is divided into a plurality of sub-areas. Objects to be displayed on different images are holographically recorded in the respective sub-areas, using reference light having the same angle of incidence, images recorded in the respective sub-areas are simultaneously reconstructed from the recorded first-stage hologram, so that a second-stage hologram recording material is located near the reconstructed object images for recording them as a reflection or transmission type volume hologram.

Fabrication process of multi-image type hologram, and multi-image type hologram fabricated by that process

The invention provides a hologram fabrication process, characterized by comprising steps of fabricating a computer-generated hologram (CGH) having amplitude information and phase information recorded by computer operation on a given recording surface, irradiating the computer-generated hologram (CGH) with the first reconstructing illumination light () to generate the first diffracted light () from the computer-generated hologram (CGH) thereby reconstructing a first reconstruction image (O'), simultaneously entering the first diffracted light () and the first reference light () in a first-stage hologram recording material () faced away from the first reconstructed image to record a first-stage hologram () in it, irradiating the recorded first-stage hologram () with the second reconstructing illumination light () to generate the second diffracted light () from the first-stage hologram () thereby reconstructing the second reconstruction image (O&#x2033;), and simultaneously entering the second diffracted light () and the second reference light () in a second-stage hologram recording material () located near the second reconstructed image (O&#x2033;) to record the second-stage hologram () in it as a reflection or transmission type volume hologram.

Hologram fabrication process, and hologram fabricated by that process

An authenticity indicator is difficult to be forged and has an authenticity that can be confirmed easily and accurately. The authenticity of the authenticity indicator can be checked by making light enter the authenticity indicator from front side and observing the light emerging from the front side or rear side. The authenticity indicator includes a polarized-light selectively reflecting layer that reflects a specified polarized component of incident light, and a transmission volume hologram layer disposed on the front side of the polarized-light selectively reflecting layer. According to this authenticity indicator, its authenticity can be checked accurately by making use of its first authenticity recognition function attributed to the diffracting action of the transmission volume hologram layer and its second authenticity recognition function attributed to the polarized-light selectivity of the polarized-light selectively reflecting layer.

Authenticity indicator

The invention relates to a security-conscious hologram which can apply a sufficient three-dimensional appearance to a reconstructed image in both its vertical and horizontal directions, and which is difficult to illegally copy and easily told from any illegal copy forged from it, and a holographic process of recording it The hologram His of a combined reflection and volume type, wherein a subject image P is recorded, and minute reflection images F and O' from a light source are recorded at least in front of, or in the rear of, the subject image P, both in a reconstructible fashion, and a viewing position E is moved along a hologram surface, so that the subject image P and the minute reflection images F and O&#x2032; are viewable at varied relative positions.

Hologram and its holographic process

The present invention provides a see-through transmitting-reflecting projection screen excellent in transparency, capable of sharply displaying, on its both sides, identical or different images even under bright environmental light. A transmitting-reflecting projection screencomprises a reflection-type screenand a transmission-type screenThe reflection-type screenreflects a specific polarized component of imaging light projected. The reflection-type screendoes not reflect a polarized component, different from the specific polarized component, of the imaging light, and this polarized component passes through the reflection-type screenand the transmission-type screen

Transmitting-reflecting projection screen, and projection system comprising the same

The present invention is characterized to provide a hologram silver halide photographic material having high sensitivity and diffraction efficiency, providing an excellent image and having less color residue and noise in a transparent part, a hologram, a method for producing the same. In the present invention, a hologram silver halide photographic material having at least one silver halide emulsion layer formed on a support, wherein an average particle diameter of silver halide particles in a silver halide emulsion is 0.03 &#x3bc;m to 0.07 &#x3bc;m; a film thickness of the silver halide emulsion layer is 4 &#x3bc;m to 9 &#x3bc;m; a silver/gelatin ratio of the silver halide emulsion layer is 0.3 to 0.6; and the silver halide emulsion layer contains sensitizing dye of specific structure.

Hologram silver halide photographic material, hologram and method for producing the same

The invention relates to a security-conscious hologram which can apply a sufficient three-dimensional appearance to a reconstructed image in both its vertical and horizontal directions, and which is difficult to illegally copy and easily told from any illegal copy forged from it, and a holographic process of recording it. The hologram His of a combined reflection and volume type, wherein a subject image P is recorded, and minute reflection images F and O' from a light source are recorded at least in front of, or in the rear of, the subject image P, both in a reconstructible fashion, and a viewing position E is moved along a hologram surface, so that the subject image P and the minute reflection images F and O&#x2032; are viewable at varied relative positions.

Growing community of inventors

Tokyo, Japan

Tomoko Kumasawa