Dai Nippon Printing Co., Ltd.

Nobuko Oikawa

Koji Eto

Minoru Azakami

Mitsuru Kitamura

Tsuyoshi Yamauchi

Tomoe Sato

Shinya Sato

Keisuke Miura

Takaki Miyachi

Dai Tsukada

Eriko Hamade

An optical member utilizing light from a point light source is enabled to visually perceive a reproduced optical image with a desired color. An optical modulation device includes an optical member having a light control part to reflect or absorb light in a predetermined wavelength and to pass through light in other than the predetermined wavelength in light in at least a visible light band, in accordance with a reproduction reference image for reproducing an original image, and a light transmissive part to pass through light in at least the visible light range including the predetermined wavelength.

Light modulation element and information recording medium

An object of the present invention is to provide a thin volume hologram sheet to be embedded sufficiently resistant to a mechanical stress such as a stress including a tensile stress, a shear stress and a compression stress at the time of processing even under a heating condition, a forgery prevention paper and a card using the same. The object is achieved by providing a volume hologram sheet to be embedded comprising a volume hologram layer, and a substrate disposed only on one side surface of the volume hologram layer using an adhesion means, wherein a peeling strength of the volume hologram layer and the substrate is 25 gf/25 mm or more.

Volume hologram sheet to be embedded, forgery prevention paper, and card

To provide an authentication device and method for a security medium including a reflective volume hologram having a light source disposed on the front surface side of the reflective volume hologram so that light emitted therefrom is incident on the reflective volume hologram, a first observation device disposed in a pre-designed diffraction direction of the reflective volume hologram, and a second observation device disposed in a direction other than the pre-designed diffraction direction of the reflective volume hologram. Light including a pre-designed diffraction wavelength is emitted from the light source to be incident on the reflective volume hologram, and when the light amount observed in the first observation device is larger in the diffraction wavelength than in other wavelengths, and the light amount observed in the second observation device is smaller in the diffraction wavelength than in other wavelengths, it is determined that the reflective volume hologram is genuine.

Authenticity determination device and method for security medium including reflective volume hologram, and security medium including reflective volume hologram

A display article includes a plurality of display areas. Display areas adjacent to each other differ in at least one of an average hue, an average brightness and an average chroma and a first object to be displayed is formed by a combination of the plurality of display areas. At least one of the display areas includes a Fourier transform hologram configured to convert incident ray from a point light source or a laser light source into a second object to be displayed.

Display article

The present invention is to provide: a photosensitive composition for volume hologram recording and a photosensitive substrate for volume hologram recording, which provide increased sensitivity during hologram recording and a high refractive index modulation amount, and which do not inhibit the decolorization of the sensitizing dye; and a volume hologram recorded medium which provides high-luminance hologram images with increased productivity. Disclosed is a photosensitive composition for volume hologram recording, comprising: a photopolymerizable monomer, a photopolymerization initiator, a sensitizing dye for sensitizing the photopolymerization initiator, a binder resin, and a thiol group-containing compound, wherein the photopolymerizable monomer contains a photoradically polymerizable monomer and a photocationically polymerizable monomer; wherein the thiol group-containing compound is a chain transfer agent for the photoradically polymerizable monomer and is a polyfunctional secondary thiol compound having two or more secondary thiol groups per molecule; and wherein the content of the thiol group-containing compound is 1.5 to 30 parts by mass with respect to 100 parts by mass of the photoradically polymerizable monomer.

Photosensitive composition for volume hologram recording, photosensitive substrate for volume hologram recording, and volume hologram recorded medium

The present invention provides a volume hologram transfer foil which has good foil cutting characteristics and is used to manufacture a volume hologram laminate by transferring a volume hologram layer to an adherend by thermocompression. The volume hologram transfer foil includes a base material, a protective layer, a volume hologram layer, and a heat seal layer, wherein the protective layer contains a hard coat component, a rupture elongation control component, and a foil cutting characteristic control component which has a thermal expansion coefficient different from those of the hard coat component and rupture elongation control component and is incompatible with the two components.

Growing community of inventors

Tokyo-to, Japan

Nobuko Oikawa