Dai Nippon Printing Co., Ltd.

Mitsuru Kitamura

Tsuyoshi Yamauchi

Akiko Kitamura

Tomohisa Hamano

Yoko Sekine

Manabu Yamamoto

Masachika Watanabe

Hiroshi Fujita

Daijiro Kodama

Makio Kurashige

Koji Eto

Akiko Tanaka

Sakurako Hatori

Tomoe Sato

Nobuko Oikawa

Masato Taninaka

Manami Yabuhara, Legal Representative

Tomoko Kumasawa

Hidekazu Okuno

Hideo Yabuhara

Kenji Ueda

Jun Sato

Yasuyuki Oyagi

Yuko Aoyama

Kimio Ito

Masayo Shima

Tomoki Yasuda

A light modulation element reproduces a light image in a specific color other than iridescence where white light is incident, without a layer that selectively transmits or reflects a specific wavelength band, and clearly reproduces a desired light image by reducing an influence of 0th-order diffracted light, and an information recording medium including the same. The light modulation element includes a factor element that reproduces a light image by modulating a phase of incident reproduction light, and has an uneven surface. A maximum diffraction efficiency Dmax in a wavelength band of between 380 nm and 780 nm in wavelength distribution of first-order diffracted light and of negative first-order diffracted light with respect to diffraction efficiency for the factor element has a local maximum value with a full width at half maximum FWHM of 200 nm or less in wavelength distribution with respect to diffraction efficiency having the maximum diffraction efficiency.

Light modulation element and information recording medium

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.

There is provided a luminescent medium which requires difficult analysis of light emitted from a luminescent material of the medium. A luminescent medium includes a substrate, and a luminescent material comprising a first luminescent material which, when irradiated with visible light, infrared light or ultraviolet light, emits first infrared light 'a', and a second luminescent material which, when irradiated with visible light, infrared light or ultraviolet light, emits second infrared light 'b'. The first luminescent material is formed in a first planar area, and the second luminescent material is formed in a second planar area. The first planar area and the second planar area overlap each other, forming an overlapping planar area in which the luminescent materials each have a concentration gradation.

Luminescent medium and method for reading luminescent medium

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

A light-emitting medium including a light-emitting image having a pattern area formed on a substrate by using a first fluorescent ink containing a first fluorescent material, a background area formed on the substrate by using a second fluorescent ink containing a second fluorescent material, and a overcoat layer formed on the first fluorescent material of the pattern area and the second fluorescent material of the background area. The first fluorescent material is made of a fluorescent material which emits light of blue color when UV-A is irradiated, and emits light of red color when UV-C is irradiated. The second fluorescent material is made of a fluorescent material which emits light of blue color or light of a color that is viewed as the same color as the blue color when the UV-A is irradiated, and emits light of green color when the UV-C is irradiated.

Light-emitting medium

The purpose of the invention is to obtain an anti-counterfeiting marker sheet that is inexpensive and with which authenticity can be assessed easily. The invention uses an anti-counterfeiting marker sheet () characterized in being provided with a substrate (), and multiple markers (), which are formed directly on the substrate () and the contour shape of which can be recognized by magnified examination. It is preferable that: the markers are not unevenly distributed but are irregularly disposed on the substrate; there are multiple marker () colors; and there are multiple types of shapes for the marker () contour shapes. It is also preferable that the minimum radius of curvature of the corners of the shapes formed when the markers () are viewed in plan view is 250 nm to less than 10 &#x3bc;m.

Anti-counterfeiting marker sheet and manufacturing method therefor, anti-counterfeiting function-imparting member, and article provided with anti-counterfeiting function

A main object of the present invention is to provide fine particles, a particle group, an anti-counterfeiting ink, an anti-counterfeiting toner, an anti-counterfeiting sheet, and an anti-counterfeiting medium enabling to achieve a high level of authentication. The object of the present invention is achieved by providing the fine particle comprising an identification information group including multiple types of identification information identifiable by magnification, characterized in that the identification information group includes first identification information and second identification information which cannot be identified at any magnifying power capable of identifying the first identification information.

Fine particles, particle group, anti-counterfeiting ink, anti-counterfeiting toner, anti-counterfeiting sheet, and anti-counterfeiting medium

Two original images to be recorded are prepared as data (S). A plurality of unit regions, each having an adequate area to record interference fringes of visible light, are defined and positioned on a hologram recording surface (S). A gradation pattern, with which appearance probabilities of two record attributes gradually change in space, is overlapped onto the recording surface, and to each unit region, one of either record attributes is assigned according to the appearance probabilities of the respective record attributes at each individual position (S). In each unit region, to which the first record attribute is assigned, the first original image is recorded as an interference fringe pattern, a diffraction grating pattern, or a scattering structure pattern, and in each unit region, to which the second record attribute is assigned, the second original image is recorded as an interference fringe pattern, a diffraction grating pattern, or a scattering structure pattern (S), and a record pattern is formed on a physical medium (S).

Method for preparing a hologram recording medium

A main object of the invention is to provide a taggant particle group that has a plurality of authentication steps and an excellent anti-counterfeit effect and can be applied to various anti-counterfeit media. The invention attains the object by providing a taggant particle group which is an aggregate of taggant particles which individually have a plurality of identification information items, wherein one identification information item among the plurality of identification information items possessed by the individual particles is common identification information that is possessed in common by the taggant particles that constitute the taggant particle group, and another identification information item among the plurality of identification information items possessed by the individual particles is non-common identification information of which the authenticity can be determined in combination with other identification information items possessed by other taggant particles that constitute the taggant particle group.

Taggant particle group; and anti-counterfeit ink, anti-counterfeit toner, anti-counterfeit sheet, and anti-counterfeit medium comprising same

A light-emitting medium having a light-emitting image including first pattern elements formed on a substrate by using a first fluorescent ink containing a first fluorescent material, and second pattern elements formed on the substrate by using a second fluorescent ink containing a second fluorescent material. The first and second pattern elements form a plurality of micro-character rows m, and the first pattern elements form a latent image in the micro-character rows m. The first fluorescent material is made of a fluorescent material which emits light of blue color when UV-A is irradiated, and emits light of red color when UV-C is irradiated. The second fluorescent material is made of a fluorescent material which emits light of blue color or light of a color that is viewed as the same color as the blue color when the UV-A is irradiated, and emits light of green color when the UV-C is irradiated.

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

A main object of the present invention is to provide a hologram observation sheet with a transmission type hologram formed integrally with other members, to be attached with various members for the use as for example an advertising medium or a decoration member. To achieve the object, the invention provides a hologram sheet comprising: a transparent substrate, a hologram layer formed on the transparent substrate and having a transmission type Fourier transform hologram region having the function of transforming a light beam incident from a point light source to a desired optical image, and a pressure-sensitive adhesive layer.

Hologram sheet and hologram observation sheet using same, and blinding device

A method of preparing a hologram where an original image is recorded as interference fringes on a predetermined recording surface by arithmetic operations using a computer, the method including: a step of defining an original image formed as a three-dimensional image, a hologram recording plane for recording the original image, and reference light to be irradiated onto the hologram recording plane, a step of defining a large number of arithmetic operation points on the hologram recording plane and arithmetically determining the intensity of the interference wave formed by an object light beam emitted from each object and the reference light for each of the arithmetic operation points and a step of preparing physical interference fringes on a medium on the basis of the intensity distribution of interference wave obtained on the recording plane in the arithmetically determining step, the front-most part of the three-dimensional image being arranged near the hologram recording plane at the time of defining the original image.

Growing community of inventors

Tokyo, Japan

Mitsuru Kitamura