Imaging apparatus and methods using diffraction-based illumination are disclosed. An example apparatus includes a diffraction grating to redirect light from a light source toward a sample to thereby illuminate the sample. The example apparatus also includes an image sensor to detect a diffraction pattern created by the illuminated sample.

The optical diffuser mastering of the subject invention includes legacy microstructure surface relief patterns, along with smaller ones, overlaid on the larger ones. The characteristic features produced by the present invention will be found useful to eliminate visible structures in/on optical diffusers, such as those used in movie projection screens (utilizing either coherent (i.e., laser-generated) and non-coherent (e.g., lamp-generated) light), head-up displays (HUDs), laser projection viewing, etc., as the present invention produces much sharper images than those afforded by traditional holographic optical diffusers.

The present invention relates to a method for forming a surface relief microstructure, especially an optically variable image (an optically variable device) on a transparent or translucent substrate and a product obtainable using the method. A further aspect of the invention is the use for the prevention of counterfeit or reproduction of a document of value and a method of forming a coating showing an angle dependent color change.

Provided are diffraction structure transfer foil that further improves usefulness of the diffraction structure transfer foil in authenticity determination by allowing a greater variety of diffracted-light patterns to be observed, and a forgery prevention medium using the diffraction structure transfer foil. The diffraction structure transfer foil (21) includes a transfer foil substrate (1), a peeling-off protective layer (2) that is laminated on one surface of the transfer foil substrate (1), a laminated body for diffracted-light delivery (13a) that is laminated on the peeling-off protective layer (2), and an adhesive layer (9) that is laminated on the laminated body for diffracted-light delivery (13a). The laminated body for diffracted-light delivery (13a) includes a diffraction structure forming body in which a plurality of diffraction structures (4 and 7) are formed, and a reflective layer (5a or 8a) that is formed in accordance with each of the plurality of diffraction structures (4 and 7). A transmission density of one reflective layer (5a) of the plurality of reflective layers (5a and 8a) is in a range of 0.01 to 0.9, and a transmission density of the other reflective layer (8a) is 1.0 or greater.

An image display according to an embodiment includes a first image-displaying portion that displays first information about a certain object as a first image of object color, and a second image-displaying portion that displays second information about the object as a second image of structural color provided by a relief structure, the relief structure including at least one structure selected from the group consisting of diffraction grating, hologram, and light-scattering structure having an anisotropic light-scattering property. According to an example, the object is a person, and the first image includes a facial image of the person. A labeled article according to another embodiment includes the image display, and a substrate supporting the image display.

A hologram transfer foil according to an embodiment is thermally transferrable to a transfer base member. The hologram transfer foil has a structure configured such that a peeling layer, a diffraction structure forming layer and an adhesive layer are stacked on one surface of a substrate. the diffraction structure forming layer includes fine concaves and convexes of a hologram or a diffraction grating. At least one of the peeling layer and the adhesive layer includes heat-conductive hidden information in a heat-conductive hidden information possession portion.

A color image display device comprising arrays of structural color pixels, where said structural color pixels may be formed on a single substrate layer or multiple substrate layers and are patterned by selective material deposition to display a color image in accordance with input color images or patterns. The structural color pixels comprise a plurality of microstructures and/or nanostructures, including without limitation, diffraction gratings, sub-wavelength structures, to display colors in red, green, blue in RGB color space or cyan, magenta, yellow in CMY color space. Examples include methods of activating and/or deactivating structural pixels using selective material deposition onto at least one layer of the color display device to form a color image. Further examples include product labels, authentication devices and security documents carrying customized or personalized information and methods for their manufacture.

A diffraction grating recording medium (3) that enhances the ability to prevent forgery and make security more reliable. The diffraction grating recording medium (3) comprises a first recording region (31) including viewing image unit cells (11a), (12a), (13a) having a light diffraction structure, and a second recording region (32) including hidden image unit cells (2a). The viewing image unit cells of the first recording region (31) has a grating pitch more than the wavelength of visible light, and the hidden image unit cells of the second recording region (32) has a grating pitch less than the wavelength of visible light.

A system for generating variable optical images in curable material using generic optical matrices, the system including an applicator configured to apply the curable material to a portion of a substrate supported by a carrier web; a transparent roller comprising surface elements formed on an outside surface of the transparent roller, the transparent roller being configured to form optical structures in the curable material, wherein the surface elements on the transparent roller form the optical structures in the curable material when the surface elements contact the curable material as the substrate travels over the outside surface of the transparent roller; a radiation source within or outside the transparent roller configured to cure the curable material after the optical structures are formed in the curable material; and an image generation component configured to obliterate portions of the optical structures to form a predetermined image.

A three-dimensional display device including a diffraction sheet including a transparent substrate, and a diffraction layer having a first diffraction pattern formed in a first array pattern and a second diffraction pattern formed in a second array pattern on the transparent substrate, the diffraction sheet measuring 10 inches or more in diagonal; one of a liquid crystal device having a plurality of pixels and a color filter having a plurality of types of color filters; and a light source. The first diffraction pattern and the second diffraction pattern are overlapped with the pixels or the color filters in a direction normal to the diffraction sheet with an amount of displacement being 1/10 or less of a pitch of the pixels or the color filters.