Abstract: A method of producing color and texture effects on a surface (210,400) without the use of pigments or actual texturing. Diffraction patterns generated by interference between two light beams (220,230) are recorded in a suitable high-resolution photographic material (210,400) and are used instead of paints or inks to provide desired color and texture effects in the various regions (440,530) of an artistic or decorative composition. The resulting composition (210,400) may contain spectrally pure or mixed colors and a wide range of static or dynamic textural illusions visible under a variety of lighting conditions.

Abstract: A method of making a security device and the device are disclosed, wherein an embossable material is applied to a substrate in multiply connected regions. (A multiply connected region is one that has more than one continuous boundary). The regions have sufficient density of coverage to cause the embossable material to appear substantially continuous to the unaided eye. A diffractive pattern is embossed into a plurality of the regions and a transparent coating is applied thereover to bond firmly to the substrate and embossable material. Removal of the transparent coating results in observable damage to the security device.

Abstract: A new class of holograms, having the properties of full-color reconstruction from a single white light source, an extended vertical viewing aperture, and extended scene depth is disclosed. These advantageous properties are provided by a hologram composed of three intermeshed holograms, each of which reconstructs only one of the three color components of the scene. Each color component hologram consists of an array of noncontiguous small dots or thin stripes so that the three-color component holograms may be intermeshed without overlap of the dots or stripes. Associated with each color component hologram is a similar array of dot or stripe color filters which allow only the appropriate color of light to reconstruct each color component hologram. The component holograms themselves are vertically focused so that the composite hologram is white light viewable.

Abstract: A system for synthesizing strip-multiplexed holograms, with or without coherent light, from a plurality of two-dimensional images. The two-dimensional images may be formed by a motion picture film of a rotating subject such that each image is a view of the subject from a different angle. The images are then non-diffusely and anamorphically projected by a lens system which compresses the image in a first direction and expands the image in a second direction orthogonal to the first direction. The projected image or object beam is then superimposed on the reference beam by a lens-beamsplitter which transforms the substantially planar object beam into a substantially cylindrical wavefront and projects it and the reference beam onto a holographic recording medium. As each two-dimensional image is sequentially projected, the holographic recording medium is shifted so that a plurality of laterally displaced strips are recorded.

Abstract: A system for generating electrical power from sunlight, comprising a focussing diffraction grating or other focussing, spectrally dispersive means and a photocell array. The diffraction grating focuses sunlight into a spectrally dispersed band. The photocell array is composed of cells with different spectral sensitivities, located in positions in the dispersed band corresponding to the cell spectral sensitivities so that the net conversion efficiency of sunlight to electricity exceeds the conversion efficiency attainable with nondispersive collectors and single material photocells. Alternate embodiments of the invention provide sun tracking means, reflective or transmissive diffraction gratings, flat or curved diffraction grating surfaces, on- or off-axis focus, and optical coatings on the photocell surfaces.