Abstract: A technique and apparatus for printing that includes the formation of a hologram, or other type of diffraction pattern, directly on a desired end product of paper, or other sheet material. The hologram, or other diffraction pattern, is formed by casting a surface relief pattern directly onto the sheet material in a limited area.

Abstract: Methods for generating holograms from a computer model of any object employ a combination of numerical and optical means. An illumination model and the light dispersion properties of the objects are specified. The hologram is synthesized from a plurality of smaller hologram elements. Each individual element sustains a field of view of the object. The light rays from the object lying within the field of view and along the lines of sight are sampled by the computer. The sample density should not exceed the resolution limit set by the size of the hologram element. Each light ray is specified by a direction and an amplitude function. The hologram element is obtainable from a Fourier Transform of the sampled rays. In one embodiment, optical means are employed to physically reproduce the sampled light rays using coherent radiation. The reproduced coherent light rays are then interfered with a coherent reference beam to form the hologram element.

Abstract: A new technique and apparatus for printing that includes the formation of a hologram, or other type of diffraction pattern, directly on a desired end product of paper, or other sheet material. The hologram, or other diffraction pattern, is formed by casting a surface relief pattern directly onto the sheet material in a limited area.

Abstract: A replica hologram structure wherein an information carrying relief pattern on one surface of the hologram is not metallized for reflection, as is the usual case, but rather air between the hologram and a supporting substrate causes incident light to be reflected from the surface relief pattern, thereby to form a reconstruction of an image or other light pattern. The surface relief pattern may be positioned immediately against the substrate, or, alternatively, held apart from it by spacers. The hologram and substrate are held together by any of a wide variety of mechanisms, including adhesive, welding and static electricity, in a manner that does not interfere with the reconstruction or viewing of the image or other light pattern from the hologram. Such a hologram structure has a use in product packaging and other applications where it is desired to be able to look through the hologram as well as be able to view the image or other light pattern reconstructed from it by reflection.

Abstract: A document or like article produced by a process which provides a three-dimensional, light-diffracting pattern comprising a hologram on a surface of a transparent material layer which may be extremely thin and non-self-supporting, and which secures this layer to a document or like substrate, with the pattern-bearing surface facing downwardly (i.e., not exposed), by an adhesive bond having a shear strength greater than that of the transparent layer so that the layer cannot be removed from the surface without being destroyed.

Abstract: Embossed holograms or diffraction patterns are formed on hard, unembossible metal substrates such as steel sheet metal. The hard metal substrate has a soft embossible metal layer such as tin formed on it, and holograms are embossed thereon by means of a surface relief, metal master. The soft metal layer must be sufficiently thick to accommodate the deepest surface relief pattern. For tinplate, the embossing can be preformed at room temperature. Among other things, the process produces tinplates and tin cans with embossed holograms.

Abstract: A spectral analysis system which may operate as a spectrograph or monochromator comprises a folded optical path within a housing wherein the optical input is provided on one side and the optical output is provided on an opposite side at a spectral focal field, thereby separating optical and electrical functions. The folded optical path is provided within a vertically extending portion of the housing providing for a narrow profile to the optical instrument and keeping the entrance and exit apertures in-line in close proximity. The grating is caused to operate in a near Littrow condition with a reflecting prism having first and second inclined surfaces which respectively reflect entrance aperture light to said grating and disperse exit aperture light from said grating along paths slightly inclined to the Littrow axis of the grating.

Abstract: Holograms, including diffraction gratings, and methods of making them, that reconstruct an image which changes as the hologram is tilted with respect to the viewer and in a manner that images reconstructed from copies made of the hologram in monochromatic light do not have that motion. The hologram is a valuable security device for authenticating documents or objects to which it is attached since it is extremely difficult to duplicate.

Abstract: Methods for generating holograms from a computer model of any object using a combination of numerical and optical means and the holograms produced thereby. An illumination model is provided to specify sources of light rays and dispersion particles of the object. Each light ray being specified by a path and an intensity function is traceable from a source via the object to a set of points in space by the computer. The hologram is synthesized from a plurality of smaller hologram elements. Each individual element sustains a field of view of the object. The light rays from the object lying within the field of view and along the lines of sight are sampled by the computer. Optical means are employed to physically reproduce the sampled light rays using coherent radiation. The reproduced coherent light rays are then interfered with a coherent reference beam to form the hologram element. Alternatively, the hologram elements are calculated by the computer with an analogous technique.

Abstract: A product whereby diffraction patterns and holograms directly onto surfaces of metal material, such as aluminum. Products include household aluminum foil with embossed holograms, and aluminum beverage cans with an embossed hologram on its outside.

Abstract: A process for embossing diffraction patterns and holograms directly onto surfaces of metal material, such as aluminum, and products made thereby. Temperature ranges for optimizing the embossing are disclosed, being related to the yield strength of the material being embossed. End products include household aluminum foil with embossed holograms, and aluminum beverage cans with an embossed hologram on its outside.

Abstract: In order to detect subsurface defects in a vehicle tire the tire is placed in a sealed pressure chamber and the pressure is rapidly reduced to a very low level, and maintained at that level for a period of time. The body of the tire creeps for a period of time following the pressure change as a result of the stresses imposed by the pressure change. During this creep period a section on the surface of the tire is illuminated with coherent light and two separate exposures of interferograms are made using the reflected light and recorded on either a photographic media or the cathode of a television image tube. The exposure may either be holographic, in which case the interferogram is produced by using a reference beam of light derived from the same source that illuminates the object surface, or shearography, in which case two focused images of the tire surface section are formed on the photosensitive media, displaced with respect to one another and overlapping one another.

Abstract: A method and apparatus for measuring strains in a test object in any of a plurality of directions. The object is illuminated with coherent light so that light is reflected to a focussing lens and a shearing diffraction grating having lines extending in a plurality of directions. The various diffracted orders interfere at the focal plane of the lens and are recorded on a photographic media. The object is then stressed and a second exposure is made on the same media, resulting in interference between the fringes produced on the two exposures. The media is developed as a transparency and subjected to optical processing to detect strain in any direction.

Abstract: Object deformations are analyzed by recording interferometric images using a television camera. The camera's photosensitive recording cathode is successively exposed to interferometric images of the object, respectively before and after a stress is applied to the object, while the camera's scanning beam is blanked out in order to record a composite image having fringe families arrayed as a function of the deformation of the object. Subsequent scanning of the cathode produces video signals representing variations of intensity in the superimposed illumination patterns of the composite image. The video signals may be digitized, analyzed and displayed on a cathode ray tube.

Abstract: A machine for performing double exposure, interferometric analysis of the changes in an object surface that result from changes in the ambient pressure on the object, as by holography, includes a pressure chamber partially formed by a horizontal base operative to support the test object and interferometric camera on its upper surface. A semispherical pressure dome is placed on the base over the test object and camera. A manifold volume bounded by a thin resilient steel disc supported beneath the base plate on a rubber gasket has its pressure equalized with the area beneath the dome by passages formed beneath the base plate. When the pressure is changed beneath the dome a similar pressure change occurs in the manifold volume beneath the base so that no net pressure forces are exerted on the base plate and no deformation of the camera or test object occurs.

Abstract: An adjustable camera is operative to perform interferometric analysis of areas on the surface of an object such as a vehicle tire using light from a coherent source. The camera mechanism includes vertical guides projecting upwardly from a support moveable in the horizontal plane along the base. A slide is adjustable vertically along the guides and carries a camera housing that is adjustable relative to the slide about a horizontal pivot axis. A coherent light source is fixed relative to the base and projects its beam parallel to the adjustment of the guide support. An optical element on the guide support projects the beam upwardly parallel to the guides to a mirror which reflects the beam horizontally about the pivot axis of the housing. A beam splitter divides the beams into an object beam and a reference beam. The object beam is projected out of the housing to illuminate a surface of the tire and cause light to be reflected to a film section supported in the housing.

Abstract: Holder and spreader fixturing for spreading and positioning the bead portions of tire casings to enable unobstructed holographic inspection of the interior of tire casings for manufacturing defects, including holder fixtures comprised of a pair of spreader rings insertable into the rim opening of the tire casing and engaging opposite bead portions of the tire casings. A plurality of U-shaped externally positioned props assembled to each of the spreader rings position the bead portions in the spread-apart position and provide an unobstructed view from the rim opening. Various configurations of the spreader rings include a split one-piece ring; a one-piece ring having trimmed side flanges; and a collapsible hinged spreader ring configuration.