Abstract: An observation device for observing a reproduced image which is reproduced by an image reconstructor uses a special light different from normal light. A special image reproducing and observing device 2 enables observation of reproduced image by irradiating an image reconstructor 4 with a special light to reproduce an image. The special image reproducing and observing device 2 has: light sources 6 and 8 which produce special light; a power supply 10 which causes a light emission by the light sources 6 and 8; and a irradiation device 8 and 12 which enables irradiation of an image reconstructor 4 with a special light that is produced at the light source 6 and 8.

Abstract: A multilayer optical film comprising: (a) an optical stack comprising alternating layers of at least a first polymer and a second polymer; and (b) a holographic image.

Abstract: A holographic shrink wrap element containing a shrink wrap film and a layer on the shrink wrap film, wherein the layer contains a holographic image. A process for preparing a holographic shrink wrap element includes providing, in the following order, a holographic polymer film having a holographic surface, a layer on the holographic surface and a shrink wrap film, and removing the holographic polymer film, leaving the holographic image on the layer.

Abstract: The present invention relates to a light intensity modulator that employs a hologram. In one embodiment, the light intensity modulator includes an electrical circuit and a holographic optical element containing the hologram. The holographic optical element is electrically coupled to and receives a variable voltage generated by the electric circuit. Additionally, the holographic optical element receives an input light from a light source. The holographic optical element receives and diffracts the input light to produce first and second output lights. An intensity of the first output light varies directly with the magnitude of the voltage. An intensity of the second output light varies indirectly with the magnitude of the voltage. The first and second output lights define a non-zero angle therebetween.

Abstract: A device and method for recording holographic gratings by the use of a single illuminating beam, two diffraction gratings, light detectors and a slit-scanning system. The beam illuminates two slits that then define two beams that are incident on the gratings. One diffracted order from one beam and one diffracted order from the other beam then interfere on a recording plane to produce sinusoidal variations of intensity. The interfering region may instantaneously be limited by a third slit. Also, another order of diffraction from one beam may be directed toward its own light detector and so is another order of diffraction from the other beam. These two detectors allow real time monitoring of the light intensity of each beam. By moving the slits in a direction parallel to the recording plane, an area larger than the slits' width can be exposed by the interfering pattern.

Abstract: A hologram recording medium comprises a hologram recording layer for recording a hologram, and a wedge substrate for varying the propagating direction of a reference light and an object light incident upon the hologram recording medium. By rotating the hologram recording medium comprising the hologram recording layer and the wedge substrate, the propagating direction of the reference light and the object light are varied, whereby angle multiplex recording of holograms can be realized with ease.

Abstract: An optical system and an imaging and display system using the optical system. The optical system has at least first and second optical elements aligned on a common axis. In one embodiment, each of the first and second optical elements can operate in an active state or in inactive state and comprise a photopolymer and liquid crystal combination. Each of the first and second optical elements is configured to transmit incident light substantially unaltered when each of the first and second optical elements operates in the inactive state. In the active state, however, each of the first and second optical elements does not transmit incident light substantially unaltered. Rather each of the first and second optical elements substantially alters light incident thereon when each of the first and second optical elements operates in the active state.

Abstract: The invention provides a multifocal optical lens having a holographic optical element that selectively redirects light to provide the wearer with a single image formed from a single focal power. The invention also provides a method for producing a multifocal optical lens having a holographic optical element.

Abstract: A hologram screen easily produced by using a transmission-type hologram film, permitting images to be seen from the side of the projector, having a transparent member 11 and a hologram film 12 stuck to the transparent member 11, and produces the image by projecting image-forming light 3 from the projector 2, the hologram film 12 being of the transmission-type, a reflector 13 for reflecting the image-forming light 3 being arranged on the back surface side 122 of the hologram film 12.

Abstract: An optical information recording and reproducing apparatus, which detachably supports a holographic memory formed of a photorefractive crystal, includes a portion for supplying a coherent reference light beam at a first wavelength into the holographic memory; a portion for supplying a coherent signal light beam at the first wavelength, modulated in accordance with image data, into the memory to produce an optical interference pattern with the reference light within the memory; a portion for supplying a gate light beam at a second wavelength into the memory for activating or deactivating an index grating in accordance with the presence or absence of the optical interference pattern to enhance a photo-sensitivity of the memory; a detector for detecting diffraction light from the index grating of the memory by the irradiation of the reference light beam; and a portion for changing and regulating a light intensity of the gate light beam.

Abstract: A holographic microscope is described along with a method for numerically reconstructing a holographic image. The method uses a coordinate transformation of the Kirchhoff-Helmholtz equation to remove the non-linear component from the phase factor. The intensity distribution in the transformed coordinate system is then interpolated on an equidistant point grid and Fast-Fourier-Transforms are used to compute the result.

Abstract: A system and method are disclosed for producing and displaying a one-step, edge-lit hologram. For production, an object beam and an edge-lit reference beam are directed at holographic recording material and to interfere with one another. The holographic recording material and the object beam and edge-lit reference beam are then translated with respect to one another. The translation successively exposes multiple portions of the holographic recording material to the interference of the object beam and the edge-lit reference beam to record an edge-lit hologram on the holographic recording material. In one embodiment, the holographic recording material is moved while the object beam and the edge-lit reference beam remain generally stationary. In another embodiment, the object beam and the edge-lit reference beam move in unison with each other while the holographic recording material remains generally stationary.

Abstract: The present invention provides a hologram screen which is capable of preventing separation, and damage to, a hologram film and which permits the hologram film to be reused easily. The present invention relates to a hologram screen that is comprised of a hologram film having the function of diffracting the light projected from a projector, and first and second transparent members that together sandwich the hologram film from the front and back surfaces thereof so as to cover the same.

Abstract: The holographic digital data storage system is compatible with a CD/DVD player. A polarization direction of the beam is altered by a first wave plate and the size of the polarized beam is expanded by a beam expander. The expanded beam is split into a vertical polarized beam and a horizontal polarized beam by a polarization splitter; a polarization direction of the horizontal polarized beam is altered by a second wave plate. An optical path of the vertical polarized beam is adjusted by a first mirror to generate a first path-controlled beam; an optical path of a third directional polarized beam is controlled by a second mirror to generate a second path-controlled beam; the first and the second path-controlled beams are concentrated by using a first and a second lenses, respectively; and the interference of two beams is recorded on a medium.

Abstract: A personalized holographic jewelry item which has the appearance, in non-coherent light, of a precious stone (which can have the exceptional quality, clarity and size). The item preferably also includes a second hologram layer, which through use of coherent-optical processing, produces an additional positive effect. By using the principle of waveband separation, the invention enables reconstruction of personalized/security data to identify and secure said jewelry item. In other applications, the second hologram enables the item to be used as an identification device for general application, while at the same time displaying holograms of precious stones. The jewelry item might additionally include a ruby, serving, besides a display effect, the purposes both of accumulating and discharging one or more pulses of coherent radiation and at the same time being made secure by means of above mentioned security data with secure user's access.

Abstract: A dot matrix hologram with a hidden image is disclosed, wherein the hidden image technology is applied to a dot matrix hologram. Although the hidden image technology has been used in a conventional hologram, it has not been used in a dot matrix hologram. Although the above two kinds of hologram both can show hidden images with illuminating laser light, the disclosed dot matrix hologram with a hidden image and the conventional hologram with a hidden image use different working principles and have different detailed characteristics to create hidden image regions.

Abstract: Apparatus for producing dot matrix holograms through laser ablation utilizing only two two-axis, low-inertia beam deflectors to control the maximum holographic direction, and the holographic coloration of the individual pixels of the holograms, and the method of utilizing that apparatus.

Abstract: The first reading beam identical to the first reference beam and the second reading beam conjugate to the second reference beam are simultaneously applied to a hologram recording medium 1, on which holograms 2 and 3 have been recorded. A hologram is formed by interference between the first beam reproduced from the first reading beam and the second reading beam. Another hologram is formed by interference between the second beam reproduced from the second reading beam and the first reading beam. These holograms are recorded and superposed on the original holograms 2 and 3, thereby reproducing the original holograms 2 and 3.

Abstract: Novel volume holographic elements were made from Bragg diffractive gratings in photo-thermo-refractive (PTR) glass with absolute diffraction efficiency ranging from greater than approximately 50% up to greater than approximately 93% and total losses below 5%. Both transmitting and reflecting volume diffractive elements were done from PTR glasses because of high spatial resolution enabling recording spatial frequencies up to 10000 mm−1. The use of such diffractive elements as angular selector, spatial filter, attenuator, switcher, modulator, beam splitter, beam sampler, beam deflectors controlled by positioning of grating matrix, by a small-angle master deflector or by spectral scanning, selector of particular wavelengths (notch filter, add/drop element, spectral shape former (gain equalizer), spectral sensor (wavelength meter/wavelocker), angular sensor (pointing locker), Bragg spectrometer (spectral analyzer), transversal and longitudinal mode selector in laser resonator were described.

Abstract: A transmission hologram allowing an illuminating light source for holographic reconstruction to be placed behind the hologram, i.e. on the side opposite to the viewing side, and permitting reconstruction of an image that is bright and clear and has low chromatic dispersion, which is the feature of the reflection type volume hologram. A transmissively viewable reflection hologram has a semitransparent reflecting mirror or a semitransparent reflecting layer placed at either side of a reflection type volume hologram member. The semitransparent reflecting mirror or the semitransparent reflecting layer is integral with or separate from the reflection type volume hologram member.

Abstract: The invention relates to a process capable of fabricating a variety of transmission holograms having a simple structure, a wide visible range and a large area and comprising the first stage of recording the wavefront to be finally reconstructed in the form of the first hologram that is a reflection hologram with a wide visible range, the second stage of using the first hologram to record the second hologram that is a combined reflection and transmission hologram, and the third stage of recording in the third hologram photosensitive material only a transmission hologram for reconstructing only the wavefront recorded in the second hologram and desired to be reconstructed.

Abstract: Characterization of an optical system is quickly and easily obtained in a single acquisition step by obtaining image data within a volume of image space. A reticle and image plane are positioned obliquely with respect to each other such that a reticle having a plurality of feature sets thereon, including periodic patterns or gratings, is imaged in a volume of space, including the depth of focus. Metrology tools are used to analyze the detected or recorded image in the volume of space through the depth of focus in a single step or exposure to determine the imaging characteristics of an optical system. Focus, field curvature, astigmatism, spherical, coma, and/or focal plane deviations can be determined. The present invention is particularly applicable to semiconductor manufacturing and photolithographic techniques used therein, and is able to quickly characterize an optical system in a single exposure with dramatically increased data quality and continuous coverage of the full parameter space.

Abstract: A method of advertising on a motor vehicle having a substantially transparent window including steps of providing a holographic film with a holographic image, and adhering the holographic film to the window, where the holographic image is substantially transparent to an operator of the motor vehicle from within the motor vehicle so that operation of the motor vehicle is not impeded, but the holographic image is visible to an observer outside the motor vehicle. The present method may also include the steps of applying a transparent adhesive to the holographic film and/or the window. The holographic image may be a product name, a corporate name and/or a corporate logo. The motor vehicle may be a motorsport vehicle adapted to be raced in a race track with at least one other vehicle. The holographic image may be a numeral that distinguishes the motorsport vehicle but is preferably a sponsor advertisement that includes a product name, a corporate name and/or a corporate logo.

Abstract: An image display apparatus comprises a hologram screen 2 formed by bonding a hologram element 20 to light-transmissible films 21 and an illumination device 11 for irradiating image light 10 onto the hologram screen and reproducing an image on the hologram screen 2. The light-transmissible film 21 positioned on the irradiation side of the image light 10 relative to the hologram element 20 has an angle deviation of not greater than 45 degrees between a direction of the light-transmissible film 21 that gives the highest thermal shrinkage ratio and an axial direction in the hologram screen 2. Therefore, the image display apparatus can provide high-quality images without the superposition of an interference pattern on the images on the hologram screen.

Abstract: An apparatus and method is disclosed for illuminating an image display with ambient light using holographic techniques. The apparatus includes a pair of holographic optical elements each having a first surface aligned on a common axis so that the first surfaces of each optical element face each other. Each of the first and second optical elements diffracts first bandwidth light. The second holographic optical element, however, diffracts first bandwidth light received on the first surface facing the first surface of the first holographic optical element. The second holographic optical element diffracts first bandwidth light received on its first surface, the diffracted light emerging from the first surface. The first and second holographic optical elements are switchable between inactive and active states. In the inactive state, each of the first and second holographic optical elements transmits substantially all light without substantial alteration.

Abstract: A composite sheet having the capability of having embossed therein a holographic image or diffraction grating image has a structure of multiple layers including a plastic film carrier, lacquer, metal and, optionally, a lacquer overlay. It may be adhered to a substrate without the necessity of removing the plastic film carrier and may have a holographic image embossed therein during the step of adhering or in a separate operation at a different time and may have printing applied to the layer of metal or to the lacquer overlay.

Abstract: The present invention provides a hologram color filter having a drastically decreased dependence of diffraction efficiency on wavelength and well corrected for a color balance among the three colors R, G and B comprising an array of converging element holograms 5′, each of which enables white light incident at a given angle &thgr; with respect to a normal line of a hologram recorded surface thereof to be spectroscopically separated by wavelength dispersion in a direction substantially along the hologram recorded surface, wherein the converging element holograms 5′ have each a plurality of hologram pieces 51 and 52 superposed on each other or multi-recorded therein, which, with respect to the white light 3 incident at the given angle &thgr;, have substantially identical spatial wavelength distributions of wavelength dispersion and different peak wavelengths of diffraction efficiency.

Abstract: An optical element comprises a volume hologram, converts an aspect ratio of an incident beam, and emits it as an outgoing beam.

Abstract: The invention relates to a process capable of fabricating a variety of transmission holograms having a simple structure, a wide visible range and a large area and comprising the first stage of recording the wavefront to be finally reconstructed in the form of the first hologram that is a reflection hologram with a wide visible range, the second stage of using the first hologram to record the second hologram that is a combined reflection and transmission hologram, and the third stage of recording in the third hologram photosensitive material only a transmission hologram for reconstructing only the wavefront recorded in the second hologram and desired to be reconstructed.

Abstract: A system and method for generating a composite display that includes at least one static three dimensional holographic image, and dynamic and/or static two dimensional images. An object hologram includes a three-dimensional object image. A silhouette hologram includes a silhouette image of the object, and can include a diffusion screen. The object hologram overlays the silhouette hologram with the object image substantially aligned with the silhouette image. Static and/or dynamic images can be projected on the diffusion screen or alternative background, forming a composite image that includes dynamic and/or static two-dimensional imagery combined with the static three-dimensional object image. The silhouette image thus provides a background for viewing the object image and occludes the two-dimensional imagery from the view of the object image.

Abstract: High storage densities using a holographic system are achievable using a stratified medium while maintaining a relatively high selectivity upon reconstruction of the stored images. Such combination of high density and high selectivity is achievable by employing a stratified medium and a recording process where selectivity does not vary with recording thickness.

Abstract: A hologram has a hologram element 3 containing a photopolymer and a cover film 22 and cover plate 21 which cover its surfaces. An adhesive 1 is used for bonding the cover film to the hologram element and the cover plate to the hologram element. The hologram has excellent humidity resistance, chemical resistance, solvent resistance and heat resistance, prevents coloration, can maintain its holographic properties and allows easy repositioning of the hologram element.

Abstract: A moire pattern technology about a dot matrix hologram for hiding a moire pattern is invented. In the moire pattern hidden region of a dot matrix hologram, the moire pattern foreground area and the moire pattern background area are formed identically by interlacing bright lines and dark lines. While position shifting is formed between the lines of the two areas. This position shifting is several times of the size of the grating dots. Thus, a moire pattern hidden in the moire pattern hidden region without being processed specially has a poor hiding ability. Often the above moire pattern can be identified by eyes directly without using a decoding film. Therefore, such kinds of moire patterns have poor hidden effects. However, the moire pattern of the present invention can prevent the aforesaid phenomenon by a well designed pretended pattern. Moreover, the appearance of such a dot matrix hologram can be beautified by the addition of the pretended patern.

Abstract: An interference lithography system is described that is capable of exposing high resolution patterns in photosensitive media and employing yield increasing active stabilization techniques needed in production environments. The inventive device utilizes a division-of-wavefront interference lithography configuration which divides a single large field size optical beam using one or more mirrors, and is actively stabilized with a subsystem employing; a phase modulator operating on each divided wavefront section; a novel feedback apparatus for observing the relative phase shifts between interfering wavefront sections; and a control system for holding the relative phase shifts constant.

Abstract: The invention provides a hologram-recording subject plate comprising a block and a variety of subjects fixedly contained therein, which ensures easy, stable yet continuous recording of a multiplicity of identical holograms or different holograms reconstructible by illuminating light as is the case with a hologram-replicating method, a hologram-making method using the same, and a hologram-recorded article. The subject plate comprises a transparent solid block 5 and a hologram-recording subject S contained therein. A photosensitive material film 1 is applied directly onto one surface of the subject plate, and the subject plate is then irradiated with laser light 7 through the photosensitive material film 1. Such simple operation enables a multiplicity of identical holograms to be recorded in an easy, stable yet continuous manner.

Abstract: A stereo image display apparatus is disclosed, in which the influence of display area edge portions on the viewing of stereo image is taken into considerations to enable display of stereo images without spoiling the viewer's sense just like the viewer is actually on the site of the image scene. The display of a left eye and a right eye image is controlled to have a binocular parallax substantially fixed in effect. (Specifically, image shifters 32L and 32R shift the left eye and right eye images according to a parallax signal.) Edge portions of a left eye and a right eye image display area are shaded off in effect and made obscure by a left eye and a right eye eyepiece optical system 12L and 12R.

Abstract: Disclosed is a curved surface element (e.g., light bulb, ornament, light pipe, etc.) which has at least a portion thereof (inner or outer surface) covered with a holographic diffraction grating which was constructed to be essentially distortion free on said curved surface, whereby such diffraction grating diffracts light to emit color to the observer. The diffraction grating can take for form of a holographic optical element (HOE) attached to the curved surface or a diffractive holographic optical pattern (HOP) embossed into the curved surface.

Abstract: The invention provides a hologram recording or replicating optical system wherein a misalignment-with-time of the center of a laser generated beam is automatically corrected so that the color balance in a color hologram surface, for instance, can be well maintained with no disturbance. In the hologram recording or replicating optical system for irradiating a photosensitive material 20 with a beam from a laser 31 through a pinhole 10, a beam position correcting mechanism 32 and a beam splitter 33 are located in an optical path between the laser 31 and the pinhole 10, and a laser beam position detector 35 is located at a position in an optical path split by the beam splitter 33 and conjugate to the pinhole 10, so that the beam position correcting mechanism 32 can be operated on the basis of a beam position error signal obtained from the laser beam position detector 35 to keep the position of the beam incident on the pinhole 10 always constant.

Abstract: A duplicating photosensitive material film is brought into close contact with an ND glass reduced in thickness so as to become flexible or a flexible sheet or an ND glass coated with a cushioning layer through an optical contacting liquid containing a surface active agent. In addition, a spacer is interposed between a hologram original plate and a duplicating photosensitive material, and a space defined by the spacer is filled with an optical contacting liquid, thereby regulating the thickness of the optical contacting liquid layer with the spacer. Therefore, when pressure is applied, the optical contacting liquid is uniformly pressed, so that it can be made uniform and thin in thickness. Accordingly, it is possible to prevent a failure of duplication of a hologram image due to undesirable flow of the optical contacting liquid.

Abstract: A positive unit magnification reflective head is used to back-reflect a primary light beam, for storing reflection microholograms at the coincident foci of the primary and reflected beams. Imaging the primary beam focus onto itself at positive unit magnification allows increasing system tolerance to tilts and transverse misalignments between the primary and reflective heads. Holograms are stored at multiple depths in a holographic storage medium. Tunable-focus primary and reflective heads are positioned on opposite sides of the storage medium. The reflective head images each storage location onto itself at positive unit magnification. Suitable reflective heads include: two lenses in an f-2f-f configuration and a planar mirror; a lens and a corner cube; a thin lens and a thick lens with a coated reflective back surface; and a thin lens and a back-coated gradient-index (GRIN) lens.

Abstract: Disclosed is a curved surface element (e.g., light bulb, ornament, light pipe, etc.) which has at least a portion thereof (inner or outer surface) covered with a holographic diffraction grating which was constructed to be essentially distortion free on said curved surface, whereby such diffraction grating diffracts light to emit color to the observer. The diffraction grating can take for form of a holographic optical element (HOE) attached to the curved surface or a diffractive holographic optical pattern (HOP) embossed into the curved surface.

Abstract: Device, method, and system for recording diffractive high resolution text, pictorial, and/or other graphical information is provided which is particularly suited to recording information that would be difficult to reproduce by typical counterfeiting methods. The information recorded may be used to authenticate the recorded item, or indirectly, an item to which the recording is attached. Such items may include legal, financial and commercial instruments, credit cards, and packaging for such items as software, art, and other items where forgery of the item may be a concern. In one embodiment of the invention light is selectively passed by a shutter, and a spatial filter then cleans the beam to remove undesirable frequency components.

Abstract: A system and method are disclosed for producing and displaying a one-step, edge-lit hologram. For production, an object beam and an edge-lit reference beam are directed at holographic recording material and to interfere with one another. The holographic recording material and the object beam and edge-lit reference beam are then translated with respect to one another. The translation successively exposes multiple portions of the holographic recording material to the interference of the object beam and the edge-lit reference beam to record an edge-lit hologram on the holographic recording material. In one embodiment, the holographic recording material is moved while the object beam and the edge-lit reference beam remain generally stationary. In another embodiment, the object beam and the edge-lit reference beam move in unison with each other while the holographic recording material remains generally stationary.

Abstract: An optical pickup device in which a light beam radiated from a semiconductor laser element is converted by a collimator lens into collimated light beam which is converged by an objective lens so as to be illuminated on an optical disc. A beam shaping element having a hologram pattern on its incident surface and/or its radiating surface is provided on a divergent optical path of the radiated light beam from the semiconductor laser element between the semiconductor laser element and the collimator lens for shaping the light beam radiated from the semiconductor laser element for forming a beam spot of an optimum shape on the optical disc.

Abstract: A method for suppressing image speckles in a holographic screen is provided in which the screen is illuminated in the hologram in a plurality of individual steps, changing the recording parameters at each step. As a result, a holographic screen is obtained that produces a speckle-free image from a hologram recorded with lasers and then illuminated by a laser. Depending on the application, the object screen can be recorded as a reflection or transmission hologram.

Abstract: A hologram-image recording method and apparatus are provided which prevents or attenuates vibrations so as to produce a bright holographic stereogram having high diffraction efficiency. Such apparatus may includes an exposing recording portion for sequentially exposing and recording interference fringes generated by an object laser beam modulated in accordance with each element image of parallax images and a reference laser beam having coherency with the object laser beam on a recording medium as an elemental hologram, wherein the object laser beam is incident on a surface of the recording medium and the reference laser beam is incident on one of said surface and an opposite surface of the recording medium. The apparatus may further include a moving device for moving the recording medium in a predetermined direction and a braking device for applying a load to the recording medium which resists the movement thereof.

Abstract: A method for fabricating light dispersive insulated glazing units is provided. According to this method a substantially sealed integral unit comprising a pair of spaced glazing lites and a heat-shrinkable light dispersive film interposed between the glazing lites and spaced apart from the glazing lites is formed, the light dispersive film being fixed along at least two of its edges with respect to the edges of the glazing lites. The assembled structure is then subjected to a heat treatment for a time and at a temperature sufficient to heat shrink the light dispersive film and cause it to become taut and wrinkle-free.

Abstract: A method is proposed, how to produce a holographic screen for projection of the three-dimensional color images, where a narrow and elongate slit-shaped diffuser is recorded on a hologram as an object to ensure the well defined viewing zone forming in the course of the image projection. Further to the back side of the holographic screen a mirror is attached to transform it into reflection mode of operation. Further, the holographic screen is rotated under a control of an eye-tracking system to provide viewing zone movement together with a viewer's eye. Also, a diffuser with vertical light scattering is attached to a surface of the holographic screen to increase a vertical size of a viewing zone of the holographic screen. In addition, two or more holographic screens manufactured by this method are combined in a mosaic manner to form a big size holographic screen.

Abstract: A phase-shift digital holographic apparatus shifts the phase of a reference wave by a phase shifting means, produces holographic image data by a holographic image pickup means having an image forming surface on which an object wave and the reference wave fall simultaneously, processes a plurality of holographic image data produced by the object wave and a plurality of reference waves of different phases determined by shifting the phase of the reference wave by the phase shifting means by an object wave calculating means to calculate phase data on the phase of the object wave and amplitude data on the amplitude of the object wave, and constitutes object wave data of the phase data on the phase of the object wave and the amplitude data on the amplitude of the object wave calculated by the object wave calculating means by a reproduced image calculating means and subjects the object wave data to a predetermined transformation process to calculate a reproduced image.

Abstract: A structural arrangement having optical diffraction qualities for use as a security element in a value bearing document, such structural arrangement having a plurality of surface regions having at least two subregions having identical relief structures which provide for an optical diffraction effect, the relief structures of adjacent subregions being displaced relative to each other by a fraction of the grating period.