Abstract: Non-volatile data memory cards, flash drives and other memory devices are customized by manufacturing core memory units all the same and then covering them by outer skins which may be made to have different appearances and/or tactile characteristics. The skins are slid over the core memory units by hand from one end. End users of such memory devices may then select how they will look and feel by separately purchasing covers. Sellers of such memory devices may more easily control how their products look and feel.

Abstract: Non-volatile data memory cards, flash drives and other memory devices are customized by manufacturing core memory units all the same and then covering them by outer skins which may be made to have different appearances and/or tactile characteristics. The skins are slid over the core memory units by hand from one end. End users of such memory devices may then select how they will look and feel by separately purchasing covers. Sellers of such memory devices may more easily control how their products look and feel.

Abstract: A holographic read only memory card which can be coupled to and read by a card reader to which electronic read only memory cards can also be coupled to and read by the card reader is disclosed. The holographic read only memory card comprises: a housing having a compartment for receiving a holographic storage medium; a holographic storage medium having stored thereon holographic data; and optionally a an electronics panel member having an electronic memory component which can be read by the card reader when the holographic read only memory card is coupled to the electronic card reader. The housing comprises one or more card locating members to thereby repeatedly position the holographic read only memory card each time the holographic read only memory card is coupled to the electronic card reader so that the holographic data can be read.

Abstract: Multi-layer cards with aesthetic and/or functional features, e.g. banking, access, or identification cards, having a bearing layer that includes an effects layer disposed directly between two core layers are disclosed herein. Among other potential benefits, the layered structure of the bearing layer reduces overall manufacturing costs, as compared to methods known in the art, by facilitating a balanced card construction while minimizing the number of layers formed from relatively expensive materials, avoiding direct imaging of the effects layer and minimizing waste associated therewith, as well as providing for reliable incorporation of the effects layer into the multi-layered structure with minimal expenditure of resources and reduced possibility of waste.

Abstract: A card embodying the invention includes marks which are randomly formed within a dedicated region of the surface of the card. The randomly formed marks may, for example, include; (a) partial-holes extending a short distance from a surface of the card; (b) through-holes extending between the top and bottom surfaces of the card; (c) burn marks, or (d) ink marks. The marks are of a size and nature such that they are not readily visible to the naked eye. The invention includes illumination apparatus for illuminating the card to reliably sense the optical pattern of the randomly formed marks. In accordance with one aspect of the invention, a reader/writer includes apparatus for generating an array of light to uniformly illuminate the back surface of the card so as to pass light through the through-holes or through the partial holes.

Abstract: An apparatus for compressing holographic data includes an image capture device for capturing an image of an interference pattern reconstructed by irradiating a reference beam and converting the image into m bits. In such an apparatus, a splitter removes least significant j bits from the m-bit data and divides m?j bits of the m-bit data into most significant k bits and remaining m?j?k bits. Thereafter, a compressor converts the most significant k bits into l bits, which is combined with the m?j?k bits to output n bits, wherein l<k and n=l+m?j?k. In this way, by compressing a certain number of most significant bits of the m-bit data and thus relatively increasing the number of the remaining least significant bits of the m-bit data, the BER of final reconstructed image data can be improved.

Abstract: Surface optical characteristics, alpha-numeric markings and other design features of memory cards, flash drives and similar devices combine to provide the devices with unique outer appearances. In one example, markings are held a distance from a reflective surface such that reflections of the markings off the surface are visible adjacent the markings. In another example, a diffusely reflecting rainbow hologram is combined with such markings or other design features.

Abstract: An optically variable device (OVD) is provided that includes a barcode rendered from a three-dimensional barcode. To increase the readability of the barcode rendered in the OVD, the bars of the three-dimensional barcode may have tapered sidewalls and depths that are small compared to their heights and widths. The barcode may be rendered in the OVD such that it is viewable only at certain angles or using certain wavelengths of light. Also provided is a barcode of multiple portions where a portion is rendered in an OVD and another portion is otherwise provided (e.g., printed). Such a barcode may have portions that are readable as independent barcodes and are also readable together as a single, compound barcode. Also provided is a method where a plurality of OVDs with unique images are associated with products, e.g., packaged together, so that receipt of a package of products with non-unique images indicates counterfeiting.

Abstract: A system and method for reading the information stored in holograms and other diffractive objects. The information is read by analyzing the diffraction pattern produced when a laser beam is focused onto a small spot on the object and scanned across the object.

Abstract: The present invention relates to merchandising components for authenticating products, combinations that include the merchandising component and a product, methods of associating the merchandising component with a product, and methods of utilizing the merchandising component to authenticate a product. More particularly, the merchandising component includes an authentication component capable of producing a two-dimensional, human readable image upon irradiation with electromagnetic radiation. Advantageously, the image produced is unambiguous and capable of being verbally described in an objective manner. The image so produced can be compared with an authentication image, or verbal description thereof, known to be associated with the product in order to reach an authentication determination about the same.

Abstract: An information reading apparatus can detect the coupling state of the input light to a waveguide of a laminated recording medium in a simple manner, so as to enable to focus the input light on a target recording layer to access the information recorded in the target recording layer quickly. The apparatus is compact and is economical to produce. The apparatus has a light source for injecting a light on an input edge of a lamination recording section, assembled into the recording medium containing a lamination of recording layers. Each recording layer has data represented by scattering centers which diffract an input light generated by a converging lens. An input light directing device directs the light source and the converging lens as a unit to focus the input light on a desired location. An image recording device records an informational image generated by guided waves produced within a laminated waveguide.

Abstract: Methods of creating tamper resistant informational articles and related products are disclosed. In one embodiment, a lens has a preformed transparent hologram, metallized portions are provided and may be altered through selective application of heat to predetermined parts thereof to create information which may be fixed or variable. Printing may be provided on the hologram before metallizing. A base portion underlies the metallized layer. In yet another embodiment of the invention, an opaque base portion has a hologram formed in the upper surface thereof with portions of the hologram being made readily visible by partial metallization covering only portions of the hologram with or without information provided as by printing overlying or underlying portions of the metallized sector or both. A transparent overlying lens is secured in overlying relationship. Metallizing may be such as to permit viewing underlying hologram portions or information or not. A corresponding method is provided.

Abstract: Methods of creating tamper resistant informational articles and related products are disclosed. In one embodiment, a tamper resistant informational article is provided by creating a base with an elongated metal core having extruded therearound a resinous plastic material. A magnetic media storage element is secured to this base. An antenna may be provided. In another embodiment, a lens is created by providing an elongated transparent layer, forming a hologram in the lower surface thereof and applying information to the hologram. The lens is then secured to a base to protectively surround the information. In another embodiment, a preformed transparent hologram-containing article has information added thereto and is then metallized. A protective resinous layer may be secured over the metallized layer.

Abstract: A method for judging coercive force of a magnetic card to judge coercive force of a magnetic card to be used. According to the method for judging coercive force of a magnetic card for reproducing or recording magnetic information formed on a low coercive force card or a high coercive force card inserted from a card slot by a magnetic head, after erasing data of an inserted card by an electric current capable of erasing data of only a low coercive force card (step S32), the data of the card is reproduced (step S33), the inserted card is judged as the low coercive force card (step S36) if the data has been destroyed (No at the step S34). Destruction of the data is judged based on the number of times of flux reversal of the reproduced data or by a fact that specific data (STX code) which should be recorded on a predetermined card is not recognized.

Abstract: The invention relates to a method for producing injection-molded cards with at least one decorative layer (2, 6) which is already applied to a foil (1, 7) or an inlay before injection molding. To protect the inks used for the decoration from thermal action and/or excessive pressures and/or high mechanical stress during injection molding, the decorative layer (2, 6) is covered according to the invention with a protective layer (3, 5) before the foil (1, 7) provided with the decoration or an inlay provided with a decoration is inserted into the injection mold.

Abstract: The CGH (computer generated hologram) readout section (4) reproduces an image of the CGH (28), which is formed in the data storage area (52) of the crude card (26). The CGH certifying section (5) judges whether the card is genuine or fake and obtains an ID (identification) information. In a case that the card is genuine, the ID information is supplied to the data processing section (6). The data processing section (6) inputs a personal information of a person to be a cardholder and also inputs a face picture of the person. These data are registered in the database (2) in response to the ID information. A part of or all of the personal information is outputted to the IC reader/writer (8) and written into the IC module (53). Further, a part of the personal information and the face picture are outputted to the color printer (7) as a printing information and printed on the surface of the crude card (26).

Abstract: This invention relates to a solar control film that blocks the sunlight, when applied to various windows of automobiles, buildings or exhibition places and that prevent any second accident caused by broken glasses at an accident. From the solar control film, a surface protective layer, a plastic film substrate, a hologram-engraved layer, a metal deposition layer, a pressure sensitive adhesive layer and a release film are laminated in due order. The solar control film of this. Hence the above-described solar film has a basic function such as an excellent blocking rate of visible and infrared rays, while demonstrating an additional antifog action and an elegant look due to the hologram effect.

Abstract: An information recording medium (10) comprises a base sheet (2a), a resin layer (2) formed on the base sheet (2a) and having a holographic region (6) provided with a diffraction grating (4) in a regular or irregular arrangement, and a ferromagnetic thin film (3) formed on the holographic region (6) of the resin layer (2). The ferromagnetic thin film (3) has a specific magnetic characteristic dependent on a holographic pattern formed in the holographic region (6). The magnetic characteristics of the ferromagnetic thin film are converted into signals corresponding to the holographic pattern.

Abstract: An information reader formed within a unitary enclosure for sensing whether information on a surface to be read is valid includes a plurality of different sensors for sensing the presence of different types of information on the surface being read. Each sensor is programmed to sense whether certain criteria pertaining to that sensor are met. In addition, the outputs of selected sensors are compared to ascertain whether the outputs of the selected sensors have a preset relationship indicative of a valid condition. In one embodiment the information reader includes a hologram sensor, a surface quality sensor, a bar code reader and a magnetic stripe read/write sensor.

Abstract: The invention proposes an arrangement of the type comprising a unit into which a badge is introduced manually into a housing in the unit, and which comprises a lever for immobilizing the badge in an active position in the unit and an electromagnet made to lock the immobilizing lever, wherein this arrangement comprises a member for manually unlocking the immobilizing lever which acts on the mobile core plunger of the electromagnet. It is applicable on board of a motor vehicle in which the anti-theft functions are partially or completely fulfilled by data processing, some of which data represents an authorized user of the vehicle.

Abstract: An information medium consists of an essentially circular or polygonal disk having at least two pairs of sides parallel to one another which have the same distance to one another in each pair. To reliably read stored data from such an information medium at high speed, a hologram is disposed on at least one side of the disk at its center or at the intersection of two crossing symmetry lines which can be reconstructed with a reference beam incident to the side at a right angle to a pattern consisting of essentially concentric circles, with the reference beam forming the axis of said pattern.

Abstract: The present invention relates to an optical scanner (20) comprising a radiation source (24) for generating a radiation beam, and means (22), (26) for giving the radiation beam a scanning movement in a first direction through an angular range &Dgr;&thgr;1 and in a second direction through an angular range &Dgr;&thgr;2. The radiation source (24) is, for example a diode laser and is tunable in wavelength, and the means comprise a rotating reflecting element and a grating.

Abstract: There is provided an optical recording medium provided with at least an optical recording layer, further comprising a cured layer provided on/over outer surface of the optical recording layer and a receiving layer provided on at least a part of the cured layer. It is possible to provide an optical recording medium which allows post-processing such as printing on the cured layer which has been very difficult to be carried out so far, without degrading the reliability of the information of the optical recording medium.

Abstract: The invention relates to a data carrier (1) with a data carrier structure (2) in which a module (9) with a plate-shaped component carrier (10) and a component (13) attached to the inside of the component carrier (10) is used, and with a plate-shaped hologram carrier (30) provided on the data carrier (1) and showing a hologram (33) by way of the main surface (31) visible from outside the data carrier (1). The invention provides that the plate-shaped hologram carrier (30) be provided on the data carrier to be covering the plate-shaped component carrier (10), and covers at least substantially the component carrier (10).

Abstract: A diffractive collector for an optical scanner includes a wedged-shaped substrate having holographic grating provided on a front surface, a conical-shaped back surface, and at least one detector. Substantially parallel light is made incident upon the front surface of the substrate, and the light is diffracted within the substrate to the back surface. The wedged shaped of the collector and the holographic grating cause the light to reflect back within the substrate at such an angle that the light remains within the substrate as the light propagates to the at least one detector.

Abstract: Methods of creating tamper resistant informational articles and related products are disclosed. In one method a metal foil has a hologram formed therein after which information is created on the metal foil at least partially over the hologram and the foil is encapsulated in a resinous plastic material. Encapsulation may be effected by extruding the resinous plastic material. The assembly may be separated into individual informational articles which resist tampering and resist undesired counterfeiting as by photocopying. In another embodiment, a tamper resistant informational article is provided by creating a base having an upper surface and a lower surface with an elongated metal core having extruded therearound a resinous plastic material. A magnetic media storage element is secured to this base. A lens is created by providing an elongated transparent layer, forming a hologram in the lower surface thereof and applying information to the hologram.

Abstract: A holographic spectroscope for a two-motor reflection system for generating scanning patterns in which a light beam is first reflected by a first reflector connected to a first motor electrically connected to a first control circuit. A second reflector for reflecting the light beam reflected by the first reflector is connected to a second motor electrically connected to a second control circuit and to form scanning patterns. A holographic spectroscope for diffracting the scanning patterns is mounted in the optical path of the light beam from the second reflector. Therefore, the scanning patterns can be improved to be more variable.

Abstract: An electronic purse card value system (10) includes terminal devices (12). Each terminal device includes a processor (26) which is in operative connection with a memory (28) and a modem (36). The terminal devices operate in response to configuration data which is stored in the terminal memory. The configuration data is enabled to be programmed into the terminal device by transferring the configuration data from the memory of a smart card (24) which is read by a card reader (22) of the terminal device. The configuration data stored in the terminal may also be transferred to a smart card through the card reader. The smart card may then be taken to other terminals and used to program those terminals with similar configuration data.

Abstract: A plastic card prepared by laminating unstretched polyester sheets to both sides of a single sheet or a laminate of a plurality of sheets of a stretched polyester film, cutting the obtained laminate to a shape of a card, and forming a cavity for embedding a chip module by milling in the laminate cut to the shape of a card. The plastic card is excellent in mechanical strength, dimensional stability, heat resistance, and property for printing, contains no hazardous halogen elements, and has a cavity for embedding a chip module which is formed without formation of burr by milling.

Abstract: The hologram card generates a hologram image in response to an illumination light beam. The hologram card comprises a substrate of a first plastic material having a first refractive index. The substrate has a contoured surface. The contoured surface is formed to include localized topological features constituting a diffractive optical element. The diffractive optical element is structured to generate a hologram image when illuminated by the illumination light beam. The hologram card also comprises a protective layer of a second plastic material having a second refractive index that differs from the first refractive index by less than 0.2. The protective layer covers the contoured surface of the substrate. The protective layer is chemically bonded to, and directly contacts, at least the topological features constituting the diffractive optical element.

Abstract: The present invention provides a method for producing double-card anti-counterfeit marks with interlock protection based on the technique which combines nuclear technology with computer-generated hologram (CGH) technology and inspecting apparatus for the mark. The invention relates to the technical field of optical information processing in physics. The technical feature of the invention is to insert potential images R,T and matched potential images R',T' in the anti-counterfeit identification marks and in the inspecting identification marks respectively by means of charged particle track image in sampling coincidence with CGH. When R coincides with R', a certain message of genuineness for an identification mark will be shown, and when T coincides with T', different specific information in thousands of ways appears to prove the genuineness of the protected objects.

Abstract: An anti-counterfeit card includes a substrate on which an anti-counterfeit membrane is attached. The substrate includes a sheet of plastic with two transparent surface layers formed on two opposite sides thereof. Printing may be selectively carried out on the two sides of the plastic sheet and the outer surfaces of the surface layers. The anti-counterfeit membrane includes a hologram film on which serration defining a hologram is formed so as to make it difficult to counterfeit the card. A method for manufacturing the anti-counterfeit card is also disclosed. A method for manufacturing the anti-counterfeit card is also disclosed, comprising the steps of providing a substrate; providing an anti-counterfeit membrane which comprises a hologram film; and attaching the anti-counterfeit membrane to the substrate to form the anti-counterfeit card.

Abstract: A holographic laser scanning system for scanning bar code symbols. The system comprises a holographic scanning disc having a plurality of holographic optical elements disposed thereon for scanning the plurality of laser beams directed at the same incident angle. Each holographic optical element as substantially the same Bragg angle. The parabolic light reflective surfaces are disposed beneath the holographic scanning disc. Each parabolic light reflective surface has an optical axis disposed off the Bragg angle of the holographic optical elements, for focusing towards a focal point above the holographic scanning disc, the reflected light rays collected by each holographic optical element. A photodetector is disposed at the focal point of the corresponding parabolic light reflective surface above the holographic scanning disc, and is radially aligned with the optical axis of one parabolic light reflective surface.

Abstract: An optical device reads the information such as bar codes on an object. A light-emitting element emits a read-beam. A lens cover has an inclined surface that is at an angle with the read-beam and reflects the read-beam toward a bar code, the read-beam emerging as a reflected-beam after reflection from the surface of the bar code. The reflected-beam contains a component directly reflected from the bar code and a component randomly reflected by the white and black areas of the bar code. An optical system in the form of a lens is arranged between the lens cover and the light-emitting element, and converges the read-beam to the bar code. The inclined surface is also at an angle with the reflected-beam and reflects the reflected-beam toward a second optical system in the form of a lens which in turn converges the reflected-beam emerging from the inclined surface to a light-sensing element. The light-sensing element detects the reflected-beam.

Abstract: A holographic security label and automated reading machine for marking and subsequently authenticating any object such as an identification badge, a pass, a ticket, a manufactured part, or a package is described. The security label is extremely difficult to copy or even to read by unauthorized persons. The system comprises a holographic security label that has been created with a coded reference wave, whose specification can be kept secret. The label contains information that can be extracted only with the coded reference wave, which is derived from a holographic key, which restricts access of the information to only the possessor of the key. A reading machine accesses the information contained in the label and compares it with data stored in the machine through the application of a joint transform correlator, which is also equipped with a reference hologram that adds additional security to the procedure.

Abstract: In a bar code reading optical apparatus including a semiconductor laser and a prism both mounted on a photodiode IC so that emitted light from a semiconductor laser is reflected by a reflective plane of a prism and signal light from a bar code to be read out enters in and detected by a photodiode, a numerical aperture conversion hologram is provided in a light path of the emitted light reflected by the reflective plane of the prism to adjust the numerical aperture of a converging lens so that the numerical aperture for the emitted light be smaller than the numerical aperture for the signal light. The numerical aperture conversion hologram may be omitted by shaping the reflective plane of the prism into a concave plane to adjust the numerical value for the emitted light smaller than the numerical value for the signal light.

Abstract: A method of providing secure identification for an article, including: providing on the article a diffraction grating strip including a pattern of a series of diffraction grating elements, each the diffraction grating element to diffract light, from a light source, in one of at least three selected different planes; serially illuminating the diffraction grating elements, detecting changes in plane of diffracted light as the diffraction grating elements are serially illuminated, and generating first information representative of the changes in plane; storing the first information representative of the changes in plane; subsequently, serially illuminating the diffraction grating elements, detecting changes in plane of diffracted light as the diffraction grating elements are serially illuminated, and generating second information representative of the changes in plane; and then, comparing the first and second information to determine the authenticity or not of the article.

Abstract: A system and method for determining which of a plurality of visually indistinguishable objects have been marked with a covert indicator in which a portion of a surface of each of a first type of objects are provided with a covert holographic indicator which is exposed to be viewed but which is detectable only when illuminated with a coherent reference light of predetermined wavelength. The surfaces of objects are scanned with a coherent reference light with the predetermined wavelength, and evaluated to determine whether the scanned surfaces include the covert holographic indicator. The presence of the covert holographic indicator indicates that the object on which the covert holographic indicator is detected is one of the first type of objects. The first type of object may be a winning game ticket, or a genuine, as opposed to counterfeit, article.

Abstract: An optical data element includes a plurality of diffraction zones wherein each zone contains a multiplicity of diffraction gratings. These zones may be illuminated and the resultant one or more diffracted beams detected to provide a signature for the element consisting of a series of discrete signature signals each generated by the plurality of zones and each including portions or relatively different intensities. At least one of the diffraction zones has a segment thereof modified whereby to discernibly alter at least one of the discrete signature signals of the signature and to thereby form a data segment of the optical data element.

Abstract: In a preferred embodiment, secure optical identification, including: a first lacquer layer; a metallic layer disposed on a first surface of the first lacquer layer, with a first surface of the metallic layer in contact with the first surface of the first lacquer layer; a diffraction pattern embossed in the first surface of the first lacquer layer through the metallic layer; a pattern formed in the metallic layer by demetallizing areas of the metallic layer; and a second lacquer layer, having the same refractive index as that of the first lacquer layer, disposed on a second surface of the metallic layer so as to fill in voids adjacent the diffraction pattern caused by the demetallizing areas of the metallic layer.

Abstract: A dual card smart card reader including a portable housing with a viewing aperture and a virtual image display positioned to provide an image at the aperture. A sensor in the housing constructed to have a first smart card with data stored thereon positioned adjacent thereto in data sensing juxtaposition and a second smart card with access data stored thereon positioned adjacent thereto in data sensing juxtaposition. The second smart card serving as a security feature and allowing for access and/or editing to certain information contained on the first smart card. Electronics mounted in the housing and connected to the sensor for receiving sensed data and sensed access data and further connected to the virtual image display for supplying image data thereto.

Abstract: Security devices which are difficult to reproduce include a grid screen metallization pattern. The grid screen metallization pattern may be laid down over a hologram or diffraction grating formed as a surface relief pattern on a substrate, to form a visually identifiable, semi-transparent security device. Additionally, the metallization pattern may include resonant structures in which information about the security device is encoded. In some embodiments of these security devices, the metallization pattern is disposed in accurate registration with the underlying hologram or diffraction grating. These security devices are made by methods which include printing an oil pattern on the substrate. Areas on which oil is deposited do not receive metal during a metallization step. Since these methods do not use caustics, metallization patterns including features which would otherwise trap and hold caustics are possible.

Abstract: A viewing device to aid in authenticating an optical surface. The device includes a laser diode which produces a beam of light. The device includes a viewing screen which receives a diffracted image produced by the beam illuminating the surface. The device further includes a lens system which causes the diffracted beam to be focused on the viewing screen.

Abstract: A smart card reader including a portable housing with a viewing aperture and a virtual image display positioned to provide an image at the aperture. A sensor in the housing constructed to have a smart card with data stored thereon positioned adjacent thereto in data sensing juxtaposition and electronics mounted in the housing and connected to the sensor for receiving sensed data and further connected to the virtual image display for supplying image data thereto.

Abstract: A microlithographic tag comprising an array of individual computer generated holographic patches having feature sizes between 250 and 75 nanometers. The tag is a composite hologram made up of the individual holographic patches and contains identifying information when read out with a laser of the proper wavelength and at the proper angles of probing and reading. The patches are fabricated in a steep angle Littrow readout geometry to maximize returns in the -1 diffracted order. The tags are useful as anti-counterfeiting markers because of the extreme difficulty in reproducing them.

Abstract: A plastic card provided with a magnetic stripe, which is very difficult to forge or alter and, even tough subjected to forgery or alteration, enables the forgery or alteration to be easily detected in appearance. The plastic card includes a card substrate and a hologram-magnetic stripe including, provided on said card substrate in the following order, an adhesive layer, a first magnetic recording layer, a second magnetic recording layer, a transparent continuous thin film layer and a hologram forming layer. The first magnetic recording layer and the second magnetic recording layer are such that one of the magnetic recording layers has a coercive force at least twice as high as the other magnetic layer and a Curie point at least 100.degree. C. below the other magnetic layer and, when the magnetic recording layers are heated at a temperature in the range of from the lower Curie point to 30.degree. C.

Abstract: A laser source and a converging lens are provided so that a laser beam emitted from the converging lens travels substantially parallel to the surface of a hologram disc. A incidence mirror is provided for causing the laser beam emitted from the lens to fall incident on the hologram disc at an angle of incidence of about 45 degrees. By merely moving or rotating the incidence mirror, the position of and the angle of incidence of laser beam to the hologram disc can be easily adjusted.

Abstract: A hologram which contains the record of a parallel bar-shaped pattern, like a bar code pattern, and which can be read with a single light-receiving element of simple structure with fewer restrictions on the installation position of the light-receiving element and with a minimal lowering in the read accuracy even if the light-receiving element is disposed a little out-of-position. Also disclosed is a method of reading such a hologram. A hologram is recorded in a region that extends in a direction intersecting each bar of a reconstructed bar-shaped pattern and that is not shorter than the length of the reconstructed bar-shaped pattern at least in the above-described direction. Alternatively, the hologram is recorded in a stripe region elongated at the above-described direction.

Abstract: In a preferred embodiment, a method of providing secure identification for an article, including: providing on the article a diffraction grating strip including a pattern of a series of diffraction grating elements, each the diffraction grating element to diffract light, from a light source, in one of at least three selected different planes; serially illuminating the diffraction grating elements, detecting changes in plane of diffracted light as the diffraction grating elements are serially illuminated, and generating first information representative of the changes in plane; storing the first information representative of the changes in plane; subsequently, serially illuminating the diffraction grating elements, detecting changes in plane of diffracted light as the diffraction grating elements are serially illuminated, and generating second information representative of the changes in plane; and then, comparing the first and second information to determine the authenticity or not of the article.

Abstract: In an article identification system comprising a plurality of identification regions affixed on an article, a light emitting device for impinging an illuminating light beam onto at least some of the identification regions, a light receiving device for detecting light diffracted by the identification regions, and a determination unit for determining the authenticity of the article according to a pattern of diffracted light detected by the light receiving device, the identification regions consist of a combination of effective and ineffective identification regions which are hardly distinguishable by naked eyes. Thus, the potential forger is not able to know which regions are indeed effective without having any access to a genuine optical reader/writer, and has to duplicate all of the identification regions at a substantial cost and requiring a substantial amount of effort.