Abstract: An improved holographic scanner includes circuitry for adjusting the frequency with which an analog photodetector signal is sampled in accordance with the focal length of the scanning beam produced by the active holographic facet. Two embodiments are shown. In one embodiment, facet-edge signals are used to track the facets. A processor retrieves a predetermined frequency scaling factor appropriate for each facet. In the other embodiment, a holographic disk carries an auxiliary data track. The track has timing indicia with spatial frequencies dependent upon the focal length of the adjacent facet. The timing indicia are used to control the output of a voltage controlled oscillator in a circuit including a phase locked loop.

Abstract: A holographic scanning system for scanning a bar coded label is disclosed in which the light beams of a laser are directed at a set of holograms located on a rotating disk in which each hologram will generate an individual scan beam having a slightly different focal length and direction angle from that of the other holograms. Each of the scanning beams is directed at a plurality of mirrors which reflect the beams in the form of a scanning pattern on a scanning area through which a coded label on an article will pass. Each of the scanning beams is projected in an overlapping relationship on the scanning area, thereby providing an enhanced depth of focus enabling a more effective reading operation. The light reflected from the bar coded label is collected by the holograms for collimating the reflected light beams. The collimated light beams are directed at a lens member which focuses the received light beams on a photodetector for use in reading the bar coded label.

Abstract: An identifiable security device comprises a carrier (1), such as a key card, credit card or document, supporting a thick film hologram (5) including at least one discrete reflective region (6) which, when illuminated reflects strongly in a specific, predetermined direction. A reader (2) incorporates a light source (7) and one or more photodiode detectors (8,11) arranged to detect the directional reflections, to discriminate against non-holographic reflections and to perform a security function on detection of appropriate reflections. The function may comprise authentication of a carrier bearing a simple hologram, but more complex hologram having a plurality of reflective regions arranged in a coded array are used, for example, on bank cheque cards to operate automatic bank dispensers and on pass cards for gaining entry to secure areas.

Abstract: A holographic scanner includes a rotating glass disk carrying a plurality of scan line generating holograms, a laser light source and means for detecting reflected optical energy. The scanner is improved by adding a plurality of relatively small position-indicating holograms in alternation with the scan line generating holograms. The position-indicating holograms redirect the laser beam along desired paths on the same side of the disk as the laser. The redirected laser beam may be detected by the system photodetector or an auxiliary photodetector to provide signals indicating the current disk position. The position information can be used by a system processor to optimize scanner parameters as a function of the characteristics of the next active scan line generating hologram.

Abstract: This disclosure describes a technique for reading bar codes scanned by focussed scan lines having different focal lengths where at least one of the scan lines has a beam that is small relative to irregularities of the surface on which the label appears. The scan lines are generated using a holographic disk so as to have a predetermined focal length and focal zone. The focal zone of each generated scan line overlaps the focal point of at least one adjacent scan line. Any bar code label which might be scanned by a beam so small that it would be degraded by surface scatter noise is also scanned by a slightly larger beam. The slightly larger beam "averages out" the surface scattering noise to produce a smoother or cleaner return signal.

Abstract: A fixed position optical scanner with a multi-faceted holographic disk includes circuitry for adjusting the lockout voltage as a function of the focal length of the active facet. The disk position is tracked to identify the active facet. A facet identifying signal is used to address a lockout table in processor memory. A digital value retrieved from the lockout table is converted to analog form and applied through a resistor to a voltage divider in the threshold circuit. The voltage divider scales down a white peak following voltage and compares it to a black peak following voltage. The facet-dependent lockout voltage biases the junction of the voltage divider to vary the effective lockout voltage as a function of the focal length of the currently active facet.

Abstract: An identification card and method of manufacturing the same in which a holographic image is embossed on a clear polyester carrier which is then coated with ferrous oxide to form a magnetic strip with an optically viewable holographic image thereon. The strip is then mounted on a plastic substrate, and the carrier discarded.

Abstract: An identification article comprise a substrate and a pattern-form Fresnel hologram provided as an identification information providing layer on the surface or in the interior of the substrate structure. The pattern-form Fresnel hologram is formed by (a) forming a Fresnel hologram by exposing a photosensitive resin layer to an interference light obtained from interference between an object light beam and a reference light beam both obtained by dividing a single coherent light, (b) exposing the Fresnel hologram to light transmitted through a mask pattern, (c) fabricating a pattern-form Fresnel hologram by developing the Fresnel hologram, and (d) reconstructing the pattern-form Fresnel hologram thus obtained. The identification article is verified by projecting a monochromatic light onto the hologram to reproduce an image and projecting this image on a screen or detecting it with a light detector.

Abstract: A reflection hologram is laminated or otherwise incorporated into the face of a magnetic-stripe credit card or other similar document. This is done to guard against counterfeiting of the document by transfering of information from the magnetic stripe or similar indicia that is not readily detectable by an operator or user of the card or document. The card is verified by inserting it into a reading device which, while reading the information on the magnetic stripe or other indicia, also illuminates the hologram, producing holographic images or spots at one or more pedetermined unique angles, so that the spots can be detected by light sensing devices. Absence of a reflection at the proper angle would immediately indicate, through sensing circuitry, that the card is of questionable validity. To render the system still more secure, the hologram can produce multiple reflective images to be detected at several predetermined positions either from a single point or from multiple points.

Abstract: An optical information-bearing debit card having servo tracks and calibration works on a recording medium for aligning a reading or writing light beam with a nearby value site area. The medium is an elongated strip of reflective information storage material adhered to a self-supporting card, like a credit card. The value site area may be decremented by the light beam changing the optical characteristics of the recording medium. The servo tracks are lengthwise, parallel to the long dimension of the strip of recording material while the calibration marks are non-continuous marks, aligned in a track parallel to the servo tracks. Tracks and calibration marks are disposed on the card so that the value area can be read bidirectionally starting from either end of the card.

Abstract: An optical scanner is improved by securing beam directing holograpic films to the transparent scanner window. The films alter the paths of beams at the window to provide scanning beams suitable for rear or side scanning of label-carrying products. A vertical scanning beam, which sweeps a path parallel to the window's leading edge, might be used to detect the approach of a product to be scanned.

Abstract: An optical scanner uses frequency modulation and detection techniques to produce and utilize multiple, simultaneous scan patterns in which corresponding scan lines have different focal lengths. Two or more solid state lasers are modulated at unique frequencies. The frequency modulated output beams pass through different combinations of focusing lenses and are deflected by a single beam deflecting apparatus. Light reflected from any scanned object is detected. The resulting multi-frequency signal is applied to a plurality of bandpass filters to separate the returned signal into a plurality of separately decodable signals.

Abstract: Operating parameters for a multiple facet holographic disc scanner are adjusted on real time basis as a function of the actual diffraction efficiency of the facet region aligned with the impinging laser beam. The operating parameters are adjusted to achieve optimum signal levels independent of facet characteristics. Diffraction efficiency is inversely related to zero order beam power for a given level of input beam power. A photodetector measures the zero order beam power. The output of this photodetector is used to control video amplifier gain and/or semiconductor laser current.

Abstract: The present invention provides a light scanning apparatus including a semiconductor laser as its light source, a hologram disk having a plurality of equidistant linear gratings of hologram arranged in the form of a circle, which is driven to rotate at constant speed in a predetermined direction, a first optical system for leading the light from the laser to be incident upon one of the gratings, and a second optical system for leading the light diffracted by said one grating to a scanning surface. In one aspect, the second optical system is so structured to maintain the scanning surface to be in conjugate relation in geometric optics with the surface of said one grating thereby allowing to keep the scan line at a desired position even if the oscillation wavelength of the light varies. In another aspect, the incident angle of the light into the one grating is varied in accordance with the oscillation wavelength of the light so as to maintain a constant diffracted angle.

Abstract: This invention describes a system for access control, wherein a control card is presented to a control means. If the control card is authenticated, then access is gained. If it is not authenticated, access is not gained, the control card is retained, and an alarm may be sounded.The control card contains at least two means; (1) machine readable indicia identifying the card, and (2) a random pattern of micro spots, which pattern is derived (by direct copying--such as by focussed laser beam) from one of a plurality of different patterns, retained in a bank of such micro patterns, each such micro pattern identified by, and selectable in accordance with, different unique indicia, identical with the machine readable indicia on said cards.In use the control card is introduced into the control means and the indicia are read. Master micro pattern corresponding to the indicia is selected from the bank. The card micro pattern and master micro pattern are compared. If the comparison okay, the card is authenticated.

Abstract: Electro-optical apparatus for verifying the authenticity of security labels of the type having a series of lenticules of predetermined spatial frequency formed thereon. The apparatus is structured to accept and support a security label to be verified so that the lenticules thereof lie in a flat or nearly flat plane. A laser beam is directed at the flat plane at a predetermined angle of incidence so that the lenticules of the security label in the flat plane diffract the laser beam into a series of wavefronts which reinforce one another to form a diffraction pattern having principle maxima that are separated by equal or nearly equal angles.

Abstract: An optical scanner in a retail store checkout stand includes a single item detector upstream of the scanner window. Output signals from the item detector and from symbol recognition logic are used to open and close a shutter in the beam path of the scanner laser. The shutter is opened and a first time out sequence is started when the beam path is interrupted. A second, short time out sequence is restarted each time a valid symbol is recognized. A third time out sequence of intermediate length supersedes the first time out sequence when the beam path is cleared. The laser shutter is closed and the symbol is transferred to a terminal or controller upon the completion of any active time out sequence or upon recognition of a predetermined number of identical symbols, whichever comes first.

Abstract: An identification card provided with secret data contained in the form of a wave guide hologram recorded in a layer on the card. Light for developing or displaying the hologram is introduced into a wave guide layer extending along the surface of the card through a grating that admits light only of a given wave length suitable for developing the wave guide hologram. The secrecy of the wave guide hologram is further enhanced by incorporating into the light coupling grating a further hologram by which light only of a predetermined pattern can be coupled to the wave guide for delivery to the wave guide hologram.

Abstract: This invention describes a system for access control, wherein a control card is presented to a control means. If the control card is authenticated, then access is gained. If it is not authenticated, access is not gained, the control card is retained, and an alarm may be sounded.The control card contains at least two means; (1) machine readable indicia identifying the card, and (2) a random pattern of micro spots, which pattern is derived (by direct copying--such as by focused laser beam) from one of a plurality of different patterns, retained in a bank of such micro patterns, each such micro pattern identified by, and selectable in accordance with, different unique indicia, identical with the machine readable indicia on said cards.In use the control card is introduced into the control means and the indicia are read. Master micro pattern corresponding to the indicia is selected from the bank. The card micro pattern and master micro pattern are compared. If the comparison okay, the card is authenticated.

Abstract: An apparatus adapted for thermally erasing or changing machine readable optical markings previously entered on a carrier of thermoplastic material which has two major sides, and wherein the optical markings cause a predetermined modification of any light rays impinging on the optical markings by either diffraction or refraction, include a erasing device adapted to be located on one major side of the carrier, for erasing or changing the markings, a reading device, operative during operation of the erasure device, and including at least two light sensors adapted to be located on the other major side of the carrier, so as to check the erasure or change of the markings effected by the erasing device. The light sensors provide output signals of respective opposite polarities following erasure or change of any one of the markings.

Abstract: A holographic scanning system for scanning bar code indicia is disclosed in which the light beam of a laser is directed to a first set of holograms located on a single rotating disc in which each hologram will generate an individual scan beam having a slightly different focal length and direction angle from that of the other holograms. The generated scanning beams are directed on a target area through which passes a label or object bearing a bar code indicia. Each of the scan beams is projected in an overlapping relationship on the target area, thereby providing an enhanced depth of focus enabling a more effective reading operation. The light reflected from the bar code indicia is picked up by a second set of holograms mounted on the rotating disc and focused at a point at which is located an optical detector for use in reading the bar code.

Abstract: A holographic scanning system for scanning a bar code indicia is disclosed in which the light beam of a laser is split into two segments, each directed through a plurality of holograms mounted on a single rotating disk for generating a scanning pattern comprising a plurality of intersecting lines on a target area through which passes a label or object bearing a bar code indicia. The light reflected from the bar code indicia is picked up by an optical detector for use in reading the bar code. A second embodiment includes a rotating disk having mounted thereon two holograms each offset to the other which generates a semicircular scan pattern used in generating an X scan pattern on the target area.

Abstract: An identification card with a holographic security safeguard in the form of a large area Lippmann-Bragg hologram recorded on a layer or sheet-like carrier disposed on a face of the identification card, capable of being read out without the use of laser light, employing merely normal light sources which produce incoherent light, whereby an image can be observed with the naked eye, and which can contain both binary and analog information, comparable, for example, with printed and other information contained on the identification card; and a method of producing such a card.

Abstract: The contents of a book, magazine or the like are digitally encoded onto a memory, and the memory is removably insertable into a portable book-like apparatus whereby the encoded information can be displayed on a screen of the apparatus.

Abstract: This invention describes a system for access control, wherein a control card is presented to a control means. If the control card is authenticated, then access is gained. If it is not authenticated, access is not gained, the control card is retained, and an alarm may be sounded.The control card contains at least two means; (1) machine readable indicia identifying the card, and (2) a random pattern of micro spots, which pattern is derived (by direct copying--such as by focussed laser beam) from one of a plurality of different patterns, retained in a bank of such micro patterns, each such micro pattern identified by, and selectable in accordance with, different unique indicia, identical with the machine readable indicia on said cards.In use the control card is introduced into the control means and the indicia are read. Master micro pattern corresponding to the indicia is selected from the bank. The card micro pattern and master micro pattern are compared. If the comparison okay, the card is authenticated.

Abstract: There is described a method of producing a document coded with machine-readable information, said document having an information carrier with a multiplicity of storage positions, wherein selected storage positions are occupied by respective machine-readable optical markings, which markings cause a predetermined modification of incident light; the geometrical position of the markings on the information carrier represents coded information. In the method disclosed, such an optical marking is introduced into each storage position, and subsequently, selected optical markings are cancelled or altered. Also described are documents coded by means of the disclosed method, as well as a device for cancelling or altering the optical markings.

Abstract: A token for use in a vending machine consists of a plastic card having at least one pair of side-by-side holograms embossed thereon. A token reader includes means to guide a token into the path of a readout beam. When two photodetectors positioned at predetermined spaced locations receive equal-amplitude first order beams from an illuminated pair of holograms, an electrically-operated plunger in the token reader operates to obliterate the pair of holograms on the token, and then a signal from a third photodetector in the token reader enables an output signal for operating the vending machine.