EP1540570A2 - Systeme anticontrefa on a motif magnetique structure - Google Patents

Systeme anticontrefa on a motif magnetique structure

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Publication number
EP1540570A2
EP1540570A2 EP03767169A EP03767169A EP1540570A2 EP 1540570 A2 EP1540570 A2 EP 1540570A2 EP 03767169 A EP03767169 A EP 03767169A EP 03767169 A EP03767169 A EP 03767169A EP 1540570 A2 EP1540570 A2 EP 1540570A2
Authority
EP
European Patent Office
Prior art keywords
magnetic
pattern
predetermined
magnetic material
character
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP03767169A
Other languages
German (de)
English (en)
Inventor
Stephen P. Mcgrew
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Verification Security Corp
Original Assignee
Verification Security Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Verification Security Corp filed Critical Verification Security Corp
Publication of EP1540570A2 publication Critical patent/EP1540570A2/fr
Withdrawn legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/14—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation using light without selection of wavelength, e.g. sensing reflected white light
    • G06K7/1404—Methods for optical code recognition
    • G06K7/1408—Methods for optical code recognition the method being specifically adapted for the type of code
    • G06K7/1417—2D bar codes
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07D—HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
    • G07D7/00—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency
    • G07D7/004—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency using digital security elements, e.g. information coded on a magnetic thread or strip
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
    • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
    • G06K19/06187—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code with magnetically detectable marking
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
    • G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
    • G06K19/08—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code using markings of different kinds or more than one marking of the same kind in the same record carrier, e.g. one marking being sensed by optical and the other by magnetic means
    • G06K19/10—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code using markings of different kinds or more than one marking of the same kind in the same record carrier, e.g. one marking being sensed by optical and the other by magnetic means at least one kind of marking being used for authentication, e.g. of credit or identity cards
    • G06K19/12—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code using markings of different kinds or more than one marking of the same kind in the same record carrier, e.g. one marking being sensed by optical and the other by magnetic means at least one kind of marking being used for authentication, e.g. of credit or identity cards the marking being sensed by magnetic means
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/08—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes
    • G06K7/082—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes using inductive or magnetic sensors
    • G06K7/087—Methods or arrangements for sensing record carriers, e.g. for reading patterns by means detecting the change of an electrostatic or magnetic field, e.g. by detecting change of capacitance between electrodes using inductive or magnetic sensors flux-sensitive, e.g. magnetic, detectors
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07D—HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
    • G07D7/00—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency
    • G07D7/04—Testing magnetic properties of the materials thereof, e.g. by detection of magnetic imprint

Definitions

  • Prior magnetic security and data encoding systems include MICR (Magnetic Ink Character Recognition) systems, magnetic bar codes, "macro-noise” and remanent noise systems, and “Flying Null” magnetic barcode systems.
  • MICR Magnetic Ink Character Recognition
  • magnetic bar codes magnetic bar codes
  • macro-noise and remanent noise systems
  • Felying Null magnetic barcode systems.
  • Micro- noise is noise caused by nonuniformities in the substrate and in the distribution of magnetic properties within the magnetic medium, and is often characterized by repeatably random variations on a spatial scale on the order of several microns or greater.
  • “Flying Null” is the name of a British company and the company's technology.
  • the Flying Null technology uses a soft magnetic medium coated in a pattern on a plastic film substrate, and reads the pattern by moving the null magnetic field region between two opposed magnetic poles across the medium and detecting the resulting switching of the magnetization of the medium as the null moves over it.
  • U.S. Patent No. USO4,806,740 by Gold, et al. describes a magnetic anticounterfeit system using a long stripe of magnetic medium printed on a document.
  • Nonuniformities in the magnetic medium due to scratches, substrate nonuniformities, or intentional nonuniform deposition of the magnetic medium provide a "repeatably sensible” random pattern.
  • a standard magnetic read head scans the stripe to extract a "repeatably sensible random” signal: a signal that is always the same every time the stripe is read, but is uncontrolled and for all practical purposes random and distinct for every such stripe.
  • the "repeatably sensible random” signal is effectively a unique fingerprint for every stripe and can be used in conjunction with a database or encrypted description to confirm the validity of a document.
  • Indeck's technique makes use of "repeatably sensible” noise, but whereas Gold's technique depends on nonuniformities having a spatial scale substantially larger than the size of the magnetic particles in the medium, Indeck's technique depends on nonuniformities having a spatial scale essentially equal to the size of the magnetic particles in the medium.
  • Figure 1 is a suitable "MagDot” or binary magnetic pixel array.
  • Figure 2 is a MagDot consisting of a single column of magnetic pixels.
  • Figure 3 is a response of a magnetic read head to an isolated column of magnetic pixels such as the MagDot in Figure 2.
  • Figure 4 is a computerized image of an enlarged microphotograph of an actual printed MagDot.
  • Figure 5 is a gray-scale MagDot (halftone magnetic pixel array).
  • Figure 6a is a MagDot with distinct columns separated by gaps.
  • Figure 6b is a plot of the vertical density function of the MagDot represented in Figure 6a.
  • Figure 7 is a signal due to the MagDot of Figure 1.
  • Figure 8 is a signal due to the MagDot of Figure 6a.
  • Figures 9a, 9b, and 9c are a MICR character "3" and two MagDots designed to produce a signal that mimics the signal from the MICR character "3".
  • Figure 10a is a vector graphic version of a MagDot.
  • Figure 11 is a diagram of a process for authenticating a document.
  • Figure 12 is a MagDot applied to the back of a holographic hot stamping foil.
  • Figure 13 is a diagram of a process for decoding a MagDot to extract encoded information.
  • Figure 14 is a document bearing a MagDot.
  • Figure 15a is a MagDot having independent information encoded in two orthogonal directions.
  • Figure 15b is a plot of the vertical density function of the MagDot of Figure 15a.
  • Figure 15c is a plot of the horizontal density function of the MagDot of Figure 15a.
  • Figure 16 is a representation of a process for reading a MagDot having independent information encoded in two orthogonal directions.
  • Figure 17 is an apparatus for reading a MagDot multiple times using a read head having multiple orientations.
  • Figure 18 is a diagram of a MagDot reader system which may include read heads in addition to a MagDot read head.
  • Figure 19 is a diagram of a MagDot security system that employs random or custom fonts that mimic MICR fonts.
  • Figure 20 is a tamper-evident seal comprising a substrate with patterned adhesion properties, a layer of magnetic material, and an overlayer with patterned adhesion properties.
  • Figure 21 is a tamper-evident seal comprising a substrate having spatially varying magnetic properties, a non-resealable adhesive layer, and an irreversibly stretchable overlayer.
  • Figure 22 is a hot-stamping die bearing bumps for applying a MagDot in the form of a magnetic material patch having an array of pits.
  • a non-random process is used to deposit magnetic material in an intricate, repeatable pattern.
  • a laser printer is used to print a high-resolution array of pixels using a magnetic toner, and the array of pixels is designed using an algorithm such that the pixel pattern encodes a particular character string or represents a pseudo-random number string.
  • a standard magnetic read head such as a MICR read head is used to scan the pattern.
  • a pattern of this type is herein generally referred to by the term, "MagDot”. Indeed, the term “MagDot” refers to any structured magnetic pattern disclosed herein, and equivalents and alternatives thereof.
  • the anticounterfeit effectiveness of embodiments of the present invention is due to at least three facts: 1 ) the fact that every printing press or laser printer prints
  • the anticounterfeit effectiveness depends on the extreme difficulty of copying small-scale patterns generated by an uncontrolled, random process.
  • the pattern resides in the spatially varying particle density in a magnetic medium
  • the pattern resides in the varying characteristics of individual particles and in their spatially varying average orientation. No information is recorded in the patterns, though the patterns are individually distinguishable.
  • a laser printer with magnetic toner such as an HP-1100 Laserjet with MICR toner, is used to print a high- resolution binary pixel pattern on a document.
  • the document may be an event ticket as illustrated in Figure 14.
  • the document may contain, for example, a graphic design 1422, a date 1420, a substrate 1424, variable information 1426 and 1428, a barcode 1432 and a MagDot 1430.
  • An example of an appropriate binary pixel pattern is illustrated in Figure 1.
  • the pattern 110 illustrated in Figure 1 is a filled rectangle 1/8 inch square. It has a solid line boundary 105 one pixel wide, and a pattern of black and white pixels e.g. 100 serving as the fill pattern.
  • the pixel resolution is 600 dots per inch.
  • the number of black pixels in each column and row varies according to a predetermined algorithm.
  • the number of black pixels in a column will be referred to as the vertical density of that column, and the ordered list of vertical densities corresponding to an ordered list of the columns will be referred to as the vertical density function.
  • a signal is produced that corresponds approximately to a convolution of the vertical density function with the impulse response function of the read head and associated electronics. For example, a single isolated vertical column of pixels as illustrated in Figure 2
  • [31936-8001 /SL032160.064] -5- 8/4/03 produces a pair of spikes as illustrated in Figure 3: a positive spike 305 corresponding to the leading edge of the column, and a negative spike 330 corresponding to the trailing edge of the column, separated by a space 325 having an interval 320.
  • the x-axis 335 represents distance, while the y-axis 330 represents intensity or magnitude.
  • the height of the spikes corresponds to the vertical density of the column. If there is remanent noise due to the magnetic particles in the medium, or "macro" noise due to variations in magnetic medium density, it should appear in the form of repeatably readable fine structure 330 in the region between the two spikes.
  • a reader for MagDots can have the general structure diagrammed in Figure 18.
  • a magnet 1800 magnetizes the magnetic medium in the MagDot 1802, as the certificate 1804 bearing the MagDot passes under the magnetic read head 1806.
  • an analog signal 1808 is generated.
  • This signal may be amplified by amplifier 1830 and passed to an A/D convertor 1810, and optionally to a MICR processor 1812 as well.
  • the A/D convertor digitizes the analog signal 1808 for subsequent processing by signal processor 1812, to form an ordered list of numbers called a "vector"1832.
  • the signal processor 1812 can have any of several different alternative forms, such as a serial processor with CPU and memory, or such as a parallel processor such as a gate array or a high-speed DSP. Whatever its structure, the signal processor 1812 may perform any of several functions on the vector 1810, including correlation, vector distance measurement, comparison with a set of vectors stored in memory 1814, Fourier transformation, and/or filtering. By comparing the signal vector 1810 with pre-recorded vectors stored in memory within the reader or at a remote location, the reader may determine which pre-recorded vector the signal vector is most similar to, and determine that the signal vector is for practical purposes identical to the pre-recorded vector if the degree of similarity is high enough. Alternatively, the processor may compare the vector with shorter vectors to decode
  • the signal vector may be a string of shorter vectors, with each shorter vector selected from an alphabet of short vectors. Decoding the signal vector then amounts to determining which of the alphabet vectors is most similar to each such shorter vector in the signal vector string, and listing a representation of those alphabet vectors.
  • Figure 13 shows an example of a process or routine for decoding a MagDot, which may be represented in software.
  • aspects of the invention described herein may be stored or distributed on computer-readable media, including magnetic and optically readable and removable computer disks, hardwired or preprogrammed in chips (e.g., EEPROM semiconductor chips), as well as distributed electronically over the Internet or over other networks (including wireless networks).
  • chips e.g., EEPROM semiconductor chips
  • portions of the invention may reside on a server computer or a network of server computers, while other portions reside on a client computer or a network of client computers.
  • Data structures and transmission of data particular to aspects of the invention are also encompassed within the scope of the invention.
  • hardware platforms such as the disclosed printers and readers, are described herein, aspects of the invention are equally applicable to any data processing device such as a computer, or even nodes on a network having corresponding resource locators to identify such nodes.
  • Figure 13 illustrates a process for decoding a structured MagDot in which information is encoded in the pixel structure of the MagDot.
  • the process comprises reading the MagDot pattern from a document, deconvolving the resulting signal using a reader impulse response function, then comparing segments of the deconvolved signal to a library of structured MagDot signals. Deconvolution is not necessary, but it can be used to normalize the signal when it may be read by readers having different impulse response functions.
  • magDots can be applied to documents in conjunction with barcodes, MICR codes, holograms, fluorescent markings, and practically any other security features. Accordingly, in addition to reading the MagDot, the reader can include one or more other feature readers 1834 such as MICR decoder, a bar code read head, fluorescent taggant reader, hologram reader, RFID tag reader, two-dimensional imager (e.g., CCD or CMOS image sensor), and so forth.
  • MICR decoder e.g., a bar code read head
  • fluorescent taggant reader e.g., hologram reader
  • RFID tag reader e.g., RFID tag reader
  • two-dimensional imager e.g., CCD or CMOS image sensor
  • MagDots can be applied to any surface at all (not necessarily two dimensional documents or objects) and can be read as long as the substrate on which they are applied does not have magnetic properties that prevent proper functioning of a magnetic read head.
  • a MagDot may be used in an encryption system to provide, for example, a private or public encryption key or to store encrypted or scrambled information.
  • the predetermined distribution of magnetic particles produced by a printing process may be selected, for example, to represent specific information such as a serial number, or it may be selected to represent an effectively random number.
  • the MagDot pattern shown in Figure 1 produces a signal 700 having representative leading and trailing edges 720 and 740, and mid portions 710 and 730, as shown in Figure 7, when read using a high-resolution magnetic read head, although the detailed structure of the signal depends on the characteristics (e.g., impulse response) of the read head and its associated electronics. Typically, a narrower gap in the read head results in sharper, narrower spikes in Figure 3 and a more highly resolved signal.
  • the characteristic frequencies correspond to a spatial size of at least 1/1200 inch, or about 21 microns and larger.
  • Magnetic toner particles on the other hand, have a size in the range of 0.1 micron to 1 micron. Thus, "remanent noise" due to the size, shape and variable properties of the individual toner particles has little effect on the shape of the signal that characterizes the MagDot pattern.
  • the detailed shape of the signal in Figure 3 depends on the nature of the surface on which the pattern is printed, and on the interactions between the magnetic toner and the surface.
  • the pattern in Figure 1 is sharply defined in a computer artwork program such as Adobe Illustrator and appears on a computer screen as indicated in Figure 1 , the pattern has a
  • the MagDot represented by the mottled rectangular area in Figure 4 is in practice often only about 1/8 inch wide. Nonetheless, the same pattern of Figure 1 printed multiple times on the same paper produces a sufficiently repeatable signal that the printed patterns are easily recognized by a magnetic reader as representing the same ideal pattern. Nonetheless, if the MagDot patterns are printed at a resolution close to the limiting resolution of a laser printer, it is extremely difficult to make a passable copy of the MagDot pattern from a sample such as that of Figure 4.
  • a magnetic reader such as a check reader detects variations in the magnetic structure of a medium, and because the amplitude of the detected signal depends on the distance between the read head and the magnetic medium
  • one way to create a MagDot is to create a pattern of indentations or bumps on a smooth surface and then to apply a substantially uniform coating of magnetic medium over the surface.
  • the indentations or bumps can be created at the same time that the coating is applied.
  • a magnetic stripe foil may be applied by hot stamping onto a smooth plastic surface, using a hot stamping die 2200 such as that illustrated in Figure 22 that has indentations or bumps 2215 in its surface 2210.
  • the resulting MagDot has a structure corresponding to the pattern of indentations or bumps, and the structure will be nearly the same for every MagDot using that hot stamping die.
  • Different dies could of course produce different patterns, as well as a die having automatically adjustable bumps to automatically vary resulting indentations in a surface or foil.
  • any form of impact printing may be employed with magnetic foil or magnetic inks in this manner to produce MagDots.
  • the identity of a document may thus be determined by reading a MagDot pattern that has previously been printed on the document.
  • the MagDot may then be read and compared to a previously recorded representation of the MagDot signal stored in a database or printed on the document.
  • Figure 11 a procedure for authenticating a document using a MagDot and a reader is illustrated, from which software may be created.
  • the pixel pattern of Figure 5 uses halftone grey-scale pixels.
  • the resulting signal has all the same characteristics as those
  • the vertical density function and the corresponding signal have a significantly periodic nature as shown in Figure 6b, due to the regular spacing of the pixel columns whose vertical density is, e.g., shown in Figure 6b.
  • the periodic nature in this case can be used to provide a timing signal to correct for any variations in reading speed, or to correct for variations in column spacing, or it may be ignored.
  • a solid vertical border 600 provides sharp leading and trailing spikes in the signal, whereas a solid horizontal border 605 only provides a small leading and trailing spike.
  • magDot pattern of Figure 1 is rotated 90 degrees and read again, it produces as indicated in Figure 15 an entirely different signal from that of Figure 7 because there is no correlation between the number of pixels in a row (horizontal density) and the number of pixels in a column (vertical density). Therefore, the signals derived from reading a MagDot in two orthogonal directions are uncorrelated and unrelated.
  • magDots whose vertical density functions are identical but whose horizontal density functions are different, such as is indicated in Figure 15.
  • the vertical density function to correspond to a given application sub-category
  • different horizontal density functions to correspond to different documents within that application sub-category. So, if the magnetic pixels in any column in Figure 6a were redistributed vertically, the signal read by a vertical read head would be unchanged but the signal read after rotating the MagDot by 90 degrees would be different according to how the pixels had been rearranged.
  • Figure 16 illustrates the steps by which is it possible to extract independent horizontal and vertical information from a MagDot.
  • the MagDot is read in two
  • magDot signal can be read through a 25-micron polyester film overlaminate, through an opaque aluminized holographic hot stamping foil, or through opaque non-magnetic ink.
  • a MagDot behind an overlaminate, a region of hot stamping foil, or a region of non-magnetic ink.
  • a holographic hot stamping foil is illustrated, with a polyester substrate 1200, release coat 1210, embossed holographic layer 1215, adhesion interlayer 1220, MagDots 1225, and heat activated adhesive 1230.
  • the MagDot is read after overlamination, coating, overprinting or any other process that could change the structure of the MagDot.
  • other information may be recorded before any obscuring overlamination.
  • the overlamination may prohibit visual light inspection (such as by a person), but a bar code or other information may be recorded in infrared ink so that the bar code may be automatically read through the overlamination with a suitable reader.
  • FIG. 9a, 9b and 9c illustrates different magnetic ink patterns that produce signals identical to the signal from a MICR character "3".
  • Figure 9a is a standard MICR "3”.
  • Figure 9b all pixels have been dropped non-overlapping to the bottom of the pattern so that the number of pixels in each column is the same as in the "3" of Figure 9a, but there are no gaps between pixels in any column.
  • a two-dimensional bar code reader or a bar code reader that illuminates a document with a thin vertical line of light that moves horizontally, or moves the line relative to the document (a raster scanner) can optically measure the vertical pixel density function of a character in such a random font, and the pixel density function signal can then be processed in the same way that a MagDot signal or MICR signal would be processed.
  • Figure 19 illustrates one possible process for using random magnetic fonts as security markings.
  • a service provider generates the random fonts and distributes the fonts to customers in an electronic form such a computer program or a look-up table.
  • the customer uses the fonts to print identifying symbols on secure documents, and distributes the documents to end users.
  • the symbols are read as MagDots and interpreted by looking them up in a database.
  • FIG. 15 shows one possible way to implement a reader whose gap orientation can be varied for multiple reads of a MagDot.
  • the read head 1735 mounted on wheel 1730, driven by a stepping motor 1715 via drive chain 1725 reads the MagDot 1710 on a document 1705 that is moved through a guide slot 1745.
  • the MagDot can be read multiple times with the stepping motor 1715 rotated to a different orientation each time. If the effective resolution of the read head across the MagDot is N pixels, and if N scan readings are taken at different orientations of the read head, then sufficient information is acquired to provide a set
  • each scan produces the information for N equations. That is, each resolvable element of the signal in a scan amounts to a sum of the signals from each pixel in a column of magnetic pixels, and with each different orientation of the read head the set of pixels forming a column is different.
  • the directions of motion of the document 1755 are represented by double arrow 1700.
  • Directions of motion of the drive chain 1725 are represented by double arrow 1720.
  • any kind of magnetic medium that can be applied to a surface in a predetermined pattern may be used to make MagDots.
  • Ion-implantation printing, laser printing, photocopiers with magnetic toners (xerography), foil transfer printing, flexo printing, any form of ink jet employing magnetic ink, any form of thermo printing employing magnetic ink, as well as any electrophotography printing techniques (including direct and indirect non-optical electrophotography), any impact printing techniques (including dot matrix, daisy wheel, and the link), gravure printing and offset printing are among the printing processes that can apply magnetic media, but there are a large number of other processes with the potential of applying magnetic media such as selectively patterned thermal evaporation, sputtered magnetic coatings with patterned laser ablation, any of the various other semiconductor fabrication techniques, as well as silk screening.
  • mag is generally used as shorthand for "magnetic”
  • More exotic reading methods may be used as well, such as magneto- optic methods, magnetic scanning probe microscopes, or "Flying NullTM” type readers.
  • the orientation of the gap in a magnetic reading head relative to a MagDot is preferably consistent in order to get consistent readings of the MagDot pattern, but need not be vertical.
  • the columns need not be vertical and the rows need not be horizontal, and the gap need not be parallel to the columns nor perpendicular to the rows.
  • the pixels can be any shape, and they can have any spacing or size.
  • magDot signal When the MagDot signal is read by moving a MagDot relative to a magnetic read head, any speed variations in the motion will distort the signal and result in ambiguities when two such signals are compared, because the precise timing of features in the signal will be only approximately known.
  • a separate timing signal on magnetic media may be provided as a way to remove those ambiguities.
  • One embodiment of the present invention uses a MagDot whose vertical density function is modulated with a constant spatial period, such as by printing the MagDot as a set of vertical columns of magnetic ink pixels, in which the columns are evenly spaced but of varying vertical density. A MagDot made this way is illustrated in Figure 6, and the signal resulting from the MagDot is illustrated in Figure 8.
  • the signal has an easily observable, distinct periodicity corresponding to the spacing of the columns in the MagDot.
  • the resulting MagDot signal will have an easily detected periodicity, but any two MagDots made the same way will nonetheless produce signals with slight differences.
  • the periodicity of the signal can be used as a timing signal, while the variations between signals can be used to distinguish between nominally identical MagDots. This technique greatly simplifies the use of a hand- swipe reader for Mag Dot-protected cards or other documents.
  • the periodicity in a MagDot made this way can be detected optically or magnetically, but magnetic detection is preferred.
  • the timing signal does not need to be periodic. If a series of MagDots are printed as illustrated in Figure 6, all having the same particular distribution of pixels, their MagDot signals will all have the same general shape. Small-scale variations between the individual MagDots can be detected by matching the large-scale components of the MagDot signals to normalize the timing between them, and then measuring the small-scale (high-frequency) differences between the normalized signals.
  • a MagDot may be used to create a tamper-evident seal or label as indicated in Figure 20.
  • a magnetic material 2000 is applied to a substrate
  • An adhesive film 2010 is applied over the magnetic material.
  • Either the substrate 2000 or the adhesive film 2010 has a spatially varying adhesion characteristic, so that when the adhesive film is peeled off of the substrate, some of the magnetic material is removed with the adhesive film and some remains on the substrate. It is extremely difficult to replace the adhesive film on the substrate so that the original structure of the magnetic medium layer is restored; so removal and replacement are easily detected.
  • An alternative tamper-evident seal as illustrated in Figure 21 employs a substrate 2100 with its own spatially varying magnetic characteristics 2105.
  • An overlayer 2110 bearing magnetic material patterns 2115 is applied over the substrate and the magnetic signal is read and recorded. If the overlayer is removed and re-applied, it is virtually impossible to re-apply it in exactly the same position. Because the MagDot pattern detected by the reader will be a composite of the magnetic pattern of the MagDot and the spatially varying magnetic characteric of the underlying substrate, the removal and replacement of the seal can be detected easily by the change in the MagDot pattern.
  • the patterns need not be pixellated. Any predetermined, controllable pattern of magnetic material may be used, such as the vector graphic pattern in Figure 10a.
  • the pattern may be composed of complex regions, lines, curves, and shapes 1000, 1020 without identifiable pixels.
  • the MagDot patterns may be formed in continuous gray scales or in discrete gray scale steps or in binary black-and-white regions. For example, one way to make a MagDot pattern is to render a photograph as a halftone image laser-printed using magnetic toner as indicated in Figure 10b.
  • MagDot pattern Another way to make a MagDot pattern is to apply an edge-enhancing filter to a photograph (or process a photographic or digital or video image any other way), and render it as a gray scale or black-and-white image.
  • any MagDot it is preferred (though not necessary) to have boundaries 1010, such as boundaries on both left and right sides, to simplify the process of detecting and locating a MagDot on a document.
  • magDot In order to conceal or obscure a MagDot, other techniques than covering, overlaminating or broad overprinting may be used including filling some of the white regions in the pattern with non-magnetic ink, or overprinting with random or unrelated nonmagnetic ink patterns.
  • a hot stamping or cold foil with a magnetic medium coated on the back may be applied in a predetermined pattern to form a MagDot; and the MagDot pattern may be concealed by applying the magnetic medium in a predetermined pattern onto the hot stamping foil.
  • a marking in the form of a pattern of magnetic ink on the back of a hot stamping foil, with the foil applied to a document in a pattern substantially unrelated to the ink pattern, provides an anticounterfeit marking that is particularly difficult to copy.
  • magnetic material refers to any kind of magnetically detectable material, including ferromagnetic materials, paramagnetic materials, "soft” magnetic materials and “hard” magnetic materials. Further, the term “magnetic material” includes any material that is magnetized before or after fabrication; for example, a MagDot may be fabricated of a ferromagnetic material, but not be magnetized until some later time, such as after the MagDot has been applied to an object.

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  • Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Artificial Intelligence (AREA)
  • Computer Security & Cryptography (AREA)
  • Health & Medical Sciences (AREA)
  • Electromagnetism (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Credit Cards Or The Like (AREA)
  • Printing Methods (AREA)

Abstract

L'invention concerne un système et un procédé associé permettant de marquer une matière destinée à être appliquée sur des marchandises. Dans une forme de réalisation, une matière magnétique est appliquée selon un motif prédéterminé. Une accumulation de matière magnétique dans une orientation dans le motif structuré peut fournir une valeur détectable automatiquement. La matière pouvant être lue magnétiquement peut être sous la forme d'un motif répétable prédéterminé ; la matière magnétique est appliquée sur une surface de manière à obtenir une résolution comprise entre au moins 100 et 10000 points par pouce.
EP03767169A 2002-08-05 2003-08-04 Systeme anticontrefa on a motif magnetique structure Withdrawn EP1540570A2 (fr)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
US40140402P 2002-08-05 2002-08-05
US401404P 2002-08-05
US46627103P 2003-04-28 2003-04-28
US466271P 2003-04-28
PCT/US2003/024389 WO2004013735A2 (fr) 2002-08-05 2003-08-04 Systeme anticontrefaçon a motif magnetique structure

Publications (1)

Publication Number Publication Date
EP1540570A2 true EP1540570A2 (fr) 2005-06-15

Family

ID=31498681

Family Applications (1)

Application Number Title Priority Date Filing Date
EP03767169A Withdrawn EP1540570A2 (fr) 2002-08-05 2003-08-04 Systeme anticontrefa on a motif magnetique structure

Country Status (3)

Country Link
EP (1) EP1540570A2 (fr)
AU (1) AU2003261365A1 (fr)
WO (1) WO2004013735A2 (fr)

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CN106156672A (zh) * 2015-04-22 2016-11-23 上海天臣防伪技术股份有限公司 对含有磁性材料的防伪标识进行防伪识别的方法

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US7891567B2 (en) 2005-01-19 2011-02-22 Agency For Science, Technology And Research Identification tag, object adapted to be identified, and related methods, devices, and systems
CA2684789A1 (fr) 2007-04-24 2008-10-30 Sicpa Holding Sa Procede de marquage d'un document ou article; procede et dispositif pour identifier le document ou article marque; utilisation de particules de polarisation circulaire
EP2248067B1 (fr) * 2008-02-19 2020-03-25 Bilcare Technologies Singapore Pte. Ltd. Dispositif de lecture destiné à identifier une étiquette ou un objet prévu pour être identifié, procédés et systèmes apparentés
IES20110196A2 (en) * 2010-04-20 2011-11-09 Limerick Inst Of Technology Improvements in and relating to a sheet orientation detection system
AT513243A1 (de) 2012-06-18 2014-02-15 Thomas Dipl Ing Fh Dipl Ing Weiss Verfahren bzw. System zur eindeutigen Kennzeichnung eines Objekts
CN104123526A (zh) * 2014-07-25 2014-10-29 无锡乐尔科技有限公司 磁性防伪***和方法
DE102017202628B4 (de) 2017-02-17 2022-03-17 Trumpf Werkzeugmaschinen Gmbh + Co. Kg Verfahren zum Kodieren eines plattenartigen Werkstücks, Verfahren zum Identifizieren eines plattenartigen Werkstücks, Strahlungsbearbeitungsvorrichtung und Kodiersystem

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US5545885A (en) * 1992-06-01 1996-08-13 Eastman Kodak Company Method and apparatus for detecting and identifying coded magnetic patterns on genuine articles such as bank notes
TR199901293T2 (en) * 1996-12-12 2000-02-21 N.V. Bekaert S.A. Evraklar�n tan�nmas� ve kontrol�

Non-Patent Citations (1)

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Title
See references of WO2004013735A2 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106156672A (zh) * 2015-04-22 2016-11-23 上海天臣防伪技术股份有限公司 对含有磁性材料的防伪标识进行防伪识别的方法
CN106156672B (zh) * 2015-04-22 2018-09-18 上海天臣防伪技术股份有限公司 对含有磁性材料的防伪标识进行防伪识别的方法

Also Published As

Publication number Publication date
AU2003261365A1 (en) 2004-02-23
WO2004013735A3 (fr) 2004-04-08
AU2003261365A8 (en) 2004-02-23
WO2004013735A2 (fr) 2004-02-12

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