Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/20—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof characterised by a particular use or purpose
  • B42D25/29—Securities; Bank notes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M3/00—Printing processes to produce particular kinds of printed work, e.g. patterns
  • B41M3/14—Security printing
  • B41M3/144—Security printing using fluorescent, luminescent or iridescent effects

Definitions

• the invention relates to a value and / or security document of the type of the independent claim.
• Such documents are special Postage stamps on letters, parcels and other packaging in the Mail sorting machines are isolated. The one when separating and sorting Achieved, high speeds have so far verified the authenticity of the Postage stamp prevented.
• value and / or Security documents banknotes, ID cards, passports, packaging, labels and Stickers, tickets, tickets and other tickets, tax signs as well To understand stocks.
• the following Disclosure all printable and otherwise with security features foreseeable products, such as packaging, as value and / or Viewed security documents.
• up-conversion elements (hereinafter referred to as up-conversion elements or UC elements) were first published in 1974 by MALMBERG et al. mentioned in a priority Swedish application (corresponding to DE 2 547 768). However, high-speed verification at speeds such as are customary nowadays with mail sorting machines was not possible.
• the invention provides that the UC-active security elements during the Printing process applied directly to the surface of the substrate become.
• the value and / or security document according to the invention with the features of the independent claim has the advantage that the authenticity of such value and / or Security documents can be machine-verified. Furthermore it is advantageous that the speed of such verification is so high can be chosen that a large number of value and / or Security documents can be verified in a short time. Also advantageous is to choose small particle sizes of the pigments, as this is a better one Miscibility with other components of the value document is possible. They therefore allow the design of different security printing motifs and their high-speed verification by means of NIR light excitation and Detection of the emission bands in different wavelength ranges.
• the value and / or security document according to the invention with anti-Stokes phosphors have the further advantage that the response and decay behavior of the Anti-Stokes phosphor is adjustable so that automatic verification with the UC phosphor (up-conversion phosphor, other name for Anti-Stokes phosphor) as a security feature Security document is possible. It is particularly necessary that Verification can achieve high speeds. The arrival and For this, the decay behavior must depend on both the pulse frequency of the laser and in Be optimizable with respect to detectable intensities of the emitted radiation.
• Another advantage is that the intensity ratios between the individual emission line groups of the anti-Stokes phosphor can be varied.
• the Yb and Tm concentrations for high readout speeds are selected within the following limits: (Gd 1-xy ) 2 O 2 S: Yb x , Tmy with 0.05 ⁇ x ⁇ 0.80 and 0.0001 ⁇ y ⁇ 0.10, and advantageous for reading speeds between 3 and 6 m / s with: 0 20 ⁇ x ⁇ 0.60 and 0.0001 ⁇ y ⁇ 0.05.
• Such an anti-Stokes luminophore for a security document has a quick verification by means of pulsed Laser matched optimal effective intensity.
• the luminescent security feature is preferably made up of individual ones Dots and lines designed graphically.
• the anti-Stokes phosphor used is a thulium-activated and ytterbium-codotated gadolinium oxysulfide of the composition (Gd 1-xy Yb x Tm x ) 2 O 2 S or also (other spelling) (Gd 1-xy ) 2 O 2 S: Yb x , Tm y where, instead of the gadolinium, at least some of the yttrium and / or lanthanum can also be used as the basic grid (host grid, matrix) material.
• the phosphor is able to convert comparatively low-energy infrared (IR) excitation radiation into higher-energy radiation (up-conversion or anti-Stokes effect). (Up-conversion is abbreviated below by UC.)
• IR infrared
• UC anti-Stokes effect
• the emission spectrum of the phosphor shows linear emissions after laser excitation.
• the observed emission lines correspond to the known transitions between the different excitation levels of the Tm 3+ ions and the corresponding ground state.
• the intensity relationships between the individual line groups can vary; they depend on the specific phosphor composition, in particular on the ytterbium or thulium concentration.
• the up-conversion elements are in the form of small ones inorganic particles smaller than 5 ⁇ m, in particular smaller than 3 ⁇ m and in particular smaller than 2 ⁇ m can be used.
• the response and decay characteristics of the Anti-Stokes phosphor used to a high degree over the achievable Detection reliability and the possible readout speed of a machine luminescence feature to be tested can e.g. through the Time required to reach the 90% saturation intensity is or by the so-called attack constant (duration for the Reaching 1 / e-th of the stationary luminescence intensity) marked become.
• the response time of the anti-Stokes luminescence is allowed not exceed a certain value if one is above the Sensitivity threshold of the detector lies effective luminescence intensity should be secured.
• This effective value of the intensity is determined by the relation determined between the stationary intensity and the response time.
• the relationships between the saturation intensity and the rise and fall times can be varied within a wide range.
• the ytterbium and / or thulium concentrations are set so that the interactions between these ions already lead to a partial quenching of the anti-Stokes luminescence (quenching of the concentration).
• the anti-Stokes phosphor's response and decay behavior can be set so that an automatic verification of the the anti-Stokes phosphor as a security feature Security document is possible. It is particularly necessary that Verification can achieve high speeds.
• the arrival and For this, the decay behavior must depend on both the pulse frequency of the laser and in Be optimizable with respect to detectable intensities of the emitted radiation.
• the high-speed verification is preferably carried out by the Measurement of the anti-Stokes emission spectrum in the visible and not visible wavelength range through non-contact measurement.
• the Intensity ratios of the emission bands and the approach and. Cooldowns are dependent parameters, so the fluorescent substance can be checked for authenticity.
• Any print motifs can be produced and the up-conversion is included Elements in at least one of the printing inks in the form of small inorganic Particles incorporated.
• the body colors of the printing inks are in shape with the up-conversion elements of inorganic particles can be designed as desired and are only slightly affected by influences the admixture of the inorganic particles.
• the up-conversion elements are in shape of inorganic particles in the substrate of value and / or Security document integrated and / or in the near-surface area of a such substrates in the form of brushing, coating, spraying, spinning, Dipping, laminating, extruding surface coating, etc. incorporated.
• One with anti-Stokes luminophores provided layer can also be a layer of at least one other layer is covered. It is important here that a Layer covering the layer provided with anti-Stokes luminophores, at least for the stimulating electromagnetic radiation and for the emitted one electromagnetic radiation is permeable. You can do this in a first Embodiment layers come into question that have a broadband Have permeability. In another embodiment, you can also Foils are used that are only used for electromagnetic radiation certain, predetermined wavelength ranges are transparent.
• the packing density i.e. the area coverage
• the anti-Stokes luminophores should be chosen so that at least one anti-Stokes luminophore in one Area of the size of the measurement window is present, with the area coverage is largely determined by the printing process and the printed motif.
• Excitation density is a high degree of area coverage and a comparative one Large layer thickness is an advantage.
• the excitation density is largely determined by Coverage and less by increasing the UC pigment concentration in the Color determines.
• the cover is made up of the two-dimensional Parameter area coverage and the three-dimensional parameter Layer thickness of the paint, varnish or coating together.
• the Coverage i.e. the area coverage and the layer thickness are thereby largely determined by the printing process used.
• the area coverage necessary for the later detection is included not necessarily by increasing the pigment concentration in the color compensated.
• adding the anti-Stokes luminophore to a color further important that the color components are not the emitted and electromagnetic radiation to be subsequently detected is noteworthy absorbed. If, for example, the visible radiation is detected, may not contain any color components that the visible radiation in the absorb significant wavelength range of interest. This applies analogously of course also for invisible electromagnetic radiation to be detected.
• the up-conversion elements are in the form of inorganic particles especially in the case of postage stamps in the Adhesive coating or rubber glue installed and can by means of Laser beam excitation can be excited through the paper substrate. As a result, the anti-Stokes emission can pass through the paper substrate be verified.
• the printing inks with the anti-Stokes luminophores are produced in such a way that first of all from the anti-Stokes luminophores and the printing process adapted varnishes a paste is generated.
• This paste is then in so-called three-roller color grinders together with the other components the colors such as color pigments, additives, auxiliary substances etc. to the actual colors processed (flat, high and low pressure).
• the pigment can also over Homogenization in the paint grinder can be incorporated directly into the paint.
• the pigments are used in the corresponding process steps incorporated as an additional additive (example: Cellulose pulp plus pigment for papers doped with UC pigments).

Landscapes

• Business, Economics & Management (AREA)
• Accounting & Taxation (AREA)
• Finance (AREA)
• Luminescent Compositions (AREA)
• Credit Cards Or The Like (AREA)
• Inspection Of Paper Currency And Valuable Securities (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)
• Printing Methods (AREA)
• Conversion Of X-Rays Into Visible Images (AREA)

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Citations (1)

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• 2001
  • 2001-03-16 DE DE10113266A patent/DE10113266B4/de not_active Expired - Lifetime
• 2002
  • 2002-03-06 EP EP02005017A patent/EP1241021B1/fr not_active Expired - Lifetime
  • 2002-03-06 AT AT02005017T patent/ATE531527T1/de active

Patent Citations (1)

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