Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/08—Photoprinting; Processes and means for preventing photoprinting
• • 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
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G21/00—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge
  • G03G21/04—Preventing copies being made of an original
  • G03G21/043—Preventing copies being made of an original by using an original which is not reproducible or only reproducible with a different appearence, e.g. originals with a photochromic layer or a colour background

Definitions

• the invention relates to a method for recognizing copies which are produced by means of a color copier of documents.
• DE-B 29 08 742 is concerned with the protection against forgery of documents which are copied by means of light-sensitive emulsions. It is assumed that the document will be printed with two colors that have the same reflectance in white light within the human visibility limit and thus appear in the same color. Outside the human visibility limit, however, one color has a steep increase in reflectance. If such a document is reproduced, there is a color shift of the one color in the copy. However, this is only possible if the subtraction color mixing process is used and the reproduction colors do not evenly cover the associated wavebands.
• a fluorescent film on a document is to be used to prevent the image on the document and under the film from appearing on the copy.
• the film absorbs part of the light from the light source of the copier up to a certain wavelength.
• the light above this Wavelength penetrates the layer and is absorbed by the image and reflected by the background. This contrast, however, is not perceived by the copier, since the layer reflects the absorbed light with a longer wavelength.
• a fluorescent material is applied to a support and the lacquer is covered with a high-gloss finish, so that the material is not recognizable in normal light, but can be recognized by UV radiation.
• a marking made of a fluorescent material is applied to the document, which emits visible light when irradiated with an IR radiation source, which light is detected by a detector, whereby a copying process can be interrupted.
• the task is to design the method in such a way that the color copies produced can be clearly distinguished from the originals.
• Both the paper or the cardboard and the printing process must therefore not be expensive.
• the second requirement is to be able to check the authenticity of these notes by mere visual inspection, preferably without the inspector holding the notes in hand must take.
• two colors of the same hue are used, one of which is fluorescent and the other non-fluorescent.
• the print on the original shows a uniform color in normal light, but the non-fluorescent color appears duller.
• the fluorescent color is falsified and also rendered dull and contrasts in color with the other color that has not been falsified copied.
• the non-fluorescent color having a hue which corresponds to the color tone of the fluorescent color which was falsified when copied.
• the original thus has different shades, one of which is dull, while the copy appears in a uniform dull shade.
• the method is particularly suitable if the documents are, for example, tickets that are checked by controllers and in which the color copies can be distinguished from the original tickets by a significantly different color.
• the color differences between the document and the color copies can be seen from afar.
• the effect of a fluorescent color is used to absorb light up to a certain wavelength and in a longer world reflect length.
• orange or yellow-orange are used as fluorescent offset colors, then these colors are reproduced on the color copy in light to medium brown color. If the fluorescent offset color is the color red, then this red appears on the copy in the color red-brown. If the fluorescent offset color is pink, then this color appears in the color copy in magenta. However, the non-fluorescent colors orange or yellow-orange, red and pink appear correct on the copy.
• a fluorescent color and a non-fluorescent color with different hues in the document, wherein the non-fluorescent color has a hue that corresponds to the distorted hue of the fluorescent color in the copy.
• the document therefore does not have a uniform color tone, while a uniform color tone is reproduced on the color copy.
• Preferred color combinations are fluorescent orange or yellow-orange and non-fluorescent medium brown, fluorescent red and non-fluorescent red-brown as well as fluorescent pink and non-fluorescent magenta.

Applications Claiming Priority (2)

Publications (3)

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ID=6393928

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Cited By (9)

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Citations (1)

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• 1989
  • 1989-11-21 DE DE3938603A patent/DE3938603A1/de not_active Withdrawn
• 1990
  • 1990-08-03 EP EP90114925A patent/EP0428828B1/fr not_active Revoked
  • 1990-08-03 DE DE59006135T patent/DE59006135D1/de not_active Revoked
  • 1990-08-03 AT AT90114925T patent/ATE107234T1/de not_active IP Right Cessation

Patent Citations (1)

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