| 摘要 |
The invention relates to a marking device (1) for a value or security document (2) and to a method for the permanent, in particular distinct, multicolored marking of value and/or security documents (2). The method for the permanent colored marking of a value or security document (2) comprises the following steps: providing a document body (40) which comprises regions having different colors, wherein each of the individual regions is single-colored; providing a marking device which comprises at least one laser light source (5) for generating laser light (6) and a light guide device (8, 8') which is coupled to the at least one laser light source (5) such that a focus (19) of the laser light (6) of the laser light source (5) can be positioned in a controlled manner on or in the document body (40) of the value or security document (2); iteratively deliberately positioning the focus (19) on or in the document body (40) and irradiating the laser light (6') in order to deliberately change the color of one or more regions locally so that subsequently the document body (40) conveys a multicolored color effect to a human observer when irradiated with white light, wherein the laser light (6) is irradiated by means of short or ultrashort laser pulses which have a pulse duration of less than 100 ps or less than 10 ps. As a result, non-linear interactions between the material of the value or security document (2) and the laser light (6') can be utilized for marking. In this way, improved focusing of the laser light (6'), and consequently a higher density of the colored markings establishing the color, can be utilized or produced, so that higher color intensity can be implemented. |
