Method for checking a value document, value document, use thereof, and value document system
A method for checking the authenticity and/or the nominal value of a value document having luminescent feature substances, comprises: a1) the step of carrying out a location-specific measurement of first luminescence intensities (L1) at a first emission wavelength at different locations of the value document that have the location coordinates (O), to thereby obtain (O/L1) measurement value pairs; b1) the step of statistically analyzing the first luminescence intensities (L1) measured in dependence on the individual location coordinates (O), by determining at least one statistical parameter using a statistical method; and c1) the step of comparing the statistical parameter determined in the step b1) with one or more threshold values.
1. A value document wherein:
the value document has first luminescent particles which emit at a first emission wavelength;
the first luminescent particles having at least two mutually delimited, certain sizes; and
the first luminescent particles are present in the value document in homogeneous spatial distribution;
wherein the at least two mutually delimited, certain sizes are produced by a mixture of smaller particles and larger single crystals, or are produced by a mixture of smaller particles and larger particles, and the larger particles are luminescent, particulate agglomerates of a solid homogeneous phase of a luminophore, and
wherein at least a part of the first luminescent particles are overprinted.
2. The value document according to claim 1 , wherein the at least two mutually delimited, certain sizes of the first luminescent particles are configured to form a bimodal size distribution in a histogram plotting grain size distribution, wherein one maximum is one and a half to 50 times greater with regard to its grain size than the other maximum.
3. The value document according to claim 1 , wherein the grain size (D99) of the luminescent particles is smaller than 30 μm.