Methods and devices for testing the colour fastness of imprinted objects
First Claim
1. A method for testing the authenticity of printed objects by measuring light emanating from an object (10) to be checked in at least two defined spectral regions, wherein the object (10) to be checked is irradiated with light having a spectrum with components in the defined spectral regions, light emanating from at least one place on the object (10) to be checked is detected in the defined spectral regions, and authenticity testing is effected on the basis of the light detected in a first spectral region and the light detected in a second spectral region, characterized in that the spectral regions where light emanating from at least one place on the object (10) to be checked is detected are outside the visible spectral region.
2 Assignments
0 Petitions
Accused Products
Abstract
The invention relates to methods and apparatuses for testing the authenticity of objects printed with security ink, for example bank notes, security documents, identification documents or documents of value, by measuring light emanating from, in particular reflected or transmitted by, an object to be checked.
To guarantee especially reliable authenticity testing it is provided that light emanating from the object to be checked is detected in spectral regions outside the visible spectral region.
To obtain easily operated and safe authenticity testing in addition, it is provided that light emanating from the object is detected at a plurality of places on the object in at least two selected spectral regions, a test series being produced for each spectral region, two test series adapted to each other, and authenticity testing then performed by comparing the adapted two test series.
An especially compact, easily operated and easily adjusted apparatus is characterized in that at least one diaphragm is provided between object and detector for adjusting the size of an area to be examined on the object.
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Citations
23 Claims
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1. A method for testing the authenticity of printed objects by measuring light emanating from an object (10) to be checked in at least two defined spectral regions, wherein
the object (10) to be checked is irradiated with light having a spectrum with components in the defined spectral regions, light emanating from at least one place on the object (10) to be checked is detected in the defined spectral regions, and authenticity testing is effected on the basis of the light detected in a first spectral region and the light detected in a second spectral region, characterized in that the spectral regions where light emanating from at least one place on the object (10) to be checked is detected are outside the visible spectral region.
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4. A method for testing the authenticity of printed objects by measuring light emanating from an object (10) to be checked in at least two defined spectral regions, wherein
the object (10) to be checked is irradiated with light having a spectrum with components in the defined spectral regions, light emanating from the object (10) to be checked is detected in the defined spectral regions, and authenticity testing is effected on the basis of the light detected in the defined spectral regions, characterized in that detection of light emanating from the object (10) is effected at a plurality of places on the object (10) so that a test series (I1, I2) is produced from individual measured values for each defined spectral region, a first (I1) and second (I2) test series are adapted to each other by determining from the measured values of the first test series (I1) values of an adapted series (I′ -
1) that deviate only slightly from the values of the second test series (I2) in at least one area (B) where the two test series (I1, I2) have substantially an identical qualitative course, and
authenticity testing is effected by comparing the adapted test series (I′
1, I2). - View Dependent Claims (5, 6, 7, 8, 9)
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1) that deviate only slightly from the values of the second test series (I2) in at least one area (B) where the two test series (I1, I2) have substantially an identical qualitative course, and
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10. An apparatus for testing the authenticity of printed objects by measuring light emanating from a object (10) to be checked in at least two defined spectral regions having
at least one light source (12) for irradiating the object (10) with light having components in the defined spectral regions, and at least one detector (13) for detecting light emanating from the object (10), the detector (13) having detection units (14) each sensitive in one of the defined spectral regions, characterized in that the defined spectral regions in which the detection units (14) are sensitive are outside the visible spectral region.
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18. An apparatus for testing the authenticity of printed objects by measuring light emanating from an object (10) to be checked in at least two defined spectral regions having
at least one light source (12) for irradiating the object (10) with light having components in the defined spectral regions, and at least one detector (13) for detecting light emanating from the object (10), characterized in that at least one diaphragm (15) is provided between object (10) and detector (13) for adjusting the size of an area to be measured on the object (10) from which light emanating from the object (10) is detected by the detector (13).
Specification