Giesecke & Devrient Gmbh

Jorg Frankenberger

Wolfgang Rauscher

Wolfgang Deckenbach

Michael Bloss

Erich Kerst

Urs Hennerkes

The invention relates to a method for checking value documents by which the similarity of the intensity spectrum of a value document to be checked to a reference spectrum can be tested. To check the similarity of the intensity spectrum recorded from the value document to be checked to the reference spectrum, not the recorded intensity spectrum itself is compared with the reference spectrum, but rather a corrected intensity spectrum adapted to the reference spectrum, which arises from the recorded intensity spectrum by a linear correction. The correction parameters of the linear correction function are ascertained by adapting the linearly corrected intensity spectrum to the reference spectrum. Through the adapting it is achieved that fluctuations of the recorded intensity spectrum that are due to measuring technology are compensated at least partly.

Method for checking value documents

A sensor for checking value documents is arranged to carry out a self-test for testing its functionality. The sensor in the self-test reacts to at least one malfunction that is ascertained during the self-test and hinders the check of the value documents by the sensor automatically employing for checking the value documents, instead of the operating mode provided for checking the value documents. A modified operating mode employs at least one other measured value of the sensor for checking the value documents than is determined in the operating mode provided for checking the value documents. In contrast to the hitherto customary function failure of the sensor, the sensor can continue being operated for checking the value documents despite the malfunction.

Sensor and method for operating the sensor

A sensor for checking different features of value documents is arranged to carry out a self-test for testing its functionality. Before the sensor carries out its self-test, at least one of the features that is to be checked by the sensor is selected. It is provided in the self-test that the sensor rates a malfunction ascertained in the self-test differently and reacts to the ascertained malfunction differently in dependence on the selected feature. While a malfunction of the sensor has hitherto always led to a failure of the sensor, the sensor, despite ascertained malfunctions, can nevertheless carry out the check of certain features. It is achieved that the number of function failures of the sensor is reduced through the different reactions of the sensor to the ascertained malfunction in dependence on the feature.

A sensor for checking value documents has an illumination device for illuminating a value document, an imaging optic and a detection device. A light source receiver has at least two light sources which have mutually different emission spectra. The illumination device contains a microlens array which contains a multiplicity of microlenses, which with the light source receiver are arranged such that each of the light sources arranged on the light source receiver has exactly one of the microlenses associated therewith.

Sensor for checking value documents

A spectral sensor for inspecting value documents, includes an illumination device for illuminating the value document, imaging optics and a detection device. The illumination device contains a plurality of light sources with emission spectra that differ from one another, and which are switched on and off in succession, to illuminate a region of the value document with an illumination sequence consisting of light pulses with different emission spectra. One measured value is detected for each of the light pulses to record the spectral intensity distribution of the detected light. The plurality of light sources cover a section of the near infra-red spectral range and/or a section of the visible spectral range in such a way that the spectral sensor can record a spectral intensity distribution in the section of the near infra-red spectral range and/or in the section of the visible spectral range.

Spectral sensor for checking documents of value

A sensor for checking value documents, which has an illumination device for illuminating a value document, an imaging optic and a detection device. The illumination device of the sensor contains a multiplicity of light sources arranged side by side, which have emission spectra that differ from each other, and a microlens array with a multiplicity of microlenses. The microlens array and the light-source receiver are arranged so that when each of the light sources is arranged on the light-source receiver there is associated therewith exactly one of the microlenses. The measuring plane of the sensor is so close to a focal point of the imaging optic that the light of the different light sources emitted by the illumination device is largely imaged onto the same illuminated region of the measuring plane.

Growing community of inventors

Markt Schwaben, Germany

Jorg Frankenberger