Frank Kappe

True color laser personalization for highly fraud-resistant ID documents

Marking of documents by means of a laser beam is a secure and efficient personalization method. The marking is based on a carbonization process, which is caused by a focused laser beam. The process of gray scale laser marking is todays standard on ID documents e.g. drivers licenses, passports. - Now it is possible to personalize these documents with colored lettering, company logos or images in photo quality, using a new laser marking method: CYMart. This development offers the possibility of a more flexible layout arrangement and increased information content. In addition, CYMart provides a new, active security feature for preventing forgeries, particularly in the ID market. The CYMart technology enables the document to be marked inside the multilayer structure, as opposed to a color print on the surface of a document. In combination with other security features e.g. Kinegram or security printing a very high level of protection against forgery is possible. The generation of color is based on a wavelength sensitive process. Multicolor is achieved by the combination of RGB laser beams and photosensitive materials which are integrated into the card layer structure.

Facets of color laser marking in high-security ID documents

Our new true-color laser personalization system (CYMartTM) for ID cards and documents does not suffer from the disadvantage of producing only black and white images as it is known from state of the art personalization systems, which use Nd-YAG lasers. These well-established black-and-white laser marking systems are valued so highly because the marking is created inside the material. Therefore, it is protected from counterfeiting and tampering. In exactly the same manner CYMartTM features an embedded image. CYMartTM is based on a three-wavelength laser system, one for each primary color (red, green and blue). A deflection system is used to direct the focused beams onto the document. The wavelength-sensitive color forming process generates true-color images comprised of a combination of the 3 primary colors. The color of any image element can be determined by the intensity of each laser beam. Unlike conventional laser marking with CYMartTM we are able to mark square-shaped dots. Until now, due to the Gaussian beam of the laser source, the marking was done with a circular beam shape, which has a non-uniform intensity profile. However, this profile results in inhomogeneous gray level of each marked dot. By introducing an aspherical phase plate into the laser beam we have the ability to manipulate the light and achieve a square-shaped dot with a uniform intensity profile. This enables us to mark an area with seamless transitions and without any color deviation.