Abstract: In the optical examination of plastic cards, the latter are illuminated with focused light, which is mixed with a diffuse component, in order reliably to discriminate even relatively slight differences in the reflectivity of the surface sections.

Abstract: A method for differentiating or detecting particles in a sample in which several classes of particles may be present by identifying signal segments of time-resolved, optical raw signals from the sample on the basis of single photon detection (single pulse detection), wherein the sample contains at least two classes of particles; the sample is illuminated by a light source; the optical raw signals emitted by the sample, which are derived from at least one measuring volume element V, V≦10−12 l, are detected with at least one detector unit; at least one particle generates a signal fraction during its residence in the measuring in the measuring volume element; a signal segment of the optical raw signals is determined by the particle's actively and/or passively entering and then leaving again the measuring volume element; the optical raw signals are segmented into arbitrary segments; at least one set of statistical data based on the optical raw signals is established for at least one arbitrarily chos

Abstract: A method of determining reflective optical quality of a reflective product includes reflecting a first gray-scale pattern off the product; obtaining a first image of the first pattern with an image pickup device after the first pattern has reflected off of the product; and determining optical quality of the product based on data obtained from the first image. An apparatus for determining reflective optical quality of such a product is also disclosed.