Abstract: A reproduction apparatus (14) for reproducing documents (12) which comprise a base material. The apparatus comprises a platen (10) for forming a scanning area and for positioning the documents (12) on its one side, scanning means (18) for scanning the scanning area, and means for obtaining a relative movement between the scanning means and the documents in order to allow for the scanning. The scanning means (18) comprise a microwave system which is constituted by microwave transceivers (26) arranged in an array such that they can detect the presence of particles (13) which have electromagnetic properties which are substantially different from the electromagnetic properties of the base material and which are incorporated in at least a part of the documents (12), irrespective of the position of the documents (12) on the scanning area.

Abstract: A wire drawing machine having a watching system of the wire diameter at one or more watched locations in the machine. The diameter is measured by measuring the wire speed as compared to the reference wire speed at a reference location where the diameter is accurately known and held in a register. This value, together with both speed values, are sent to a computer module for calculating the wire diameter and sending this to the computer output. When a new wire enters in the drawing machine, the operation is temporarily inversed that is the lastly computed diameter is temporarily taken as the reference diameter and stored in the register, and from there the new reference diameter at the entrance is calculated and entered in the register.

Abstract: A method and an apparatus for checking the authenticity of documents, such as banknotes or credit-cards. The documents comprise a number of randomly distributed conductive fibres of which the distribution is scanned by microwaves and the response is transformed into a digital coded signal. A digital mark on the document, which is representative for the distribution of an individual document, is read off, transcoded, and compared with said coded signal for producing an approval signal. The use of a microwave scanning system in conjunction with documents having a random distribution of suitable fibres ensures a great repetitivity and security of the system.

Abstract: An apparatus for the identification by microwaves of a sheet article composed of an electrically non conductive material, the article being marked for identification by the incorporation therein of electrically conductive fibers. The apparatus comprises at least two microwave emitter devices one adjacent the other with detectors for the waves reflected by the article when advanced before said devices. The apparatus comprises also detectors for the waves transmitted through the article and placed in front of said emitter devices. Regulating methods of the apparatus are also described for raising the sensitivity of the identification signals through setting of the distances between the emitter devices, detectors for transmitted waves and support for the interposed article.

Abstract: An apparatus for the identification by microwaves of a sheet article composed of an electrically non-conductive material, the article being marked for identification by the incorporation therein of electrically conductive fibers. The apparatus comprises: at least two microwave emitter devices one adjacent the other; detectors of waves reflected by the article when advanced before said devices; a screen placed in front of at least one of the emitters; and, regulating means for raising the sensitivity of the identification signals by setting the distances between the emitter device, screen and support for the interposed article.