Abstract: A marking device for encoding metallic workpieces with two-dimensional matrix codes includes a striking tool for forming the code recesses, driven by an electromagnetic device. The driving movement is performed against the force of a return device. A positioning device displaceable on two axes (x, y) of a plane perpendicular to the striking direction (z) is used for positioning the striking tool in the desired code positions. An electronic control device for controlling movement of the striking tool includes means for presetting a higher current for the electromagnet device during a first acceleration phase of the striking tool and a lower current during a subsequent moving phase until the workpiece is impinged. In this manner, the precision of the code recesses in the workpiece can be exactly set or maintained, so that readability of the coding is substantially improved.

Abstract: A quality control method for two-dimensional matrix codes on metallic workpieces, the codes being in the form of stamped marking dots is disclosed. The stamping process for the marking dots is carried out by a marking tool (17) with the aid of predetermined digital positional data. The corresponding image data is then recorded for analysis by an image processing device (22), exclusively at the locations that have been predetermined by the positional data, or additional image data that has been previously generated is also used for the analysis, to establish whether a correct marking dot with the required quality characteristics is present.