Method and apparatus for laser marking an object

摘要

A method and apparatus is disclosed for marking an object (10). For example, the method may be used to produce precision marks (28) for a metrological scale in the form of a stainless steel ribbon (10). A laser (21) is used to produce pulses (e.g. ultra-short pulses) at repeated instants that form markings on the object (10). The apparatus is operated by a controller (200). A reader, e.g. formed by two or more scale readers (23a and 23b), is used to determine the distance between two or more markings produced when the object (10) is subjected to the beam and for issuing a pitch signal to the controller (200). The controller (200) uses the pitch signal to control the repeated instants at which the laser (21) emits its beam.