Controlling power transmitted by laser beam at reference point, especially in brazing articles onto support, by varying emission power from source dependent on presence or absent of mask for the beam

摘要

In a method for controlling the power transmitted by a laser beam (24) at a reference point (28), where the beam is periodically interrupted by a mask (30) between the reference point and beam source (22), the emission power of the source is varied between maximum and minimum values, with the periods of minimum power emission coinciding with the periods when the beam is masked. Independent claims are included for: (1) corresponding power controlling device, having a power controller (32) for varying the source emission power between maximum and minimum values; (2) apparatus for brazing an article (12) on a first face (F1) of a support (14), where a laser beam is emitted from a source onto the second face (F2) of the support opposite the article to be welded, which includes a power controlling device as above to control the power transmitted by the beam at a reference point consisting of the focusing point of the beam on the second face; and (3) a corresponding brazing procedure, in which the support has a metal part (PM) (including the opposite faces (F1, F2)) at least partially bordered by a plastics part (PS) and the power is controlled by a device as above.