Laser processing machine with gas cleaned beam guiding cavity

摘要

Laser processing machine comprises a gas-rinsed beam guiding chamber (3); an optical element (2) which limits the chamber on the light inlet side; an inlet opening (10) for rinsing gas in the chamber close to the optical element; and a throttle valve which forms an optical screen (7) for shaping the laser beam (4). The laser beam is focussed onto the screen. An Independent claim is also included for a process for protecting an optical element from impurities comprising adjusting the pressure of the rinsing gas passing through the beam guiding chamber so that the optical screen acts as a throttle valve for the gas. Preferred Features: A focussing device (5) is integrated in the optical element or arranged within the beam guiding chamber.