| 摘要 |
<p>A protection device which can be associated with a machine 1 utilising a carbon dioxide laser 2 to define the working zone for a laser beam and to prevent the beam itself from striking objects disposed outside the working zone 7. The protection device is provided with an inspection window 9 closed by a transparent body 11 made by superimposing at least two layers of polymethyl methacrylate between which there is interposed an electrical conductor constituting part of a safety circuit 17. Change of an electrical parameter of the electrical conductor, upon being struck by the laser beam, is sensed by the circuit 17 which causes the laser to be turned off and/or warning devices to be actuated. <IMAGE></p> |
