Patent ID: 7863544

Claim:
Apparatus ( 1 ) for the on-line monitoring of the quality of a laser process exerted on a workpiece ( 3 ), comprising a laser source transmitting a laser beam ( 4 ) to the workpiece ( 3 ), the thermal process of the laser beam ( 4 ) causing emission of electromagnetic radiation ( 7 ) from the process zone on the workpiece ( 3 ); a heat detection camera ( 8 ) for detecting the electromagnetic radiation ( 7 ) emitted from the process zone of the workpiece ( 3 ), wherein the arrangement ( 1 ) is provided with a tilted mirror ( 5 ) such that the laser beam ( 4 ) which is transmitted by the laser source is let through the tilted mirror ( 5 ) towards the working piece ( 3 ), and the electromagnetic radiation ( 7 ) emitted from the process zone on the workpiece ( 3 ) is reflected by the tilted mirror ( 5 ) towards the heat detection camera ( 8 ), wherein the tilted mirror ( 5 ) is a non-focusing mirror provided with an opening through which the laser beam ( 4 ) transmitted from the laser source can propagate unhindered; between the mirror ( 5 ) and the heat detection camera ( 8 ), an objective lens ( 6 ) is provided for focussing the electromagnetic radiation ( 7 ) emitted from the process zone on the workpiece ( 3 ) and reflected by the mirror ( 5 ); between the objective lens ( 6 ) and the heat detection camera a smallband filter ( 10 ) is provided for filtering the focused electromagnetic radiation ( 7 ) to electromagnetic radiation with one wavelength situated in the infrared zone of the electromagnetic spectrum with a single wavelength between 1.1 and 2.5 Î¼m, and said heat detection camera ( 10 ) is a short wavelength infrared camera sensitive for radiation ranging from 0.9-2.5 Î¼m provided for detecting said filtered electromagnetic radiation ( 12 ) having said single wavelength.