Method for calibrating one or more optical sensors of a laser machining head, laser machining head, and laser machining system

A laser machining system including a laser machining head for machining a workpiece by a machining laser beam and a computing device, wherein

• said laser machining head comprises a first optical sensor, a deflection device and a focusing device;
• said deflection device and said focusing device lie in a beam path of said first optical sensor;
• said deflection device is configured to deflect the beam path of said first optical sensor to a first position on a first reference;
• said first optical sensor is configured to receive measurement light from the first position on said first reference and to generate a first optical measurement signal based on the measurement light;
• and
• said computing device is configured to determine a correction value for calibrating said first optical sensor based on the first optical measurement signal and according to a deviation of the first position on said first reference from a first target position,
• wherein the at least one optical sensor comprises an optical interference device or an optical coherence tomograph and said reference is a calibration plate having a plurality of recesses at predetermined positions.

A method for calibrating at least first and second optical sensors of a laser machining head for machining a workpiece using a machining laser beam, wherein said laser machining head includes a first optical sensor, a second optical sensor, a deflection device and a focusing device and beam paths of said first and second optical sensors pass through said deflection device and said focusing device, said method comprising the steps of:

• deflecting the beam path of said first optical sensor by said deflection device to a first position on a first reference;
• generating a first optical measurement signal based on measurement light received by said first optical sensor from the first position on said first reference;
• and
• determining a first correction value for calibrating said first optical sensor based on the first optical measurement signal and according to a deviation of the first position on said first reference from a first target position,
• deflecting the beam path of said second optical sensor by said deflection device to a first position on a second reference;
• generating a second optical measurement signal based on measurement light received by said second optical sensor from the first position on said second reference;
• and
• determining a second correction value for calibrating said second optical sensor based on the second optical measurement signal and according to a deviation of the first position on said second reference from a second target position.