Measurement of the separation between a laser-machining tool and the surface of a workpiece being worked, using an optical measurement method that is insensitive to alignment of the laser processing head

摘要

Method in which a measurement object (25) is imaged on the surface (16) of a workpiece (17). The image (26) of the measurement object is imaged with a receiver arrangement in which the incident image of the measurement object is subjected to spatial filtering. The spatially filtered light beam is measured with at least two wavelength ranges to produce two corresponding measurement signals. The measurement signals are compared with theoretical values for the set machining head (10) to workpiece surface separation and a corresponding output signal generated. Independent claims are included for the following; (1) a distance or separation sensor; (2) a laser machining tool.