Distance sensor for determining distance and/or distance variations between processing laser and workpiece by laser triangulation, comprises measuring laser to generate laser light beam directed to workpiece surface, and photo-receiver

摘要

The distance sensor (1) for determining a distance and/or distance variations between a processing laser (3) and a workpiece (4) by laser triangulation, comprises a measuring laser (5) for generating a laser light beam directed to a surface (6) of the workpiece, a photo-receiver (8) for detecting a light beam reflected from the surface, and a fixedly disposed optics arranged to the measuring laser and the photo-receiver. A mechanical coupling device is provided between the photo-receiver and the measuring laser, and has a lever mechanism. The measuring laser is a pulsed laser. The distance sensor (1) for determining a distance and/or distance variations between a processing laser (3) and a workpiece (4) by laser triangulation, comprises a measuring laser (5) for generating a laser light beam directed to a surface (6) of the workpiece, a photo-receiver (8) for detecting a light beam reflected from the surface, and a fixedly disposed optics arranged to the measuring laser and the photo-receiver. A mechanical coupling device is provided between the photo-receiver and the measuring laser, and has a lever mechanism. The measuring laser is a pulsed laser. The measuring laser and the photo-receiver are movable relative to the optics, so that an optical axis of the measuring laser and an optical axis of the photo-receiver cut in an intersection point between a beam axis of the processing laser and the surface of the workpiece during a change of the distance between the processing laser and the workpiece. A movement of the measuring laser is coupled to a movement of the photo-receiver. An electronic device is provided for coupling the movement of the photo-receiver and the measuring laser. The photo-receiver has two photo-diodes arranged next to each other, where a difference signal formed from the receiving signals of the photo-diodes is used for controlling the movement of the photo-receiver. The determination of the difference signal takes place using a sample-and-hold-switch. A driving device that is controlled in dependent of the receiving signals of the photo-diodes is provided for the movement of the photo-receiver, and is a stepper motor or a direct current motor. Eddy current sensors and/or capacitive distance sensors are arranged to the photo-receiver. The photo-receiver has an interference filter. The distance sensor is laterally fixed onto the processing laser. An independent claim is included for a method for determining a distance and/or distance variations between a processing laser and a workpiece by laser triangulation.