| 摘要 |
This invention relates to a method and device for detecting the focusing position in a laser processing apparatus, such as a machine for cutting plate-shaped workpieces by laser beams. The method includes the steps of placing a light shielding member and a light sensor in a path of laser light beams irradiated through a condenser lens to the workpiece to be processed; moving at least either one of the light shielding member and light sensor along the optical axis of the laser beams; and detecting the position at which electrical output of the light sensor becomes either a minimum or a maximum; whereby the focusing position is determined. The detector device comprises a condenser lens for converging laser beams which pass therethrough; a light shielding member installed along the optical axis of the laser beam between the condenser lens and the workpiece to be processed; a light sensor installed along the optical axis between the light shielding member and the workpiece to be processed; and a support for fitting the light shielding member and the light sensor thereto so that at least either one of the light shielding member and light sensor is installed in a freely movable manner on the support for adjustment purposes along the optical axis. |
