PURPOSE: To correct and hold automatically an optical axis of a laser at a prescribed position by detecting a shift of the laser optical axis by at least three pieces or more of temperature sensors immediately before a condenser lens, and controlling the position of a mirror in accordance with its detecting quantity.
CONSTITUTION: When the position of a luminous flux 13 of a laser is shifted against a condenser lens 10 due to thermal deformation of laser transmission and a supporting member of mirrors 3, 4, 5 and 6, and a mechanical error, etc. of a moving part of a laser working machine, etc., the irradiating way of a laser on four pieces of temperature sensors 14 becomes unequal, an outputs of the four temperature sensors 14 also become unequal. As a result, the mirror 5 is slid in the X direction by a driving device 7 by a prescribed quantity corresponding to the unbalanced quantity in the X direction of the temperature sensor 14. Also, the mirror 6 is slid in the Y direction by a driving device 8 by a quantity corresponding to the unbalanced quantity in the Y direction, and the sift of an optical axis 13 of the laser is corrected. In this regard, three pieces or five pieces or more of sensers can be placed at equal intervals.
YAMADA KIYOSHI
AOKI HIDEKAZU
