Patent ID: 8324529

Claim:
A laser machining device for machining an object to be machined by irradiating a machining region in the object with a converged laser beam, the device comprising: a laser light source for outputting a laser beam; a phase-modulating spatial light modulator for inputting the laser beam outputted from the laser light source, displaying a hologram modulating a phase of the laser beam at each of a plurality of pixels arranged two-dimensionally, and outputting the phase-modulated laser beam; a converging optical system disposed downstream of the spatial light modulator; and a controller for causing the spatial light modulator to display such a hologram that the laser beam outputted from the spatial light modulator is converged at a plurality of converging positions by the converging optical system; wherein the controller causes the spatial light modulator to display a plurality of holograms sequentially and, when the laser beam outputted from the spatial light modulator displaying each of the plurality of holograms is fed into the converging optical system, lets the converging optical system converge the laser beam at converging positions having a fixed number of M, selectively places N converging positions out of the M converging positions into the machining region, and machines the object, where M is an integer of 2 or greater, and N is an integer of at least 1 but less than M.