Patent ID: 6922420

Claim:
A method of controlling hardening of a workpiece with a laser beam, comprising: irradiating a workpiece with a laser beam, and moving the laser beam along an oscillating scanning track with a predetermined scanning cycle and scanning amplitude, thereby heating said workpiece over a length determined by a feed path and a width determined by an amplitude of the scanning track; and controlling a power output of said laser beam in such a manner that said power output of the laser beam over said scanning cycle is lower at both opposite scanning peaks of said oscillating scanning track, than said laser beam power output at a center portion of said oscillating scanning track; wherein said laser beam power output is adjusted to obtain a predetermined hardening temperature of said workpiece when heated by irradiating with said laser beam, at all portions of said workpiece to be hardened; and wherein said hardening temperature of said workpiece is measured by acquiring reflected light of said laser beam when irradiating said workpiece.