LIGHT IRRADIATING DEVICE AND WELDING METHOD

摘要

To be able to obtain an optical output having a desired light intensity profile suitable for such purposes as the expansion of a welding area without increasing a light emission intensity more than necessary. Such a constitution is used that output light beams from a plurality of output end faces (115) arranged on the output surface (114) of a light source unit (122) are condensed to one light beam by a condensing lens to be applied to an object of irradiation, and one light beam applied to the object is allowed to have a desired light intensity profile by a combination of positions at which respective output end faces (115) are disposed and the intensity distribution of light beams output from the respective output end faces (115), whereby a desired light intensity profile required for one output light beam can be realized by setting the locations of the plurality of output end faces (115) and setting or variably controlling the intensity distribution of respective output end faces (115).