METHOD FOR MONITORING SURFACE OF OBJECT TO BE PROCESSED, AND MONITORING DEVICE

摘要

PROBLEM TO BE SOLVED: To make possible to grasp, by use of a relatively low-priced device, the melting state of a surface of an object to be processed which is being thermally treated by laser light including a pulsed laser light.SOLUTION: The monitoring device is a device for monitoring the condition of a surface of an object to be processed which is being thermally treated by irradiation of laser light including a pulsed laser light. The monitoring device comprises: a reference-light source for generating a reference light; a reference-light optical system for guiding the reference light from the reference-light source and irradiating the object to be processed with the reference light; a reflection-light detector unit for detecting a reflection light resulting from the reflection of the reference light by the heated object to be processed to take a surface image of the object to be processed; and a reflection-light optical system for guiding the reflection light to the reflection-light detector unit. The monitoring device irradiates the object to be processed with a pulse of reference light according to the timing of the pulsed laser light, or receives a pulse of reflection light resulting from the reflection by the object to be processed according to the timing of the pulsed laser light.