OPTICAL NONDESTRUCTIVE INSPECTION DEVICE AND OPTICAL NONDESTRUCTIVE INSPECTION METHOD

摘要

To provide an optical nondestructive inspection device and an optical nondestructive inspection method with which it is possible to obtain the waveform of a more-distortion-suppressed sine wave (waveform of a detection signal from infrared-ray intensity detection means) without affecting phase difference measurement, and to obtain a more stable phase difference.SOLUTION: The optical nondestructive inspection device comprises: a laser output device 27 for emitting a laser for heating whose intensity changes in shape of a sinusoidal wave to a measurement point SP on the surface of a first member joined at a junction interface; laser intensity detection means 41; infrared-ray intensity detection means 31 for detecting the intensity of an infrared ray from the measurement point; a phase difference detection device 60 for detecting a phase difference between the laser intensity and the infrared-ray intensity; and a determination device 70 for finding the junction area of the junction interface on the basis of the phase difference. The output characteristic of the infrared-ray intensity detection means is a non-linear characteristic, and linearity correction means 31S for correcting the non-linear characteristic of an infrared-ray intensity detection signal to a linear characteristic is provided between the infrared-ray intensity detection means and the phase difference detection device or inside the phase difference detection device.SELECTED DRAWING: Figure 1