| 摘要 |
PURPOSE: A laser ultrasonic device with multiple beams heads and a signal processing method using the same are provided to arrange the multiple beams heads in a width direction of an inspecting object, thereby accurately measuring material distribution in the width direction even though the inspecting object is transferred at a high speed. CONSTITUTION: A laser ultrasonic device with multiple beams heads comprises a first laser source(100), a second laser source(101), optical units(120,121,122,123), a single laser interferometer(140), and a light detecting unit(160). The first laser light source generates ultrasonic waves on a surface of an inspecting object(S) by irradiating first laser beams. The second laser light source irradiates second laser beams to the surface of the inspecting object for detecting the ultrasonic waves. The optical units obtain the second laser beams reflected by the inspecting object while inducing the first laser beams generated by the first laser source and second laser beams generated by the second laser source to the surface of the inspecting object The laser interferometer outputs changes in a frequency of the second laser beams generated by the vibration of the ultrasonic waves as the intensity of interference lights. The light detecting unit converts the intensity of the interference lights into electrical signals. |
