| 摘要 |
PURPOSE:To make it possible to hasten the detection of a surface flaw by 7-10 times or more as compared with conventional technique in detection of high resolving power, by applying beam matched filtering processing to the pattern of an interference fringe. CONSTITUTION:Beam irradiated from argon laser is spread by a collimation lens 2 and split into two beams by a beam splitter and one of them passes through a condensing lens 3a to irradiate an article 4 to be measured while the other is incident to a reference mirror 5 inclined by an angle alpha with respect to an optical axis. Two beams are reflected and again synthesized by the beam splitter 6 to generate an interference fringe. When the article 4 to be measured has a flaw, the interference fringe is bent. The interference fringe receives Fourier conversion by a Fourier conversion lens 7 to be allowed to irradiate a matched filter 8. When the incident interference fringe is equal to the matched filter, no beam is incident to a detector and, in the case of the bent interference fringe, beam is made incident to the detector 9. |
