2004 年 70 巻 1 号 p. 91-95
A machine which can detect flaws deeper than 30μm and longer than 200μm on edges of vanes, produced by the barrel finishing process is developed. The edge part is illuminated with LEDs and Fresnel lens from the direction of ±60° and ±30°, which is measured from the vector normal to the edge, in a plane composed of an edge and a normal vector. The flaw on the edge is detected with a lens and a line CCD camera. This machine achieves the thoughtput of 8 pieces/s. A detectable angle of the flaw surface is analyzed theoretically and compared with experimental results. A method of classifying the detected images into two groups, the dust images and the flaw images, is also developed. All flaws can be automatically detected using the developed machine.