Detection And Identification Of Visually Indiscernible Defects From Textural Background Of An Unpolished Quartz Crystal
Sing‐Tze Bow, Ting Chen, Darrell E. Newell · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1990
Quartz devices play an important role in the field of radio communication and are also well known for their popular use in electronic clocks and watches. Detection of scratches and cracks on the crystals is the key quality control in their production. Difficulties encountered in these inspections are due to the fact that such defects are so thin and short that they are almost indiscernible from the blurred textural background of the crystal unless a special illumination and torsional viewing mechanism are provided. In this paper, image processing and pattern recognition techniques are introduced for the automatic detection and delineation of these indiscernible imperfections so that high quality in crystal production can be assured.