Optical Tomography Using Confocal Fan-Beam Illumination and Its Application to LCD Panel Inspection

摘要

This paper describes optical tomography using oblique and confocal fan-beam illumination devised for transparent-layered objects. This 3-D imaging method has the advantage of area-at-a-time sensing and it is free from disturbances caused by defects on the object surface, compared with the conventional confocal microscopy based on point-by-point sensing and co-axial illumination. The method was applied to LCD panel inspection and was successful in efficiently detecting foreign substances between the constituent layers in LCD. Furthermore, it was robust against scratches and dust on the protection film surface of the LCD.