| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ring-like lighting system for lighting an inspected object having an extreme step such as a vessel and allowing detection of a micro defect of the inspected object. <P>SOLUTION: This ring lighting system 10 that lights the inspected object, and has, as light sources 2, a plurality of light emitting diodes arranged in a plurality of rows in a ring shape on a doughnut-like substrate 11 horizontally stuck to the upper part of a retaining frame 13. The light emitting diode is attached to the substrate 11 so as to make the optical axis orthogonal to it, and a first reflection plate 14 having a reflector inside it, is arranged between an inner periphery side light emitting diode group 2a and an outer periphery side light emitting diode group 2b of the light emitting diode while being tilted by a predetermined angle with respect to the optical axis of the light emitting diode. A second reflection plate 15 having a reflector inside it and also having a tilt angle smaller than that of the first reflection plate 14, is arranged outside a predetermined row on the outer periphery side, and a diffusion plate 16 that has a circular opening 12a for photograph at its center and diffuses light from the light source 2 is disposed on the lower part of the retaining frame 13. <P>COPYRIGHT: (C)2007,JPO&INPIT |
