| 摘要 |
PROBLEM TO BE SOLVED: To illuminate an element to be inspected with un-polarized light (light of polarization degree with approximately 0%).SOLUTION: A lighting device 80 for illuminating an irradiation object comprises: a light source 1 for generating un-polarized light; a folding mirror 5 for bending at least part of an optical path of the light generated by the light source; and a polarization correction plate 8 which has transmissivity to light, and which reduces a polarization degree of the light increased by the folding mirror 5. The polarization correction plate 8 is placed at a position P1 where the light emitted from a center of the light source 1 becomes substantially parallel to an optical axis AX of the lighting device 80.SELECTED DRAWING: Figure 1 |
