| 摘要 |
PROBLEM TO BE SOLVED: To prevent appearance of variation in a polarization axis of polarized light even when a filter is arranged on the incidence side of a wire grid polarizing element.SOLUTION: A wire grid polarizing element 81 is provided in a lamp house 60 housing a bar-shaped lamp 11 and a gutter-shaped reflecting mirror 12, and a filter 90 is provided between the lamp 11 and the wire grid polarizing element 81. Light from the lamp 11 becomes polarized light by the wire grid polarizing element 81 and is radiated to a workpiece W. The filter 90 is larger than the wire grid polarizing element 81 when viewed in a direction vertical to a lengthwise direction of the lamp 11. Since outside oblique incident light Lo is not shielded, variation in a polarization axis does not appear at an end point E of an effective irradiation area. |
