| 摘要 |
PROBLEM TO BE SOLVED: To detect the intensity of reflected light at appropriate sensitivity and resolution without increasing the number of wavelength filter.SOLUTION: An optical detector comprises: a lens element (17) configured to condense irradiation light from a light source (18) to a detection object (16) and condenses light from the detection object (16); a lens element moving part (29) configured to move the lens element (17) in the direction of an optical axis; a filter element (23) configured to block light of specific wavelength; a filter element movement part configured to move the filter element (23) such that the element (23) is present on or absent from the optical axis; a light detection part (26) configured to detect light condensed by a lens element (17) and passed through an opening of a light shield member (25); and a control section configured to control the operations of the lens element moving part (29) and the filter element moving part. In a second measurement mode in which light from the detection object (16), which has the same wavelength as the irradiation light, is detected, the control section sets such that light from the detection object (16) is condensed into the opening of the light shield member (25) at a diameter larger than that of the opening and the filter element (23) is absent from the optical axis of the lens element (17). |
