| 摘要 |
PURPOSE:To obtain reflected luminous flux necessary for measurement even if dust, water drops, etc., stick on a body to be measured to some extent, and to perform the measurement by causing polarized luminous flux which has a short diameter in a scanning direction to strike the body to be measured. CONSTITUTION:A polarizing means 3 deflects luminous flux from a light source 1 with good directivity within a specific angle range. A scanning means 4 converges angle-deflected luminous flux to obtain luminous flux scanned in parallel. Then, a polarized luminous flux generating means 8 placed on the optical path between a light source 1 and the body 5 to be measured polarizes luminous flux with which the body 5 is irradiated so that it has the short diameter in the scanning direction. Consequently, the long diameter of the polarized luminous flux is made much larger than the width size of dust, etc., to reduce the degree of a decrease in the photodetection amount. |
