| 摘要 |
PURPOSE:To make it possible to measure the glossiness of a reflex mirror having an oval cross-sectional area, by providing a linear light source to the focus of a trough shaped reflex mirror having an oval cross-sectional area while receiving positive reflected light and scattered reflected light by one set of a pinhole and a light receiving element by using a flat mirror. CONSTITUTION:A linear light source 11 is provided to the focus 12 of a trough shaped reflex mirror having an oval cross-sectional area and the emitted light from the linear light source 11 is allowed to irradiate an oval reflex mirror 10 while the positive reflected light of the reflex mirror 10 to said emitted light is condensed to the focus 12. In this case, said positive reflected light is guided to a pinhole 13 by flat mirrors 15, 14. At this time, if the optical distance from the reflex mirror 10 is made equal to the distance from the reflex mirror 10 to the focus 12, the positive reflected light from the reflex mirror 10 is condensed to the pinhole 13. By this constitution, the glossiness of the reflected mirror having the oval cross-sectional area can be measured. |
