| 摘要 |
PURPOSE:To improve the accuracy of measurement by compensation of marginal light attenuation of a lens to be examined by constituting light emitting coils of light sources in such a way as to illuminate plural objects at the higher radiation illuminance as the angles of view are larger and lighting the coils in series. CONSTITUTION:Light sources 11-13 are constituted of temp. radiation type light sources 11a-13a respectively having light emitting coils 40a-40c which are mutually equal in, for example, pitch (p) and mandrel diameter DM and differ in coil length lK to l1-l3, whereby the power consumption of the light emitting coils of the light sources 11-13 is increased with an increase in the half angles of view of objects 2-7 to be illuminated with respect to the optical axis of a lens 20 to be examined. The currents flowing in the coils 40a-40c are made the same by connecting the respective light emitting coils in mutually series to an electric power supply 43 and lighting said coils, whereby the color temps. of the respective light sources are made the same. |
