| 摘要 |
PURPOSE:To perform inspection in various directions by illuminating a periodic pattern by a light source for illuminating, projecting and throwing the image thereof onto a screen and observing the projected image on the screen. CONSTITUTION:A shadow mask 16 is illuminated by lamps 11-13 and the image thereof is projected onto the screen 17 to be observed. When it is illuminated by the lamp 11 or 13, the image formed with oblique light is projected onto the screen 17 and when it is illuminated by the lamp 12, the projected image with the illuminating light transmitted nearly in a beam direction is thrown onto the screen. By observing the image thrown onto the screen, the inspection of pattern is performed. If the lamps are switched one after another, the inspection in the direction set by an illuminating device can be performed just by observing the screen from a front. |
