| 摘要 |
PURPOSE:To surely detect the imaging state of images by comparing the scanning signals of the images formed by an image forming optical system and evaluating the imaging state from the differences in the illuminances of the proximate two positions of the images. CONSTITUTION:The images formed by an image forming optical system 1 are scanned by a semiconductor image sensor 4 such as of BBD photo diode array or the like provided at the intended focal plane or in the position conjugate with said focal plane. At this time, the time-series scanning signals and the scanning signals scanned immediate before going through a delay circuit 7 are applied to a differential amplifier 8 whereby they are made to differential signals which are then held in a holding circuit 12 by way of an absolute value circuit 8, gamma converting circuit 10 adding specified weights, integrating circuit 11, etc. and are displayed in a display meter 13. Hence, the illuminance differences of the proximate two positions of the images for the image state are evaluated by the meter 13 and the imaging state of the images may be detected surely. |
