| 摘要 |
PURPOSE:To form an image at a solid-state image pickup element and to adjust automatically the focus of an image-forming lens by arranging the solid-state image pickup element outside the light path of an image-forming lens and providing movably the reflecting mirror on the light path between a screen and the image forming lens. CONSTITUTION:The image of a microfilm F is projected to a screen S by an image forming lens 2h. Outside the light path of the image forming lens 2h, a solid-state image pickup element 5 is arranged and in the light path between the screen S and the image forming lens 2h, a reflecting mirror 8 is movably provided. By moving the reflecting mirror 8 on the light path of the image forming lens 2h at the time of adjusting the focus, the image is formed on the solid-state image pickup element 5 arranged together with the screen S surface through the reflecting mirror 8 temporarily, and by the output, the focus of the image forming lens 2h is automatically adjusted through an electric control circuit 7. By the light quantity detected by the image pickup element 5, a focus matching discriminating circuit 6 stores a program in a microcomputer so as to discriminate whether or not the focus is matched.
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