| 摘要 |
PURPOSE:To attain an accurate and rapid adjustment, by performing the adjustment of magnification, and focusing, based on a detected mark image picked up on an image sensor. CONSTITUTION:The titled device is provided with a detecting mark 12 provided in the neighborhood of an original surface 15 in an original holding means 1, a line image sensor 11 arranged so as to project the detecting mark in the neighborhood of a projecting surface 10, an electronic circuit 13 which processes a detected electrical signal 21 read by the image sensor, and a magnification adjusting mechanism 16, and a focusing mechanism 14, driven by the outputs 19 and 18 of the electronic circuit. In other words, the detecting mark provided on the same surface of an original is image-formed on the line image sensor provided at a position having an equal distance to a photosensitive body separating from the original, by an original image-forming lens, and it is decided and processed whether the focusing and the magnification of the detected mark image is accurate or not, from a signal obtained by the image sensor, and the position of an optical system is adjusted so as to correct an error between the values of accurate focusing and magnification. Therefore, it is possible to correct the focusing and the magnification at every desired magnification at the time of changing the magnification, and to rapidly image-form an original image on the photosensitive body in a state that the focusing is obtained by the accurate magnification. |
