UNMAGNIFIED IMAGE FORMING OPTICAL DEVICE

摘要

PURPOSE:To prevent resolution from decreasing by rotating and adjusting a converging rod lens array and a couple of reflecting mirrors integrally about the length center of the converging rod lens array in the optical-axis direction as a center of rotation. CONSTITUTION:A light source 20 illuminates an original surface and reflected light is guided to a photosensitive drum 19 through the reflecting mirrors 11 and 12 and converging rod lens array 10; and an original platen 17 is moved as shown by an arrow and a photosensitive drum 19 is rotated as shown by an arrow to form an electrostatically charged image on the photosensitive drum 19. Namely, variation in the length between the couple of reflecting mirrors 11 and 12 which varies simultaneously with the length of the convergent rod lens array 10 in the optical-axis direction is absorbed between the reflecting mirrors 11 and 12 and original, and the reflecting mirrors 11 and 12 and photosensitive drum or a contact type photoelectric transducer respectively, so that the image formation position of an unmagnified image forming optical system is set on the original surface and photosensitive drum or contact type photoelectric transducer while the distance between the original surface and photosensitive drum or contact type photoelectric transducer is fixed.