Microfilm duplicating apparatus

A microfilm duplication apparatus for duplicating images, recorded on a master film, onto a duplicate film, which apparatus comprises:

• a light source means for illuminating any one of the images on the master film from rear;
• a single mirror member for reflecting a luminous flux, which has been emitted from the light source means and passed through the master film while carrying the image to be duplicated, so as to travel towards the duplicate film;
• and
• an inage forming lens means disposed on the path of travel of the luminous flux;
• said mirror memeber being so disposed that the luminous flux incident upon the mirror member and the luminous flux reflected from the mirror member forms an angle no greater than a right angle, and wherein said image forming lens means comprises a pair of image forming lens units of equal focal length each having an objective lens element, said lens units being arranged with respective objective lens elements facing each other and at a position intermediate of the path of travel of the luminous flux, and wherein the image forming lens units of equal focal length each have a focusing distance set at infinity thereby providing a photographic optical system of high resolving power with a one to one magnification anf constituting an inexpensive assembly, whereby, the close positioning of the dual image forming lens units thereby avoids vignetting of oblique rays with an afocal relationship created between the image forming lens units eliminating the need for precise optical adjustment of the spacing between the image forming lens units.