Microfilm reader printer equipped with improved exposure amount control arrangement

摘要

A microfilm reader printer which includes a photo detector provided in a light path from a light source to a projecting surface, a control arrangement for setting quantity of light on the projecting surface to a predetermined value in accordance with an output of the photo detector, and an arrangement for compensating an error between change in output of the photo detector and change in quantity of light on the projecting surface in response to changeover of the projection magnification, in accordance with the changed projection magnification. By the above arrangement, the quantity of light on the projecting surface is maintained at the predetermined constant value regardless of the changeover of the projection magnification.