Pako Corporation

Kenneth B Schrupp

Gerald A Jensen

Ronald B Harvey

John Pone, Jr

Patrick J Gilligan

An automatic density control device for photographic printers for sensing and correcting for a 'subject failure' in a photographic negative, where the subject area of the negative is out of the optimum density ratio to the background area, which device includes a frusto-pyramidal radiation directing member having its enlarged end proximate to the negative and its small end remote therefrom and being positioned to receive the radiation from a source through the negative and having subject sensing means mounted at the central portion of the enlarged proximate end of said member to sense the radiation passing through the central subject area of the negative and also having background sensing means mounted at the diminished remote end to sense the radiation passing through the marginal portions of the negative and the marginal portions of the enlarged end of said member and including circuitry for comparing the signals produced by said subject sensing means and background sensing means and thus deriving a density signal which is used to control the exposure time during the printing process.

Growing community of inventors

Minneapolis, MN, United States of America

Kenneth B Schrupp