Patents by Inventor Darrel K. Yoder

Darrel K. Yoder has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4821079
    Abstract: The present invention relates to a device designed to enable one to make a series of photographic test prints of the same image or the same portion of an image on a single piece of photographic paper so that the test prints may be compared with one another to decide which combination of parameters will be used in the developing process. The parameters which may be selectively altered include density, color balance, lens aperture, filtration and length of exposure, among others. The invention utilizes a fixed base and a turntable and includes structure allowing the photographic paper to be rotated with respect to a fixed aperture fixedly aligned with the image of the negative or slide which is to be reproduced.
    Type: Grant
    Filed: October 23, 1987
    Date of Patent: April 11, 1989
    Inventor: Darrel K. Yoder