Patents by Inventor Ludovicus Petrus Maria van Valkenburg

Ludovicus Petrus Maria van Valkenburg 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: 4120591
    Abstract: Color detection apparatus wherein only light that has been diffuse-reflected, and has not been mirror-reflected, from the object whose color is to be detected is processed. Light from a source passes through a first polarizer before the light is incident on the object whose color is to be detected. Light reflected from this target object passes through a second polarizer which blocks all mirror-reflected light while permitting a portion of the diffuse-reflected light to pass. After passing through the second polarizer a portion of the light is directed onto a color filter after which the intensity of the transmitted light is detected. The intensity of the portion of light not applied to the color filter is also detected. The ratio of the output of the two detectors is a function of the color of the reflected light.
    Type: Grant
    Filed: December 1, 1976
    Date of Patent: October 17, 1978
    Inventor: Ludovicus Petrus Maria van Valkenburg