Patents Assigned to EmCal
  • Patent number: 6449088
    Abstract: A variable dark-field illumination method and apparatus to produce microscopic and macroscopic images with a variable dark-field effect thereby making best use of various detector response characteristics. The variable dark-field of the invention is particularly characterized by an adjustable object contrast which optimizes the use of the various detectors dynamic range. The invention is particularly useful when coupled with a video camera and for macroscopic systems having a large depth object field. The dark-fields of the art have geometries which are objectionable because those geometries have very limited depths of field. The invention is particularly distinguished from the art as the dark-field methods and apparatuses of the art are generally geometrically restrictive and they do not provide variable contrast control for input images.
    Type: Grant
    Filed: November 5, 1993
    Date of Patent: September 10, 2002
    Assignee: EmCal
    Inventors: James T. Pettingell, James T. Snyder