Patent 7901096 was granted and assigned to Dorsey Metrology International on March, 2011 by the United States Patent and Trademark Office.
The invention is directed to a method for illuminating an object and projecting its image on a ground glass screen. Optical comparators conventionally use incandescent illumination, either mercury arc or halogen. The use of an array of high intensity LED devices, provides many options for packaging the required optical components used in comparators.