The device facilitates the quick location of a wanted detail depicted on information material, which is divided into at least two grid squares by a large-scale grid of lines at an angle to each other. At least one of these grid squares contains the wanted detail. A fine division is provided on at least...http://www.google.fr/patents/US4836785?utm_source=gb-gplus-shareBrevet US4836785 - Device for locating a detail
