ABSTRACT
Patents are limited monopoly rights granted by governments that allow inventors to prevent others from making, using, or selling their inventions for up to 20 years. In exchange, inventors must disclose details about their inventions. Patent documents are a valuable open source of scientific and technical information, some of which does not appear in other types of publications. For more than 200 years patent offices have disseminated patent information to the public in order to promote awareness of patent rights and to further technological development. During that time patent documents have evolved from handwritten manuscripts to printed documents to electronic text. Print-based search tools such as indexes and patent classification manuals have given way to online databases and hyperlinked documents. Today, patent searchers can search and retrieve millions of patent documents from numerous free Web-based databases hosted by patent offices and independent organizations.
