Canadian Intellectual Property Office
The Canadian Intellectual Property Office (CIPO) is the patent, trademark, and copyright administration body of Canada. Structurally the CIPO functions as a Special Operating Agency (SOA) which is associated with Innovation, Science and Economic Development Canada.
EPO European Patent Office
Espacenet offers free access to more than 70 million patent documents worldwide, containing information about inventions and technical developments from 1836 to today.
Free Patents Online
A searchable database of the more recent U.S., European, and Japanese patents
Google's Advanced Patent Search
Searches by: word or phrase, patent number, title, inventor, original assignee, current U.S. classification, international classification, patent type/status, and date. **NOTE: Google's Patent search is not as up-to-date as the USPTO's databases.
U.S. Patents
The United States Patent and Trademark Office (USPTO) is the federal agency for granting U.S. patents and registering trademarks. In doing this, the USPTO fulfills the mandate of Article I, Section 8, Clause 8, of the Constitution that the legislative branch "promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries." The USPTO registers trademarks based on the commerce clause of the Constitution (Article I, Section 8, Clause 3).
