U.S. Patent Databases

The best free U.S. patent databases are:

USPTO Patent Databases
The official United States Patent and Trademark Office site includes access to the full-text of patents from 1976-. Full-page images of patents are included from 1790-.

•You may need to download a specific TIFF image browser plugin to view the actual page images of the patents (be sure to read the directions.)

•Use the "Advanced Search" link on the front page for more complex searches.

Delphion Intellectual Property Network
The Delphion Intellectual Property Network contains searchable bibliographic data (information about the patent) and the complete text of all patents since 1974, and bibliographic text and some images from 1971.

•It also includes the full images for patents dated 1790-1971.

•You may find the Delphion site easier to use than the USPTO site. You must register in order to use the free portions of this Web site. This site also provides many additional services for a fee.

freepatentsonline
This site includes the searchable text of patents from patent number 4,000,000 (December 1976) to the present. While not as complete as the first two databases, it is easy to search and has some nice display features.


Google
Web www.patent-search-information.com