Searching for Patents
If you intend to make, use, or sell an invention of yours, you should find out whether someone else has created something like it already. You have a number of options when it comes to searching for patents.
The US Patent & Trademark Office (USPTO) has many resources available online. Below are some of the resources available. For a complete listing of USPTO web resources and their limitations, please see the USPTO website.
- Independent Inventor's Resources, An FAQ website by USPTO.
- Web patent database. The database includes full text and drawings of US patents issued since 1790.
To view images of patents, you will need what is called a plug-in that works with your web browser. For more info, see USPTO's plug-in information. The database can be searched on the web, with the following important restrictions:
|Patents issued since January 1, 1976 - present||All fields searchable|
|Images of patents issued 1790 - 1975||Searchable by current class number and patent number only.|
- can be searched or browsed online.Classification Index
- Information found in the Official Gazette. Please see the USPTO website for limitations.
- Roster of patent agents and attorneys is maintained by USPTO.
Once you've identified a patent that you'd like to look at, the easiest way to view the patent is to use Patent Fetcher or another patent printing resource. Just enter patent number, and these sites can generate a PDF file that you can download.
General Patent Searching - Resources
Unless otherwise noted, websites are accessible from any computer, on or off-site.
US Patent & Trademark Office - Patent Searching http://www.uspto.gov/patft/ Covers US patents issued from 1790 to the most recent weekly issue date. See the USPTO website for important notices concerning the database.
European Patent Office http://worldwide.espacenet.com/advancedSearch?locale=en_EP Search for European, US, PCT, Japanese and other worldwide patents.
CIPO - Canadian Patents Database http://patents1.ic.gc.ca/intro-e.htmlA Canadian Patent database with data from 1989 to the present, and includes the patent number, classification, and title of patents.
Japan Patent Office http://www.jpo.go.jp/A searchable database of Japanese patent abstracts, which includes the patent number, title, inventor, company, and abstract of the patent.
PubEAST and PubWEST Searching Covers 1920-most recent weekly issue. Onsite use at the Art, Architecture & Engineering Library.
Free Patents Online http://www.freepatentsonline.com/ Covers patents and applications from USPTO, EPO, WIPO and JPL abstracts
Google Patents http://www.google.com/patentsSearch and view over 7 million patents the Google way. Includes full images
Other Ways to Search for Patents
The material that existed before resources were made available on the World Wide Web still exists in many places.
If a Patent and Trademark Resources Center Library is nearby (e.g., the University of Michigan's Art, Architecture & Engineering Library), you can search using the Index of Patents series of books. These work particularly well when you know the patentee's name (usually patentee=inventor) and roughly when the patent got issued. They are also important for finding information about older (pre-1970) patents.
If you want to search using other criteria, such as words you would expect to see in the title or abstract of your patent, you can search using the USPTO World Wide Web resources, or the other resources listed above.
Online Tutorials and Guides
- Conducting a Preliminary US Patent Search: A tutorial
- Tutorial from the Physical and Mathematical Sciences Library at Penn State