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Government Information: Federal, State & Local: Patents/Trademarks

A guide to finding federal, state and foreign government information.


U.S. Patent and Trademark Office (USPTO)
Search issued patents, patent applications, and trademarks.

  • Patents issued between 1790 and 1975 may be searched by Patent Number and Current US Classification (the classification code assigneed to the patent to indicate its subject matter). You may search patents issued since 1976 using any of the sections (fields) within the full-text documents.
  • Patent Applications are available since March 15, 2001.
  • The Trademark Electronic Search System (TESS) allows you to search trademarks. Active trademarks and trademark applications, as well as inactive ones since 1984, are included.
  • Guides to Searching

    General Information Concerning Patents - see especially "What is a Patent?"

    The 7-step strategy - the search process described is complex, recommended for professional patent searchers

    How do I use the U.S. Patent Classification Site
    ? - explains searching by Classification numbers

    How to Access Full-page Images. How to view and print full text patent images including drawings.

    Tips on Fielded Searching - probably the most useful guide for the novice patent searcher, since searching within fields (sections) is easy to understand and results in precise, although not comprehensive, searches

    Manual of Classification - guide to the classification schedule used to classify patents and patent applications; searchable by class, subclass, and keyword

    USPC Index - browsable index to the entire US Patent Classification