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Patents Online: Basics for Researchers: Searching U.S. Patents

patents, intellectual property, sciences, business

Search Engines for U.S. Patents

  • USPTO – official website for U.S. patents and comprehensive research. See the Patent Full-Text Databases page.
  • Google Patents – best algorithms for identifying relevant primarily U.S. patents using keywords. Not comprehensive research.

Searching U.S. Patents by Technology (Classification) Area

Patents CANNOT be searched by keyword alone. The U.S. and other countries have classification systems that categorize issued and pending patents into technology groups identified by a number, and these must be used in order to do a thorough search. Start with a keyword search in Google Patents to identify relevant patents, examine their classifications, and then search key classifications. Google Patents may be used on its own to identify just one or two relevant patents.

Steps to Starting a Preliminary U.S. Patent Search

•1. Do a keyword search in Google Patents,
•2. Locate several patent(s) that are relevant to your research
•3. Review the abstract, images, and claims

4. In the blue box:
     Download the PDF
     See Patent citations – other patents cited by this patent
     See Cited by – patents that have cited this patent
     Click on the USPTO link to view the patent at USPTO

•5. Classifications
     Note the CPC classifications/technology areas
     Review the definitions

•6.Search the CPC and U.S. classes at USPTO for more complete results. Use Current CPC Class and Current US Class

     Issued patents

Searching Patents by Classification

  • Determine the classifications or technology areas that relate to your research.
  • Review the class definitions.
  • Search CPC classifications or technology areas that relate to your research using USPTO databases to identify trends in research and product development.