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Conducting a Patent Search

The United States Patent and Trademark Officeexternal link (USPTO) web site allows you to search for patents and published patent applications.  The full-text of patents from 1976 to the present is searchable.  Patents from 1790 to 1975 are searchable only by current U.S. classification number, patent number or issue date.  The full-text of published patent applications since March 15, 2001 is searchable.

The USPTO advises that the most comprehensive patentability search of U.S. patents will be a search conducted by Cooperative Patent Classification (CPC) number in their patent database.

The USPTO web site also contains various tools that will help you conduct a preliminary patentability search:

As a Patent and Trademark Depository Library, the New York State Library also provides access to the USPTO's PubWEST and PubEAST search systems. These time-saving tools, are not available on the Internet, can help you perform a more thorough patent search.

The New York State Library has trained staff who will assist you in learning to use these tools. Appointments are not required to use the collection but are recommended if you would like assistance in using these tools. Appointments can be made by calling 518-474-5355 or by e-mail. The staff are not, however, patent attorneys or registered agents, and cannot:

  • provide legal advice,
  • interpret your search results or strategies, or
  • provide opinions on the viability of a patent application. 

The USPTO's Office of Enrollment and Discipline provides tools to help find a patent attorney or agent.external link 

Other online search tools:

  • Esp@cenetexternal link – the European Patent Office's free search engine for international patents.  Includes over 70 countries, coverage varies from country to country.  One of the features for US patents is inventor name and patent title searching from 1920 to present.
  • Google Patent Searchexternal link – provides optical character recognition searching of scanned US patent images from 1790 to recent years.

Patent Offices in Other Countries

Canadian Intellectual Property Office: Governmental unit responsible for patents, trademarks and copyright in Canada. Searchable patent and trademark databases.

European Patent Office: The search page allows free searching of EP (European), WIPO (World Intellectual Property Association), Japanese (PAJ) and "worldwide" patent documents. Provides full text images of the documents as PDF files. You can use Espacenet to search for older US patents by inventor name. 

Japan Patent Office: The official web site for the Japan Patent Office. It offers search tools for patents, designs, and trademarks.

Other Brand and Trade Name Sources

The Library has other publications where you can find brand and trade names. Some examples are annual trade directories such as:

  • Companies and Their Brands, Brands and Their Companies, the international versions of those publications, and
  • the brand name indexes in Thomas Register of American Manufacturers, Standard Directory of Advertisers and Corporate Affiliations.
Last Updated: January 20, 2022