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
- Brainstorm terms describing your invention. Try to think of alternative words to describe your concept. For example, an umbrella could also be called a parasol or a sunshade.
- Conduct a keyword search using Patent Public Search. You can begin with a broad search for your main concept, and then narrow the search results by adding additional features of your invention. Review the front pages of patents and published patent applications, eliminating those that are irrelevant. Guidance on how to search is available in our Quick Reference Guides.
- Conduct an in-depth review of the documents found by your search. Review in detail the complete patents and published patent applications you found that are similar to your invention. Don’t forget to review the drawings, specification and claims for similarities to your invention.
- Expand the search with relevant CPC classifications. Go to the Classification Resources page and select the CPC classification system. Find a relevant classification and use it in a classification search in Patent Public Search’s Advanced Search with the .CPC. field code.
- Review cited references. The front page of a patent includes a section of cited references provided by the applicant and/or the patent examiner. Review the U.S. patents and published patent applications that a patent has cited and/or the patents that have cited them since their publication. Patent Public Search can provide a search of both the backward and forward citations.
- Broaden your search with foreign patents, non-patent literature and/or a patent professional’s search. Check Espacenet, the European Patent Office’s worldwide patent publication database of over 140 million patent publications. Also search books, journals, websites, technical catalogs, and conference proceedings in the applicable field. You may want to hire a registered patent attorney or patent agent to review the search.
More information on Multi-Step U.S. Patent Search Strategy - prepared by the USPTO.
