How to Find Patents

This research guide is designed to help individuals find both U.S. and foreign patents. The guide details print materials, free online resources, and subscription resources available in the library and remotely to Sandra Day O’Connor College of Law students, faculty, and staff. 

 Print Resources 

Patent Searching: Tools & Techniques (2007)
By David Hunt, Long Nguyen, and Matthew Rodgers
Patent Searching: Tools & Techniques provides an overview of the U.S. patent system, the types of patent searches, and patent analysis. It also offers a detailed look at the mechanics of patent searching and analyzes the various search tools available for locating patents.
An Introduction to U.S. Patent Searching: The Process (2001)
By Susan Ardis
An Introduction to U.S. Patent Searching traces the history of patents and describes the elements of the patent document. It also discusses how the USPTO organizes patents and how to search for them. 

Online Resources for Finding United States Patents 

United States Patent and Trademark Office
The United States Patent and Trademark Office (USPTO) is the federal agency that grants U.S. patents and registers trademarks. The USPTO website offers information on searching and applying for patents, registering trademarks, and about IP law and policy. 
  • Office of Patent ClassificationThe USPTO Office of Patent Classification organizes patents through a system of classification. Until January 1, 2013, the United States Patent Classification (USPC) system was the official classification system, but this system is being replaced by the Cooperative Patent Classification (CPC) system. The CPC is a patent classification system developed jointly by the USPTO and the European Patent Office that will be used exclusively by both organizations within a few years.  
  • Seven Step Strategy for Finding Patents The USPTO recommends a seven-step strategy for finding patents:
  1. Brainstorm keywords related to the purpose, use and composition of the invention.
  2.  Look up those keywords in the Index to the USPC to determine the class/subclasses that best fit the subject matter of the invention you are looking for.
  3. Verify the relevancy of the class/subclass by using the online Classification Schedule in the Manual of Classification (this is also useful for finding a relevant CPC classification from a known USPC classification)
  4. Read the Classification Definitions to verify the scope of the subclasses.
  5. Search the Issued Patents (PatFT database) and Published Patent Applications (AppFT database) by “Current U.S. Classification” to access the full-text of patents and published applications.
  6. Review the claims, specifications, and drawings of documents for relevancy.
  7. Check all references and note the designated classification for additional class/subclasses to search.
Google Patents
Google Patents provides online access to granted patents and published patent applications from the United States Patent and Trademark Office from 1790-present and European Patent Office from 1978-present. It offers both a basic search and advanced search.

 Bloomberg Law
  • U.S. Patent Search This Bloomberg Law database contains U.S. patent grants including utility patents (1836-present), design patents (1843-present), plant patents (1931-present), and reissue patents (1838-present).  
  • U.S. Patent Assignment Search This Bloomberg Law database contains published patent assignments from 1980-present.

Online Resources for Finding Foreign Patents

The World Intellectual Property Organization is an international organization dedicated to the development and use of the international intellectual property system. The WIPO website offers a variety of resources on international intellectual property law and the systems that promote intellectual property protection.
  • PATENTSCOPE search PATENTSCOPE search allows searching of over 30 million patent documents including 2.2 published international patent applications.
  • Directory of Intellectual Property Offices This list provides hyperlinks to the websites of intellectual property agencies of individual countries and organizations.
European Patent Office (EPO)
The European Patent Office is part of the European Patent Organisation, a 38-member intergovernmental organization that grants European patents. The EPO website offers information for inventors seeking European patents and a variety of patent searching tools.
  • European Patent Register The European Patent Register contains all publicly available information on European patent applications as they pass through the grant procedures.
  • Espacenet Espacenet offers searching of more than 70 million patent documents from 1836-present in the EPO database. Patents can be searched in English, German, French, Chinese, Japanese, and Korean.

International Intellectual Property Offices and Patent Databases

The WIPO Directory of Intellectual Property Offices lists international intellectual property offices alphabetically by country.

Many countries offer free online access to patent collections in English and provide searchable databases. Below is a select list of English-language websites and searchable patent databases:

Patent Treatise

If you would like to learn more about patent law, Chisum on Patents provides thorough and authoritative coverage of the subject.
Chisum on Patents: A Treatise on the Law of Patentability, Validity, and Infringement
By Donald S. Chisum
This 33-volume treatise by Donald S. Chisum is one of the most-cited patent law resources and is kept up to date by looseleaf releases.   The treatise covers all issues relating to patent law and includes references to legal doctrine, statutes, regulations, and case law.  Specific topics addressed include eligibility, validity, infringement, defenses, remedies, ownership, and transfer.

updated 6/2013

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