Patent Search for Prior Art

Patent searches may be performed to gather market information, to track technological advances or even to better understand the conventions for patent structure and vocabulary. While these are all valid reasons to perform a patent search, the most common reason inventors conduct such a search is to ensure that no previous patent interferes with their plan to file a new patent application.

Some inventors have mistakenly assumed that performing a patent search means simply searching for the product or application they would like to patent online through Google or another similar search engine. However, patents and trademarks are not contained on web pages. Inventors can only access them through online database systems linked from the United States Patent and Trademark Office (USPTO) website.

Can first time patent filers conduct a patent search on their own? While it is not impossible, conducting a thorough patent search is far from easy. Many inventors choose to seek out the help of a registered patent attorney for assistance. At the very least, it is advisable that patent filers contact their nearest Patent and Trademark Resource Center (PTRC) for expert help in setting up a search strategy. To understand why patent searching is a difficult task that many novices decide not to undertake on their own, consider the seven basic steps the USPTO recommends for conducting a preliminary search of U.S. patents and published patent applications:

  1. Come up with terms to describe the invention.

  1. Use the terms to find an initial USPC class and subclass in the Index to the U.S. Patent Classification.

  1. Use the U.S. Patent Classification Schedule to verify the relevancy of the class and subclass found previously.

  1. Use the U.S. Patent Classification Definitions, which can be accessed from the U.S. Patent Classification Schedule page, to confirm the scope of the subclass.

  1. Use the Patents Full-Text (PatFT) and Applications Full-Text (AppFT) databases to retrieve and review the complete list of U.S. published applications and patent documents by USPC classification.

  1. Using the previously determined classification, use the Statistical Mapping from USPC to Cooperative Patent Classifications (CPC) tool on the USPTO website to find and review published applications and patent documents with these CPC classifications in the PatFT and AppFT databases.

  1. Finally, perform a classification search of CPC class schemes on the European Patent Office’s Espacenet website to find additional relevant CPC classifications and use these to perform a final search in the PatFT and AppFT databases.

Inventors may benefit greatly from conducting a patent search prior to preparation and submission of a patent application. Regardless of whether an applicant conducts his or her own search, after the application is filed, the USPTO will conduct a thorough patent search and if prior art is found a patent will not be issued. Conducting a patent search prior to filing a patent application can result in long term financial savings, not to mention stronger patent claims.

Kelly G. Swartz is a patent attorney licensed to practice in front of the United States Patent and Trademark Office and in the state of Florida.  She limits her practice to intellectual property law including patent, trademark, copyright, and trade secrets.  More information about patents and other IP may be found at