A patent search is a subset of the prior art search in which you look for mention of similar ideas in academic and technical literature, etc. You must conduct a prior art search, including a patent search, and submit your findings along with your application to the USPTO. An inventor has a legal obligation to disclose relevant information of which they have knowledge. If it is discovered that you knew about other similar inventions or relevant information, and did not submit that information to the USPTO, your patent may be held unenforceable, and you may be responsible for legal costs of an infringer. This is called inequitable conduct or fraud on the patent office.

If, however, you search for and submit relevant prior art, and the USPTO accepts how you have distinguished your invention over the prior art, such acceptance in an issued patent application carries a legal presumption of validity. This is extremely difficult for others to challenge. Many parties that infringe a patent will attempt to challenge a patent’s validity by searching for prior art that the patent holder did not include in the patent application. Including and distinguishing prior art in the patent application, which will be noted in a patent if and when a patent ultimately issues, entitles the patent holder to this tremendous presumptive advantage, by law.

Additionally, if an inventor seeks funding (see Chapter 11), sophisticated investors will always perform due diligence and evaluate the strength of a patent should anyone ever challenge it. Conducting an adequate prior art search and distinguishing your invention from the prior art strengthens any ultimately issued patent.

You'd be astonished how many "new" ideas already have been patented, even if you've never seen anything remotely resembling them on store shelves or in catalogues. Before you spend time and money filing for a patent—even before you develop a prototype—conduct a patent search. It's a critical investment to assess your invention's commercial potential and to avoid inadvertently infringing on someone else's patent. You'll also gain valuable technical insight into your invention, which you can use to refine your idea, and possibly gather information about companies that may be potentially interested in licensing your patent.

Conducting a patent search, however, is painstaking. If you're new to the game, you’re likely to get less comprehensive results than those of experienced searchers. For the most thorough and expert job, consider hiring a patent agent or attorney, who is bound by a professional code of conduct to maintain the invention's confidentiality and not make use of it for personal gain.

You may, however, reduce your expenses by conducting the search on your own or performing a preliminary survey with the US Patent and Trademark Office (USPTO) prior to meeting with an attorney.


To conduct a patent search, you may access:

Online databases: The USPTO has made online searching of its databases available to the public at no charge at http://www.uspto.gov. A few other free online search systems are CASSIS (a CD-ROM based search engine), the Delphion Research Intellectual Property Network (formerly the IBM patent site), and the Source Translation and Optimization (STO) Internet Patent Search System.

The Public Search Room of the USPTO in Crystal City, Virginia: Your local patent depository library, describes the US Patent and Trademark Depository Library Program, as well as gives the names and locations of patent depository libraries, state by state. Note: not every patent depository library has a complete record of USPTO information.

A reputable patent practitioner or professional organization: Patent attorneys and agents who meet specific legal, technical and ethical qualifications are registered by the USPTO. Be aware, though, that the USPTO has no control over patent practitioners or organizations, and reputable search firms use the same advertising techniques as unscrupulous ones. That's why it's advisable to check the reputation of any invention promotion firm.


A few dollar-wise tips:

  • Find out early the total cost of services, which vary with the complexity of the subject matter.
  • Be cautious of extremely low-cost searches; a slapdash search yielding false or limited information could end up costing you a lot of money.
  • Consumer protection agencies, the Better Business Bureau and your state's Attorney General's Office can provide information on any complaints filed against the practitioner or company.

The Inventor Handbook is written as a preliminary guide for inventors and where legal rights are concerned, the reader should consult a qualified attorney.