Frequently Asked Questions about Prior Art Searches

What is prior art?

Generally, prior art constitutes all information that has been made available to the public in any form before a given date that might be relevant to a patent's claims of originality. The precise meaning, application, and reference date of prior art is defined by the various national patent laws. For example, oral disclosures of an inventive concept constitute prior art in some countries but not in others.

Relevant art is "prior" if its reference date precedes an invention's "critical date," which (in most of the world, including the U.S.) means the filing date of a patent application. Thus, a disclosure is only prior art to a patent application or issued patent if its reference date precedes the patent application filing date.

The most general definition of prior art is that it refers to earlier existing public knowledge that is relevant to a patent's claims of originality. Note that trade secret information subject to a non-disclosure agreement would not be prior art. Thus, prior art refers to all technology that is relevant to an inventive concept and was publicly available (e.g., described in a publication or offered for sale) at the time a patent application was filed.

More particularly, prior art refers to any such technology that would invalidate a patent or limit its scope. The process of prosecuting a patent or interpreting its claims largely consists of identifying the relevant prior art and distinguishing the claimed invention from that prior art.

What are the sources of prior art?

The reservoir of prior art is vast. The most common sources of prior art are patents, published patent applications, and non-patent literature, such as journals, books, academic work, product literature, and internet publications. Prior art also includes physical embodiments of products and evidence of sale or public use. The United States patent system alone includes more than eight million issued United States patents, and is classified in over 140,000 classes and subclasses. Even a Donald Duck story can be used as prior art.

Each of these sources of prior art requires a different search approach and are more or less applicable depending on the subject area of technology.

Patent collections are distinguished from other prior art information sources by their excellent organization and accessibility. Patents are one of the most thoroughly indexed and documented forms of literature, allowing specific prior art database search information to be retrieved and reviewed with considerable accuracy. Typically, 80% of information published in patents is not published elsewhere.

The patents issued or patent applications published by the USPTO, EPO, PCT, and JPO cover more than 90% of patents and applications filed worldwide. Thus, a patent prior art search is usually a search of patents emanating from these patent offices.

Since patent documents must describe inventions in sufficient detail that persons skilled in the art can reproduce them, (insufficient disclosure can result in the rejection of a patent application) these documents will contain detailed information you will not find in classic scientific publications.

Depending on your needs, we can conduct a non-patent literature (NPL) prior art search, although such searches can difficult to search and be expensive. Academic papers are in the forefront of innovation but more often tend to lack trivial technical detail that is required for the case. No single source comes close to covering all publications available. The need to conduct an NPL prior art search varies by technology and type of search.

For example, the mechanical and electrical hardware arts tend to be well-covered by patents, whereas practitioners in the fields of computer science, medicine and biotechnology tend to publish more frequently in journals. For a typical patentability search, non-patent literature is often ignored, whereas for validity searches with a great deal of money at stake all sources of prior art must be searched.

What is the date of invention?

A prior art search attempts to locate prior art patents or non-patent publications that predate a critical date that corresponds to the date of invention of the target patent. In most of the world, which will include the U.S. as of March 16, 2013, the date of invention is the filing date of the patent application. In such a country, a prior art search attempts to locate relevant references that precede the filing date of the patent application.

Do I need to conduct a patentability search?

No patent office requires that an applicant conduct a prior art search before filing a patent application. In the U.S., the Court of Appeals for the Federal Circuit has stated that patent applicants have "no duty to conduct a prior art search." Frazier v. Roussel Cine Photo Tech, Inc., 417 F.3d 1230 (Fed. Cir. 2005).

Although a prior art search is not legally required, we recommend that a client perform one in most situations. In particular, before an individual inventor expends substantial effort and expense, we advise that a prior art search be performed to determine whether others have already staked a claim to that inventive concept.

The patentability search will flush out prior art before the patent application is filed. The patent attorney or patent agent will then use the search results to draw up the broadest possible set of claims without treading on the known prior art. Without a solid understanding of the prior art, it is difficult to draft novel claims with the appropriate scope.

Ideally, this preemptive patentability search will locate the prior art that an Examiner would have asserted in a first office action, and will lead to a better set of claims being allowed at an earlier date.

Thus, a patentability search will determine whether to file the patent application, anticipate many of the issues that will arise during prosecution, and assist with claim interpretation.

Can I conduct a patentability search myself?

Yes, some patent applicants conduct a patentability search themselves. Other applicants shop around for the cheapest prior art search they can find. However, there are subtleties of semantics and strategy in researching patent specifications that make it advisable to engage an experienced patent search professional. Conducting a free patentability search may save you money; however, such a search may not be as efficient as one conducted by a professional patent searcher.

In our opinion, only experienced searchers using professional tools can reach an adequate degree of search completeness. You cannot expect to be search proficient with a few minutes of training. In addition, it can be more efficient to hire a professional directly than to use free patent search tools yourself. A specialist uses fee-based professional tools and gets the most out of all possible sources.

It is unwise to skimp on a prior art search, only to discover later that others have already locked up the rights to the invention. As the old adage goes, “The bitterness of poor quality remains long after the sweetness of low price is forgotten.” (Benjamin Franklin)

How much does a search cost?

Due to the many different types of searches, the varying degrees of invention complexity, the number of possible approaches (U.S. patents-only or also including foreign patents or non-patent literature), the various searchable geographic areas, various client preferences, and so on, we cannot provide a menu of rates for each search. will provide you with an estimate for work within a specified budget once we have reviewed a search request. We can tailor the time spent and databases accessed for a given patent search to meet your needs and budget.

Please contact us for further information on estimates and pricing.

Should I use invention promotion companies?

The field of intellectual property is plagued by the scourge of unethical "invention promotion companies." Some of these companies will attempt to draw in inventors by offering patent search services. Many invention promotion companies provide little or no value to the inventor. They prey on the inventor's desire to bring his or her product to market, making false promises about their ability to promote the product, sometimes supported by their own "market studies" of dubious value.

The United States Federal Trade Commission has a page on this topic to warn inventors: Invention Promotion Firms. The United States Patent and Trademark Office also publishes a Scam Prevention Warning.

We recommend that you avoid dealing with any invention promotion company that you have not thoroughly checked out through the FTC, Better Business Bureau, and other appropriate agencies.