Daniel Porter
Oct 16, 2012

Patent Knowledge: Prior art search

Last week’s article detailed prior art and patentability, and defined prior art as all information pertinent to a patent that was publicly available before that patent’s application was submitted. This information is important because novelty is an important part of patentability.

What is “prior art search?”

If prior art exists that also describes the idea in a particular patent, that patent is invalid and the USPTO should not have issued it in the first place. A “prior art search” is the process of searching through the existing body of publicly available information.

When to conduct a prior art search

There are three major categories of prior art search, each roughly defined by the circumstances in which they are needed. The first case is a novelty search, initiated by an inventor to discover whether their invention is novel before filing a patent application. Patent filing is a costly and time-consuming endeavor, and one that could be wasted if the invention is not novel. This is also the type of search that the patent examiner performs when evaluating an application based on the standards of novelty and obviousness discussed in the previous article.

Once the USPTO issues a patent, a person or company may perform a validity search. The goal of this type of prior art search is to locate documentation that the patent examiner did not locate in the original novelty search before issuing the patent. When a patent holder accuses another party of infringing on its patent, the infringing party will often initiate this type of search with the goal of demonstrating that the patent in question is invalid because it is not original under the requirements of 35 U.S.C.

The final type of search seeks to demonstrate a company’s freedom to operate. When a company releases a new product or process, they want to make sure that product doesn’t infringe on any intellectual property rights. This type of search focuses on determining whether or not a particular ideas has been described in previous patents other other intellectual property documentation.

Where to look

Knowing where to look, and therefore exactly what qualifies as prior art, is crucial to a good prior art search. In essence, all publicly available publications constitute the body of prior art for a patent. As with many legal matters, this definition leaves room for interpretation. The wording provided by the USPTO describes documents that have “been disseminated or otherwise made available to the extent that persons interested and ordinarily skilled in the subject matter or art, exercising reasonable diligence, can locate it.”

The courts have set numerous legal precedents to establish the precise meaning of this language and how it applies, and in practice the definition is very broad. Previously published patents, scientific papers published in journals, newspaper articles, graduate theses, documents made publicly available on the internet, patents issued in other countries, documents available in foreign languages... The list of potential prior art is extensive.

Problems with prior art search

In 2011 the USPTO issued its 8 millionth patent. This means that a patent examiner needs to effectively search through 8 million documents just to determine if application describes an invention already patented. With the broad definition given above, particularly with today’s availability of information, the field of search for an examiner to determine whether or not an invention is novel is nearly infinite.

As a result patent examiners, already overburdened with too many applications, can’t search everything. Their novelty searches frequently miss sources, and this has given way to the prevalence of wasteful validity searches for patents which should not have been issued in the first place.