What is Prior Art?

By: Mark R. Malek

In my last article, I noted that an inventor has a duty to disclose prior art that they know of  when filing a patent application.  But what is prior art?  The answer to this question is extraordinarily important in determining not only patentability of an invention, but also in determining whether or not an issued patent is valid.  Broadly speaking, prior art refers to any information that is relevant to patentability of an invention that predates the date of invention.

So that opens a huge can of worms.  Many inventors think that if it is not described in a patent application, then it is not prior art.  WRONG!  If you go into the patent process with that mindset, then the validity of any patent that may issues is certainly in question.  Don’t get me wrong – a great place to start a patent search is with patent records, but the search should not be limited to that.

Title 35, Section 102(a) (35 U.S.C. Section 102) of the United States Code provides that a person is entitled to a patent unless “the invention was known or used by others in this country, or patented or described in a printed publication in this or a foreign country, before the invention thereof by the applicant for patent.” Section 102(b) of the Code indicates that a person is entitled to a patent unless “the invention was patented or described in a printed publication in this or a foreign country or in public use or on sale in this country, more than one year prior to the date of the application for patent in the United States.”

In the interest of keeping this simple, prior art can be any printed publication.  The big key here is that you should not limit prior art only to other patents.  Quite often, Examiners will issue a rejection of claims of a patent application based on foreign patent references, or even general internet searches that disclose the invention.  In fact, there is an old story that John White (famous teacher of the PLI Patent Bar Review course) cited the bible as prior art back when he was an Examiner!  Therefore, try to keep in mind that prior art can come from anywhere.