Prior art

Definition

U.S. patent law

Prior art constitutes all information that was available to the public in any form before a given date that might be relevant to a patent's claims of originality. If an invention has been described in prior art, a patent on that invention is not valid. Prior art consists of materials — often patents and publications, although affidavits and testimony also may present prior art — that reflect one or more of the features or elements of the claimed invention.

Overview

In most patent systems, in order to anticipate a claim, prior art must provide a description sufficient to inform the average worker in the field (or a person of ordinary skill in the art) of some subject matter falling within the scope of the claim. Prior art must be available in some way to the public, and many countries require the information to be recorded in a fixed form.

Patents disclose to society how an invention is practiced, in return for the right (for a limited term) to exclude others from manufacturing, selling, offering for sale or using the patented invention without the patentee's permission. Patent offices deal with prior art searches in the context of the patent granting procedure. To assess the validity of a patent application, patent offices explore the prior art that was disclosed before the invention occurred (in the United States) or before the filing date (in the rest of the world).

As a special exception, earlier-filed and unpublished patent applications do qualify as prior art as of their filing date in certain circumstances.

Trade secrets

Information kept secret, for instance as a trade secret, is not usually prior art provided that employees and others with access to the information are under a non-disclosure obligation. Absent such an obligation, the information will typically be regarded as prior art. Generally, this means that a patent may be granted on an invention despite the fact that someone else knew of the invention. A person who used an invention in secret may in some jurisdictions be able to claim "prior user rights" and thereby gain the right to continue using the invention.

Software patents

The quality and availability of the published (as opposed to product) prior art, or known technology, is often cited as affecting the quality of issued patents. The U.S. Patent and Trademark Office relies upon its database of prior art to determine whether the invention defined in a patent application meets the patentability criteria set forth in statute. It is against this collection of prior art literature (including earlier patents) that the PTO compares the claimed invention and decides whether the claimed invention possesses the requisite novelty and nonobviousness.

A major problem for patent-system administration with respect to software-related inventions and algorithms has been the incomplete stock of prior art available to patent examiners in evaluating patent applications for processes involving computers, especially those involving software and algorithms. “Filling in” the prior art database (with both patent and nonpatent prior art) is important for improving the quality of examination.

Among the reasons cited for the perceived problem of prior art is the extensive use of trade secret protection for computer software. Unlike patent and copyright protection, a trade secret does not require disclosure of information that is the subject of protection. Rather, a trade secret requires that the holder of the trade secret make a deliberate effort to maintain the secret quality of the information. Such secret information cannot, by definition, function as part of the “known” technology available as a standard for patentability as required in the patent law.

In the course of development of the computer sciences, some advances in the field were published in journals and industry communications, most especially within the academic community. However, many new innovations were not published because they were simply embodied in a product or not considered the type of “invention” which would be the subject of a publication. The prior art that is not the subject of a patent is not always considered to be as rich in the computer science field as in other disciplines. As a result, in large part, the resources available to the PTO for determining obviousness and novelty are more limited than in other fields; in large part the prior art database is limited to software that is already the subject of other patents for software-related inventions. It is therefore often difficult to determine what can be considered the current state of the technology and what can be considered, in the words of the patent statute, "obvious to the ordinary person skilled in the art" for purposes of determining patentability.

The patent law does not provide for a free system for third parties to add to the present general stock of prior art. However, it does allow parties to submit art that maybe pertinent to the patentability of particular issued patents. As a result, it has been suggested that a private database of prior art be developed by the industry itself, which would allow for free contribution of prior art in an effort to improve the quality of the prior art database available to the PTO and, consequently, of the patents issued.