Prior art

Prior art (also known as state of the art, which also has other meanings), in most systems of patent law, 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. If an invention has been described in prior art, a patent on that invention is not valid.

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. With such an obligation, the information will typically not be regarded as prior art. Therefore, a patent may be granted on an invention, although someone else already 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. As a special exception, earlier-filed and unpublished patent applications do qualify as prior art as of their filing date in certain circumstances.

In order to anticipate a claim, prior art is generally expected to provide a description sufficient to inform an average worker in the field (or the person skilled 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 in many countries, the information needs to be recorded in a fixed form somehow. Prior art generally does not include unpublished work or mere conversations (though according to the European Patent Convention, oral disclosures also form prior art — see Article 54(2) EPC). It is disputed whether traditional knowledge (e.g., of medical properties of a certain plant) constitutes prior art.

Patents disclose to society how an invention is practiced, in return for the right (during 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).

First-to-invent versus first-to-file

Main article: First to file and first to invent

A first-to-invent rule is followed in the United States. Invention is generally defined to comprise two steps: conception of the invention and reduction to practice of the invention. When an inventor conceives of an invention and diligently reduces the invention to practice (by filing a patent application, by practicing the invention, and so on), the inventor's date of invention will be the date of conception. Thus, provided an inventor is diligent in reducing an application to practice, he or she will be the first inventor, and the inventor entitled to patent, even if another files a patent application (reduces the invention to practice) before the inventor.

A first-to-file rule is followed in most countries other than the United States. Under the rule, regardless of who the first inventor was, the person or legal entity who files a patent application first is the one who is granted patent. The United States is one of the only few countries which follows the first-to-invent rule. Efforts are currently being made to unify the patent laws of various countries, so that inventors have the same rights regardless of the country where a patent is granted.

Other considerations

Although patents normally go to the first inventor under a first-to-file system, an inventor who keeps the information secret or does not publish it does not establish prior art and loses the right to the patent. Without prior art, a subsequent inventor can get a valid patent on the same invention and then apply it against earlier inventor(s). An earlier inventor can forestall such an act by a subsequent inventor by recognizing the invention and applying for a patent, or by publishing details of how to practice the invention, thus creating prior art.

Searching

A "novelty search" is a prior art search that is often conducted by patent attorneys, patent agents or professional patent searchers before an inventor files a patent application. A novelty search helps an inventor to determine if the invention is novel before the inventor commits the resources necessary to obtain a patent. The search may include searching in databases of patents, patent applications and other documents such as utility models and in the scientific literature.

A "validity search" is a prior art search done after a patent issues. The purpose of a validity (or invalidity) search is to find prior art that the patent examiner overlooked so that a patent can be declared invalid. This might be done by an entity infringing, or potentially infringing, the patent, or it might be done by a patent owner or other entity that has a financial stake in a patent to confirm the validity of a patent.

A clearance search is a search of issued patents to see if a given product or process violates someone else's existing patent. If so, then a validity search may be done to try to find prior art that would invalidate the patent. A clearance search is a search targeting patents being in force and may be limited to a particular country and group of countries, or a specific market.

Duty of disclosure

In the United States, inventors and their patent agents or attorneys are required by law to submit any references they are aware of to the United States Patent and Trademark Office that may be material to the patentability of the claims in a patent application they have filed. The patent examiner will then determine if the references qualify as "prior art" and may then take them into account when examining the patent application. If the attorney/agent or inventor fails to properly disclose the potentially relevant references they are aware of, then a patent can be found invalid for inequitable conduct.

At least Japan also has a duty of disclosure. Australia has abolished its duty of disclosure with regard to the results of documentary searches by, or on behalf of, foreign patent offices, except where: (a) normal exam was requested prior to April 22, 2007, and (b) the foreign patent office search issued prior to April 22, 2007, and (c) acceptance (allowance) was officially advertised prior to July 22, 2007.

Public participation in patent examination

Main article: Public participation in patent examination

With the advent of the Internet, a number of initiatives have been undertaken to create a forum where the public at large can participate in prior art searches. These forums have been related to both issued patents and pending patent applications.

A free public wiki service directed specifically to patent and prior art searching, called Intellogist (www.Intellogist.com), was introduced by patent search company Landon IP, Inc. in April of 2009. The site includes a wiki area for registered users to contribute useful search methods (called "best practices" on the site), and to contribute information about the coverage, accuracy, and effectiveness of known free and commercial search products.

Pending patent applications

More recently, different attempts to employ open Internet-based discussions for encouraging public participation commenting on pending U.S. applications have been started. These may take the form of a wiki:

• Peer-to-patent online system for open, community patent review.
• Wikipatents. Public patent clarity: the public can add prior art references for a given patent.

Patent examiners often use the online encyclopedia Wikipedia as a reference to get an overall feel for a given subject. Citations of Wikipedia as actual prior art are problematic, however, due to the fluid and open nature of its editing.

See also

• Defensive publication
• Information disclosure statement (IDS)
• Internet as a source of prior art
• Micropatent
• Patent classification
• Patent watch
• Priority right
• Public participation in patent examination
• Search report

Notable prior art databases

• Espacenet - European Patent Office public prior art database.
• Google Patents - search engine from Google that indexes patents from the United States Patent and Trademark Office (USPTO)

For other patent search services, see Category:Patent search services.

Further reading

• Arnoud Engelfriet, When is something prior art against a patent?, iusmentis.com web site, October 1, 2005, retrieved on June 3, 2006
• Walter J. Blenko, Considering What Constitutes Prior Art in the United States, JOM, 43 (6) (1991), p. 45

External links

Educational and/or Community Resources related to Prior Art Searching

• Intellogist

Official institutions

• WIPO
  • WIPO search engine for international PCT patent applications
  • Links to national patent offices including US, Japan, UK etc.
• USPTO
  • USPTO.gov - Free access to US patents.
  • USPTO search engine for patent and patent application file histories. Displays reasons why patents are issued, by application number or customer number.
  • 7-Step Search Strategy - USPTO 7-Step U.S. Patent Search Strategy
• PATLIB - European Patent Library network
• EPO
  • EPO [1]
  • EPO Guidelines for examination on "State of the art": http://www.european-patent-office.org/legal/guiex/e/b_vi.htm