Prior art

Concept in patent law

Patent law

Overviews

* Patent
* Patent claim
* History
* Economics
* Criticism

Procedural concepts

* Application
* Prosecution
* Opposition
* Valuation
* Licensing
* Infringement

Patentability requirements and related concepts

* Patentable subject matter
* Inventorship
* Novelty
* Inventive step and non-obviousness
* Industrial applicability
* Utility
* Person skilled in the art
* Prior art

Other legal requirements

* Sufficiency of disclosure
* Unity of invention

By region / country

* Patent Cooperation Treaty (PCT)
* Australia
* Canada
* China
* Europe
* Germany
* Japan
* Netherlands
* United States

By specific subject matter

* Biological
* Business method
* Chemical
* Insurance
* Software
* Tax

See also

* Patent analysis
* Pirate Party
* Category
* Glossary

* v
* t
* e

Prior art (also known as state of the art[1] or background art[2]) is a concept in patent law used to determine the patentability of an invention, in particular whether an invention meets the novelty and the inventive step or non-obviousness criteria for patentability. In most systems of patent law,[3] prior art is generally defined as anything that is made available, or disclosed, to the public that might be relevant to a patent's claim before the effective filing date of a patent application for an invention. However, notable differences exist in how prior art is specifically defined under different national, regional, and international patent systems.[4][5][6]

The prior art is evaluated by patent offices as part of the patent granting process in what is called "substantive examination" of a patent application in order to determine whether an invention claimed in the patent application meets the novelty and inventive step or non-obviousness criteria for patentability. It may also be considered by patent offices or courts in opposition or invalidity proceedings. 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. A patent search is frequently carried out by patent offices or patent applicants in order to identify relevant prior art.[7][8] Certain patent offices may also rely on the patent search results of other patent offices or cooperate with other patent offices in order to identify relevant prior art.[9] Prior art may also be submitted by the public for consideration in examination or in opposition or invalidity proceedings. Relevant prior art identified by patent offices or patent applicants are often cited by patent applicants in patent applications and by patent offices in patent search reports.[10]

## Defining prior art

[edit]

Prior art may comprise information that is disclosed to the public in written form, oral form, or by use. Sources of disclosure in written form may include published patents or patent applications or scientific and technical books and journals. Unpublished patent applications may also be considered prior art under certain circumstances, for example where an unpublished patent application was filed at the same patent office before the effective filing date of the patent application in question.

To anticipate the subject-matter of a patent 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.

### Specific cases

[edit]

Traditional knowledge, such as traditional medicine, may be considered prior art.[11] Information covered by non-disclosure agreements or similar may not be considered to have been disclosed to the public and thus not prior art.[12]

If an invention has been described in the prior art or would have been obvious from what has been described in the 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 is typically not regarded as prior art. Therefore, a patent may be granted on an invention, even though 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.

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).

## Effective date of patents and patent applications as prior art

[edit]

It is typical for a patent office to treat its own patents and published patent applications as prior art as of their filing dates,[13][14][15] although under the European Patent Convention, this applies only to novelty rather than inventive step.[16] However, United States patent law before the Leahy-Smith America Invents Act (AIA) included the Hilmer doctrine, under which United States patents and patent application publications were prior art only as of their earliest effective United States filing dates, i.e., disregarding any foreign priority claimed in those patents and patent application publications. The AIA has abolished the Hilmer doctrine and makes United States patents and patent application publications that name another inventor prior art as of when they were "effectively filed."[17]

## Usage in litigation

[edit]

Arguments claiming prior art are used in defending and attacking patent validity. In one U.S. case on the issue, the court said:

> One attacking the validity of a patent must present clear and convincing evidence establishing facts that lead to the legal conclusion of invalidity. 35 U.S.C. § 282. To establish invalidity under 35 U.S.C. § 103, certain factual predicates are required before the legal conclusion of obviousness or nonobviousness can be reached. The underlying factual determinations to be made are

>   * (1) the scope and content of the prior art;
>   * (2) the differences between the claimed invention and the prior art;
>   * (3) the level of ordinary skill in the art; and
>   * (4) objective evidence of non-obviousness, such as commercial success, long-felt but unsolved need, failure of others, copying, and unexpected results.

> — Graham v. John Deere Co., 383 U.S. 1, 17, 148 USPQ 459, 467 (1966).[18][19]

## Prior art searches

[edit]

Patent offices deal with prior art searches in the context of the patent granting procedure. A patent search is frequently carried out by patent offices or patent applicants in order to identify relevant prior art.[7][8] Certain patent offices may also rely on the patent search results of other patent offices or cooperate with other patent offices in order to identify relevant prior art.[9] Prior art may also be submitted by the public for consideration in examination or in opposition or invalidity proceedings. Relevant prior art identified by patent offices or patent applicants are often cited by patent applicants in patent applications and by patent offices in patent search reports.[10]

### Types of prior art searches

[edit]

#### Novelty

[edit]

A "novelty search" is a prior art search that is often conducted by patent attorneys, patent agents or professional patent searchers before a patent application is filed. A novelty search helps an inventor determine if the invention is novel before committing 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. Novelty searches can also be used to help an inventor determine what is unique about their invention. Anything not found in the prior art can be potentially patentable. Thomas Edison, for example, did not get a patent on the basic concept of the light bulb. It was already patented and therefore forms part of the prior art. Instead, Edison got a patent on his improvements to the light bulb. These improvements included a very thin filament and a reliable technique for joining the white hot filament to the room temperature lead wires.[20]

A novelty search is also conducted by patent examiners during prosecution of the patent application. For instance, examiner's search guidelines applicable to the United States are found in the U.S. Manual of Patent Examining Procedure (MPEP) 904.02 General Search Guidelines, Prior Art, Classification, and Search.[21]

#### Validity

[edit]

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. Crowdsourcing, where a large number of interested people search for prior art, may be effective where references would otherwise be difficult to find.[22]

#### Clearance

[edit]

A clearance search is a search of issued patents to assess whether 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.

### Notable prior art databases

[edit]

See also: Category:Patent search services

* DEPATISnet – Public patent database made available by the German Patent and Trademark Office, serving as official publication source for German patents and patent applications and covering numerous other national and regional patent collections
* Espacenet—European Patent Office public patent literature database, with patents from many patent offices.
* Google Patents—public search engine from Google that indexes patents from the United States Patent and Trademark Office (USPTO) and other international patent offices, and machine-CPC-classified non-patent literature from Google Scholar.
* PATENTSCOPE – the PATENTSCOPE public patent database provided by the World Intellectual Property Organization (WIPO) serves as official publication source for patent applications filed under the Patent Cooperation Treaty and covering numerous national and regional patent collections.
* Patent Register Portal provides online patent hosts registers, gazettes, and legal-status-related information from over 200 jurisdictions and patent information collections.

The Internet Archive Wayback Machine is recognized by the USPTO as a valid source of prior art on the Internet, though generally the date of archiving is considered the first published date, rather than the date on any documents that have been archived.[23][24]

## Duty of disclosure

[edit]

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 a person having a duty to disclose, acting with deceptive intent, fails to properly disclose the material references of which they are aware, then a patent can be found unenforceable for inequitable conduct.[25]

Japan also has a duty of disclosure.[26][27][28]

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 before April 22, 2007,
* (b) the foreign patent office search issued before April 22, 2007, and
* (c) acceptance (allowance) was officially advertised before July 22, 2007.[29]

## Public participation in patent examination

[edit]

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.

### Pending patent applications

[edit]

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.
* patents@stackexchange. A Q&A site for people interested in improving and participating in the patent system.

Patent examiners often use the online encyclopedia Wikipedia as a reference to get an overall feel for a given subject.[30][31] Citations of Wikipedia as actual prior art can be problematic, however, due to the fluid and open nature of its editing, and Patents Commissioner Doll said the agency used Wikipedia entries as background and not as a basis for accepting or rejecting an application.[31]

## See also

[edit]

* Defensive publication
* Illegal number, illegal prime
* Information disclosure statement (IDS)
* Internet as a source of prior art
* Micropatent
* Non-binding opinion (United Kingdom patent law)
* Patent classification
* Patent watch
* Priority right
* Public participation in patent examination

## References

[edit]

1. ^ Sreenivasulu, N. S.; Raju, C. B. (2008). Biotechnology and Patent Law: Patenting Living Beings. Manupatra. p. 95\. ISBN 9788189542313. "The European Patent Convention uses the term 'state of the art' which is equivalent to prior art (...)"
2. ^ "The expression 'background art' ... must have the same meaning as the more familiar expression 'prior art'" in EPO Board of appeal decision T 11/82 of 15 April 1983 Archived 29 July 2018 at the Wayback Machine, Headnote II and Reasons 15. See also Rule 42(1)(b) and(c) EPC (previously Rule 27(1)(b) and (c) EPC 1973, where the term is used).
3. ^ See for example Article 54(2) EPC and 35 U.S.C. § 102
4. ^ "Regulations under the PCT: Rule 33 Relevant Prior Art for the International Search". WIPO. Archived from the original on 29 December 2021. Retrieved 29 December 2021.
5. ^ "Certain aspects of National/Regional Patent Laws" (PDF). WIPO. October 2021. Retrieved 29 December 2021.
6. ^ "Regulations under the PCT: Rule 64 Prior Art for International Preliminary Examination". WIPO. Archived from the original on 29 December 2021. Retrieved 29 December 2021.
7. ^ a b "Finding Technology Using Patents - An Introduction". WIPO. 2015. Retrieved 23 May 2025.
8. ^ a b "WIPO Guide to Using Patent Information" (PDF). WIPO. 2015. Retrieved 23 May 2025.
9. ^ a b "Alternatives in Patent Search and Examination" (PDF). WIPO. 2014. Archived (PDF) from the original on 20 January 2022. Retrieved 29 December 2021.
10. ^ a b "Handbook on Industrial Property Information and Documentation: Standard St.14 Recommendation For The Inclusion Of References Cited In Patent Documents" (PDF). WIPO. March 2016. Retrieved 29 December 2021.
11. ^ Ruiz, Manuel (October 2002). "The International Debate On Traditional Knowledge As Prior Art In The Patent System: Issues And Options For Developing Countries" (PDF). Centre for International Environmental Law. Archived (PDF) from the original on 20 January 2022. Retrieved 29 December 2021.
12. ^ European Commission, Executive Agency for Small and Medium-sized Enterprises, Non-disclosure agreement : a business tool, Publications Office, 2021, doi:10.2826/547286
13. ^ 35 U.S.C. § 102
14. ^ Article 54 EPC "Novelty"
15. ^ Japan Patent Act, Chapter II
16. ^ Article 56 EPC "Inventive step"
17. ^ Brinckerhoff, Courtenay (October 20, 2011). "The Disharmonious Loss Of The Hilmer Doctrine". Patent Law Practice Center. Practising Law Institute. Archived from the original on May 30, 2023.
18. ^ Graham v. John Deere Co. of Kansas City Archived 2017-04-24 at the Wayback Machine, 383 US 1, Sup. Ct., 1966.
19. ^ Tokai Corp. v. Easton Enterprises, Inc., 632 F. 3d 1358 at 1363-64, Ct. App. (Fed. Cir.), 2011.
20. ^ "Mark Nowotarski, "Why Inventors Should Not Rely On Their Own Search", IPWatchdog, 11 October 2014". Archived from the original on 9 January 2015. Retrieved 13 October 2014.
21. ^ USPTO, Manual of Patent Examining Procedure Archived 2011-09-26 at the Wayback Machine, "General Search Guidelines [R-3] - 900 Prior Art, Classification, and Search", July 2010.
22. ^ Nowotarski, Mark (July 2012). "Patent Invalidity Search". Insurance IP Bulletin. Archived from the original on July 19, 2012. Retrieved March 1, 2013.
23. ^ All Things Pros blog Archived 2015-04-02 at the Wayback Machine, Board decisions involving the Wayback Machine to show status as prior art (Part I), Sunday, December 29, 2013
24. ^ The Wayback Machine: The State of Dating Online Materials Archived 2015-04-02 at the Wayback Machine, Intellogist patent research blog, Posted February 1, 2011 by Chris Jagalla
25. ^ Therasense, Inc. v. Becton, Dickinson and Co. Archived 2015-05-14 at the Wayback Machine, 649 F. 3d 1276, Ct. App. (Fed. Cir.), 2011.
26. ^ Patent e-Bulletin, Summer '2002 Developments: Following The United States, Japan And Australia Enact Duty Of Disclosure Requirements, Gastle & Associates (through archive.org)
27. ^ See also Japan's Examination Guidelines for Patent and Utility Model in Japan Archived 2012-02-04 at the Wayback Machine, Examination Standards Office, December 2011; and Japan's Right Obtainment Procedures Archived 2012-02-04 at the Wayback Machine.
28. ^ Japan Patent Office, Publication of the "Examination Guidelines on Requirement for Disclosure of Information on Prior Art Documents" Archived 2012-04-19 at the Wayback Machine, Last updated 30 August 2002.
29. ^ Australian Patent Office Manual of Practice and Procedure, 2.13.10 Considering Subsection 45(3) Search Results, 2011-08-15.; see also Changes to regulations made under sections of the Patents Act 1990, (sections 27(1), 45(3) and 101D) Australian Official Journal of Patents, 2007-11-01.
30. ^ Office of the Chief Information Officer, Secure Application Development Coding Policy OCIO[permanent dead link], USPTO, May 22, 2009.
31. ^ a b USPTO Bans Wikipedia Archived 2007-05-07 at the Wayback Machine, The Patent Librarian's Notebook, 2006-09-10, citing Stead, Deborah, Up Front: Kicking Wiki Out Of The Patent Office, Bloomberg Business Week, 2006-09-04.

## Further reading

[edit]

* Tran, Jasper (2014–15). "Timing Matters: Prior Art's Age Infers Patent Nonobviousness". Gonzaga Law Review. 50: 189. SSRN 2562948.
* Blenko, Walter J., Considering What Constitutes Prior Art in the United States, JOM, 43 (6) (1991), p. 45\. Retrieved 2012-01-27.

## External links

[edit]

### Official institutions

[edit]

* World Intellectual Property Organization
* PatentScope, WIPO search tool for international and national patent collections.
* WIPO Intellectual Property Resources, a free public search tool gateway for WIPO's global collections of searchable IP data.
* United States Patent and Trademark Office
* Patent Application Information Retrieval (PAIR), the USPTO search engine for patent and patent application file histories displays reasons why patents are issued; search by application number or customer number.
* Seven Step Strategy, USPTO patent search strategy.
* European Patent Office
* Guidelines for Examination in the EPO, section b-vi ("The state of the art at the search stage")
* Guidelines for Examination in the EPO, section g-iv ("State of the art", examination)
* Legal Research Service for the Boards of Appeal, European Patent Office, Case Law of the Boards of Appeal of the EPO (9th edition, July 2019), i.c.2 : "State of the art"

Authority control databases: National |

* United States
* Israel

|

*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template