Information sources: Patents

Why patents?

Patents are a form of intellectual property, which can provide useful technical information.

There are several reasons for searching the patent literature:

  • Technical information: Patents contain a wealth of technical information, which is often unavailable in journal articles and conference papers. Researchers who ignore the patent literature run a serious risk that they will miss important documents and waste time and money by duplicating previous research.
  • Novelty or patentability of a new invention, ie whether it can be patented
  • Freedom to operate or infringement: Before a company starts using a new process, staff should check whether it infringes another company's patent.
  • Competitive intelligence: For example, by analysing a rival company's patent activity over several years, it's possible to detect changes in its research direction.


Caution: Patents are legal documents and the information they contain may be difficult to read because of its legal vocabulary. A patent may also be difficult to read because of deliberate obfuscation, eg a patent's main purpose may be omitted. Also, the technical details may be imprecise and need further research work, eg several materials may be given without identifying the best compound, or a range of temperatures may be quoted. If refereed journal articles are available, you will probably find them much clearer than the equivalent patent. However, around 80 per cent of patents are never published as journal articles, and for those which are published as journal articles, the patent is usually published first.

If you are considering the patentability of a new invention, staff in the University's Research Support & Development Office can provide assistance. The Chartered Institute of Patent Agents (CIPA) provide a directory of patent agents, which can be searched by region, location and company name.

E-mail: Jon Ford, Contracts and IP Officer,

About patents

A patent is a document, which describes a new invention. It is a legal document conferring exclusive rights to a person or organisation for a process or product for a limited period of time in return for the disclosure of the invention and various payments.

Three sections: A patent has three sections: the front page, specification and claims. The front page includes: a title, abstract (summary), patent number, date, inventor and applicant (the company or individual applying for the patent). The American term for an applicant is assignee. Each piece of information is identified by a unique number - so, for example, a patent's date can be distinguished even if the language is unfamiliar. Some common two letter country codes are: (CH) Switzerland, (DE) Germany, (EP) European Patent Office, (FR) France, (GB) United Kingdom, (JP) Japan, (NL) Netherlands, (US) USA and (WO) Patent Co-operation Treaty.

The second section is the specification, which describes the invention and may include examples, drawings and an account of the prior art (background technology) . The third section has the claims which define the legal boundaries of the patent - usually there is a series of claims, which start with broad claims and then become progressively narrower in scope.

Publication: In most countries a first patent document is published eighteen months after the application and then a second patent document is published when it is granted. The first document (the A patent) is particularly important for its information content, whilst the second document (the B patent) is more important for legal purposes.

In most countries, for a patent to be granted, the invention must not be public knowledge anywhere in the world before the date of the first application. In order to meet this requirement, it is essential that details of the invention should not be published or publicly demonstrated, prior to the application. Also, visitors should be prohibited from seeing the invention in research laboratories and theses with patent potential should not be publicly available in a library.

European patents: These were introduced by the European Patent Convention in 1978. Originally they were seen primarily as a way of reducing the work load on national patent offices and thereby cutting a processing backlog. The first publication of a European patent occurs eighteen months after the application and must be in one of the three official languages: English, French and German. Most west European countries participate in the system and the European patenting route has become very popular. Indeed, British companies usually opt for the European patent route rather than the national route, because they want patent protection in several European countries and it is less expensive. There are European Patent Offices in Munich, The Hague, Berlin and Vienna.

Patent duration: In most countries the patent term continues for twenty years from the application date, assuming that the annual fees are paid. Sometimes, however, the fees are not paid and then the patent will lapse. Whether a patent is "in force", lapsed or not yet granted, is very important for infringement and licensing issues.

Finding patents

Esp@cenet is European Patent Office's database providing access to national websites, which share a common interface. The British website offers:

  • Full text European patents from around 1978 onwards, in English, French or German
  • National full text patents for: UK, US, France, Germany and Switzerland
  • World Intellectual Propery Organisation (WIPO) full text patents
  • Abstracts for other European countries' patents

The USPTO website offers: the full page images of US applications for patents from 2001; the full text of granted US patents from 1976; and full page images of US patents from 1790 to 1975. The images are displayed as TIFF files (a plug-in can be downloaded from the USPTO website). This database is updated weekly, usually each Tuesday.

Other sources

The coverage of the main websites is wide ranging. However, if you cannot find the patent you require, you could request it through our inter-library loan service or visit the British Library.

For inter-library loans, please include the country, patent number and patent date when you complete the form.

Alternatively, you may want to visit the British Library at St. Pancras, the UK's national patent library. As well as British patents, the British Library holds patent specifications from more than 40 other countries and international authorities. This collection comprises many web, print, microfiche and CD patents. The British Library's website offers extensive information about patent and other intellectual property resources.

Mediated searching

Mediated searching is a fee based search service, performed by an intermediary, which may include databases beyond those offered by Brunel Library. Before contacting such a service, we recommend that you try using the free websites, such as Esp@cenet. However, if you do decide that you want a mediated patent search, then you could consider the services offered by the Intellectual Property Office and the British Library. Staff at both these services would have access to the Derwent World Patents Index (DWPI), amongst other databases.

DWPI is a key patent database, covering patents from over 40 countries. One of its special features is that patents for the same invention in different countries are grouped together. In DWPI, the first patent to be published is called the basic patent, subsequent patents from other countries are called equivalents and the group of related patents is called a patent family. DWPI's other special features include: enhanced titles, abstracts written by in-house staff and indexing. Start dates vary by subject: 1963 for pharmaceuticals, 1966 onwards for polymers, 1970 onwards for general chemicals, and 1974 onwards for electrical/electronic engineering patents.

The Intellectual Property Office performs patentability, freedom to operate and grant assessment searches. Some of the researchers in the British Library's Research Service specialise in patents.