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Patents are documents which offer protection to inventors to exploit their invention in a particular country for a specified length of time (20 years in the UK).

Because Patents are interested in documenting invention and innovation they contain information not found anywhere else, in fact, 70% of patent information is never published elsewhere.

There are three key free patent databases, esp@cenet from the European Patent Office, US patents through Google Patents, and the database of the USPTO.

Esp@cenet contains 45 million patent documents from around the world (mainly applications rather than granted patents).

Coverage is extensive; for example, GB patents in facsimile back to 1920. USPTO also have a searchable database of all US patents which is full text searchable from 1976 to the present and which contains full page images from 1790 to the present.

Endnote®: References to patents can be sent to Endnote or Endnote Web from the Web of Knowledge™ database, which indexes over 23,000,000 patents including European and US patents.

To search the Web of Knowledge for patents, use the topic search and then refine the results by Document Types and Patents.


Notes on patent searching

Searching for a known item

If at all possible try and get as much information about the Patent, including the applicant details, date of application and patent number. Enter this information into the relevant fields of esp@cenet, Google Patents or USPTO, and hopefully this should give you the results you want.

Searching for patents on a particular subject

This is more complicated:

  1. Review your results and find a patent that is a "good match" for your subject.
  2. Then re-do the search using the International Patent Classification (IPC) number of the "good match" patent. You may find it worthwhile checking the classification number of the patent against the International Patent Classification to ensure relevance.
  3. Move on to search the Google Patents if you cannot find relevant results in esp@cenet.

PLEASE NOTE: If you are searching patents in preparation for applying for a patent yourself, it is best to approach a professional patent agent. More information can be found by contacting the Chartered institute of Patent Agents.

British patents


Esp@cenet covers UK and EU patents and is freely available from the European Patent Office.

The Quick search option works well with patent numbers. To search by subject you must use Advanced search as using this you can combine terms.

Search terms

  • AND combines the search results from two terms, good for limiting searches (note: only three terms can be combined within the search).
  • OR is good for broadening searches, useful to link several terms which may be used interchangeably.
  • NOT is good to exclude a term if you are getting lots of erroneous results.
  • * (asterisk) can be used to replace any number of characters i.e.: automo* will retrieve automotive, automobile and automobiles.
  • Question Mark (?) replaces a single optional character - i.e.: colo?r finds color and colour
  • Hash, (#) replaces a single compulsory character, i.e.: wom#n finds woman and women).

Viewing and using your results

Click on the patent title to call up the document record. This will take you to the bibliographic data display option which provides information about the patent E.g. The inventor, the date etc., an abstract is also given (if available).

There are also links to extra information that can be found along the top and include the following:

  • Description - an outline of the invention;
  • Claims - what the invention does, how it is "new";
  • Mosaics - Diagrams;
  • Original document (in PDF format, if available); and
  • INPADOC legal status - these codes indicate whether the patent was granted, is still in force, or has been amended.

On the right hand side there may also be links to the PDF documents for corresponding patents that have been granted in other countries. For example, a European Patent may also have an equivalent World Patent and a US Patent.

Many patents are available in full-text. Those that are not may be obtained via Inter-Library loans.

Saving and downloading patents from esp@cenet

Once you click on the "Original Document" tab to open the full document as PDF, you should see Print and Save Full document options where available.

British patents local availability

Locally British Patents are held at the Business and Patents Service, 3rd Floor Suite, Central Library, Calverley Street, Leeds LS1 3AB. Tel: 0113 247 8266, fax: 0113 247 8268, or email: They also hold sets of foreign patents and can answer many enquiries. 

US patents

Google Patents

Google purchase access to patents data from the USPTO. Their search interface is easier to use than that of USPTO and there is no need to download the TIFF viewer as patents are viewed as PDF documents. Try the Google Patents search first, and then USPTO. It covers patents issued in the 1790s through to those issued relatively recently. It does not include patent applications or international patents.

Google Patents is quite intuitive to use but Google Patents help is available if needed.

USPTO - using the database

The United States Patent and Trademark Office also have a patent search service. It is not as intuitive as the Google interface.

The service has full page images of all patents right back to 1790, however, to access them you will need to download a TIFF viewer. More information is available from the USPTO website.

On entering there are two searchable categories:

  • Issued patents (PatFT); and
  • Published applications (AppFT).

The following search options are available:

  • Quick search;
  • Advanced search; and
  • Patent number search (or Publication number search if looking for an application).

If you know the number of the patent you can use it to search otherwise the quick search should be adequate.

  1. Enter the search terms (keywords) in the boxes on the right hand side.
  2. Use the drop-down lists on the right to either search all fields or one field only.
  3. Select a date range if necessary from the drop down menu near the bottom.
  4. Click on Search.

Viewing Results

  1. To select a result, click on the hypertext link of the patent number or title. This will display the full text application in HTML format with no images.
  2. To view images, you will need to have the TIFF viewer installed, and select the images button from the top of the screen. A colour screen with images and a menu on the left should then load. From the menu, select the section of the patent that you require.
  3. Depending which TIFF viewer you have installed you may be able to print. A combination of AlternaTIFF and IE6 worked, but Quicktime and Mozilla did not.

Further assistance

Contact your Subject Librarian for further information and assistance.