What is Prior Art?

This article also answers the following questions:

  • Why should I search for prior art?
  • How do I search for prior art?

What is Prior Art?

In a patent application, all the information that is publicly known, disclosed or recorded in any form before a given date which may be relevant or dispute the patent’s claims of originality is known as prior art.  The Inventors Handbook by the EPO has a detailed article which gives more information on the definition of prior art.

Why search Prior Art?

A search of prior art which may be related to a new invention is an extremely important step in the patent process.  Commonly known as a novelty search, a thorough search of published work (and, in some jurisdictions, unpublished such as oral disclosures may be accepted as a form of prior art) is conducted by patent attorneys or patent examiners and allows the inventor to determine if their invention is indeed novel and involves an inventive step, before committing to the substantial costs and time of continuing the patent application process.

A clearance, or freedom-to-operate, search targets granted or pending patents to check if the product or process violates an existing patent.  The outcome may change how the applicant develops the product, or the scope of manufacture and market.  If a clearance search raises a possible infringement, then the more detailed validity search is carried out.

A validity search is identical to a novelty search, but is carried out after the publication of a patent.  This may be carried out to potentially infringe the patent, whereby a piece of prior art which was overlooked by the patent examiner indicates that the invention already exists and has been previously patented.  This could lead to the patent being invalidated.  Validity searches are useful for both aspects: either if a patent holder is considering taking legal action for infringement of their patent, or if a competitor is threatening the patent holder with infringement proceedings.

How Do I Search for Prior Art?

Conducting a prior art search involves extensive searching of different databases to locate information that has been previously disclosed to the public.  The investigation is usually assigned to a professional patent searcher due to their expertise in the field.    Typically, a multifaceted approach is used, to minimise the risk of missing an important piece of prior art (take a look at the EPO Inventor’s Handbook section Prior Art Searching).  In the UK, a Search and Advisory Service is offered by UKIPO, with a basic novelty search typically £500 – £1000, a clearance search  approximately £1000 – £5000, and a validity search costing upwards of £1000.

  1. Online patent databases are searched, using keywords to describe the invention.  A direct link to one of the largest searchable databases, the European Patent Office Espacenet, is given here, and holds over 70 million patent documents from around the world.
  2. Known related inventors and companies are searched.
  3. Other forms of information such as technical papers, academic publications, published journals and books,     conference proceedings, magazines and newspapers are likely to be systematically searched for mention of any related technologies.
  4.  A full list of all relevant documents are sent to the inventor who can then determine the next step they would like to take.