Patent invalidity and revocation
Patent invalidity and revocation

The following IP guidance note provides comprehensive and up to date legal information covering:

  • Patent invalidity and revocation
  • What is a patent
  • Grounds for patent revocation
  • Claim construction/scope
  • Lack of novelty (anticipation)
  • Lack of inventive step (obviousness)
  • The Windsurfing (Pozzoli) test
  • EPO approach—problem and solution approach (AgrEvo obviousness and technical contribution)
  • Obvious to try
  • Obviousness over prior art or prior use and CGK
  • more

What is a patent

A ‘patent’ is a document conferring so-called monopoly rights to an inventor. A patent protects new inventions and may cover aspects such as how things work, what they are made of and how they are made. The rationale behind patents is that they encourage innovation by rewarding the patent owner with 20 or more years during which they can prevent others from making, using, importing or selling the invention without permission (even if they are not deliberately infringing), which is why they are said to confer ‘monopoly’ rights.

A patent is granted following a formal application and registration procedure. During this process (which is referred to as patent prosecution), the patent application is examined by a patent examiner at the relevant intellectual property office (eg the UK Intellectual Property Office and European Patent Office (EPO)) to check whether the invention claimed is patentable and that the patent application meets certain formal requirements.

For more information about applying for a patent, see Practice Notes:

  1. Applying for a UK national patent

  2. Applying for a European Patent

  3. Applying for a patent under the Patent Cooperation Treat

Grounds for patent revocation

Patent examiners cannot exhaustively check that all of the criteria have been fulfilled prior to grant. For example, they cannot check all of the prior art worldwide to ensure