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General Exceptions to Patent infringement

Written by Zerbakht Khan on 02 December 2010

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There are three general exceptions to Patent infringement. This article will briefly look at each of them in turn.


Experimental Use


The Patents Act 1977 (the "Act") permits the usage of patented subject matter for experimental use (section 60(5)(b)). This provision acts as an exception to direct infringement of a patent. The law permits such an exception as it is part of the quid pro quo of the patent system in which an inventor is protected by a patent in exchange for disclosing his invention. Society can then use the disclosure to make a work around or build upon current inventions.


Examples of legitimate experimental purposes include the testing of a hypothesis, discovering the unknown and creating an equally effective solution with a different combination of substances.

The dominant motive behind the acts must be that of experimentation. For example, if the motive is mainly to gather information for the use of a third party, this will not be protected by the exception (Monsanto Co v Stauffer Chemical Co).

The experimental purpose must also relate to the subject matter of the invention (SFK v Evans). The subject matter of an invention is found in the claims of patent claiming to be infringed. Merely using the patented product on another invention but not actually subjecting the patented product to any experiment will not protect your acts from liability.

Private Use


Acts done for private non-commercial purposes are excluded from infringement under section 60(5)(a) of the Act. The scope of this exemption is far narrower than experimental use because here there is a strict requirement of a non-commercial purpose (a subjective test - SKF v Evans).

Prior Use


Another exclusion is that of prior use where acts were committed prior to the patents in the UK in good faith (section 64). Prior use can be used to challenge the validity of a patent entirely for failure of establishing novelty. However, it seems that there can be scenarios where a patent is established, but there is no infringement because of the prior use exclusion. For example, on top of where the defendant has made the patented product before the priority date, the Act will also protect a defendant where he or she has made "serious and effective preparation". This "serious and effect preparation" requirement will mean that mere preliminary plans to create the product will not grant access to this exclusion.

Once a prior act has been established, the defendant will be protected in relation to any acts which are the same or substantially the same as the prior acts after the priority date. In deciding whether this substantial similarity requirement is satisfied, it has been held obiter that the court will look at all the circumstances including technological and commercial matters (per Jacob J Lubrizol Corp v Esso Petroleum Co).



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