This article briefly looks at the available defences to patent infringements.
The first potential defence is that the patentee (being the owner of the patent) consented to the use by way of a licence.
However the main “defence” used in patent claims is not actually a defence at all and instead is an attack on the validity of the paent, if the patent (as a whole or particular claims) is proved to be invalid then the defendant may not be liable for having infringed the patent.Another slightly obvious defence is that the defendant is actually a co-owner of the patent (PA 1977, s 36). The question of ‘use’ has a dramtic effect on the number of trade mark infiringement claims, for example repairing a patent infringement: Betts v Wilmottett or Sirdar Rubber v Wallington, Weston & Co.
Further defences arise from the EC rules on free movement of goods, simply goods sold on other EU member states markets may be parallel imported into the UK. This would be legitimate and would not infringe the patent.
Finally the Patents Act 1977 provides for further defences:
S60 (5): An act which, apart from this subsection, would constitute an infringement of a patent for am invention shall not do so if-
a) it is done privately and for purposes which are not commercial;
b) it is done for experimental purposes relating to the subject matter of the invention.