The doctrine of equivalence plays an inevitable role in balancing the interests of the patent holder on the one side and the legal certainty of others on the other side. This on the first sight easily seeming question of drawing the line between the area that only the patent holder is entitled to use, due to his inventive achievement, and the area that every competitor may use in order to compete in the market, has been subject to many discussions and judicial developments.
Even though the rules governing the scope of protection of patents have a common base in the European Patent Convention, in art 69 EPC and its Protocol on Interpretation, its application is in the hands of the national courts. Hence the approaches taken by respective countries to the determination of the extent of protection and specifically the relevance of equivalents in patent infringements differ from each other and the deserved harmonisation has not been achieved.
This research aims a deep analysis of the doctrine of equivalence as developed by the case law in Germany and the UK, as ones of the most important patent litigation jurisdictions of Europe. Before 2017, were the German and the UK approaches to the scope of patent protection considered as the most differing ones. The UK has for long time denied the doctrine of equivalence as such, and applied solely one-step purposive construction. In 2017 the UKSC issued its landmark decision in Actavis v. Eli Lilly, which introduced the doctrine of equivalence in to the UK practice, which is a very important step towards a harmonised approach across Europe. In this decision, Lord Neuberger accused the former UK approach of conflating two issues, the normal interpretation as a tool of the literal infringement and the doctrine of equivalence. With this step the UK for the first time gave up the purposive construction as the sole tool for assessing infringement and turns towards a two-step structure which is common for the most European jurisdictions.
The aim of this work is the comparative analysis of the doctrines of equivalence with their partial questions, as developed by the courts in the UK and Germany. The comparative analysis will show if and to which extent a harmonised approach to the concrete tests of the doctrine of equivalents has been achieved. After in-depth analysis conclusions will be made, how the extent of protection should be best approached to be well in line with art 69 EPC and its Protocol, which differences in the respective doctrines of equivalence need to be overcome to reach a harmonised approach to equivalents. Furthermore recommendations as to how the differences could be overcome and suggestions for improvements will be made as to how the doctrine of equivalence should be best formulated to guarantee a balance between fair protection to the patentee and legal certainty for third parties, which could potentially be followed also by the UPC in the future when dealing with equivalent patent infringements.