The recent case Unilin Beheer v Berry Floor NV, Information Management Consultancy Limited (t/a Responsive Designs and/or Tapis UK) and B&Q plc [2007] EWCA Civ 364 explores the crossover of issues between national courts and the European Patent Office (“EPO”) in relation to granted national patents which are subject to a validity challenge before the EPO. Unilin sued Berry Floor and B&Q for infringement under their EP(UK) patent and Berry Floor filed an opposition against the European patent. In the UK proceedings, the patent was held valid and infringed. In the EPO, the opposition proceedings are still ongoing.

At the heart of this matter before the Court of Appeal, was the question of whether the defendant was liable to pay damages for a patent held to be valid and infringed by a UK court, if the patent was subsequently found to be invalid ab initio by the EPO. The Court accepted that any injunction based on the finding of validity in the UK would fall away if the patent was later found invalid.

Whether the leading authority was the EPO or the UK Court was not a helpful way of viewing the problem, and the Court accepted that some might say it would be an injustice for a man to have to pay for doing what, with hindsight, was known to have been lawful. Conversely, the Court also noted that a person paying royalties for an invalid patent would not get their money back and a person refraining from some commercial activity could not be compensated if he later found out it was lawful to undertake such activity. Rather, the Court took into account the importance of public policy of providing certainty for business and in court decisions.

The Court accepted that several issues would arise if the patent was revoked before the EPO but also stated that there is nothing in the Patents Act 1997 which suggests that rules as to estoppel (which form part of our procedural law) are displaced by a revocation in an opposition. The Court highlighted several points in relation to this matter:

  • English law viewed the judgment of a court not as a course of action but as a piece of ‘property’ in itself – a right to claim damages;
  • the EPC said nothing about taking national courts’ autonomy with regard to procedure – and thus the property right of the judgment;
  • that the law of estoppel was of “fundamental importance” to English law and there was nothing in the 1977 Patents Act to suggest that final and binding decisions of UK courts were to be regarded as anything more than provisional;
  • that parties had one opportunity to put their best case in proceedings and no more than that.

Whilst it appears unjust that there is potential for a defendant to be liable for infringing a patent that is later revoked, this case results from the slow and unpredictable nature of EPO postgrant opposition proceedings. As the Court noted, the legal relationship between the national court and EPO proceedings is a necessary but inadequate compromise. Tribunals should attempt to make decisions that do not conflict with one another, and speeding up granting procedures would give business the clarity and certainty it required. The case has become another example in support of the creation of a single European patent litigation tribunal.