Case Studies - Priority Documents

In a recent decision of the Technical Board of Appeal (T 1983/14), the EPO reaffirmed that in order to benefit from the filing date of a priority application that any amendment that you make during the course of prosecution of a European application is directly and unambiguously derivable from priority document.

In this case, the original priority document was filed with a set of five figures which were supplemented with an additional seven figures when filing the PCT application. During the course of prosecution, the patentee amended to features that were described with reference to the embodiments described in the additional figures. With this amendment, a patent was granted.

In the course of opposition, where Barry Moore and Conor Boyce acted for the opponent, we argued that the amendment was not supported by the original disclosure of the priority document- it was not directly and unambiguously derivable. The patentee had also admitted to prior use within the convention period which was novelty anticipatory. Faced with the inescapable trap of not being able to amend to restore priority without impermissibly broadening the patent, the Opposition Division concluded that the patent should be revoked.

This interlocutory decision was appealed. In the course of oral proceedings before the Appeal Board, despite the protestations of the patentee, Conor Boyce representing the opponent, reiterated the argument that any interpretation of the priority document to support the interpretation necessary for the patentee was once that relied on hindsight and hence impermissible. The requirement for support is direct and unambiguous disclosure and faced with this strict test, the Board had no alternative but to dismiss the Appeal. 

The conclusion - always look to the priority document when making amendment. The EPO will require direct and unambiguous basis and if you cannot support your amendment in the priority document, you may find yourself arguing against the relevance of prior use by the applicant within the priority convention year. 


Image: iStock


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