EPO: T 1410/14, Board of Appeal, 14 October 2015

An EPO board considered the burden of proof of public prior use when the invention had been publicly visible only for a short period of time. The Board required proof beyond a reasonable doubt that a claim feature could be directly and unambiguously derived from the public availability in the time interval. The opponent failed to show this because it could not be assumed with enough certainty that the patented feature was visible during the time interval or, if it was, that the patented feature would have been a distinguishable feature. Repeated public visibility did not change this.

A full summary of this case has been published on Kluwer IP Law.