The life of a patent attorney is hard enough as it is, but using
the EPO claim drafting convention, one would be forgiven for
thinking that after carefully steering around the prior art in the
'pre-characterising' portion of the claim, that would be
enough. Not so.
In the recent Court of Appeal decision of Lufthansa Technik
AG v Astronics Advanced Electronics Systems and ors [2022]
EWCA Civ 20 the distinction fell to be considered. In the judgement
of LJ Birss, he said:
This case highlights a curiosity of the pre/post characterising
approach to claim drafting. When drafted this way the
characterising features of the claim explain what the patentee
thought were features not disclosed in the prior art on which the
pre-characterising part was based..... In other words these
characterising features are presented as representing the inventive
step over that prior art. However the challengers to validity in
this case, as they are entitled to, rely on different prior art.
