Inventive step: is 'long felt want' still worth arguing?

VPG Systems UK Ltd v Air-Weigh Europe Ltd [2015] EWHC 1862 (IPEC), is a tidy little decision of Judge Richard Hacon, sitting in the Intellectual Property Enterprise Court, England and Wales, on 1 July, where the court found that VPG's patent for a device for indicating to the driver of a commercial vehicle that load limits for that vehicle had been reached or exceeded was invalid as lacking an inventive step [this is the second blogpost on issues arising between these parties: here's the first].

Of particular interest to this blogger is the judge's comment at [66]:

"I would only add this. No argument of long felt want was run by VPG. Superficially one might have expected an argument of that kind in these proceedings. The evidence from the experts suggested that this was a field in which the performance of inclinometers and accelerometers was advancing at quite a rapid rate in the period leading up to the Patent's priority date. Had long felt want been run, it is possible that it was around 2006 when such advances made a system of the type claimed in the Patent commercially attractive. As it is, long felt want was not enrolled to assist VPG's case so the change in performance of inclinometers is neutral".

'Long felt want' is an argument that had its heyday in the previous century, when a patent's inventive step (a.k.a. lack of obviousness) was something that was more often than not established by the application of rules of thumb which established that an invention was not obvious if, e.g., there had long been felt to be a want of it but that want had not been hitherto satisfied, or that it was obvious if it consisted of the application of a known principle for a known purpose or was reasonable for the person skilled in the art to try it. However, after (i) the Court of Appeal in Windsurfing International Inc v Tabur Marine (Great Britain) Ltd [1985] RPC 59 created a formula that looked specifically at the difference between the alleged patentable invention and the prior art and (ii) advances in computer storage, retrieval and search made the prior art far more accessible than had previously been the case, reliance on rules of thumb -- including 'long felt want' -- appears to have declined.

This is very much a personal impression, but this blogger feels that the very fact that a party raises 'long felt want' as an argument that its patent is not obvious is a flag being waved in the direction of the court that the argument in favour of there being an inventive step is a really weak one. A search of patent cases on the BAILII database suggests that the words 'long felt want' have scarcely been uttered by any British judge over the past five years.