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When Does Public Testing Of An Invention Invalidate a Patent?

By Brian Whitehead, Consultant

The decision of the IPEC Judge, HHJ Hacon in Claydon Yield-O-Meter v Mzuri provides an interesting reminder as to the strict approach of the English courts toward prior disclosure. The details of the action are unimportant, save to say that the patent relates to a new method and apparatus for planting seed to produce agricultural crops. An apparatus made to the invention is a large piece of agricultural machinery, pulled by a tractor. Prior to filing his application, the inventor tested a prototype on a field on his farm. It was apparently tested for ten hours, including travel to and from the inventor’s workshop, split over two days. The defendant contended that the prototype could have been observed from nearby roads and from a footpath to which the public had access, and that such observations would give the skilled person enough to obtain an enabling understanding of the invention.

The judge accepted that, had anyone observed the test even with their unaided eye, they would have learned enough to deduce the details of the invention i.e. it would have been an enabling disclosure. The patentee contended, however, that there was no evidence that anyone actually viewed the prototype in action during the test. In deciding whether the test of the prototype invalidated the patent, the judge reviewed the authorities. These include Lux Traffic Controls v Pike Signals, in which Aldous J held “… it is settled law that there is no need to prove that anybody actually saw the disclosure provided the relevant disclosure was in public. Thus an anticipating description of a book will invalidate a patent if the book is on the shelf of a library open to the public, whether or not anybody read the book and whether or not it was situated in a dark and dusty corner of the library”. This was further developed in Folding Attic Stairs v Loft Stairs, in which Peter Prescott QC said “The law must draw the line somewhere, as I have said, and it does so by adopting the rule that inasmuch as the public had a right to be there, they are deemed to have the right to access the information. In the same way, if it is proven that all sorts of members of the public could enter private factory premises, no obligation as to confidentiality being imposed, the law will consider that whatever could be seen there has become part of the state of the art. In those circumstances the law cannot start speculating about who did or did not see the thing”.

The patentee sought to rely on another recent case concerning testing of a prototype, E. Mishan & Sons Inc v Hozelock, which concerned patents relating to an expandable hosepipe. In that action, the inventor had tested his prototype in his garden, which was overlooked by a public road. Based on the inventor’s evidence to the Court, Nugee J found as fact that had any member of the public actually tried to observe the inventor testing his hose in his garden, he would have stopped what he was doing and hidden the invention away. The judge held that on the facts of that case, no member of the public could in fact have obtained any information about the invention. HHJ Hacon distinguished the Hozelock case, however, because he did not accept that the inventor could, upon seeing a member of the public, have taken action that would have prevented the skilled person from seeing or inferring the essential features of the patent claim. In that regard, it is noteworthy that the essential features were the appearance of the prototype itself and the appearance of soil left in its wake. As the judge observed, “preventing a member of the public from seeing a prototype seed drill would have been a good deal more difficult than hiding a prototype garden hose”. Accordingly, notwithstanding that there was no evidence that anyone actually observed the test of the prototype, HHJ Hacon held the patent invalid for lack of novelty.

In the author’s view, the outcome, whilst unfortunate for the inventor, was entirely in accordance with principle. As Jacob LJ memorably put it in Unilin Beheer BV v Berry Floor, an enabling disclosure “written in Sanskrit wrongly placed in the children’s section of Alice Springs public library” will still suffice to invalidate a patent, even if nobody ever read it. HHJ Hacon’s decision simply applies that same principle to a different set of facts. Save in unusual circumstances, such as those in Hozelock, a test which could be observed by the public, and which would, if observed, teach the skilled person enough to implement the patent will serve to invalidate the patent if done before the filing date. The only solution, therefore, is for inventors to ensure that any open-air tests are done in an area which cannot lawfully be observed by members of the public, for example in a field surrounded by private land in which there are no public footpaths. The author observes that this is particularly harsh on amateur or smaller scale inventors, who are unlikely to have access to such testing facilities, but as Peter Prescott QC observed, “The law must draw the line somewhere”, and it has chosen to draw the line at a point which leaves little or no wiggle room for inventors.

This is for general information only and does not constitute legal advice. Should you require advice on this or any other topic then please contact or your usual Haseltine Lake Kempner advisor.