Schrödinger's Seed Drill - A short review of Prior Use cases in the UK

10 juin 2021

Dr. Erwin Schrödinger's "thought experiment" was that if a cat was placed in a box with a single radioactive atom, which had the capacity to kill it, then until the box was opened, it was conjecture as to whether the cat was alive or dead, and as such, it was, in a sense, in both of those states. It was not until it was observed that its status was ascertained.

Recent High Court reasoning addressing arguments of invalidity based on prior use addresses a similar thought experiment. If the alleged disclosure takes place in the open, but there is no allegation that it was actually observed, just what actually constitutes a level of disclosure sufficient to invalidate a patent? The judgments suggest that there is no baseline requirement as to either the duration of a prior use or its actual observation, if it happened in a place that was visible to the public. That cat was either dead or alive - not both. Is this right?

To go into more detail, download our full consideration of the recent cases involving prior use in patent law.



We can start with the Patents Act 1949. Section 14(1)(d) described one of the grounds of opposition to the grant of a patent as being that " the invention…was used in the United Kingdom before the priority date". The Court of Appeal in Bristol-Myers Application (Lord Denning) noted that s.14(1)(d) did not include any gloss such as "publicly used". Simply "used" was enough.

The Patents Act 1977 was implemented to align UK patent law with the EPC. It changed the structure of the legislation in this area. Section 2 states that an invention shall be taken to be new if it does not form part of the 'state of the art'. The state of the art "shall be taken to comprise all matter…which has at any time before the priority date…been made available to the public…by written or oral description, by use or in any other way".

Interestingly, article 54(2) EPC defines the state of the art as comprising "everything made available to the public by means of a written or oral description, by use, or in any other way, before the date of filing…." The words "at any time" in s.2 1977 Act are not found in article 54(2) EPC.

The first relevant judgment on the interpretation of s.2 was Lux v Pike. Aldous J's reasoning has been drawn upon ever since:

….it is settled law that there is no need to prove that anybody actually saw the disclosure provided that relevant disclosure was in public.

How could this be a statement of "settled" law under the 1977 Act when it was the first case to address the point under that Act, as Aldous J acknowledged? The assertion ignored the change from used (1949 Act) to made available to the public (1977 Act).

In Lux, the use relied upon was of prototype traffic lights on public roads. The issue was not whether the use was public or that information was made available to the public, but what information was made available and whether this was sufficient to disclose the invention of claim 1. Aldous J noted that what was made available could depend upon the level of examination afforded. The patent was anticipated.

The HL (Lord Hoffmann) provided some important guidance, focused upon the language of article 54, in Merrell Dow v Norton:

… to be part of the state of the art, the invention must have been made available to the public. An invention is a piece of information. Making matter available to the public within the meaning of section 2(2) therefore requires the communication of information. The use of a product makes the invention part of the state of the art only so far as that use makes available the necessary information.

In Folding Attic Stairs v Loft Stairs, deputy judge Peter Prescott QC distinguished between information made available to the public at large and information made available to specific individuals without restriction as to their onward use of it. In that case, the former concerned photographs of a prototype published in a newspaper, and the judge considered what had been made available to the public from the perspective of the skilled person – the relevant aspect of the claimed invention would not have been discerned. The latter concerned access given to two individuals (a visiting Minister and the photographer) to inspect the prototype without obligations as to confidence. There was no evidence that they actually inspected it. The deputy judge considered what had been made available to the individuals concerned - there was no reason why "a normal human being, not being interested in the manufacture of folding ladders, could care less" and so the invention had not been made available for s.2 on this basis either.

More recently, Mishan v Hozelock concerned tests of an expanding water hose carried out by the inventor in his garden, visible from the street. While drawing on the "settled law" referred to in Lux, Nugee J found that if anyone had tried to observe the inventor, they would not have seen anything because he would have packed everything up. The information in issue therefore was not "made available to the public". Further, the happenings on any single particular day would not have been enough to disclose the invention. The judge drew heavily on case law under the 1949 Act and later judgments importing the earlier principles to make general observations of uncertain assistance in the application of the statutory test:

It is one thing to say that if the public is given access to information, in whatever guise, that information is made available to the public and it does not matter that no member of the public in fact took up the opportunity…But it is quite another thing to say that the law treats information as available to the public when no member of the public could in fact have accessed it.

Most recently, reported this year, Claydon v Mzuri concerned Claydon's tests of a prototype seed drill in his field. Along one side ran a little-used footpath (behind a six foot hedge that had three gaps). Judge Hacon concluded that the skilled person on the footpath would have discerned all the features of the claimed invention. Although whether information was made available to the public appears not to have been in issue, the judge's view was that Mr Claydon could not have taken action that would have prevented the skilled person from seeing or inferring the features of the invention.

In further discussion, he went on to say that if there was evidence that the skilled person habitually carried a phone with a zoom lens, then it may be that a case could go forward on the basis that the information made available included information obtained using such a phone.

The recent authorities seem, like Lux, to conflate "in public" with "making available to the public". Little of the English countryside will be out of sight of any footpath or road, even less if zoom cameras (or drones) are allowable, but the question of what in fact has been made available to the public is marginalised. This seems out of step with article 54(2) EPC and s.2 1977 Act.

Much is made in the judgments of the parallel between a book at the back of a dusty library shelf, and disclosure in a public place. They are not the same thing. First, the book was almost certainly written by someone other than the inventor of the patent under consideration, so if the disclosure in the book is indeed enabling, it is evidence that someone else got there first. Secondly, the book, once found, is available for perusal, translation, and detailed consideration. It is not only the subject of a cursory glance across a field or a garden.

To reflect the plain language of article 54(2), Lord Hoffmann's observation that it requires the communication of information and Aldous J's observation that the level of information made available depends upon the opportunity for examination, "made available to the public" should be interpreted as requiring actual communication of either the relevant information, or when/where the relevant information is to be made available.

For a written document placed on the shelves of a library, this would be satisfied by the act of cataloguing (so making it available to the public). For use in a publicly accessible but isolated place, this would require communication to at least someone that the use would be taking place.

This seems a much more appropriate approach, respecting the "patent bargain", but remaining fair to the patent owner and avoiding an absurd descent into speculation about cameras, phones, binoculars and drones.

Download our full article underlying this summary


CECI NE CONSTITUE PAS UN AVIS JURIDIQUE. L'information qui est présentée dans le site Web sous quelque forme que ce soit est fournie à titre informatif uniquement. Elle ne constitue pas un avis juridique et ne devrait pas être interprétée comme tel. Aucun utilisateur ne devrait prendre ou négliger de prendre des décisions en se fiant uniquement à ces renseignements, ni ignorer les conseils juridiques d'un professionnel ou tarder à consulter un professionnel sur la base de ce qu'il a lu dans ce site Web. Les professionnels de Gowling WLG seront heureux de discuter avec l'utilisateur des différentes options possibles concernant certaines questions juridiques précises.