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How showing your invention to nobody can invalidate your patent

Adamson Jones

If a tree falls in a forest and no one is around to hear it, does it make a sound? Yes? No? Maybe? I guess it depends on how you define “sound”?

But what if an inventor shows their invention in a forest and no one is around to see it: does this count as a public disclosure? In other words, could this destroy the novelty of a later patent application? To find out, we must turn to Claydon Yield-O-Meter v Mzuri Ltd & Anor [2021] EWHC 1007 (IPEC).

The patent at hand


The decision relates to a UK patent GB 2400296 and European Patent EP(UK) 2051576 which describe seed drills for sowing seeds. Broadly speaking, the invention relates to providing two rows of tines, one row for slotting and one row seeding. The tines on each row are aligned to improve the drilling process.

Prior to filing of the UK application, Mr Claydon tested a prototype of his seed drill which had all the features of the invention. The prototype was made in Claydon’s farm workshop by Mr Claydon, his brother and a Claydon employee. It was tested in a field on the farm for ten hours, including travel to and from the workshop, split over two days. The issue was therefore whether at any time during those two days the invention of was made available to the public.

Public disclosure – the law as it stands


In Folding Attic Stairs Ltd v Loft Stairs Co Ltd [2009] EWHC 1221 (Pat) it was held that if members of the public could enter private premises with no obligation of confidentiality, whatever could be seen there, forms part of the state of the art. In such circumstances the law cannot start speculating about who did or did not see the thing.

In E. Mishan & Sons Inc v Hozelock Ltd [2019] EWHC 991 (Pat) it was held that the actions of the inventor should be considered when assessing whether an enabling disclosure, for example, whether the inventor made efforts to maintain secrecy.

So was the field test a public disclosure? 


Claydon was aware that a prior disclosure could invalidate a patent application. It was therefore in his mind that he would prevent anyone who happened to be nearby from seeing the prototype. He was in a tractor cab and from that vantage point could see anyone in the vicinity before they could see what was happening in the field. He discussed what to do with his brother, who was present, before the tests began. If anyone had been seen they would have moved away so that this other person would not be close enough to see any relevant detail of the prototype.

However, Claydon’s prototype could have been observed from nearby roads and there is a public footpath that skirts the edge of the field where the testing took place, albeit unmarked and unmaintained at the time. Additionally, once the tractor reached the edge of the field, the system would have been lifted clear of the ground, allowing a potential observer to see the invention, as well as the aligned rows created by the invention. It was therefore deemed Claydon did not take action that would have prevented an observer from seeing or inferring the alignment of the tines, even if such an observer was not actually present. The UK patent was therefore deemed invalid due to a lack of novelty because of the prior use of the invention.

Coming back to our question, if an inventor shows their invention in a forest and no one is around to see it, does this count as a public disclosure? In this case, (and against Betteridge’s Law of headlines), the answer is “Yes”.

What does this mean for applicants?


It is therefore important to remember that “prior disclosure” can occur in any place where the public can access or observe the invention, even if no actual member of public is present. Care should be taken to avoid any undesirable disclosure of your invention, for example, by ensuring:

  • The invention is kept in an area where it is not visible to the public (e.g. indoors).
  • The public are not able to access any areas where the invention is kept.
  • Any demonstration of the invention to a further party should be made under an obligation of confidence (e.g. using an NDA).
  • Details of the invention are not stored or shared on any publicly accessible website or server, including social media.
  • If outdoor testing is performed, the invention is obscured or covered, and/or the public are actively prevented from observing the invention 

If in doubt, it is recommended a patent application is filed before the invention is stored, used or tested in any environment where the invention is visible to the public.

To speak to a patent attorney in confidence about intellectual property protection for your new product or service please contact us on +44 (0)115 947 7977 or email contact@adamson-jones.co.uk.