A recent decision of the UK Patent Court examined some interesting questions regarding a challenge to a patent on the basis of disclosure prior to the priority date of the patent.

The case in question was that of Folding Attic Stairs Limited (Attic) v The Loft Stairs Company Limited (Loft) and unsurprisingly surrounded the manufacture and sale of folding attic ladders.

Loft had been a customer of Attic over a period of time but following a dispute between the parties Loft began to manufacture loft stairs itself rather than purchasing them from Attic. Upon discovering this Attic decided to raise an action against Loft for infringement of Attic's patent.

The patent in question covered a key component of how folding stairs for loft access were constructed and in particular a folding mechanism.

There were two issues examined by the Court. The first related to the interpretation of certain phrases in the claims of the patent and the second concerned whether the invention had been disclosed to the public prior to the submission of the patent application.

It is the second of these issues that this article focuses upon. There was little debate to be had about whether the actions of Loft would constitute infringement of the patent if it were valid as Loft were making stairs to Attic's design. The issue to be considered was therefore whether the disclosure to the public would result in a successful challenge to the validity of the patent.

The Court heard that Attic had provided members of the public, including an Irish minister and a press photographer, access to its premises before the patent had been applied for. A prototype of the folding stairs protected by the patent was seen and photographed by these members of the public and a picture subsequently appeared in the press that showed the prototype in the background.

The question that the Court was required to answer therefore was whether this disclosure of the prototype prior to the date of submission of the patent application was sufficient to constitute a disclosure of the invention to the public.

Attic presented arguments that the prototype had not been made available in a public place and that it was only available to a very limited group of people, the minister and the photographer. It further argued that those people were not skilled in the art, had no interest in manufacturing folding stairs and did not have any particular interest in the folding mechanism covered by the patent.

Loft argued that despite the limited group of individuals and their apparent disinterest in the invention they were "free to examine the unit if so minded, they were free to impart to anyone in the world whatever recollection they had of it, and so its construction must be considered to have been made available to the public".

The Court held that it was clear law that if the prototype had been made available in a public place where anyone might have been able to examine it then the invention would have been made available to the public.

In the present case however, it agreed with the arguments put forward by Attic and held that the prototype had not been in a public place at all, had been disclosed to a limited group who were not skilled in the art and had no interest in the invention or in manufacturing folding stairs.

The Court commented that even if "some officious person had stopped them on the way out and asked them to describe the test unit, it was unlikely that they would have been able to describe the presence of an inner frame with side beams spaced from the sides of the ladder".

Having considered this and the other issues raised in the action, the Court therefore upheld the validity of the patent and that it had been infringed by Loft's product.

Despite the Court's view that a patent is not invalidated by the limited disclosure in this case, we still recommend restricting disclosure and using non-disclosure agreements.