T 1886/06 – Dealing With Undefined Claim Features

In a recent post I have alluded to the present decision. Here it is at last. 

Although the Board decided to dismiss the appeal against the revocation of the opposed patent, as it had found the claims to lack inventive step, it chose to comment on the objection of insufficiency of disclosure. The opponent had based its argumentation on the claim feature “non-dusting” (nichtstaubend).

What is claimed is a non-dusting, homogeneous pigment preparation comprising at least four ingredients, wherein the ingredients are present in certain ranges of amounts (Mengenbereiche). According to paragraph 42 of the opposed patent, the pigment preparation is produced by mixing and homogenising of the ingredients in a mixer. Moreover, the claims cover dry preparations obtained from these pigment preparations by concrete shaping steps and which, as the case may be, are stripped from the solvent.

If the properties “non-dusting” and “homogeneous” are indeed functional features – as pointed out by the [opponent] – i.e. the result if a composition of the four components in certain ranges of amounts, it is not surprising if not all the compositions do lead to these properties, even if it comprises the four components in amounts that fall into the indicated weight ranges. As a matter of fact, claim 1 (of all requests) does not require that all possible compositions which contain the four components in the indicated ranges of amounts result in non-dusting, homogeneous pigment preparations.

The example given by the [opponent] comprising 99 % by weight of dry pigment and the compositions chosen for its comparative trials having a low solvent and polyacrylate contents therefore are not covered by the wording of claim 1 if they do not possess the properties “non-dusting” and/or “homogeneous”. [1.4.1]

As regards the missing definition of the expression “non-dusting”, the question is whether there is a need for explanation or whether the meaning attached to the expression is not sufficient to convey a sufficient technical teaching to the skilled person whom the patent addresses. Moreover, the competent [opponent] itself has pointed out that it is not coherent with the teaching of the opposed patent if the pigment preparations dust as much as – or even more than – pure pigment powders.

The [opponent] has invoked decision T 256/87 according to which the lack of a method for determining a parameter that is unusual in the art is not prejudicial to sufficient disclosure according to A 83 if the skilled person having read the patent can carry out the invention in all its essential parts and knows when he/she is working in the prohibited domain covered by the claims. In the case underlying T 256/87 this was considered achievable via indirect empirical investigations, because of the respective general knowledge (Fachkunde).

However, the conclusion reached in T 256/87 cannot mean that – conversely – the use in the claims of an expression that is undefined under A 84 necessarily leads to the invention not being executable within the meaning of A 83 if there are no indications for a possible definition in the description or in the respective general knowledge. As a matter of fact, doubts concerning a lack of sufficiency of disclosure have to be substantiated with verifiable facts. The mere supposition that the extent of protection extends to non disclosed variants is not sufficient.

In principle the use of an undefined expression in the claims – for example, the use of a relative expression – is problematic under A 84 according to which the claims shall define the matter for which protection is sought and shall be clear and concise and be supported by the description. In opposition and opposition appeal proceedings the lack of delimitation of the protected domain by such an expression leads to taking into account a more extensive prior art, i.e. the state of the art corresponding to all the technically meaningful possibilities of interpretation of the undefined expression. In the extreme case where no concrete meaning can be ascribed to the expression, it completely loses its limitative effect with respect to the prior art to be taken into account.

The patentee cannot object to this that it is not acceptable to take into account a more extensive prior art because it is possible to give a limitative interpretation of the expression based on the description and the drawings. This possibility of interpretation which follows from A 69(1) only concerns, as can be deduced from the wording of this provision, the content of the claims that determines the extent of protection of a patent, so that a patent proprietor has to accept such a limitative interpretation of the extent of protection of its patent by an infringer against whom the patent is invoked. This means that A 69(1) can only be used for answering the question whether a competitor can know if and when it works in the prohibited domain. This, however, is only a question whether the claims have the clarity that is required for satisfying A 84.

However, the extent of protection of the claims or of the patent are not even considered in A 83. This provision only requires that the patent discloses the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art. [1.4.2]

[…] The Board has come to the conviction that the objection of insufficient disclosure is unfounded. The requirements of A 83 are fulfilled for all requests. [1.5] 

To read the whole decision (in German), click here.