1.13. Disclosure in drawings
1.13.3 Negative features
In T 170/87 (OJ 1989, 441) the board held that a figure which served only to give a schematic explanation of the principle of the subject-matter of the patent and not to represent it in every detail did not allow the sure conclusion to be drawn that the disclosed teaching purposively excluded a feature not represented. Such a "negative" feature (in this case, "with no internal fittings") could not subsequently be incorporated into the claim (see also T 410/91, T 1120/05, T 474/15 and T 621/15). Regarding the absence of a feature in a figure which served only to give a schematic explanation of the principle of the invention, see also T 264/99, in which the board found the circumstances to be different from those in T 170/87.
T 1120/05 also followed the conclusion in T 170/87 that negative features could not be deduced from a schematic drawing alone. In T 1120/05 the invention concerned an "arrangement for and a method of managing a herd of freely walking animals" and the amendment introduced a negative feature namely "but not to the milking station". This negative feature was not expressly disclosed in the description and in the claims of the patent application as filed. Features could be taken from the drawings if their structure and function were clearly, unmistakably and fully derivable from the drawings (T 169/83). It was not possible to derive a negative or missing feature on its own, i.e. without the context of the other, existing features of the claim. Moreover, arbitrarily choosing one of many possible negative features was not permitted (see also T 777/07), because the skilled person not only had to realise the possible negative features, but – because they were derived from the drawings – he also had to establish which one of the features was essential to the invention and which ones were not. The board found that in the absence of a teaching from the description, the skilled person would be unable to establish the essential nature of a single negative feature, seen against a background of a multitude of potentially essential features, even if this selected single negative feature in the drawings could be recognised by the skilled person in the drawings.
- T 0195/23
In T 195/23 was an appeal against the interlocutory decision of the opposition division concerning the maintenance of the patent in amended form. The opponents disputed the decision's finding that the priority claim was valid. In particular, they challenged the validity of the priority claim for the alternative "wherein the smoke modifying additive is disposed only in said axial region of the filter material of the first filter section" in the feature directed to the location of the smoke modifying article in claim 1 of auxiliary request 3.
The board concurred with the proprietor that the drawings in the priority document were specifically intended to show the location of the smoke modifying additive. In fact, figures 1-5 of the priority document depicted various types of additive located in the central region of a filter section. For example, in figures 1 and 4, a capsule was located in an axial region of a first filter section. In figures 2 and 5, the absorbent material had an additive carrying thread disposed therein in an axial region. In figure 3, the absorbent material 47 had a plurality of microcapsules disposed therein in an axial region thereof. However, none of these passages contained a statement to the effect that the depicted smoke modifying additive was the only additive in the filter. In the board's view, these drawings therefore could only serve as a basis for a positive feature directed to the presence of such additive in a central region of the filter. Such a positive feature did not rule out the presence of some further, non-depicted additive in another region of the filter.
In contrast, the board construed the feature "only in the axial region" as a negative feature which was directed to the absence of any smoke modifying additive from other regions of the filter, e.g. its peripheral region. The board referred to established jurisprudence (see CLB, II.E.1.13.3, 10th edition) according to which, a negative feature, i.e. the absence of not depicted elements, usually cannot be derived from drawings. This was aggravated in the present case by the disclosure in the priority document, which explicitly stated that there could be additive – though at a lower concentration – in non-axial regions of the filter. In light of this explicit disclosure in the priority document, which did not contradict the drawings and the corresponding explanations to the drawings in the description, the board was not convinced by the respondent's argument that the skilled person would interpret the drawings as such, rather than entertaining the notion that they did not illustrate some smoke modifying additive. As a consequence, the board did not consider the feature directed to the smoke modifying additive being disposed only in the axial region of the first filter section to be an implicit feature of the priority document.
The board concluded that the application underlying the patent in suit was not filed in respect of the same invention for the alternative "wherein the smoke modifying additive is disposed only in said axial region of the filter material of the first filter section" of claim 1 of auxiliary request 3, and thus, the patent proprietor should not enjoy a right of priority for this alternative..
The above conclusions also applied to independent claim 1 of auxiliary requests 5 to 18, which also contained the alternative "wherein the smoke modifying additive is disposed only in said axial region of the filter material of the first filter section".