1.13.1 General

When examining whether there is support for a feature in a drawing the exact same standards must be applied as for the description: the crucial point is what the skilled person would derive directly and unambiguously from the drawing using common general knowledge (T 2537/10).

The case law according to T 169/83 (OJ 1985, 193) - which has been frequently cited -, T 523/88 and T 818/93 shows that the EPC does not prohibit the amendment of claims to include features from drawings, provided the structure and the function of such features were clearly, unmistakably and fully derivable from the drawings by the skilled person and not at odds with the other parts of the disclosure. Nor could any element be dropped.

Indeed, in T 169/83 (OJ 1985, 193), T 465/88 and T 308/90 it was pointed out that where drawings existed they were to be regarded as an integral part of the documents disclosing the invention. Drawings were to be treated on an equal footing with the other parts of the application (see also chapter II.E.1.2.1 "Description, claims and drawings"). Further, the fact that features were disclosed solely in the drawings did not preclude these features from becoming essential in the course of the proceedings (T 818/93). The features for which a skilled person could clearly derive the structure and function from the drawings could be used to define more precisely the subject-matter for which protection was sought (T 372/90).

In T 676/90 the board underlined that a drawing could never be interpreted in isolation from the overall content of the application but only in that general context. The content of an application was defined not only by features mentioned or shown therein but also by their relationship to each other.

In T 191/93 amendments were based exclusively on the original drawings and introduced only some of the features disclosed in the drawings. The board held that the subject-matter of the patent had been extended compared to the application as filed because it was not derivable from the drawings that the two newly introduced features could be isolated from the other features shown in the drawings. For further cases where the isolation of features from a drawing amounted to an unallowable intermediate generalisation, see T 1408/04 and T 983/12.

In T 398/92 the patent claims as amended contained features that had not been mentioned expressis verbis in the written part of the original application but had been derived from the figures for the application as filed. The drawings in question illustrated the curves in a system of Cartesian co-ordinates with a precise, defined scale. The curves therefore could not be compared to the schematised representation of an invention given by a graph. The board recognised that the points of these curves were not purely intellectual graphic constructions but, on the contrary, corresponded to real experimental values, representing the percentages of a particular drug released in solution. Although these percentages were not mentioned expressis verbis in the original document, the board was of the opinion that for a skilled person they would have been clearly and unambiguously derivable from the scale given on the Y-axis, since the figures were sufficiently precise for the ordinate values to be read exactly and thus for the same numerical features as introduced in the claims to be derived from them. The incorporation into the text of the claims of the numerical features derived from the curves therefore did not contravene Art. 123(2) EPC 1973 (as far as a graph representing a mathematical equation is concerned, see T 145/87).

In T 1544/08 the board observed that, if drawings were originally filed in colour at the date of filing of an application, then the technical content of these original colour drawings should be determined when establishing the content of the application as filed, for the purpose of examining compliance of amendments with Art. 123(2) EPC.