1.13.2 Schematic drawings

In T 748/91 the board, agreeing with the appellant, held that schematic drawings depicted all the essential features. The board reached the conclusion that size ratios could be inferred even from a schematic drawing as long as the delineation provided the relevant skilled person with discernible and reproducible technical teaching (with reference to T 451/88). In the case at issue the description provided the skilled person a sufficient teaching for an unambiguous interpretation of the drawing.

In T 497/97 the board noted that, since drawings were often approximate and therefore unreliable, they could only be used in interpreting amended claims if the description did not contain a more precise indication of what was meant.

Likewise, in T 906/97 the board held that the parent application as filed failed to disclose unambiguously the position of a door. The only indication of this position could be found in some figures, and in the board's view there was no suggestion whatsoever in the description itself that this detail of the schematic representation was actually meant to correspond to a technical feature of the apparatus shown in the figures, rather than being merely an expression of the draughtsman's artistic freedom.

In the same vein, in T 2481/18 the board explained that schematic representations of an invention or of elements of an invention did not normally on their own constitute a sufficient basis for amending the claims. This general assessment relied, first, on the findings that such schematic representations were not to be construed in isolation. Instead, they had to be construed in the light of the accompanying description. In effect, the embodiment referred to by reference to drawings would incorporate much more information than could be derived from the drawings alone. Second, such schematic representations might also contain further limitations which were not the result of deliberate technical considerations but merely reflected the choices made by the draughtsperson without any bearing on the technical content of the application.

In T 1148/12 the board distinguished the case at hand from the one in T 748/91. In the case at issue in T 1148/12, the schematic nature of the figures did not allow the skilled person to clearly and unmistakably derive the feature in question (parallel arrangement of electrodes), nor did the description of the original application allow him to clearly and unmistakably derive anything related to the function of the purported parallel arrangement.

In T 614/12 the board found that the drawing did not show any measurements or scale or give any other indication that it was an exact engineering drawing reproducing the construction elements to scale. It was thus no more than a schematic illustration of the kind commonly found in patent documentation. The imprecision of such an illustration made it impossible to measure angle sizes.

In T 398/00 the appellant sought to derive a feature (concerning the positioning of an engine) from the drawings. Referring to T 169/83 (OJ 1985, 193) the board explained that what would be required was that the person skilled in the art would clearly unmistakeably recognise from the drawings, in the context of the description as a whole, that locating the engine according to this feature was the deliberate result of technical considerations directed to the solution of the technical problem involved. Given in particular the schematic nature of the illustration of the engine, this was however not the case. Cited in T 886/15.

In T 324/21 the amendment comprised some of the features illustrated in two schematic drawings as well additional features originally disclosed only in the description of two detailed drawings of the application as filed. The board explained that the description of a drawing may be inextricably linked to the specific disclosure of this drawing. If a feature in the description of the drawing was extracted from the very specific context of the drawing in order to be included in a claim, the specific disclosure of the drawing had to be taken into account. If there was no literal support for this specific disclosure in the application as filed which could be used to supplement the feature used to amend the claim, it may not be possible to avoid an unallowable intermediate generalisation. This could in particular occur if a feature from a specific and detailed embodiment was included in the context of a schematic drawing.