T 0204/83 - Features taken from schematic drawings - #70

Citation rank: 70
No. of citations: 71

T 204/83 made comments on how much technical information is contained in schematic drawings.

In the underlying examination case, the ED made measurements in a Figure 9 of a prior art document, which Figure, according to the description, was a "diagrammatic representation of an embodiment of the invention". According to the ED, the figure clearly showed a cylindrical portion, in which "the height h as measured between the two horizontal lines defining the narrower cylindrical portion was greater than 0.5 d and less than 0.66 d, d being taken as the distance between the hatched walls defining the internal diameter of the cylindrical portion", i.e., a feature of the claim under examination. Based on this interpretation of the Figure, the ED refused the application.

The Board generally confirmed that features only shown in the drawings form part of the disclosure of a document, however, whether or not such features can indeed be extracted depends on the circumstances of the specific case. They stated:

"When a feature is shown solely in a drawing without any other clarifying description a careful check should be made to establish whether the mere diagrammatic representation enables a person skilled in the art to derive a practical technical teaching therefrom. It would be impossible to lay down general rules as to how this should be done because the reply in each case will depend on the knowledge of the person skilled in the art and of the way in which the feature is shown in the drawing. Thus if a drawing is specifically devoted to disclosing a certain feature or if that feature is systematically included in a number of drawings a person skilled in the art will see it as an important item of technical information even if the illustration is unaccompanied by a verbal description or numerical information. If on the other hand, the feature is shown in the drawing merely as an ancillary element of a complicated device a person skilled in the art will sometimes be unable to elicit useful technical information from the drawing, at least without the information supplied in the newly filed patent application." (point 4 of the reasons)

The Board considered that "diagrammatic representations" cannot be regarded as exact representations of the represented subject-matter. Dimensions obtained only by measurements on a diagrammatic representation do not constitute part of the disclosure. Thus Figure 9 was considered not to disclose that the cylindrical portion of the claimed Venturi tube which must have a height greater than 0.5 d and less than 0.66 d. The decision of the ED to refuse was thus set aside.

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Headnote:

Features shown solely in a drawing form part of the state of the art when a person skilled in that art is able, in the absence of any other description, to derive a technical teaching from them. Dimensions obtained merely by measuring a diagrammatic representation in a document do not form part of the disclosure.

The full text of the decision can be accessed here.