T 1688/08 – Language Skills

The home of the skilled person

This is an appeal against the refusal of an application by the Examining Division (ED).

According to the ED, the subject-matter of independent claim 3, which was directed at a 1 x N optical coupler, did not comprise an inventive step over the combined teachings of GB application D5 and Japanese application D6. A skilled person faced with the problem of determining how the device disclosed in document D6 worked, would seek a translation or, should this not be available, similar devices with a functional description. Document D5 discloses such a device excepting use of an annular mixer guide 45 in place of an annular core. Document D5 thus enabled a skilled person to understand that the function of a coupler according to document D6 had to be based on multimode interference.

The Board did not find this approach persuasive:

[3] In relation to claim 3, the division assumed that the skilled person knows that a device according to document D6 is based on the interference of different modes because it works with high efficiency, as set out in the corresponding English abstract, but did not explain how such knowledge relates to a number of features in the claim, for example, to the radial single mode. In fact, in the context of high efficiency, all that the abstract of document D6 discloses is simply

“To reduce the insertion loss, to equalize the photo coupling, and to execute it with high efficiency, by using a repeating rod having a cylindrical optical conductor part whose thickness is similar to the core diameter of an input/output fibre”.

Moreover, the division considered it not possible to determine scaling from the drawings of patent applications as they are typically schematic and of illustrative nature only. In other words, the division could determine neither core diameters nor fibre lengths from the drawing and did not show how, without knowledge of the subject matter claimed, the skilled person’s knowledge provides such features.

[4] Since the division did not find all the claimed features in Japanese-language document D6 and assumed that the skilled person did not understand Japanese, the division removed inconsistencies with the claimed subject matter by reference to the teaching of document D5. This approach is not very convincing because the language of a patent document alone cannot be decisive for the question of whether or not the skilled person considers the technical content of that document. Otherwise, there would be a differentiation between skilled persons according to the language(s) they speak. This would be against the objective assessment of the inventive step. (See, by analogy, T 426/88 [6.4]) In the board’s view, it is not credible either that the skilled person would have believed that another document, such as document D5, having only some features not dissimilar to those actually disclosed in document D6, would correspond to the disclosure of document D6 in relation to subject-matter claimed. This lack of credibility leads to a gap in the chain of reasoning of the ED, the gap then leading the board not to be persuaded by the case of the division.

[5] The board does not disagree with the case of the appellant on inventive step and is therefore satisfied that the subject matter of independent claims 1 to 3 can be considered to involve an inventive step.

[6] In view of the foregoing and since the board sees no other bar to grant of a patent, the board considers it appropriate to exercise powers within the competence of the first instance and order grant of a patent (A 111(1)).

NB: T 1157/06 is another relevant decision on this issue; a partial translation is available here.

Should you wish to download the whole decision, just click here.

The file wrapper can be found here.