9. Beweisfragen

In T 1489/23 the patent related to additive manufacturing process control, in particular for Selective Laser Sintering (SLS). The patent proposed "real-time statistical process control monitoring and control". It relied on monitoring the "spark plume" created during sintering.

Regarding the particular way in which sufficiency of disclosure had been challenged by the appellant (opponent), the board observed that an objection to sufficiency had to be reasoned. This burden was with the party raising the objection. According to the board, to justify an objection to sufficiency, one may contest factual allegations in the disclosure (for example, that certain things can be done in a certain way or that a technical effect is effectively achieved), or one may point out gaps in the disclosure, i.e. to information, which is missing from the disclosure but required for the skilled person to carry out the invention over the full scope of the claims. For either argument to be convincing, it must raise "serious doubts". It cannot be limited to mere allegations of insufficiency, but has to be reasoned in a way that allows the deciding body to evaluate, i.e. "verify" its merit.

The board explained that to make an objection of the "first type", it may be appropriate to submit evidence showing that an alleged fact was actually incorrect. It may be less straightforward to provide evidence to substantiate an objection of the "second type", because establishing a gap in the disclosure was similar to "proving a negative". For the same reason, it was unclear to what extent an objection of the latter type could be based on "verifiable facts".

In the case in hand the appellant had pointed to specific information missing from the disclosure and the common general knowledge. The corresponding arguments were in part verifiable and otherwise sufficiently substantiated for the board to assess them. In the board's judgement, therefore, the appellant had provided sufficient reasons to substantiate its objection of insufficient disclosure.

The board agreed with the respondent that the patent taught that the spark plume may be an indicator for in-process quality factors and also that it provided a list of characteristics that may be useful as indicators. The board was of the opinion that the skilled person would be capable of extracting specifically given image characteristics from suitably "derived" image data using common-place image processing tools. This was part of the common general knowledge. Considering the cited prior art, the board was also convinced that at least some useful information existed in the image of the spark plume. For some instances, the success of the claimed method was predictable.

Regarding the alleged gaps in the disclosure, the board considered that the patent did not (a) define the intended meaning of the term "spark plume", i.e. which incandescent matter (plasma, spatter, condensate) was to be monitored; (b) disclose which characteristics of the so-defined spark plume were (not just might be) useful as indicators, and for which quality factors; or (c) provide any evidence to that effect. Based on the evidence on file, this missing information was not part of the common general knowledge. Because the patent provided no working examples, the skilled person had to make three choices without any guidance, namely which "plume" constituents to identify in the image, which characteristics to derive from that image, and in view of which quality factors to assess abnormality of the derived characteristics.

The complexity of the task that the skilled person had to accomplish was therefore of combinatorial nature, and without any guarantee of success. It did not appear trivial to make appropriate selections for a large number of quality factors, manufacturing processes and products. It was not even clear which quality factors may be reflected at all in any of the plume characteristics. It may be possible with reasonable effort to find parameter combinations which work for some cases, but it appeared difficult to identify such cases beforehand. In the board's judgment, the successful accomplishment of this task by the skilled person required a considerable effort and went well beyond routine experimentation. It therefore amounted to an undue burden.

The board concluded that the claimed invention was insufficiently disclosed for it to be carried out, over its full breadth, by the skilled person.