8. The relationship between Article 83 and Article 84 EPC

In T 250/15 the board, ruling on sufficiency of the description, considered that the claimed parameter for characterising a polymer was widely used and clearly defined and that the skilled person knew of at least two methods of determining it. It held that the uncertainties possibly arising from any differences between the measurement results obtained by applying the different methods known would not impair the skilled person's ability to choose a suitable polyamide, using their own knowledge and the information disclosed in the patent, and observed that its finding was in line with the boards' current case law. The opponent requested that the board make a referral to the Enlarged Board of Appeal, essentially to establish whether the difficulty the skilled person might encounter in determining whether subject-matter fell within the scope of protection conferred by a claim was a matter of the claim's clarity or more one of sufficiency of disclosure. Citing T 1811/13, however, the board observed that there was now a clearly predominant opinion among the boards that the definition of the "forbidden area" of a claim should not be considered a matter relating to Art. 83 EPC. The board in T 1811/13 had added that this was not to say that a lack of clarity could not result in an insufficient disclosure of the invention. For the sake of completeness, the board in T 250/15 held that, in view of decision T 1811/13, T 626/14 did not call into question that an imprecise scope of protection did not amount to insufficient disclosure. Lastly, the board noted that T 626/14, like T 464/05, had concerned a specific constellation in a particular technical field. The case now before it, however, differed in that the parameter concerned a clearly defined property intrinsic to the material. Moreover, it had not been disputed that a limited number of appropriate and generally known measurement methods were available to the skilled person. The board refused to make a referral to the Enlarged Board of Appeal. It also explained precisely how the facts of the case in T 250/15 differed from those in T 593/09, T 466/05, T 225/93 and T 626/14.

The board, in T 1305/15, was aware that according to case law, uncertainties in the measurement of a parameter did not necessarily amount to an insufficiency objection but might merely represent a hidden clarity objection under Art. 84 EPC (T 608/07). This might be the case for example when no measurement method was specified in the patent and different known methods were available to the skilled person, possibly leading to different results (T 1768/15). However, when the claimed parameter (the ZP in T 1305/15) is crucial for solving the problem underlying the invention, the method used to measure it should produce consistent values, such that the skilled person will know when carrying out the invention whether what he produces will solve the problem or not (T 815/07). Due to the severe lack of information concerning the ZP measurement method, the ZP on the inner membrane surface was so ill defined that the skilled person, when trying to reproduce the hollow fibre membrane according to the contested patent, was at a loss whether or not the produced membrane was able to solve the problem underlying the invention. This posed an undue burden on the skilled person, depriving him of the promise of the invention, and thus amounted to insufficiency of disclosure (citing T 593/09).