In T 500/89 it could only be seen from the disclosure considered in its entirety that the prior art document did not deprive the claimed invention of novelty, because the method constituting the closest prior art differed from the claimed method in one functional characteristic. The disputed patent related to a method for the production of photographic material by the simultaneous application of several layers of fluid photographic coating materials. Although the document cited in support of the opposition listed the numerical ranges for layer thickness, viscosity, coating speed, etc. used in the method claimed, the latter was nevertheless held to be new because the cited document described the choice of these numerical ranges as leading to intermixing between two particular layers. The contested patent was to be assessed according to a different criterion because it described the application of the layers as being "substantially free from intermixing". The "intermixing" described as an objective in the citation was not merely a stated purpose not constituting one of the technical features of the method described, but a functional feature - a criterion, in effect - forming an essential element of the teaching set out in this publication.
In T 872/09 the board stated that the claimed sensor was defined by reference to characteristics of its response when used in a measurement set-up. Since none of the determining aspects of the measurement set-up was defined in claim 1, the technical features of the claimed sensor which were responsible for providing the measurement referred to in the claim remained obscure. Legal certainty required that a claimed subject-matter cannot be regarded as novel over the prior art on the basis of an ambiguous feature (see T 1049/99). Hence, defining a functional feature of the claimed electrochemical sensor under undefined operating conditions was not appropriate to provide any distinction of the claimed subject-matter over the prior-art electrochemical sensors. in the case at hand.
Date retrieved: 30 December 2018