In T 694/92 (OJ 1997, 408) the board, with reference to T 939/92 (OJ 1996, 309), explained that Art. 56 EPC 1973 required the claimed invention, i.e. the proposed technical solution for a given technical problem, not to be obvious to a skilled person from the state of the art. If the inventive step of a claimed invention was based on a given technical effect, the latter should, in principle, be achievable over the whole area claimed (see also T 583/93, OJ 1996, 496).
T 939/92 (OJ 1996, 309) contained fundamental rulings on broad claims in the field of chemistry. The board held that in view of the state of the art the technical problem which the patent in suit addressed was the provision of further chemical compounds with herbicidal activity. It was necessary for all the claimed compounds to possess this activity. Moreover, the question as to whether or not such a technical effect was achieved by all the chemical compounds covered by such a claim, might properly arise under Art. 56 EPC 1973, if this technical effect turned out to be the sole reason for the alleged inventiveness of these compounds. The appellants' submission that the test results contained in the description showed that some of the claimed compounds were indeed herbicidally active could not be regarded as sufficient evidence to lead to the inference that substantially all the claimed compounds possessed this activity. In such a case the burden of proof rested with the appellants. The requirements of Art. 56 EPC 1973 had not therefore been met (T 268/00, T 1188/00, T 320/01, T 1064/01, T 924/02, T 488/16).
Following T 939/92 (OJ 1996, 309), the board stated in T 668/94 that the technical problem could only be taken into account in the assessment of inventive step if it could be accepted as having been successfully solved, i.e. if it were credible that substantially all the claimed compounds possessed the plant growth regulating activity. When only some and not substantially all claimed compounds exhibited a particular technical effect, the conclusion had to be that the invention as broadly defined in the independent claim was not a solution to the technical problem of achieving the given technical effect, with the consequence that the alleged technical effect of some of the claimed compounds was to be disregarded when determining the objective problem underlying the invention and thus when assessing inventive step.
In T 942/98 the problem as per the application was the preparation of improved selective herbicides. With reference to T 939/92 (OJ 1996, 309), the board did not agree with the applicant that, in the case in hand, he merely had to show an improved effect at the direct interface between prior art and the application in order to demonstrate, without providing further details, that such an improvement applied without qualification for the entire breadth of the claim. The appellant's position, in the board's view, amounted to allowing the applicant to decide how broad a claim could be, whether or not an improvement in the effect of all the compounds claimed was actually credible.
In T 415/11 the board stated when the credibility that a technical effect is achieved by substantially all claimed compounds is at issue and in a situation where, it is prima facie unlikely that this is credible, it is not the opponent, but the patentee who has the burden of proving that the effect is achieved (referring to T 939/92, OJ 1996, 309; T 97/00).
In T 41/16 the board observed that it was the boards' established case law that a technical effect on which inventive step was based had to be achieved over substantially the whole of the claimed range (see e.g. T 939/92, OJ 1996, 309). However, that did not mean that every composition encompassed by a claim had to show an improvement over any composition comprised in the prior art, or even just over the one closest to the claim. What was required instead was that each composition according to the invention that differed from an equivalent composition in the closest prior art only in that it had the feature distinguishing the claim from the prior art showed the alleged improvement.
- T 1265/17
If a claim is unduly broadened with respect to the scope of the examples used to illustrate a technical effect, particularly when this broadening concerns the feature/s allegedly providing that effect, the burden of proof might shift back to the proprietor to prove that the effect observed in the examples would also be obtained throughout the entire scope of the claims. If no evidence is provided in this respect, a conclusion may have to be drawn on the basis of plausibility arguments (reasons 2.2.5-2.2.7).