4.3. Solving the technical problem
4.3.1 Sufficient evidence for alleged advantages
According to the established case law of the boards of appeal, alleged advantages to which the patent proprietor/applicant merely refers, without offering sufficient evidence to support the comparison with the closest prior art, cannot be taken into consideration in determining the problem underlying the invention and therefore in assessing inventive step (see e.g. T 20/81, OJ 1982, 217; T 181/82, OJ 1984, 401; T 1051/97; T 632/03; T 1211/07; T 736/12; T 2400/12; T 1764/16, T 225/18, T 825/18; T 2210/19). In T 1027/08 the board added that there was no reason to deviate from this case law as it was based on the understandable rule that a patent could only properly be granted for a solution claimed as non-obvious if it actually achieved the alleged effect.
If the patent proprietor/applicant alleges the fact that the claimed invention improves a technical effect, then the burden of proof for that fact rests upon them (T 355/97, T 1213/03, T 1097/09, T 2418/10, T 1487/16). In the absence of any data confirming the alleged improvement, such an effect cannot be taken into account in the formulation of the technical problem (T 2044/09). In T 1616/22, the respondent (patent proprietor) argued that it was up to the appellant to show that the effect was not achieved over the whole scope. The board held that while it was usually up to the party alleging a fact in opposition to provide evidence for it, if the patent proprietor alleged the fact that the claimed invention improved a technical effect, the burden of proof for that fact rested upon them. The appellant had moreover provided, inter alia, a document representing common general knowledge to raise serious doubts that the effect could be achieved over the whole scope claimed. It was therefore up to the respondent to dispel those doubts.
In T 524/17 the board found it was not credible that the problem was solved over the whole range claimed. It held that where the closest prior art already showed improved values for certain properties which were said in the patent to be improved, it was up to the proprietor to show by means of suitable evidence that there was indeed such an improvement. In the absence of such evidence, it must be concluded that there was no such improvement and, thus, the problem was not solved. In T 1346/16 the board concluded that the claimed subject-matter could be plausibly considered to have solved the technical problem ("technically plausible").
In T 946/16 the board rejected the patent proprietor's formulation of the problem because it defined the quality of the copolymers obtained by the claimed method purely in absolute terms ("high quality"). To arrive at a an objective definition of the problem actually solved as compared with the closest prior art (D2), it instead had to be established whether the copolymer quality achieved using the claimed method was higher, similar or lower than that achieved in D2. In view of the technical arguments and the evidence adduced, the board considered that the patent proprietor had failed to show that the alleged improvement in copolymer quality over that achieved using the prior-art method was credible.
In T 2514/16 the board found that the respondent had demonstrated with D16 that an effect was achieved for at least part of the claim at issue and that the burden of proving that this effect was not achievable across the whole breadth of the claim thus lay with appellant 1. Appellant 1 contended that, according to T 1188/00, it was for the patent proprietor to prove this. The board, however, considered that the reason that conclusion had been reached in T 1188/00 was that the effect (improvement) alleged by the patent proprietor there had been found to be not credible, and so the circumstances were not comparable with those now at issue. In the absence of relevant comparative tests, appellant 1's objection was held to be unconvincing.
In T 575/17 the board held that, where there was no direct or plausible disclosure in the application as a whole of how the envisaged effect of the invention was achieved or of why the problem was solved by the claimed features, how this worked could also be deduced from the teaching of other (pre-published) documents. In the case in hand, the board, referring to documents E1 to E3 and E5, observed that using prefabricated implants for better thermal conductivity had long been known in detail. The skilled person would have no technical difficulty in applying the teaching of these documents to the "insulated metal substrate" technology that had later become established. It did not matter that the documents recorded an "old technology"; they contained the general technical teaching that an object inserted into the metal (substrate) could be used to improve the conduction of an electrical component's heat.
In T 2524/19 the board rejected the respondent's arguments based on decisions T 716/08 and T 578/06 that there was no requirement for an absolute proof for a technical effect in a patent. T 716/08 was concerned with whether the claimed solution actually solved the technical problem, but not as to whether the technical differences between the claimed subject-matter and the closest prior art imparted a technical effect. T 578/06 highlighted that the disclosure of experimental data was not always required to establish that the claimed subject-matter solved the objective technical problem. Neither decision supported the respondent's argument that a technical effect did not need to be attributed to the distinguishing features between the claimed subject-matter and the closest prior art. Moreover, the board disagreed that it was on the appellant to prove that the technical difference failed to provide any improved protein titer yield in the case in hand. Rather, it was on the respondent, who wanted to rely on this effect mentioned in the patent to show that the claimed method led to this advantageous effect when compared to the closest prior art.
In T 1289/22 the board stated that the conclusion in T 578/06 that experimental data and results were not required by the EPC to demonstrate that the claimed subject-matter solved the objective technical problem did not mean that a technical effect attributed to the distinguishing features in relation to the closest prior art did not have to be made "plausible" by means of comparative examples or in some other way.
- T 0449/23
In T 449/23, regarding claim 1 of auxiliary request 1 (claims 1 and 2 being identical to claims 2 and 3 of the main request, after claim 1 of the main request was deleted following a finding of lack of inventive step over D5), the board came to the conclusion that the alleged effects of the distinguishing features were not credible, contrary to the arguments of the patent proprietor. Hence, any alleged effects arising from this comparison could not be taken into account in the formulation of the objective technical problem. The patent proprietor also argued that the burden of proof lay with the opponent to demonstrate that the alleged technical effects were not present. The board disagreed, stating:
(a) that the legal burden of proof was the duty of a party to persuade the deciding body of allegations of facts on which the party’s case rested. In principle, a party must prove alleged facts (assertions) from which it infers a legal consequence, i.e. which establish the basis for the party's legal claims. Thus, the allocation of the burden of proof depends on a party’s substantive case.
(b) that to discharge its legal duty of persuasion, a party must prove the alleged facts by appropriate evidence to the required standard of proof. The party with whom the legal burden of proof lies therefore bears the risk that the alleged facts remain unproven, and thus that the deciding body will decide against that party and reject its legal claims. Thus, the legal burden of proof requires the production of appropriate evidence to persuade the deciding body to the required standard.
(c) that in principle the legal burden of proof does not shift. References in the case law to a shift of burden of proof relate to the so-called evidentiary/evidential burden of proof (see for this distinction T 741/91), the notion of which relates to the state of the evidence produced in the course of proceedings. Once the party bearing the legal burden of proof has adduced sufficient evidence to support its allegations of facts to the required standard of proof, the onus is on the adverse party to rebut the asserted facts with appropriate evidence. Otherwise, the adverse party risks that the deciding body is persuaded of the existence of the facts and allows the claims. Thus, if the party having the legal burden of proof has made a "strong case" by filing convincing evidence, the onus of producing counter-evidence shifts to the adverse party. However, this does not mean that the legal burden of proof is on the adverse party to prove the non-existence or the contrary of asserted factual allegations. It is sufficient that the adverse party raises substantiated doubts that prevent the deciding body from being persuaded of the existence of the alleged facts.
(d) that in opposition and opposition-appeal proceedings, each of the parties carries the legal burden of proof for the asserted allegations of facts on which their respective substantive case rests. As regards an alleged lack of inventive step, the burden is on the opponent to adduce appropriate prior art which – when following the established substantive test, i.e. the problem-solution approach – persuades the opposition division or the board of the obviousness of the solution provided by the subject-matter claimed. On the other hand, if the patent proprietor asserts that, in comparison to the prior art, there is an advantage or effect giving rise to a more ambitious formulation of the objective technical problem than that presented by the opponent and hence to an inventive step, the burden of proving this advantage or effect to the required standard of proof is on the patent proprietor. The mere assertion in the patent specification of an advantage or effect cannot be regarded as evidence of such an assertion.
The board listed a number of decisions (T 97/00, T 355/97, T 1097/09, T 1392/04), in which the underlying circumstances were comparable, confirming these principles. The board also observed that T 1797/09 submitted by the patent proprietor remained a singular decision not followed. The subject-matter of claim 1 of auxiliary request 1 lacked inventive step.