4. The technical problem

In case T 1465/23, the opposed patent addressed the problem of securing wireless communications for hearing devices. The board was not satisfied that the technical effects mentioned by the respondent (proprietor) were credibly achieved by the claimed features over the whole scope of claim 1 as granted.

Given that the alleged technical effect was not credibly achieved and the board could not identify an effect either, it was not possible for the board to formulate an objective technical problem that was directly and causally related to the claimed invention, in particular to the alleged distinguishing features (b) to (h). The board recalled the principles established in G 1/19, that the problem-solution approach may be "terminated" at this stage if the distinguishing features do not credibly achieve any technical effect over the whole scope claimed. The introduction of a distinguishing feature having no credible technical effect may then be considered to be no more than an arbitrary modification of the design of a known subject-matter which, being arbitrary, cannot involve an inventive step.

The respondent argued that the principles of G 1/19 were limited to computer-implemented simulations and that the board should instead have applied the "ab initio implausibility" standard addressed in the referral case underlying G 2/21. This line of argument was not persuasive. Recalling the purpose of Art. 112(1) EPC, the board observed that the Enlarged Board in G 1/19 itself designated its findings in point 82 of the Reasons as a "general principle" and this confirmed that a technical effect must be achieved over the whole scope of a claim to be considered as the basis for the objective technical problem. The respondent further argued that the expressions "substantially all embodiments" in G 1/19 and "substantially the whole scope of the claims" in T 814/20 allowed for a more lenient application of the test "credibly achieved over the whole scope claimed". However, the board noted the concept of "substantially over the whole scope claimed" appeared to provide merely a "narrow safe harbour" for well-defined inventions that may have isolated, peripheral flaws; it could not rescue a claim that was fundamentally deficient such that the distinguishing features were considered to have no effect at all.

The respondent also raised specific doubts in view of the board "terminating" the problem-solution approach after the conclusion that there was no credible technical effect over the whole scope claimed. Reflecting on the two paths provided for in the established practice to overcome such an objection: amendment of the claim to a narrower scope by the patentee, or reformulation of the objective technical problem to a less ambitious one by the board, the board noted that in some instances there may be no credible technical effect whatsoever that could be attributed to the distinguishing features. In such a case, the board considered these distinguishing features to be an arbitrary or non-functional modification of the prior art, which cannot support an inventive step. Consequently, this particular way of applying the problem-solution approach did not represent a "failure" or an "incomplete application" of the problem-solution approach, rather it was its logical endpoint: the demonstration that the claimed differences provided no technical effect at all, i.e. no contribution over the prior art, constituted the very proof of their "obviousness". Overall, the board stated that if there was no technical effect that was credibly derivable from the wording of a claim on the basis of its distinguishing features, it was usually unnecessary to – artificially – formulate an (unsolved) objective technical problem, such as finding an "alternative way to achieve a (non-existent) technical effect". In such cases, the distinguishing features simply constituted arbitrary or non-functional modifications of the available prior art which could not involve an inventive step within the meaning of Art. 56 EPC.

In case T 1065/23, the purpose of the invention was the provision of a pea protein composition comprising pea proteins having a low solubility. Such protein extracts had superior properties when used in processes for manufacturing bakery products and beverages.

Opponent 2 argued that as solubility was a relative property, it should not be taken into account for selecting the closest prior art. In the board’s view, this argument was not convincing. From the patent and the documents used for formulating the inventive-step attacks, it was evident that before the relevant date, the skilled person distinguished pea proteins having a "high" versus a "low" solubility. Thus, even in the absence of precise thresholds, the skilled person distinguished these protein forms. The board found that D2, which aimed to obtain proteins having a high solubility, did not represent the closest prior art. D12 could be considered the closest prior art..

Relying on the submission in opponent 1's statement of grounds of appeal, opponent 2 argued that experimental report D30 provided evidence that the alleged effects could not be achieved across the entire scope claimed. The desired nitrogen solubility index of less than 15% was thus not achieved across the entire scope claimed. The board stated, however, that opponent 1's new allegation of facts based on D30 was not only late filed but also raised new complex issues which should have been addressed during the opposition proceedings (not admitted – Art. 12(4) and (6) RPBA).

Opponent 2 considered that the underlying technical problem was merely the provision of an alternative method for extracting pea proteins and an alternative pea protein extract. The board did not agree. Starting from D12 and taking into account the effects shown in the patent, the underlying technical problem was the provision of a pea protein extract and a method for its manufacture, where the extract had a combination of a lower nitrogen solubility index, gel strength and viscosity, resulting in improvements in processes (for bakery products and beverages).

As to obviousness, opponent 2 also argued that the selection of the cut-off values 4.0 and 5.8 defining the claimed pH range was arbitrary and could thus not involve an inventive step. The experimental report D15 showed that the preferred low nitrogen solubility index of less than 15% mentioned in claim 11 was obtained not only when the pH was inside, but also when it was outside the claimed pH range, e.g. at a pH of 6.2. For this reason alone, the claimed subject-matter was obvious over the teaching of D12. The board was not convinced by this argument; Table 2 of D15 showed that all protein extracts heated at a pH of 6.2, i.e. above the claimed range, had a higher nitrogen solubility index than those heated at a pH within the claimed range. The results showed a clear pattern indicating the advantage of working within rather than outside the claimed pH range. For claim 1 to be inventive, it was not necessary to achieve a nitrogen solubility index lower than 15%. This was not an absolute threshold required for the method to be inventive. What was relevant was that the nitrogen solubility index obtained was lower than that obtained at pHs outside the range..

The fact that the cut-off values 4.0 and 5.8 of the claimed pH range might exclude lower or higher pH values suitable for achieving advantageous effects was not, as such, a reason to consider the selection of the claimed cut-off values as "arbitrary" and the claimed subject-matter as obvious in view of the prior art. It would be illogical if a claim defining a feature by reference to a range was considered to lack an inventive step for the sole reason that the invention could have been claimed more broadly, specifying a broader range. This would lead to the absurd situation that a claim defining a broad range involved an inventive step, whereas a claim defining a narrower range, falling within that broad range, did not (see also Catchword). What counts is that the available evidence makes it credible that subjecting a slurry containing precipitated pea protein at a pH within the claimed range to the claimed heating step induces effects which go beyond those obtainable by carrying out the method of the prior art.

In T 1632/22, In ex parte case T 1632/22, the application related to liveness detection in relation to authentication, e.g. when unlocking a phone based on a face image. The application proposed to categorise the images as a function of their "quality" and to use different liveness detectors for each quality type. The examining division concluded there was a lack of inventive step over D1 (face authentication).

With an amendment in substance to define the quality parameter used to define the quality type, the new feature of claim 1 was not disclosed in D1. The board saw only two differences between claim 1 and D1 which might support the presence of an inventive step, namely that the claimed method was used for liveness detection and that it considered also quality parameters other than those disclosed for the "specialized classifiers" of D1. For the appellant, D1 did not qualify as the closest prior art as it was concerned with authentication rather than with liveness detection.

In the board’s view, the novelty requirement provides that no patent can be granted for anything that is already known. The inventive step requirement raises the bar to a patent by also excluding matter which is obvious over what is known. That which is obvious to the skilled person cannot depend on anything that the skilled person does not know yet. In particular, what is obvious at the filing date of a patent application cannot depend on the content of that patent application. Conversely, an argument that a skilled person having regard to some piece of prior art will find something to be obvious cannot be rebutted on the basis of what the application says. In particular, the application cannot be invoked to limit the prior art under consideration or the expertise of the skilled person (their "art") on the basis of the stated "field of the invention". That essentially any piece of prior art can be considered in an inventive step analysis has been stated several times in the case law. The definite articles in the phrase "the person skilled in the art" in Art. 56 EPC are not meant to limit the relevant "arts". Any successful rebuttal of an inventive step objection must address the obviousness argument directly, without reference to the application.

It is a matter of efficiency when assessing inventive step to consider only persons skilled in arts related to the claimed invention, and, consequently, only prior art which such a person may have regard to. The board considered that a person skilled in some art may well have regard to prior art from a field which is not, in a narrow sense, their "own field". It is reasonable to assume, for instance, that persons skilled in one field will typically keep themselves informed about developments in related fields, and in this sense have regard to prior art in related fields. The board disagreed with T 646/22 and held that in principle, all problems which the skilled person would have addressed (or been asked to address) based on the prior art alone are valid ones. In the present case, the board assumed a person skilled in liveness detection methods. Such a person was, generally, interested in improving, or finding alternatives to, known liveness detection methods, based on the knowledge that known methods have known pitfalls. Liveness detection for authentication and authentication were closely related technical areas. The board noted that it was typical to try adapting developments in neighbouring fields to the own area of interest. It was certainly common practice in image processing, in particular when the images were of the same type. Thus, in the board's judgement, the person skilled in the art in liveness detection would have regard to D1 and would have reason to adapt its solution to liveness detection in a way leading to the invention according to claim 1 of the main request before the examining division. The current requests differed from that request ("quality parameter").

Finally, the board noted that during examination a relatively large number of documents were cited, some of them concerned with liveness detection, but were not discussed in the decision. A positive decision on inventive step could not be issued before at least these documents have been discussed (Remittal).

In T 646/22, the invention concerned input/output circuits and devices having physically corresponding status indicators. It followed from the conclusions on novelty that claim 1 as granted differed from D7 in that the two status indicators were capable of displaying different statuses and that the second status indicator comprised a transparent or translucent portion which surrounded the terminal opening (feature [1.9]).

The parties did not agree whether or not these features provided together a synergistic technical effect over D7. The opponent was of the opinion that the features distinguishing claim 1 from D7 were to be assessed separately as no synergistic technical effect was apparent. It would have been obvious to the skilled person to provide an additional status indicator in D7 to display a second status, if they so desired.

The board did not follow the opponent’s argument, mainly because it did not accept the formulated technical problem. The formulation of the technical problem took for a given that the skilled person wished to display a second terminal status of the terminal in D7 and that the only problem was how to do that. However, D7 did not envisage the display of any second status different from the status it already displayed. Hence, it could not be accepted that the only problem the skilled person would be faced with was how to display such a second status. In the board's opinion, in order to arrive at the claimed invention the skilled person when starting from D7 would first have to find a motivation for displaying a second status of the terminal, then to find a way to modify the described light sources such that they were capable of displaying different statuses and would only then have to start contemplating here to place an additional status indicator. The board considered that such activities went beyond what could be considered obvious for the skilled person in the present context.

Regarding feature [1.9], the opponent pointed to the description of D7, and argued that it would thus have been obvious for the skilled person to increase the size of given indicators if they wanted to improve visibility from all sides even further. The board did not follow the opponent in this respect, either. The formulated technical problem of improving the visibility of the status indicator was not related to the claimed invention..

The board stated that in the so-called "problem-solution-approach", the formulated objective technical problem should be one that corresponds to the technical effect obtained by the features distinguishing the claimed invention from the prior art. In other words, these distinguishing features should provide a technical advantage to the claimed invention that the prior art has not. In the present case, the terminal block of the claimed invention had no curved surface and there was no technical advantage related to the visibility of the status indicators from all sides. The problem of improving the visibility of the status indicators concerned only D7 and the I/O block it described, but was not a problem to be solved which related to any technical effect the distinguishing features provided to the claimed invention with respect to the prior art. The board, hence, found the opponent's argument not convincing.

The board proposed the following Catchword: The objective technical problem formulated in the context of the problem-solution approach should stem from a technical effect the distinguishing features provide to the claimed invention with respect to the closest prior art and not from a possible improvement of the prior art itself. 

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.

In T 1272/22 the appellant (opponent) and respondents (patent proprietors) disputed whether there was a synergistic effect between the distinguishing features, even if it were considered they served the same purpose. The board, applying Headnote II of G 2/21, could not see that the skilled person would have derived the synergistic technical effect referred to by the respondents when considering the application as originally filed. There was no explicit mention of any relationship between the two features and the position of the critical section for the efficiency of the connection, which the respondents had also relied on in its arguments in support of there being synergy, was not defined in the contested patent. The alleged synergy did not appear to the board to be derivable by the skilled person from the application as originally filed and it therefore held the partial problem approach was thus justified in the case in hand.