9. Assessment of inventive step
9.6. Features not contributing to the solution of the problem
According to the established case law of the boards of appeal, features which do not contribute to the solution of the problem set in the description are not to be considered in assessing the inventive step of a combination of features (T 574/92). In T 37/82 (OJ 1984, 71) The board held that in assessing the inventive step of a combination of features, consideration had to be given to a feature only if the applicant had provided evidence that it contributed, either independently or in conjunction with one or more of the other features, to the solution of the problem set in the description (see also T 65/87, T 144/90, T 206/91, T 226/94, T 912/94, T 15/97, T 471/98, T 442/02). Therefore, only those claimed features are to be considered which contribute causally to the solution of the problem (T 285/91). In T 294/89 the board stated that the additional feature provided no surprising advantage and did not make any contribution to solving the problem indicated. Hence, the said additional feature was not relevant for assessing the inventive step of the combination of features claimed.
In T 589/95 the terms of the solution of the technical problem extended into an area of use where it had been admitted that the relevant problem was known not to arise in practice. The board stated that, for such an area, the features of the solution did not contribute to the solution of the technical problem and could not be taken into account in the assessment of inventive step.
With reference to T 119/82, Board 3.3.05 held in T 72/95, T 157/97, T 176/97 and T 158/97 that similar considerations applied to technically non-functional modifications. An inventive step could not be claimed on the basis of a non-functional modification of a known device. If a known device was modified by adding a feature which had no technical function, this modification could not be inventive (see also in this chapter I.D.9.1. "Assessment of inventive step in the case of mixed-type inventions").
In T 1009/12 the board took the view referring to T 206/91 that an ineffective concentration of a compound was considered as an arbitrary feature not contributing to the solution of the underlying problem and therefore not further considered. Since there were no further distinguishing features it was not feasible to identify the technical problem to be solved and the claim lacked inventive step.
In T 2044/09 the board held that even if there was no pointer or suggestion in the prior art towards the addition of a distinguishing feature, if said modification was not linked to a particular functionality, then it could not per se constitute the basis for acknowledging an inventive step (see also T 1289/22).
In T 2287/16 the board had no objection to the examining division ignoring, in an inventive-step assessment, a feature that it found to contravene Art. 123(2) EPC. The board considered that the examining division was not obliged to anticipate the replacement of such a feature with a similar one that might have been originally disclosed and to provide a speculative inventive-step assessment of a so-amended claim.
In T 2623/17 the board held that a skilled person would retain those features of a prior art document which would also serve a technical purpose in the context of the claimed subject-matter, i.e. after the starting point of the prior art had undergone the proposed inventive development. The board illustrated this concept by way of analogy. If a skilled person wanted to improve a car with a diesel engine so as to be less harmful to the environment, and the solution to this problem was to provide the car with an electrical motor, a skilled person would have a good reason to retain the rear view mirror of the diesel car, because it was still necessary to supervise the rear of the car even when it was modified to have an electrical drive. However, the urea injection and catalyst of the diesel engine ceased to be useful when the latter was replaced by an electrical drive. A skilled person would therefore not have any motivation to retain it, even though it was mentioned in the prior art as an improvement over a diesel engine without NOx particle reduction.
In T 885/20 the board found the distinguishing feature did not credibly lead to any technical effect over essentially the whole scope of the claimed subject-matter. Hence, the distinguishing feature amounted to an arbitrary, non-functional modification of the prior art, and according to the established case law, any such arbitrary modification was to be disregarded in the assessment of inventive step
- T 1465/23
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.
- T 0746/22
In T 746/22 both the opponent and the patentee had appealed against the interlocutory decision of the opposition division maintaining the European patent in amended form.
Regarding independent claim 15 of the main request, both parties agreed with the board's finding that feature F2 was the only distinguishing feature in view of the objective lens described in table 1 of D4 (closest prior art). F2 defined a mathematical relation between the focal length of a "first rear positive lens" (f3) and the total focal length (f) of the five lenses of the claimed objective lens system.
The board was unable to see any effect of feature F2 other than to arbitrarily define a mathematical relationship between the focal length f3 of one of the lenses of the objective lens system with respect to the total focal length f of the objective lens system. However, in the present case, where the optical parameters of the claimed objective lens system were only very incompletely defined, the selection of a maximum value of f3 when f was fixed, or the selection of a minimum value of f when f3 was fixed, did not provide a technical effect relevant to the claimed invention.
In view of the absence of any relevant technical effect related to the feature F2, the board found that no objective technical problem solved by feature F2 could be defined, and as was explained in T 176/97 , if the distinguishing feature of a claim has no effect of technical relevance on the claimed subject-matter and does not credibly solve an objective technical problem, then no inventive step can be based on it. In the present case, the objective lens system of claim 15 was considered to be no more than an arbitrary modification of the objective lens system of D4, which did not involve an inventive step within the meaning of Art. 56 EPC.
The patentee argued that starting from the precise lens design in Table 1 of document D4, a skilled person would have a “perfect” lens design and thus no reason to modify any parameters without using hindsight from the invention. However, the board found this argumentation unconvincing because it assumed that, starting from the objective lens system disclosed in table 1 of D4, the skilled person would need a concrete incentive to modify it in a certain direction. This overlooked the point that the difference between the lens systems of claim 15 and of D4 was only an arbitrary modification of the lens design of D4. The question of whether there was a motivation to change the lens design of D4 did not arise in the present case. An arbitrary change to the lens design resulting in no relevant technical effect was in itself devoid of any inventive step.
Claim 1 of the first auxiliary request also lacked an inventive step in view of D1 in combination with D4. The patentee had argued that D1 already disclosed a perfectly optimised lens system and that the objective lens system of D4 was no better than that of D1. Again, the board was unable to follow the patentee’s argument that only with hindsight would the skilled person consider replacing the lens of D1 with the lens of D4. D1 merely disclosed a general lens without further details of its optical characteristics. Thus, it was not hindsight, but simply the fact that the teaching of D1 was put into practice that leads the skilled person to search for a specific lens design and eventually find the objective lens system of D4. As with claim 15, the feature at issue in claim 1 provided no technical effect other than arbitrarily modifying the lens design of D4. Therefore, this distinguishing feature did not contribute to inventive step. The subject-matter of claim 1 of the second and the third auxiliary requests lacked an inventive step in view of D1 in combination with D4 for the same reasons.