6.3.2 Overlapping ranges and multiple selection

For inventions which consist of parameter ranges that overlap with ranges disclosed in the prior art or of multiple selections (e.g. with sub-ranges, overlapping ranges and/or selection(s) from one or more lists), novelty is not assessed by looking at the various parameters and their nature, ranges, or values separately from each other. Provided the claimed subject-matter is not disclosed explicitly in the prior art, novelty is acknowledged unless there is a pointer in the prior art to the particular combination claimed.

This was established in case T 653/93, in which the appellant argued that the process of claim 1 was novel as it referred to a combination of three process features with selected ranges and product features with specific limits, a combination not disclosed in the prior art document. The board of appeal emphasised that in such situations the question of novelty could not be answered by contemplating the ranges of the various parameters separately. This would, in the board's judgment, be an artificial and unjustified approach, since it was not the specified ranges of the three parameters or their agglomeration that formed the subject-matter of claim 1, but the group of processes defined by the combination of these ranges, which was rather small when compared with the group of processes disclosed in the prior art document. Thus the claimed group of processes, characterised by the combination of three specific process parameters, was not explicitly disclosed in the prior art document which contained no pointer to the particular combination of ranges, and therefore could be said to result from a "multiple (i.e. threefold) selection". The novelty of the technical teaching of claim 1 was corroborated by experimental evidence showing that the products resulting from the claimed processes could not have been obtained by processes which were close to but nevertheless outside the range of the processes claimed. It followed that the subject-matter of claim 1 was not considered as having been disclosed in the prior art document (see also T 1095/18). The board distinguished the situation in this case from T 198/84 (selections from a numerical range of only one single parameter) and that in T 666/89 (clear teaching in the prior art regarding the claimed particular combination of features).

In T 929/00, the board stressed that the situation in which an area of overlap with the prior art can only be constructed by a combination of several selections from a plurality of lists, is to be distinguished from a situation in which the claimed subject-matter represents a single selection – of a sub-range – within a piece of prior art (on which see the above chapter I.C.6.3.1). The board reiterated that only what can be directly and unambiguously derived from a prior art document is relevant for the assessment of novelty, be it explicitly or by necessary implication. After examining the prior art document at issue including each of its examples cited, the board concluded that there was no indication in that document that would have necessarily led the skilled person to modify the explicitly disclosed compositions to arrive at the claimed subject-matter.

In T 261/15, the claimed composition overlapped with the generic composition of the pearlitic rail disclosed by D1. Since the different alloying elements interacted with each other to form precipitates and solid solutions their content ranges were not to be considered in isolation but in combination. Hence, the range of overlap was narrow in respect of the composition of D1. Considering the preferred ranges for some elements (such as C) while disregarding them for other elements (such as S for which the preferred range did not overlap with the claimed range) constituted cherry-picking within D1, which created a novel combination of features. See also T 2623/19 for another example with respect to a claim to a type of steel.

In T 1132/22, the board endorsed the reasoning in T 261/15, T 2623/19 while highlighting (with reference to T 1688/20) that the criterion to be applied when evaluating the novelty of ranges is the "gold standard" of whether there is a direct and unambiguous disclosure in the prior art. It also noted that in the case of multiple ranges, the concept of "seriously contemplating" as described in T 26/85 is not in line with this standard and is a concept that belongs to the inventive-step assessment (see also T 989/22).

In T 1571/15 the overlap between the composition as claimed and the broad composition of D1 was narrow. D1 disclosed a preferred composition range and there was no pointer to work outside this range. The board stated that while it was true that the person skilled in the art might seriously contemplate working in the centre region of a prior art range when no other pointer (for instance in the form of examples of preferred ranges) to another region was present, this was no longer true if, as in the present case, such a pointer was present and was directed to another region.

In T 1834/13 the appellant argued that D7 destroyed the novelty of claim 1 because it described all its features, which meant that an embodiment, although not literally disclosed, had been made publicly available (implicit disclosure). Conceding that there was some overlap, the board nonetheless held that, although D7 encompassed the tapes according to claim 1 as a concept, it did not disclose them directly and unambiguously. The subject-matter of claim 1 was a specific combination resulting from a multiple selection from among the alternatives proposed in D7 but there was no incentive in D7 to choose that combination. T 198/84 and T 65/96 did not apply because they did not concern multiple selections.

The earlier case law on novelty of overlapping ranges was based on decision T 666/89 (OJ 1993, 495) (and further refined in T 245/91), in which the board gave a ruling on novelty assessment in cases of overlapping numerical ranges. The patent related in particular to a shampoo comprising 8-25% anionic surfactant and 0.001-0.1% cationic polymer. In an earlier patent application a shampoo composition had been disclosed containing 5-25% anionic surfactant and 0.1-5.0% cationic polymer. The board held that the composition was not new. In the board's view, there was no fundamental difference between examining novelty in situations of so-called "overlap" or "selection", and in doing so in other situations, although it might be helpful, in order to verify a preliminary conclusion of a novelty examination in cases of overlap, to investigate whether or not a particular technical effect was associated with the narrow range in question. It needed to be stressed, however, that such a particular effect was neither a prerequisite for novelty nor could it as such confer novelty; its existence could merely serve to confirm a finding of novelty already achieved. The term "available" in Art. 54(2) EPC 1973 clearly went beyond literal or diagrammatical description, and implied the communication, express or implicit, of technical information by other means as well. Thus it was clear that matter that was hidden, not in the sense of being deliberately concealed but rather in the sense of being reconditely submerged in a document, would not have been "made available" in the above sense. In the case of overlapping ranges of physical parameters between a claim and a prior art disclosure, what would often help to determine what was "hidden" as opposed to what had been made available was whether or not a skilled person would find it difficult to carry out the prior art teaching in the range of overlap. Provided the information in the prior art document, in combination with the skilled person's common general knowledge, was sufficient to enable him to practise the technical teaching, and if it could reasonably be assumed that he would do so, then the claim in question would lack novelty. Novelty was carefully analysed on the basis of comparable considerations in T 366/90 and T 565/90.

For further decisions in the wake of T 666/89, see CLB, 10th edn. 2022, I.C.6.3.