5.4. Invention to be performed over whole range claimed

Under the established case law of the boards of appeal, the requirements of sufficiency of disclosure are met if a person skilled in the art can carry out the invention as defined in the independent claims over the whole scope of the claims without undue burden using their common general knowledge (e.g. T 409/91, OJ 1994, 653; T 435/91, OJ 1995, 188).

The disclosure of one way of performing an invention is only sufficient if it allows the invention to be performed in the whole range claimed rather than only in some members of the claimed class to be obtained (T 409/91, OJ 1994, 653; T 435/91, OJ 1995, 188; and T 172/99). This is considered a question of fact. Sufficiency of disclosure thus presupposes that the skilled person is able to obtain substantially all embodiments falling within the ambit of the claims. This view has been taken by the board in numerous decisions, for example T 19/90 (OJ 1990, 476), T 418/91, T 548/91, T 659/93, T 435/91 (OJ 1995, 188) and T 923/92 (OJ 1996, 564; even more recently, issue discussed in detail in T 1727/12 ("Biogen Sufficiency")). This principle applies to any invention irrespective of the way in which it is defined, be it by way of a functional feature or not. The peculiarity of the functional definition of a technical feature resides in the fact that it is defined by means of its effect. That mode of definition comprises an indefinite and abstract host of possible alternatives, which is acceptable as long as all alternatives are available and achieve the desired result; it therefore has to be established whether or not the patent discloses a technical concept fit for generalisation which makes the host of variants encompassed by the functional definition available to the skilled person (T 1121/03 (no technical concept fit for generalisation – undue burden in carrying out the invention over the whole scope claimed – research programme) and T 369/05; see also T 2128/13). With respect to a claimed process defined in a functional manner, i.e. by its outcome, the board in T 1051/09 concluded that what was lacking was a generalisable teaching applicable within the scope of the claims, i.e. beyond the specific examples.

More technical details and more than one example may be necessary in order to support claims of a broad scope (T 612/92, T 694/92, OJ 1997, 408; T 187/93). This must be decided on a case-by-case basis. The board must also be satisfied firstly that the patent specification put the skilled person in possession of at least one way of putting the claimed invention into practice, and secondly that the skilled person could put the invention into practice over the whole scope of the claim. If the board was not satisfied on the first point that one way existed, the second point did not need to be considered (T 792/00).

According to the decision in T 517/98 (grains of superconductor material – density) the patent in suit had only shown the way of achieving the goal to some extent and within set limits, but certainly not over the whole ambit of the claim. In the board's judgement, broad protection such as that claimed was therefore unjustified since such a claim encompassed speculative subject-matter which could not be produced by the skilled person without inventive ingenuity (see also T 409/91). The main request failed (Art. 83 EPC).

In T 1064/15, the invention related to barbed suture-needle combinations useful for connecting body tissue in various surgical contexts. Claim 1's requirements could be implemented for circular cross-sections, but the question of sufficiency of disclosure arose for non-circular cross-sections. The respondent (patent proprietor) himself intended the teaching of the patent to be applicable to both circular and non-circular cross-sections and specifically sought protection for both types of embodiment. It would be insufficient and disproportionate if the sole disclosed possibility of carrying out the invention with circular cross-section elongated bodies were enough to satisfy the requirements of sufficiency of disclosure. Such an approach could not have been intended by the legislator, because in the board's view this would go against the general principle that the protection obtained with the patent had to be commensurate with the disclosed teaching. When it came to non-circular cross-sections, this was not the case for the patent in suit. On the basis of the patent disclosure as a whole, taking common general knowledge into account, the person skilled in the art was not able to determine which dimension was meant by the diameter (SD) for an essential part of the claim, or in other words, with a needle having a given diameter, he did not know how to select the cross-section dimension of a non-circular suture in order to improve the closure strength, which was supposed to be an essential part of the teaching of the patent in suit (T 1064/15, which is cited and summarised in T 1756/16).

In T 713/15 the patent related to a novel preventive and/or therapeutic agent (anti IL-6 receptor antibody) for vasculitis in general and did not distinguish between various types of vasculitis. There was no teaching in the application as filed on how to treat vasculitis in all its forms (like Behçet's disease). The subject-matter of claim 1 of the main request was therefore not sufficiently disclosed over the whole scope of the claim. The patent proprietor had filed an expert declaration based on clinical data, but it did not address D(49) and D(50) submitted by the opponent and so could not provide crucial input.

In T 553/10, the board stated that the passages cited by the appellant disclosed a method for producing lithium nickel manganese cobalt oxides which fell either within or outside the ambit of claim 1. An additional process step required when seeking to prepare oxides falling within the ambit of claim 1 was missing. The application lacked guidance, and this could not be overcome by drawing on common general knowledge. A declaration written by an employee of the appellant was therefore of little probative value for establishing what was common general knowledge in the art.

In T 239/13 of 5 July 2017 date: 2017-07-05, claim 1 as granted did not require the "granules" to be acidic. The board considered that a solution of the claimed granules per se might have an alkaline pH despite the presence of some acidic component. As regards acidic granules, the description – which dealt exclusively with acidic granules – provided the skilled person with technical information and guidance sufficient to enable him to prepare, without undue burden, acidic granules having "improved storage properties" across the whole ambit of claim 1. As regards alkaline granules, in the absence of a concrete teaching the skilled person would have to start a research programme. The board concluded that the skilled person, following the teaching of the description, was not provided with technical information and guidance sufficient to enable him to prepare granules as claimed without undue burden and across the whole ambit of claim 1.

In T 1994/12 (rubber composition), as to the argument that the requirement for sufficiency of disclosure was not met because the skilled person in view of the ambiguity in respect of the nature of the asphalt would not be able to reproduce the examples of the patent, the board stated that sufficiency of disclosure was not concerned with the invention the applicant might have had in mind when drafting the application, but rather with the invention defined by the claims in terms of the technical features of the invention (see R. 43(1) EPC), as is done for assessing other criteria for patentability such as novelty and inventive step.

In T 116/18 (OJ 2022, A76) synergism was not a feature of the claims of the patent in suit. Consequently, whether this effect was achieved over the entire breadth of the claims was not to be assessed under Art. 100(b) EPC but Art. 56 EPC (G 1/03 (OJ 2004, 413), point 2.5.2 of the Reasons). Case T 116/18 is a referral pending under G 2/21.

In T 623/16 (OLEDs) the description proposed varying a plurality of parameters to achieve a white emitting device. There was no indication in the claims that several parameters, such as concentration and thickness on the one hand and the addition of a blocking layer (or other parameters) on the other, should be varied at the same time. If the skilled person were to make a first experiment and obtain a device which did not emit white, they would find no explicit guidance in the patent for deciding on what to start with to yield white emission. Thus, guidance had to be given in the claims as to which features were essential for carrying out the invention over the whole range in order to achieve a device emitting white light. Once the skilled person was aware that these features were crucial for carrying out the invention, changing only concentration and thicknesses was no longer an undue burden. The description provided enough details on carrying out the invention. Claim 1 of the main request did not comprise features that were essential to the invention and crucial to carry it out over the whole range claimed. Omitting these features led to a device that did not emit white light (Art. 83 EPC not complied with). With amendments introducing the essential features, it was no longer an undue burden for the skilled person (new first auxiliary request satisfied Art. 83 EPC).

In T 2773/18 (mechanics) the patent concerned a wind turbine with a cooling device using outside air, in particular for marine environments. In support of an alleged lack of sufficient disclosure concerning the expression "upper part of the tower", the appellant (opponent) argued that not only was the claim was not limited to an offshore wind turbine but the dimension of the lower and upper parts was also not limited to a minimum size or height. The scope of claim 1 thus covered embodiments where the inlet was located quite low above sea level and therefore unable to achieve the technical effect of drawing outside air with a low water and salt content. This argument failed to convince the board, not least because it misapplied case law developed in the field of chemistry – for where a claimed invention was in a compositional range or other range of values but the associated effect was perhaps not proven or plausible for large parts of that range – to an invention claimed in the field of mechanics, even though it claimed no ranges. By its very nature, a claim in the field of mechanics, which – often in functional or other generic terms – attempted to capture the essence of some specific machine or mechanical structure (or its operation), was schematic and allowed for some breadth of interpretation. It might be that, on clever construction, subject-matter could be found to be covered by that breadth that might not solve the problem or achieve the desired effect. However, this was normally not an issue of lack of disclosure, but rather of claim construction. Whether the claims, description and figures provided the skilled person with sufficient information to carry out an invention was a purely technical question that was separate from that of what reasonably fell within the ambit of the claim wording. In the board's view, if the skilled person, upon consideration of the entire disclosure and possibly using common general knowledge, could infer what would and what would not work, a claimed invention was sufficiently disclosed, even if a broad construction might also encompass what did not work. In the case in hand, the skilled person would be able to directly recognise and exclude embodiments which obviously would not achieve the effect sought. In particular, the skilled person would disregard an upper part placed much lower than 30 metres above sea level. The board thus confirmed the opposition division's positive assessment of sufficiency (Art. 100(b) EPC).

In T 1583/17 the invention concerned the use of coated films. The board stated that it was important to note that there was a difference between whether or not a product met a pre-set quality requirement (here: the absence of glossy spots) and whether or not it met the requirements set out in a claim. That the quality of the coatings obtained did not satisfy the intended quality standard did not mean that those coatings did not satisfy the requirements of claim 1, which was the only relevant point when discussing sufficiency of disclosure. The alleged lack of enablement over the entire range had not been shown.

See also in this chapter II.C.7.1.2.

Objection of insufficient disclosure based on the subject-matter of a dependent claim

In T 2007/16 the opposition division had referred to what it called the "main rule" for Art. 83 EPC, according to which only one way to perform the invention needed to be clear to the skilled person. It had argued that a patent could not conflict with Art. 83 EPC if those skilled in the art could perform the subject-matter of an independent claim, irrespective of whether they could perform the subject-matter of a dependent claim. The board could not endorse this approach; the "main rule" asserted by the opposition division had no basis in the EPC or in the case law of the boards of appeal. A dependent claim directed at a particular embodiment could give rise to an objection under Art. 83 EPC if the skilled person did not know how to obtain this embodiment. Also, a dependent claim directed at subject-matter that the skilled person would not know how to obtain indicated that the invention defined in the corresponding independent claim was not sufficiently disclosed over the whole scope encompassed by the claim.