6.3.1 General principles

In T 1849/23 claim 1 as granted was directed to a trailer oscillation and stability control device comprising, among other things, an angular rate sensor positioned and configured to measure the rate of angular trailer deflection about a hitch pivot point and to generate corresponding angular trailer deflection rate signals.

In response to a novelty objection based on a prior art document, which disclosed a yaw rate sensor on the trailer, the respondent (patent proprietor) had argued that the absolute yaw rate and the rate of angular trailer deflection about the hitch pivot point were distinct physical quantities, even if their values coincided during straight-line vehicle operation. These two physical quantities did not become the same physical quantity simply because their values coincided in one specific condition. The claim clearly defined the angular rate sensor as being configured to measure the rate of angular trailer deflection about a hitch pivot point.

The board agreed that, when the claim was read in isolation, that feature could be read literally such that the angular rate measured by the sensor was the rate of the angle made by an axis passing through the hitch pivot point with respect to a reference axis. However, in accordance with G 1/24, claim interpretation required taking into consideration the wording of the claim and the content of the description..

The board observed that the patent disclosed a gyroscope sensor (i.e. a sensor for measuring the yaw rate) as the only specific implementation of the claimed angular rate sensor. This was not only denoted in figures 3 and 4 as a "gyro", but the description of the preferred embodiments of the invention also described the sensor as a raw angular rate sensor, i.e. a sensor measuring absolute yaw rate. A measure of the yaw rate of the trailer coincides with the rate of the angle made by an axis passing through the hitch pivot point with respect to a reference axis, when the yaw rate of the towing vehicle is null or negligible (e.g. when the towing vehicle is moving along a straight line). Consequently, when consulting the description the claim could not be strictly construed as requiring the measurement of the rate of the angle made by an axis passing through the hitch pivot point with respect to a reference axis under any conditions or movements of the towing vehicle. The claim had to be construed in a broader manner, i.e. as only requiring that said measurement could be made under certain conditions.

In T 1999/23 stellte die Kammer fest, dass die Fachperson unter dem Begriff "Anregungsfläche" (in Merkmal M1.7) für sich genommen die Querschnittsfläche des Anregungslichts auf der Probe verstehen würde – unabhängig von der Entfernung zwischen Probe und fotothermischem Gerät. Allerdings wurde dieser für die Fachperson klare Begriff in Absatz [0008] der Beschreibung des Streitpatents in einschränkender Weise definiert: "Der Begriff 'Anregungsfläche' meint die Querschnittsfläche des Anregungslichts im Fokus..

Die Kammer erläuterte, dass die Große Beschwerdekammer in G 1/24 klargestellt habe, dass bei der Auslegung von Patentansprüchen die Beschreibung heranzuziehen sei, im Übrigen aber auf die durch die Rechtsprechung entwickelten Grundsätze verwiesen habe. Einer dieser Grundsätze laute, dass eine einschränkende Begriffsdefinition in der Beschreibung nicht dazu verwendet werden dürfe, den ansonsten für die Fachperson eindeutig breiteren Anspruchsgegenstand einzuschränken (siehe Rechtsprechung der Beschwerdekammern, 10. Aufl. 2022, II.A.6.3.4). Dieser Grundsatz behalte auch nach der Entscheidung G 1/24 Gültigkeit, da die Große Beschwerdekammer betont habe, dass die Auslegung bei den Patentansprüchen beginnt und auf ihnen beruht.

Im vorliegenden Fall habe die Patentinhaberin durch die inkonsistente Verwendung des Begriffs "Anregungsfläche" – einerseits im Anspruch ohne Einschränkung, andererseits in der Beschreibung mit fachunüblicher Einschränkung – eine Zweideutigkeit geschaffen..

Die Kammer sah keinen sachlichen Grund, weshalb es einem Patentinhaber gestattet sein sollte, bei der Formulierung des Gegenstands, von dessen Nutzung Dritte ausgeschlossen werden sollen, von der fachlich etablierten Terminologie ohne erkennbare Rechtfertigung abzuweichen und hierauf nur in der Beschreibung hinzuweisen. Ein uneingeschränktes Recht hierzu würde die Rechtssicherheit untergraben. Zwar möge es im Einzelfall rechtfertigende sachliche Gründe geben. Im vorliegenden Fall sei ein solcher Grund für die Kammer jedoch nicht ersichtlich.

Im Ergebnis zeige der Blick in die Beschreibung lediglich, dass in der Beschreibung eine begriffliche Abweichung von der fachüblichen Terminologie bestehe, die sich im Anspruch nicht widerspiegele. Diese Zweideutigkeit zulasten desjenigen aufzulösen, der sie ohne sachliche Notwendigkeit geschaffen habe, entspreche dem Prinzip der Rechtssicherheit sowie dem in der Entscheidung G 1/24 bekräftigten Vorrang der Patentansprüche.

Daher sei der Begriff "Anregungsfläche" im Anspruch im Sinne seiner fachüblichen Bedeutung als "Querschnittsfläche des Anregungslichtes unabhängig vom Abstand" und nicht eingeschränkt als "Querschnittsfläche des Anregungslichts im Fokus" zu verstehen.

In T 2027/23 the board identified three major takeaways from G 1/24.

First, the wording of the claims forms the "basis" for their interpretation and the description and the drawings should always be "consulted" or "referred to". However, G 1/24 is silent as to the very purpose of such "consultation" or "reference". In particular, it cannot be inferred from G 1/24 whether the description and the drawings should be "consulted" for the purpose of, for example, deriving "explanatory aids" to claim interpretation (see e.g. UPC_CoA_335/2023, second headnote), confirming the ordinary meaning of a claim feature, determining the function or the purpose of a claim feature, or simply defining the technically skilled reader of a claim (see e.g. T 1924/20).

Second, discrepancies in claim interpretation practice between national courts, the UPC and the Boards of Appeal are undesirable and should thus be avoided.

Third, it is up to a patentee to remedy discrepancies between the description and the claims. In other words, patentees are the masters of their fate.

Moreover, the board stated that it found no authority for interpreting a claim more narrowly than the wording of the claim as understood by the person skilled in the art would allow, and that this was for several reasons.

(a) First, because "consulting the description" did not imply any specific result of such consultation: A consultation of two conflicting authorities did not a priori determine who is master. Decision G 1/24 did not require the boards to give the description preference over the wording of the claim. To the contrary, according to the Order of G 1/24, "the claims are the starting point and the basis for assessing the patentability of an invention", and as the present board added, in line with UPC_CoA_335/2023, second headnote, the claims are the "decisive basis".

(b) Second, such interpretation would contradict the well-established jurisprudence of the Boards of Appeal, which was essentially confirmed in decision G 1/24 (see e.g. also T 1999/23).

(c) Third, such an interpretation would directly contradict the second takeaway from decision G 1/24, namely a harmonised claim interpretation between national courts or the UPC and the Boards of Appeal..

The board referred to decisions from the UPC and the German Federal Court of Justice and concluded that to align the judicial practice of the Boards of Appeal with that of the national courts and the UPC, a claim should not be interpreted, based on features set out in embodiments of an invention, as having a meaning narrower than the wording of the claim as understood by the person skilled in the art. In cases of discrepancy between the claim language and the description, it falls upon the patentee to remedy this incongruence by amending the claim. It is not the task of the Boards of Appeal to reach such alignment by way of interpretative somersaults.

In the present case, the board "consulted" the description and drawings to define the technically skilled reader from whose perspective the claim features (d) to (f) were to be interpreted.

In T 2651/22 the patent related to impedance matched microwave quantum circuit systems, in particular to a system comprising a parametric amplifier for amplifying a qubit readout. The interpretation of the feature "impedance matching circuit" in claim 1 was relevant to assess inventive step.

The respondent (patent proprietor) submitted that the claim could not be interpreted as covering a single integrated circuit. Feature 1.3 defined a quantum circuit device. Feature 1.4 defined an impedance matching circuit coupled to the quantum device. For the person skilled in the art it was clear that these were two different circuits. The scope of protection did not extend to one integrated circuit with double functionality as that of D8. Had the patentee desired to cover such a circuit it would have worded the claim differently, for instance to define an impedance matched circuit, not an impedance matching circuit. The specification was also consistent in describing two different circuits (figures 5, 6, 8A and 8B), one of which being placed in front of the amplifier and providing only impedance matching functionality and no amplification.

The appellant (opponent) argued that the patentee's intention when drafting the claim was irrelevant. If the claimed technical features could be mapped to the prior art then that was sufficient for the features to be disclosed. In order to establish a difference vis-à-vis D8 the claim should have been limited by inserting features from the specification into the claim, instead of relying on the specification for interpretation.

The board found the position of both parties to be reasoned and reasonable. The problem lay in the inherent difficulty of defining whether and when circuitry which is part of a larger circuitry can be identified as one circuit separate from the rest, or as fulfilling only one function. In the present case for instance, the presence of an impedance matching circuit as described in the specification also influenced the amplifying function; it improved it by reducing losses.

Considering this context, the board was of the opinion that the claim had to be interpreted in the light of the description. On that basis the board concluded that the claimed impedance matching circuit was to be interpreted as a circuit designed specifically for the (sole) purpose of impedance matching of a preexisting quantum device circuit to external circuitry.

It was undisputed that D8 did not disclose such a circuit. Further, the appellant did not argue that under this interpretation the claimed matter was obvious. Accordingly, the board came to the conclusion that claim 1 of the patent as maintained was inventive over D8.

In G 1/24 the Enlarged Board ("EBA") considered the points of law referred to it by Technical Board of Appeal 3.2.01 in T 439/22 of 24 June 2024. The first question was whether Art. 69(1), second sentence, EPC and Art. 1 of the Protocol on the Interpretation of Article 69 EPC are to be applied to the interpretation of patent claims when assessing the patentability of an invention under Art. 52 to 57 EPC. The second question concerned whether the description and figures are to be consulted when interpreting the claims to assess patentability and, if so, whether this may be done generally or only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation. The third and final question was whether a definition or similar information on a term used in the claims, which is explicitly given in the description, can be disregarded when interpreting the claims to assess patentability and, if so, under what conditions.

The EBA confirmed that the departments of the EPO were required to interpret patent claims when assessing the patentability of an invention under Art. 52 to 57 EPC. As regards Question 1, the EBA held that there was no clear legal basis, in terms of an article of the EPC, for claim interpretation when assessing patentability. Article 69 EPC and Art. 1 of the Protocol were arguably only concerned with infringement actions and therefore were not entirely satisfactory as a basis for claim interpretation when assessing patentability. Article 84 EPC could also be criticised as an alternative legal basis as it addresses the content of the patent application and is formal in nature without providing guidance on how to interpret claims. It only sets out an instruction to the drafter of what needs to be in the claims and an instruction to the EPO to determine whether the claims meet that purpose. The EBA considered, however, that there was an existing body of case law of the Boards of Appeal which applied the wording of the aforementioned provisions in an analogous way to the examination of patentability under Art. 52 to 57 EPC, and from which the applicable principles of claim interpretation could be extracted.

The EBA further held it a settled point in the case law of the Boards of Appeal that the claims are the starting point and the basis for assessing the patentability of an invention under Art. 52 to 57 EPC.

As regards Question 2, the EBA stated that the description and any drawings must always be consulted when interpreting the claims, and not just in the case of unclarity or ambiguity. In adopting this position, the EBA rejected the case law of the Boards of Appeal that sees no need to refer to the descriptions and drawings when interpreting a claim, unless the claim is unclear or ambiguous. It found that this case law was contrary to the wording, and hence the principles, of Art. 69 EPC. It was also contrary to the practice of both the national courts of the EPC contracting states and the UPC. Moreover, from a logical point of view, the finding that the language of a claim is clear and unambiguous was an act of interpretation, not a preliminary stage to such an interpretative act.

Question 3 was held inadmissible by the EBA, which considered it to be encompassed by Question 2.

The EBA also referred to the harmonisation philosophy behind the EPC and noted that the case law of the UPC Court of Appeal on claim interpretation appeared to be consistent with the above conclusions. It further highlighted the importance of the examining division carrying out a high quality examination of whether a claim fulfils the clarity requirements of Art. 84 EPC, and stated that the correct response to any unclarity in a claim was amendment.

The order by the EBA in G 1/24 reads as follows: "The claims are the starting point and the basis for assessing the patentability of an invention under Articles 52 to 57 EPC. The description and drawings shall always be consulted to interpret the claims when assessing the patentability of an invention under Articles 52 to 57 EPC, and not only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation."