Zusammenfassung von Article 123(2) EPC für die Entscheidung T0873/23 vom 06.05.2025

In T 873/23 claim 1 as granted was amended with respect to claim 1 as originally filed inter alia by Feature 1.5x, specifying that, for an electric coil cooktop and an electric glass ceramic cooktop, the control device was configured to control the power level of the cooktop "by turning the heating element continuously on and off". It was common ground that there was no literal basis for "continuously" in the context of "turning the heating element on and off" in the application as filed. However, the board observed that there were other occurrences of the term "continuously" in the description (both as filed and as granted) and in claim 1 as granted in the context of monitoring/sensing the temperature and calculating a rate of change of the sensed temperature. The parties agreed that, according to the patent, in these occurrences "continuously" meant "periodically", albeit with different time periods for monitoring and calculating. The board agreed in principle with the "two-step approach" for the assessment of added matter set out in the Catchword of T 367/20. The patent claims first had to be interpreted in order to determine the subject-matter they contained after the amendment. They were interpreted in line with G 1/24, which states, in the context of assessing the "patentability of an invention under Articles 52 to 57", that the claims are the starting point and the basis for the assessment, and the description and drawings are always to be consulted to interpret the claims. The board considered this to be true not only for the question of "patentability of an invention under Articles 52 to 57" but also for the issue of Art. 123(2) EPC. In a second step, it had to be assessed whether the subject-matter of the amended claim contained subject-matter which extended beyond the content of the application as filed. In this regard, in accordance with G 2/10, the decisive factor was whether the skilled person was presented with new technical information after the amendment. The board disagreed with the two interpretations of Feature 1.5x submitted by the appellant (patent proprietor). The board considered that the only convincing interpretation of the expression "by turning the heating element continuously on and off" was that of periodically turning the heating element on and off (at fixed intervals) as submitted by the respondent, which included pulse-width modulation of the heating element in accordance with a predetermined duty cycle. In reply to the appellant’s argument that this interpretation "was not in line with the disclosure in the patent", the board explained that, according to T 367/20, a claim feature had to be interpreted not in isolation but in the context of the whole document it formed part of. This was, however, to be done by taking due account of the primacy of the claims (see also T 1473/19). This was also in line with G 1/24, which states that the "claims are the starting point and the basis" (see also UPC_CoA_335/2023, second Headnote, according to which the claims were the "decisive basis"). The board observed that the application as filed disclosed embodiments in which the heating element was controlled on the basis of a duty cycle and was thus "continuously" turned on and off. However, even in the algorithm using duty cycles, different duty cycles and phases of keeping the heating element "on" for a specific period of time were employed. The heating element was thus not always "periodically" turned on and off, and the "continuity" of the duty cycle was interrupted under certain conditions. As claim 1 as granted did not include these more specific aspects of the power control for the electric glass ceramic cooktop of the application as filed, and as the application as filed did not disclose a periodicity throughout the algorithm, the amendment in Feature 1.5x was at least an unallowable intermediate generalisation of the original disclosure. Moreover, the application as originally filed did not contain a corresponding disclosure (power control algorithm based on a duty cycle) for the electric coil cooktop (Feature 1.5a). Accordingly, the combination of Feature 1.5x with Feature 1.5a extended beyond the content of the application as filed. The maintenance of the patent as granted according to the main request was thus prejudiced by the ground of opposition under Art. 100(c) EPC. Since none of the claim requests was allowable, the appeal was dismissed.