A prejudicial ambiguity
Decision T 0837/24 illustrates the risks associated with introducing, during examination, an ambiguous feature into a claim. The question before the Board was whether, where a claim allows several technically valid interpretations, it is sufficient for one of them to be supported by the application as filed in order for the claim to be allowable.
Amendment of the claim
The invention relates to a method for indicating the presence of a user in a communication system in order to determine whether a user is available or engaged in a communication, in particular via a desktop telephone or via a mobile telephone.
During the examination proceedings, claim 1 was amended to introduce the feature “with or without using the headset” in order to specify that the communication via the desktop telephone or via the mobile telephone could be carried out with or without using a headset.
Decision of the Opposition Division
During the opposition proceedings, in response to the summons to oral proceedings under Rule 115(1) issued by the Opposition Division, the opponent filed, for the first time, an objection under Article 123(2) EPC. He considered that the feature “a presence message indicating whether said mobile telephone/desktop telephone is involved in a phone call with or without using the headset” could be interpreted as meaning that the presence message contained an indication specifying whether or not a headset was being used during the telephone call, and that this interpretation was not supported by the description as filed.
This objection was not admitted by the Opposition Division, which considered that the wording of the claims was clear and was to be interpreted as meaning “involved in a phone call whether or not a headset is used”. The Opposition Division added that there was, prima facie, no reason to read this feature otherwise and therefore decided not to admit this late-filed ground for opposition. The Opposition Division decided to maintain the patent according to a first auxiliary request filed by the patent proprietor, in order to overcome an insufficiency of disclosure under Article 83.
The Board of Appeal revokes the patent
The opponent filed an appeal against the decision of the Opposition Division. The Board of Appeal considered that the Opposition Division had carried out only a superficial prima facie assessment of the claims’ compliance with Article 123(2) EPC. According to the Board, the interpretation of the claim proposed by the patent proprietor and accepted by the Opposition Division, according to which the presence message merely indicated that a call was in progress, amounted to disregarding the feature “with or without using a headset”. Such an omission could not constitute a good-faith interpretation of the claim, since the skilled person seeking to understand the invention aims to give technical meaning to each feature of the claim.
The Board of Appeal also considered that a claim must be interpreted according to the technical information it contains and that all technically valid interpretations must be taken into account, and that none of those interpretations may extend beyond the content of the application as filed, in order to comply with Article 123(2) EPC.
Thus, even if the description provides an interpretation, whether preferred or not, of a feature of a claim that complies with Article 123(2) EPC, it is necessary to ensure that the other technically possible interpretations of that feature also comply with Article 123(2) EPC.
By analogy, the Board of Appeal considered that, if a granted claim allows several technically valid interpretations, none of those interpretations must extend the protection conferred, in order to comply with Article 123(3) EPC.
In decision T 0837/24, due to the lack of support in the description for one of the interpretations of the claim, and in the absence of an admissible request under Article 123(3) EPC capable of remedying this, the patent was revoked.
Practical lessons
The omission of a technically significant feature does not constitute a good-faith interpretation of the claim. Where a claim allows several technically possible interpretations, it is necessary to ensure that none of them is contrary to Article 123(2) EPC.
Thus, when adding a feature to a claim, it is essential to examine all possible interpretations and to verify that they are all supported by the application as filed.
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