Rieter CZ is the holder of EP3118356 for a method of safely starting or stopping a rotor in a rotor spinning machine. Opponent Saurer challenged the validity of the patent. Although the Opposition Division maintained the patent in amended form, Saurer appealed. The Technical Board held that answers from LLMs such as ChatGPT are not representative of the understanding of the skilled person, as they are based on unknown training data and are sensitive to context and the precise formulation of the question. The earlier decision was overturned and the patent was revoked.
Rieter CZ is the holder of EP3118356, for a method for the safe starting and/or stopping of a rotor in a rotor spinning machine. Opponent Saurer challenged the validity of the patent, and the opposition division had previously ruled that the patent, in amended form, complied with the requirements of the European Patent Convention (EPC). The opponent appealed this decision (all documents).
Use of Large Language Models (LLMs) such as ChatGPT
In its reasoning, the board emphasized that the increasing dissemination and use of chatbots based on language models ("large language models") and/or "artificial intelligence" does not in itself justify the assumption that a received answer — which is based on training data unknown to the user and can furthermore be highly sensitive to context and the precise wording of the question(s) — necessarily reflects the understanding of the skilled person in the respective technical field (at the relevant point in time). In other words, the answers of LLMs such as ChatGPT cannot be considered representative of the skilled person's understanding in the context of patent granting. This is because the generated responses are based on training data that are unknown to the user and can be strongly dependent on the context and the exact phrasing of the questions.
The Technical Board of Appeal overturned the contested decision and the patent was revoked.
ECLI:EP:BA:2025:T119323.20250415
