Originally published on IPKat.
The EBA decision in G 1/24, on the role of the description in claim interpretation, left a key question unanswered. Whilst the description must always be “consulted” following G 1/24, does this mean that a definition in the description can or should be used to override an otherwise clear technical meaning of a term in the claim? The first Board of Appeal decision to apply G 1/24 (T 1561/23) noted this ambiguity but did not need to decide on it for the case at hand. We now have the first decision to directly address this important question (T 1999/23). This decision provides the first application of G 1/24 to a case in which the description and claims are in direct conflict. The Board of Appeal was unequivocal in its finding that, whilst the description should be consulted, clear claim language retains its primacy over restrictive definitions provided in the description.
Legal background: G 1/24 and consulting the description to interpret the claims
In G 1/24, the EBA stated that:
The claims are the starting point and the basis for assessing the patentability of an invention […] The description and drawings shall always be consulted to interpret the claims when assessing the patentability of an invention […] and not only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation.
As we pointed out when G 1/24 was first released, the EBA did not stipulate in G 1/24 that the description should always be used to interpret the claims. The EBA instead stated that the description should always be consulted. To us, the act of consulting the description does not necessarily mean that the description should be used to override otherwise clear claim language. Interestingly, the first Board of Appeal decision to apply G 1/24, also chose to highlight this point even though it was not relevant to the facts of the case in question (T 1561/23). The Board of Appeal particularly noted in T 1561/23 that G 1/24 “does not define what it means to consider the description and drawings in a specific case […], G 1/24 does not even explicitly require that the definition of a term from the description must be used for the interpretation of a claim” (machine translation from the German).
Case Background: LED excitation area
We now have the first decision to directly consider how G 1/24 should be applied in cases of a description definition that contradicts the normal clear meaning of a term used in the claims. The case T 1999/23 involved an appeal of the Opposition Division decision to uphold EP 3086087 in amended form. The patent related to a photothermal measuring device. Claim 1 on appeal specified a device comprising a light source for heating a sample and an infrared detector to detect the thermal radiation from that heated sample. Claim 1 required that the light source be an LED having an “excitation area” of a specified size. The main substantive issue on appeal was the novelty of the invention in view of a novelty only prior art document. The novelty question itself depended almost entirely on how the term “excitation area” should be interpreted.
Applying G 1/24 to description definitions
The Board of Appeal considered the different approaches to how the claim term “excitation area” should be construed. The Board of Appeal first noted that the term excitation area had a clear meaning in the art. The Board of Appeal found that a person skilled in the art would normally understand “excitation area” to mean the cross-sectional area of the excitation light on a sample, which varies with the distance from the measuring head and is not inherently limited. By contrast, however, the patent’s description contained its own very specific, and restrictive, definition of the term. The description particularly stated that the term “excitation area” meant “the cross-sectional area of the excitation light at the focus.”
The Board of Appeal therefore had to decide which definition of the term had primacy and should be used for patentability analysis: Should the claim be interpreted according to the skilled person’s normal understanding of a clear, broad technical term in the claim, or should the claim be interpreted using the more restrictive definition of the term provided in the description? Referencing G 1/24, the Board of Appeal acknowledged that the description must be considered. However, for the Board of Appeal it remained a core principle of claim interpretation, supported by established case law, that “a restrictive definition of a term in the description may not be used to restrict the subject-matter of the claim, which would otherwise appear clearly broader to the skilled person” (translation from the German) (see also Case Law of the Boards of Appeal, II-A-6.3.4). G 1/24 did not change this principle.
The Board of Appeal thus saw no good reason to deviate from the clear technical terminology of the claim term. The Board of Appeal also noted that allowing a Patentee the unrestricted right to redefine clear terms would undermine legal certainty.
The Board of Appeal thus concluded that the term “excitation area” should be interpreted in its usual, broad technical sense, and not limited to the area at the focus. Using this interpretation, the novelty point became straightforward. The Board of Appeal found that in the device of the prior art, “any size excitation area can be generated by choosing a suitable distance.” The Board of Appeal concluded by rejecting all of the Patentee’s requests and ordering revocation of the patent.
Final thoughts
Applying G 1/24, the Board of Appeal in T 1999/23 consulted the description, found a definition that was inconsistent with the clear technical meaning of the term used in the claim, and ultimately gave primacy to the claim’s wording to ensure legal certainty. Therefore, for this Board of Appeal at least, consulting the description does not mean the definitions in the description should be used to override otherwise clear claim language, especially when doing so would run counter to established technical terminology.
We will now have to wait to see if other Boards of Appeal follow this interpretation of G 1/24. There are a number of pending appeal cases that will have to make their own judgement on the same question of whether description definitions can or should override clear claim language, not least the referring case in G 1/24 and a case involving the same patentee (T 0941/23).
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Author: Rose Hughes