Another case of catastrophic comma loss (T 1473/19): Interpreting the claims in view of the description

http://ipkitten.blogspot.com/2023/01/another-case-of-catastrophic-comma-loss.html

The Board of Appeal in the recent decision T 1473/19 revoked a patent for added matter following a normal interpretation of the claims that lacked basis in the description. The discrepancy between the meaning of the claims and the description was the result of a loss of commas delineating a crucial sub-clause in the claims. The decision in T 1473/19 has many similarities with that of T 1127/16, in which the Board of Appeal revoked a patent for added matter occasioned by the lack of a single comma in the claims (IPKat). Both decisions support the primacy of the claims over the description, and argue against the use of the description as a way to change the meaning of clear and unambiguous claim language. There are also a number of reasoned points in T 1473/19 relevant to the ongoing debate over adaptation of the description to the allowed claims.  

Case background: Do missing commas add matter?

At Opposition, the Opponent failed in their argument that the patent as granted contained added matter (Article 123(2) EPC). The Opponent appealed the decision. On appeal, the Patentee requested that the patent be maintained as granted. The patent (EP2621341) related to a rotary joint for a CT scanner. Claim 1 as granted related to a contactless rotary joint comprising inter alia a rotary joint body:

“said body having a free inner bore holding a capacitive data link” 

The Opponent argued that it was unambiguously clear that this phrase should be interpreted as meaning that the bore, and not the rotary joint body, held the capacitive data link. By contrast, the disclosure throughout the description was of a joint wherein the rotary joint body, and not the bore, held the capacitive data link. 

Don’t forget your commas

Given that the language of the claim was prima facie clear, the Opponent argued that there was no reason to consult the description in order to interpret the claims. Furthermore, the Opponent argued that the lack of a disclosure in the application as filed of the embodiment specified by the claim meant that the claims added matter over the application as filed. 

The patentee submitted that the patent did not add matter given that the description could be used to interpret the claims. The patentee also submitted auxiliary requests for correction of the claims in line with the description (Rule 139 EPC), e.g. by adding commas:

“said body, having a free inner bore, holding a capacitive data link” 

However, the Opponent argued that these corrections would extend the scopes of protection conferred by the patent (the “inescapable added matter trap”) (Article 123(3) EPC). It was therefore necessary for the Board of Appeal to interpret the claims in order to determine both whether the granted claims contained added matter under Article 123(2) EPC and whether correction of the granted claims would extend the scope of protection under Article 123(3) EPC. 

Does Article 69 EPC apply to claim interpretation in proceedings before the EPO?

The two provisions considered relevant to claim interpretation are Article 69 EPC and Article 84 EPC. 

Article 84 EPC provides that: “The claims shall define the matter for which protection is sought. They shall be clear and concise and be supported by the description.“

Article 69 EPC provides that: “The extent of the protection conferred by a European patent or a European patent application shall be determined by the claims. Nevertheless, the description and drawings shall be used to interpret the claims.“

Importantly, the scope of the claims may be distinct from the subject matter specified by the language of the claim. The claim scope may, for example, be found in national proceedings to encompass equivalent embodiments that do not fall under the normal meaning of the claim. In the previous decision T 1279/04, the Board of Appeal found that Article 69 EPC relates to claim scope, and so primarily relates to interpretation of the claims in infringement proceedings before the national courts. By contrast, in proceedings before the EPO, this Board of Appeal found that a literal interpretation of the claims should be applied pursuant to Article 84 EPC.

The Board of Appeal in the present case disagreed with this approach. The Board of Appeal acknowledged that interpretation of the claims under Article 69 EPC may involve consideration of infringement by equivalence, and thus involve determination of a claim scope going beyond the subject matter delineated by the claim language. However, the Board of Appeal noted that, in infringement analysis, the first step will still be the interpretation of the claim scope under a normal construction. The Board of Appeal further noted that a general application of Article 69 EPC is of legitimate interest, both in proceedings before the EPO and in proceedings of the national and unitary patent courts. The Board of Appeal thus concluded that the Article 69 EPC was relevant to claim interpretation in EPO proceedings, and particularly to the interpretation of the claims under both Article 123(2) and (3) EPC.

Taking the description into account in claim interpretation

The Board of Appeal found that, according to established case law, the claim of a patent should be interpreted through the eyes of the skilled person who should try to arrive at a sensible interpretation, “taking into account the whole disclosure of the patent”. The Board of Appeal however noted divergent case law over the degree to which the description should be used to interpret the claims. According to some decisions, the description should only be used to interpret claim features that are otherwise ambiguous (T 197/10, T 1127/16). According to other Boards of Appeal decisions, the description and the drawings should be used to interpret the claims (T 2365/15, T 1167/13, T 2773/18)

The question for the Board of Appeal thus became whether Article 69 EPC should be interpreted as requiring the description to be taken into account in claim interpretation. The Board of Appeal noted that the description provides context-specific information about the claimed subject matter, and that taking this into account would make claim interpretation more accurate and thus contribute to legal certainty (“all the more so if, as is often the case, patentees use terms idiosyncratically in the claims”). 

However, the Board of Appeal was clear that the description should not therefore, in any way, be considered to have the same weight as the claims. “Only the claims determine the extent of protection” (r. 3.16). In the case of a contradiction between the description and the claims, the ordinary meaning of the words in the claims should take precedence.

At Opposition, the OD agreed with the patentee that the claim should be interpreted in the context of the description, and that therefore, the granted claim should be read as including commas defining the “free inner bore” as a subclause not possessing the capacitive data link. However, the Board of Appeal found that, without the commas, the interpretation that the free inner bore possessed the capacitive data link was “technically sensible and plausible”, and that there was no technical reason for the skilled person to depart from this interpretation. The Board of Appeal thus found no reason to depart from the normal meaning of the description and the patent was revoked for added matter. 

The Board of Appeal also rejected the patentee’s auxiliary requests for correction of the claims. Applying the same interpretation of the claim language, the Board of Appeal agreed with the Opponent that the correction would extend the scope of protection of the patent to cover subject matter not covered by the granted claims. Furthermore, the Board of Appeal found that the correction would not have been obvious to a skilled person given that the claim made technical sense under a normal interpretation (Rule 139 EPC).  

Final Thoughts: Description amendments and claim interpretation

The question of interpretation of the claims in view of the description is highly relevant to the recent controversies over the EPO’s strict provisions that the description be amended in line with the allowed claims. Interestingly, the Board of Appeal in T 1473/19 resoundingly rejected the argument that Article 84 EPC (often used to justify the description amendment requirement) should be understood as relating to claim interpretation. The Board of Appeal particularly found that Article 84 EPC “[a]t most defines the standard applied when assessing clarity”. This puts the Board of Appeal in this case at odds with the decisions supporting the description amendment requirement as justified by Article 84 EPC e.g. T 3097/19 (IPKat). 

The Board of Appeal in T 1473/19 also made an interesting distinction between the “description and drawings” mentioned in Article 69 EPC, and “the application as filed” “which is not referred to in Article 69 EPC” (r. 4.4). Are we therefore to understand that an amended description may be used to interpret the claims in a way distinct to that of the description in the application as filed (as was suggested in T 471/20 (IPKat)? This reasoning appears to heighten the risk that a patent may be revoked for added matter in view of amendments made to the description during prosecution. 

On the other hand, an important reason that the Board of Appeal chose not to depart from the normal meaning of the claim wording in view of the description, was that the description did not expressly exclude the possibility of an embodiment following under the normal meaning of the claims. If the patentee had amended the description before grant to expressly exclude this embodiment, would this have saved the patent? The risk of added matter from non-disclosed disclaimers is a whole issue in itself (IPKat). 

If nothing else, T 1473/19 is yet another example of how easy it can be to fall into the inescapable added matter trap at the EPO, with even the loss of a simple comma or two from the claims causing the irretrievable invalidity of a granted patent. 

Further reading

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