Boeing the US aerospace giant ended up losing a very crucial patent due to a misplaced comma in the patent claim.
Background: The patent under question was EP1798 872 dealing with the method of handling aircraft communication. The method discloses the use of different communication networks to send information related to flight routes and other associated data. All the communication channels are not always active and hence a preference list is used by the system to identify the currently available network for transmission of the information. The patent was filed in 2006, and was granted in 2011 but the Boeing’s competitor Airbus opposed the grant in 2012.
The issue: Claim 1 of the EP patent has a claim limitation:
“Evaluating a preference to determine a preferred network of the plurality of transmission networks, wherein the preference comprises a preference list identifying a selection of the plurality of broadcast networks in order of preference and identifying the highest in preference of the plurality of broadcast networks in the preference list that is available.”
In the above claim limitation, there is a comma after term ‘’plurality of transmission networks” but there is no comma after the term ‘’preference’’ followed by the terms “and identifying the highest” see below:
“Wherein the preference comprises a preference list identifying a selection of the plurality of broadcast networks in order of preference and identifying the highest in preference of the plurality of broadcast networks in the preference list that is available.”
As a result, the claim limitation is read in a different manner, due to the absence of a comma, the two features are read together. Therefore, the list not only comprises information about identifying a selection of networks but also identifying the highest preference broadcast network in the preference list that is available.
Boeing went on appealing the case as the patent was revoked by the patent office, Boeing argued that “The patent must be construed by a mind willing to understand not a mind desirous of misunderstanding”. Therefore, the patent’s description and drawing should be referred to for the proper interpretation of the terms.
However, the appeal board believed that the description and drawing of the patent is not an automatic choice for reference if an “ambiguous” feature is encountered in the claim. In this case, the feature under question has theoretically more than one interpretation. Hence, if the claim includes inconsistencies or vague descriptions that cannot help, claims are judged on their own merits.
Also, due to the absence of a comma, the claimed features are read together and support for such interpretation is not present/disclosed in the patent application.
Figure from the EP’872 patent
Claim vagueness at linguistic level:
The use of the same verb in the feature for identifying a preference list and then identifying the highest preference network would result in associating the second identifying subclause with the preference list, see below:
“A preference list identifying a selection of the plurality of broadcast networks in order of preference and identifying the highest in preference of the plurality of broadcast networks in the preference list that is available.”
It cannot be expected from a skilled person to apply commas at different places within the claim to speculate different meanings out of the claimed invention. Therefore, it puts “undue burden on the reader” of the patent claim.
Claim vagueness at technical level: The claim uses the term preference “list” and “lists” inconsistently in different clauses (clause g and clause h) and also the absence of explicit mention of availability in the preference list in the below clause prevents the technically accurate interpretation of the claim.
“Re-evaluating the preferences of the message according to changes in availability of the broadcast networks to determine a current preferred network corresponding to a highest in preference of the plurality of broadcast networks in the preference lists corresponding to the message.” Conclusion:
- A through review of patent claims is crucial for each patent clause, even if you file 100s of patents every year.
- A competent patent attorney is critical for a patent. You may end up losing a very crucial invention due to poor choice of claim drafter.
- For Boeing, it’s a business loss too not just a patent loss, because they couldn’t stop their competitors from practicing their critical invention which went public due to the patent application.
- The appeal board like a critical review of claims to be provided for the examination phase of the patents, basically during the patent prosecution stage to avoid such loss.
Written by Nikesh Dodwani, Head of Patent Monetization, Photon Legal