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Strategic Use of Dependence Claims Patent Applications

09.08.2023

The Federal Circuit recently issued decisions invalidating issued patent claims in two unrelated cases: Sisvel International S.A. v. Sierra Wireless, Inc., Appeal No. 22-1387 (Fed. Cir. September 1, 2023) and Dali Wireless Inc. v. CommScope Techs. LLC, Appeal No. 20-1045 (Fed. Cir. Sept. 6, 2023).

In both cases, the patent challengers argued for broad claim constructions of pivotal claims terms, while the patentees argued for narrow claim constructions, pointing to specific examples described in the specifications. And in both cases, the Federal Circuit declined to narrow the claims to those specification embodiments because the language supported broader plain meanings.

This case illustrates the importance of forward thinking during the patent drafting process. While it is likely impossible to foresee all possible challenges that could be encountered by the claim language, it can be extremely helpful to explore different claim scopes among the different claims. 

For example, a primary purpose of dependent claims is to increase the patentability of the claimed technology by further limiting one or more of the preceding claims. When properly used, dependent claims can provide a safety nets of sorts should the claims issue as patent and become subject to some eventual third-party challenge. Unfortunately for some patentees, the usefulness of dependent claims is largely forfeited in many patents and patent applications, particularly when the dependent claims are merely used as filler to reach an imagined minimum claim count.

Extra thought and effort taken during the patent drafting process could prove critical for a future resulting patent.  

Both cases demonstrate the Federal Circuit’s reluctance to confine claims to specification embodiments when the language can support a broader plain meaning. Again, one take-away for patent prosecutors is to look closely to the described embodiments and consider express limitations that cover only those embodiments.