A panel at the Patent Trial and Appeal Board (PTAB) recently held that a certificate of correction fixing an error in a patent's claim of priority did not apply retroactively in light of an already issued final written decision in an inter partes review (IPR).

Petitioner Emerson Electric Co. filed a petition for IPR challenging a patent owned by SIPCO, LLC (Patent Owner). The Board instituted the IPR and ultimately issued a final written decision finding obvious all challenged claims. A Federal Circuit appeal ensued, and while the appeal was pending, the Patent Office issued a certificate of correction changing the claim of priority in the challenged patent. Patent Owner had sought that correction in an attempt to remove as prior art a particular reference asserted in the IPR. Upon issuance of the certificate, the Federal Circuit granted Patent Owner's motion for remand with instructions for the Board to consider what effect, if any, the certificate had on the final written decision in the IPR.

On remand, Petitioner argued to the Board that the certificate of correction had no impact on the final written decision because under 35 U.S.C. § 255, which governs certificates of correction for errors such as that in a claim of priority, a certificate applies only prospectively to actions that arise after the certificate issues. In support of its argument, Petitioner pointed to the express language of § 255 which states that any certificate of correction that issues shall have an effect on "trial of actions . . . thereafter arising" (emphasis added). Petitioner further contended that allowing Patent Owner to change its patent at this stage of the proceeding essentially creates a "moving target" that would unfairly prejudice Petitioner. In response, Patent Owner countered that the language of § 255 instructing that a certificate of correction only applies prospectively does not apply to IPRs because an IPR is not a "trial of actions" under the statute. Patent Owner further argued that failing to give retroactive effect to a certificate of correction would waste Patent Office resources because "it would be illogical . . . to cancel claims of an uncorrected patent if the [Patent Office] has issued a certificate correcting the patent."

After considering the parties' positions, the Board sided with Petitioner and held that the certificate of correction had no impact on the final written decision in this proceeding. The Board began its analysis by explaining that it would reach the same outcome whether or not the IPR proceeding qualifies as a "trial of actions" under § 255. Thus, if the IPR were a "trial of actions," under the express wording of the statute, the certificate of correction would only apply if the IPR arose after the certificate issued. This was not the case because by the time the certificate of correction issued, the IPR had already commenced and the Board had issued its final written decision. Conversely, the Board held that even if the IPR were not a "trial of actions" under § 255, the certificate of correction would still only apply prospectively, citing the absence of affirmative language in the statute indicating any intent to retroactively apply a certificate of correction. The Board also noted that its ruling was consistent with the interpretation given to § 255's "sister provisions" including § 256, which allows for correction of named inventor errors. Section 256 explicitly states that inventorship errors "shall not invalidate the patent in which such error occurred," thereby indicating that certificates issued under this section have retroactive effect. This is in contrast to § 255, which does not include any similar provision. Finally, the Board found that its ability to exercise discretion to stay or prohibit the filing of a certificate of correction during an IPR supports its determination, stating that it would be "inconsistent" to grant the Board this discretion "yet mandate retroactive effect when a certificate issues."

Practice Tip: A patent owner should be diligent in checking for, and correcting, errors in a patent when it issues, including any errors relating to a claim of priority. Any delay creates a risk that corrections made later during the pendency of a post-grant proceeding, such as an IPR, will not be effective.

Emerson Elec. Co. v. SIPCO, LLC, IPR2016-00984, Paper 52 (PTAB January 24, 2020)

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