Error Not Apparent from the Face of the Patent Correctable Only by USPTO
Even though the PTO has the authority to correct its own errors under Â§254, we have held that in some circumstances the district court can correct
errors retroactively. But the district court can correct an error only if the
error is evident from the face of the patent. Novo Indus., L.P. v. Micro MoldsCorp., 350 F.3d 1348, 1357 (Fed. Cir. 2003). "A district court can correct a patent only if (1) the correction is not subject to reasonable debate based on consideration of the claim language and the specification and (2) the
prosecution history does not suggest a different interpretation of the claims."
Id. (emphasis added). Because a reader of the patent at issue in Novo Industries
could not ascertain the error from the face of the patent, we held that it was
beyond the district courtâ€™s authority to guess at what was intended, and that
the error, if any, could only be corrected by the PTO. Id. at 1357-58. We
recently followed Novo Industries in Hoffer, holding that an error apparent from the face of the patent could have been corrected by the district court. Hoffer v. Microsoft Corp., No. 04-1103, slip op. at 7-8 (Fed. Cir. Apr. 22, 2005).
This rule also comports with our prior case law. In Lemelson, we permitted correction of a patent by inserting the word "toy" in a claim where the patent on its face was clearly directed at a toy trackway rather than an actual trackway. Lemelson v. Gen. Mills, Inc., 968 F.2d 1202, 1203 & n.3 (Fed. Cir. 1992). In Southwest Software, the patent lacked multiple pages of software code due to a PTO error, and the content of the missing code could not be known by simply looking at the face of the patent lacking the code. Southwest Software, Inc. v. Harlequin Inc., 226 F.3d 1280, 1291, 1296 (Fed. Cir. 2000); see also Arlington Indus., Inc. v. Bridgeport Fittings, Inc., 345 F.3d 1318, 1331 n.1 (Fed. Cir. 2003) (court refused to correct PTO error not apparent from the face of the patent). While we upheld the PTOâ€™s issuance of a certificate of correction, we limited the effect of the correction to actions arising after the correction, and assumed that the district court could not correct the error. Southwest Software, 226 F.3d at 1293-97.