In LG Electronics v. Immervision, the Federal Circuit clarified the standard for evaluating whether a prior art reference includes an obvious typographical error. See 39 F.4th 1364, 1365 (Fed. Cir. 2022). Under this standard, established 50 years ago in In re Yale, a prior art disclosure that relies on a typographical error is not invalidating if that error would have been apparent (i.e. obvious) to a person of ordinary skill in the art (“POSA”). See id. at 1371-72.

At the PTAB, LG Electronics (“LG”) challenged Immervision’s patent, which claimed a method of compressing and expanding different parts of a photo to improve resolution. See id. at 1366. LG’s prior art patent (“Tada”) did not expressly disclose the compression and expansion limitations, but it included data (“Table 5”) that LG’s expert relied on to opine that Tada was invalidating prior art. See id. at 1367. However, after analyzing Tada and its priority application, Immervision’s expert identified a transcription error in Table 5. See id. at 1367-71. Immervision argued this error would have been apparent to a POSA, and therefore Table 5’s data did not invalidate Immervision’s patent. See id. The PTAB agreed with Immervision, and LG appealed. See id. at 1371.

In affirming the PTAB’s decision, the Federal Circuit identified evidence of the obvious typo, including the different Table 5 values in Tada and its priority application, and inconsistent references to Table 5’s values throughout Tada’s specification. See id. at 1372-73. Notably, the Federal Circuit rejected LG’s argument that a POSA must immediately recognize an apparent error, finding that Yale does not impose this temporal requirement, and explaining that a POSA’s time and effort in finding the error was just one factor to be considered. See id. at 1373-74. LG also attempted to distinguish the “copy and paste” error in Tada from Yale’s run-of-the-mill typo, but the Court found these errors were not sufficiently distinct to warrant a different result. See id. at 1374.

Takeaway: The LG Electronics decision underscores the need for Petitioners and their experts to closely examine prior art references for typographical errors that could be fatal to their invalidity arguments. This includes not only a close review of the reference itself, but also its priority application(s).