952 F.3d 1336
Fed. Cir.2020Background
- The ’091 patent claims methods for decrypting broadcast programming by receiving "an encrypted digital information transmission including encrypted information." Claims 13 and 20 include the phrase "encrypted digital information transmission;" claim 26 recites only "an information transmission including encrypted information."
- Apple petitioned for inter partes review (IPR) of multiple claims; the PTAB instituted review and found the challenged claims anticipated/obvious based on prior art that disclosed mixed analog/digital transmissions.
- The PTAB construed the phrase at issue to permit mixed analog/digital transmissions, reasoning that (1) the claims do not say "entirely digital," (2) the specification discloses mixed embodiments, and (3) "encrypting" had been used interchangeably with analog "scrambling" in the 1980s.
- PMC argued the phrase must be limited to entirely digital transmissions (i.e., the entire transmission is digital, with at least a portion encrypted); PMC relied heavily on prosecution history where the applicant amended claims to add "encrypted digital" and repeatedly asserted that encryption requires a digital signal.
- The Federal Circuit applied the broadest reasonable interpretation standard (applicable to this pre-2018 IPR), concluded the prosecution history meaningfully informed claim scope, held the disputed phrase is limited to all-digital transmissions, reversed the PTAB as to claims 13–16, 18, 20, 21, 23, and 24, and affirmed as to claims 26, 27, and 30.
Issues
| Issue | Plaintiff's Argument (PMC) | Defendant's Argument (Apple/PTAB) | Held |
|---|---|---|---|
| Proper construction of "an encrypted digital information transmission including encrypted information" | Must be limited to entirely digital transmissions (encryption requires a digital signal) | May include transmissions that are partially or entirely digital; can cover mixed analog/digital embodiments | Construed in favor of PMC: limited to all-digital transmissions; PTAB erred in allowing mixed analog/digital scope |
| Role of prosecution history — whether applicant statements/claim amendment limit scope | Applicant repeatedly and consistently distinguished prior art as analog (scrambling) and stated "encryption requires a digital signal;" amendment adding "encrypted digital" made that clear | PTAB: prosecution history was murky/ambiguous and did not rise to clear and unmistakable disclaimer; thus should not limit claim scope | Prosecution statements and amendment were persuasive and dispositive here; even if not formal disclaimer, they inform and resolve ambiguity in favor of PMC |
| Impact on PTAB invalidity findings based on mixed analog/digital prior art | Prior art using mixed analog/digital signals does not anticipate/obvious claims that require all-digital transmissions | Prior art anticipates/obvious regardless of construction | Because claims requiring "encrypted digital" are limited to all-digital, PTAB's invalidity findings dependent on mixed analog prior art reversed for claims with that term; PTAB decision affirmed for claims lacking the "digital" modifier (claims 26, 27, 30) |
Key Cases Cited
- Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) (claim construction principles; reliance on intrinsic evidence)
- Sunovion Pharm., Inc. v. Teva Pharm. USA, Inc., 731 F.3d 1271 (Fed. Cir. 2013) (prosecution history can be critical to term meaning)
- Shire Dev., LLC v. Watson Pharm., Inc., 787 F.3d 1359 (Fed. Cir. 2015) (prosecution statements inform construction even if not unmistakable disclaimer)
- Tempo Lighting, Inc. v. Tivoli, LLC, 742 F.3d 973 (Fed. Cir. 2014) (amendment plus explanatory remarks can define term meaning)
- Realtime Data, LLC v. Iancu, 912 F.3d 1368 (Fed. Cir. 2019) (broadest reasonable interpretation must consider entire patent context)
- In re Translogic Tech., Inc., 504 F.3d 1249 (Fed. Cir. 2007) (applying Phillips best practices under BRI)
- Rambus Inc. v. Infineon Techs. AG, 318 F.3d 1081 (Fed. Cir. 2003) (prosecution history waiver principles)
- Inverness Med. Switz. GmbH v. Warner Lambert Co., 309 F.3d 1373 (Fed. Cir. 2002) (prosecution history and disclaimer analysis)