Background
CyWee Group Ltd. holds U.S. Patent No. 8,441,438 on a three-dimensional pointing device used in smartphones — technology for accurately measuring yaw, pitch, and roll in a 3D reference frame. ZTE (USA), Inc. filed an inter partes review (IPR) petition challenging the patent. LG later filed its own IPR petition on the same patent and sought to join ZTE’s already-instituted IPR. LG was granted joinder, but on the condition that it would participate only passively unless ZTE ceased to participate.
During the IPR, CyWee filed a revised motion to amend its patent claims — seeking to substitute new, narrowed claims for the challenged original claims. ZTE indicated it would not oppose the amendment. LG, which had joined as a passive understudy, argued that since ZTE was no longer meaningfully adversarial on the amendment issue, LG should be allowed to step up and oppose the motion. The PTAB granted LG leave to oppose. CyWee argued on appeal that LG — as a time-barred joined party — was prohibited by statute from introducing new issues, and that opposing a motion to amend constitutes raising a new issue.
The Court’s Holding
The Federal Circuit affirmed. The court addressed the interplay between § 315(c) — which governs joinder and restricts time-barred joined parties from introducing new issues — and the motion-to-amend procedure available to patent owners under § 316(d). The court held that the new-issue restriction in § 315(c) is directed at the merits phase of the IPR, where a joined party could attempt to expand the scope of the challenge. It does not apply to a patent owner’s motion to amend.
The court reasoned that when a patent owner files a motion to amend its own claims, the patent owner itself introduces new claim language into the proceeding — it is the patent owner, not the joined party, who opens the door to new issues. In that context, allowing the joined party to oppose the amended claims is not the joined party “introducing” new issues; it is the joined party responding to issues introduced by the patent owner. The court also affirmed the PTAB’s underlying obviousness finding on the original claims.
Key Takeaways
- The § 315(c) prohibition on time-barred joined parties introducing new issues applies to the merits phase of IPR proceedings, not to a patent owner’s motion to amend substitute claims.
- When a patent owner files a motion to amend and proposes new claim language, joined parties — including those who joined under restrictive “passive understudy” conditions — may be permitted to oppose the amended claims.
- A joined party can step into an active role opposing a motion to amend if the original petitioner is no longer meaningfully adversarial on that issue, even if the joined party originally agreed to be passive.
- Patent owners in IPR proceedings who file motions to amend should anticipate opposition from all joined parties, not just the original petitioner — amendment can activate previously passive participants.
Why It Matters
CyWee v. ZTE clarifies a nuanced but practically important aspect of IPR procedure: the new-issues restriction on joined parties has limits, and those limits matter when patent owners try to use motions to amend as a mechanism to narrow claims in the absence of an active opponent. The decision forecloses a potential strategy in which a patent owner, facing a passive joined petitioner after the original petitioner withdraws, amends claims hoping to face no meaningful opposition. Under this ruling, the joined party can step up when the patent owner amends — ensuring that substitute claims receive adversarial scrutiny.
For companies managing IPR proceedings as joined parties, the case clarifies when it is permissible — and perhaps strategically necessary — to become active participants. And for patent owners, it underscores that filing a motion to amend invites opposition from the entire petitioner side, regardless of joinder limitations.