Parus v. Google: Federal Circuit Affirms Voice Patent Invalidity
Updated on Dec. 9, 2025 | Written by Patsnap Team
Introduction
The U.S. Court of Appeals for the Federal Circuit has affirmed a judgment holding a key voice technology patent asserted by Parus Holdings, Inc. against Google, LLC invalid. The appeal, case number 23-2297, centered on U.S. Patent 8,185,402 (“the ’402 patent”) concerning a “robust voice browser system.” The court’s affirmation that the patent claims were ineligible under 35 U.S.C. § 101 provides a clear precedent for patent litigation in the voice-enabled technology and AI sector, highlighting the ongoing application of the Alice framework to software-implemented inventions.
Case Summary
| Field | Details |
|---|---|
| Case Name | Parus Holdings, Inc. v. Google, LLC |
| Case Number | 23-2297 |
| Court | U.S. Court of Appeals for the Federal Circuit |
| Filing/Closure | 08/17/2023 – 03/06/2025 (567 days) |
| Outcome | AFFIRMED (Patent Invalid) |
| Patents | US8185402B2 |
| Products | Robust voice browser system and voice activated device controller |
| Plaintiff Counsel | McKool Smith PC (John Bruce Campbell) |
| Defendant Counsel | O’Melveny & Myers LLP (Benjamin Haber) |
| Termination Basis | Unpatentable (35 U.S.C. § 101) |
Case Overview
The Parties:
- Parus Holdings, Inc. is the plaintiff and holder of the ’402 patent.
- Google, LLC is the defendant and a leading developer of voice-activated technologies like the Google Assistant.
The Patent(s) at Issue:
The sole patent in this appeal was U.S. Patent No. 8,185,402, titled “Robust voice browser system and voice activated device controller.” The patent describes systems for accessing information using voice commands via a telephone or network. To research patent families on Patsnap Eureka IP, this case serves as a relevant example.
The Accused Product(s):
Parus alleged infringement by Google’s voice-activated products and services, including technology underlying the Google Assistant.
Legal Representation:
Parus was represented by McKool Smith PC and attorney John Bruce Campbell. Google’s defense was led by O’Melveny & Myers LLP and attorney Benjamin Haber.
Litigation Timeline & Procedural History
This was an appellate case before the Federal Circuit (23-2297), filed on August 17, 2023, and closed on March 6, 2025. The appeal affirmed a prior judgment from a lower tribunal that found the ’402 patent unpatentable. The 567-day duration indicates a standard appellate process including briefing and deliberation.
The Verdict & Legal Analysis
Outcome
The Federal Circuit’s judgment was AFFIRMED, upholding the finding that the claims of the ’402 patent were invalid under 35 U.S.C. § 101. The basis for termination was “Unpatentable.”
Verdict Cause Analysis: Patentability Under § 101
The decision applied the two-step framework from Alice Corp. v. CLS Bank International to assess patent validity.
- Step One – Abstract Idea: The court agreed the claims were directed to the abstract idea of retrieving information using voice commands.
- Step Two – Inventive Concept: The court found no inventive concept, ruling that applying this abstract idea using generic voice and computer components was routine and conventional.
💡 Key Insight: This Parus Holdings Google patent case analysis shows that patents on fundamental interaction paradigms (voice command/response) are vulnerable to § 101 challenges if the claims merely computerize the process without a novel technical architecture. This is critical for FTO (freedom to operate) analysis.
For more on the legal standards, see the USPTO’s Manual of Patent Examining Procedure (MPEP) Section 2106 on Patent Subject Matter Eligibility.
Strategic Takeaways
⚖️ For Patent Practitioners: Prosecution and claim drafting must focus on specific, non-conventional technical mechanisms, not just the functional result. The claim construction battle often begins with the § 101 analysis.
⚖️ For Defendants: This case reinforces the strategy of filing early motions on eligibility grounds in voice technology patent infringement suits.
🔬 For R&D Teams: Document technical problems solved, not just user benefits. Analyze patent landscapes on Patsnap Eureka IP to inform design-around strategies.
Industry & Competitive Implications
This affirmation provides clarity for large-scale developers of voice AI, potentially narrowing the scope of viable infringement assertions in this domain. It may influence settlement dynamics in similar disputes. The ruling emphasizes the continued centrality of § 101 as a filter for software-related patents. To track litigation trends with Patsnap Eureka IP in this evolving area is a prudent competitive intelligence practice.
Key Takeaways
📊 For Patent Attorneys: The Federal Circuit’s application of Alice remains strict for software/voice patents. Prior art challenges are often preceded by successful § 101 arguments.
⚖️ For IP Professionals: Proactively audit portfolios for similar abstract claim structures. This District of Columbia court patent case (Federal Circuit) is a key reference.
🔬 For R&D Leaders: Collaboration with patent counsel early in the innovation cycle is essential to identify and document patent-eligible subject matter.
FAQ Section
What patent was involved?
The case involved U.S. Patent No. 8,185,402, concerning voice-controlled information retrieval.
What was the basis for the verdict?
The patent was found unpatentable under 35 U.S.C. § 101 for claiming an abstract idea without an inventive concept.
How might this affect future litigation?
It strengthens an early dispositive defense for companies accused of infringing patents on core voice interaction models.
Disclaimer: This article is for informational purposes only and does not constitute legal advice. The outcome of any legal matter depends on the specific facts and circumstances involved. For legal advice on patent litigation or strategy, consult a qualified attorney.
To conduct detailed analysis of patent validity or competitive landscapes, start your patent research on Patsnap Eureka IP.
