Nanoco v. LG Electronics: Quantum Dot Patent Dispute Dismissed Without Prejudice
UK-based quantum dot pioneer Nanoco Technologies filed a four-patent infringement action against LG Electronics in the Eastern District of Texas, targeting quantum dot technology embedded in LG’s TVs, monitors, laptops, tablets, and mobile phones. The parties jointly stipulated to dismissal without prejudice after 223 days, leaving Nanoco’s claims legally alive.
Nanoco’s quantum dot IP campaign reaches LG — then pauses
On April 24, 2025, Nanoco Technologies, Ltd. — a Manchester-based developer of cadmium-free quantum dot materials — filed a patent infringement complaint against LG Electronics, Inc. and LG Electronics U.S.A., Inc. in the Eastern District of Texas (Marshall Division) before Judge Rodney Gilstrap. The action asserted four U.S. patents — US7867557B2, US7803423B2, US8524365B2, and US7588828B2 — covering quantum dot compositions and manufacturing methods against LG’s broad consumer electronics portfolio.
On December 3, 2025, after 223 days of litigation, the parties filed a Joint Stipulation of Dismissal under Fed. R. Civ. P. 41(a)(1)(A)(ii). The Court accepted and acknowledged the stipulation, dismissing all claims without prejudice. Notably, the verdict text explicitly states the parties agreed to dismissal ‘with prejudice’ pursuant to Rule 41, yet the Court’s order reads ‘DISMISSED WITHOUT PREJUDICE’ — a discrepancy in the public record that may be significant. Each party was ordered to bear its own costs and attorneys’ fees.
A pre-trial resolution at the 223-day mark — before any Markman ruling or summary judgment briefing — is consistent with either an ongoing licensing negotiation or a strategic procedural pause. The without-prejudice dismissal means Nanoco’s claims are not extinguished and could be refiled. The cost-bearing arrangement suggests neither party extracted financial concessions publicly, though a confidential license or settlement payment cannot be ruled out from the public record alone.
Filing to Dismissed without Prejudice in 223 days
223 days — faster than the E.D. Texas median for multi-patent infringement actions
Dismissed without prejudice: what the stipulation means for both parties
Rule 41(a)(1)(A)(ii): joint stipulation dismissal explained
A Rule 41(a)(1)(A)(ii) dismissal requires agreement from all parties who have appeared. It is a consensual exit — no court merits ruling is issued. The Court here accepted and acknowledged the stipulation, ordering the case closed. Critically, the order reads ‘dismissed without prejudice,’ meaning no res judicata bar attaches and Nanoco may refile the same claims subject to applicable statutes of limitations.
No merits adjudicationWith prejudice vs. without prejudice: the public record is ambiguous
The stipulation text states the parties agreed to dismissal ‘with prejudice,’ yet the Court’s operative order dismisses the case ‘without prejudice.’ These carry materially different consequences: with prejudice bars Nanoco from refiling; without prejudice does not. The Court’s order controls as the operative instrument, but the discrepancy in the public record is unusual and its origin — clerical, intentional, or negotiated — is not explained in publicly available filings.
Order controls over stipulation textNanoco retains right to refile — four patents remain enforceable
Because the dismissal is without prejudice per the Court’s order, Nanoco’s four quantum dot patents remain fully enforceable and no claim preclusion bars a future action against LG. Nanoco has historically pursued serial licensing campaigns across the display and semiconductor industry. This resolution preserves all enforcement options, including refiling in E.D. Texas or pursuing inter partes licensing discussions backed by live patent rights.
Claims survive; patents intactLG exits without prejudice — litigation risk not fully extinguished
LG Electronics avoids an adverse merits ruling and any damages exposure in this action. However, the without-prejudice dismissal means LG has not obtained a covenant not to sue or a final judgment that would shield it from a future Nanoco filing on the same patents. LG’s quantum dot product lines — spanning QLED TVs, monitors, and mobile devices — remain potentially exposed until the underlying patents expire or a license is confirmed. Each party bearing its own costs suggests no declared winner.
No covenant not to sue obtainedFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Nanoco Technologies, Ltd. | Company | Quantum dot materials developer — holder of US7867557B2 and 3 related patentsSearch in Eureka ↗ |
| Defendant | LG Electronics, Inc. | Company | South Korean consumer electronics manufacturer; global leader in QLED TVs and displaysSearch in Eureka ↗ |
| Plaintiff counsel | Andrea Leigh Fair | Attorney | Counsel for Nanoco Technologies, Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Bjorn A. Blomquist | Attorney | Counsel for Nanoco Technologies, Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Bradley Wayne Caldwell | Attorney | Counsel for Nanoco Technologies, Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Hamad M. Hamad | Attorney | Counsel for Nanoco Technologies, Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Robert Seth Reich , Jr. | Attorney | Counsel for Nanoco Technologies, Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Warren Joseph McCarty , III | Attorney | Counsel for Nanoco Technologies, Ltd.Search in Eureka ↗ |
| Plaintiff law firm | Caldwell Cassady Curry PC | Law Firm | Representing Nanoco Technologies, Ltd.Search in Eureka ↗ |
| Plaintiff law firm | Miller Fair Henry PLLC | Law Firm | Representing Nanoco Technologies, Ltd.Search in Eureka ↗ |
| Plaintiff law firm | The McCarty Firm PC | Law Firm | Representing Nanoco Technologies, Ltd.Search in Eureka ↗ |
| Defendant counsel | Brett M. Sandford | Attorney | Counsel for LG Electronics, Inc.Search in Eureka ↗ |
| Defendant counsel | Charles Howard Sanders | Attorney | Counsel for LG Electronics, Inc.Search in Eureka ↗ |
| Defendant counsel | Kimberly Q. Li | Attorney | Counsel for LG Electronics, Inc.Search in Eureka ↗ |
| Defendant counsel | Melissa Richards Smith | Attorney | Counsel for LG Electronics, Inc.Search in Eureka ↗ |
| Defendant counsel | Richard G. Frenkel | Attorney | Counsel for LG Electronics, Inc.Search in Eureka ↗ |
| Defendant law firm | Gillam & Smith, LLP | Law Firm | Representing LG Electronics, Inc.Search in Eureka ↗ |
| Defendant law firm | Latham & Watkins LLP | Law Firm | Representing LG Electronics, Inc.Search in Eureka ↗ |
| Defendant law firm | Latham & Watkins, LLP (Boston) | Law Firm | Representing LG Electronics, Inc.Search in Eureka ↗ |
| Defendant law firm | Latham & Watkins LLP (Menlo Park) | Law Firm | Representing LG Electronics, Inc.Search in Eureka ↗ |
| Presiding judge | Judge Rodney Gilstrap | Judge | Texas Eastern District CourtSearch in Eureka ↗ |
Official order — verbatim text
The Court’s order presents a notable internal tension: the parties’ stipulation invokes dismissal ‘with prejudice’ under Rule 41(a)(1)(A)(ii), yet the operative court order dismisses all claims ‘without prejudice.’ As the controlling instrument, the Court’s order governs. An without-prejudice dismissal imposes no res judicata effect, leaving Nanoco free to refile. The cost-neutrality provision — each party bears its own fees — is standard for negotiated exits and provides no signal as to which party, if any, extracted commercial concessions outside the public record.
US7867557B2 — Cadmium-free quantum dot nanoparticle compositions
The four asserted patents — US7867557B2, US7803423B2, US8524365B2, and US7588828B2 — cover compositions, synthesis methods, and application of cadmium-free quantum dot nanoparticles. Nanoco’s core technology relates to Group III-V and Group II-VI semiconductor nanocrystals engineered for precise optical emission, enabling high colour-gamut display backlighting without toxic heavy metals. The application dates span the mid-2000s to early 2010s, placing these patents at the foundation of the commercial quantum dot display market.
Quantum dot technology is now embedded across the premium consumer electronics supply chain — QLED TVs, high-resolution monitors, tablets, and mobile displays. Nanoco’s patents sit upstream of the display stack, potentially reading on the quantum dot materials themselves rather than only finished products. This makes the IP relevant not just to OEMs like LG but also to quantum dot material suppliers and panel manufacturers. For competitors and supply chain participants, the breadth of composition and method claims across four patents creates a multi-vector infringement exposure that is difficult to design around without accessing Nanoco’s proprietary synthesis know-how.
Should your team run an FTO against Nanoco’s quantum dot patent portfolio?
Any company developing, sourcing, or integrating quantum dot materials into display products — including TVs, monitors, laptops, tablets, and mobile phones — should treat Nanoco’s portfolio as a primary FTO reference. With four patents asserted against LG and prior actions against Samsung, Nanoco has demonstrated a consistent willingness to enforce broadly. The without-prejudice dismissal here does not reduce that risk. Product teams planning next-generation quantum dot display designs should map current claim scope before design freeze.
PatSnap Eureka’s FTO Search Agent can rapidly map the claim language of US7867557B2, US7803423B2, US8524365B2, and US7588828B2 against your product architecture, identify prior art that could support invalidity arguments, and flag related Nanoco continuation or divisional applications that may extend the enforcement window. Eureka’s portfolio visualisation tools also allow IP teams to benchmark Nanoco’s citation network against competitor filings in the quantum dot materials space.
Run a freedom-to-operate analysis on US7867557B2 to assess your product’s exposure
Run FTO in Eureka →Similar quantum dot patent cases in E.D. Texas and related venues
Explore comparable quantum dot display technology infringement actions filed in the Eastern District of Texas, including prior Nanoco assertions against major OEMs.
What this case signals for the quantum dot display IP landscape
Nanoco’s pattern of asserting cadmium-free quantum dot patents against major display OEMs makes this dismissal a signal worth watching closely.
Without-prejudice dismissal keeps Nanoco’s enforcement options fully open
A without-prejudice outcome is not a win for LG in any durable sense. Nanoco’s four quantum dot patents remain live and unencumbered by any adverse ruling. Display OEMs and their supply chain partners sourcing quantum dot components should treat this as a pause, not a resolution, and maintain active patent monitoring on Nanoco’s portfolio.
Judge Gilstrap’s court remains the preferred venue for quantum dot assertions
The Eastern District of Texas under Judge Gilstrap continues to attract high-value display technology patent assertions. The combination of experienced patent counsel (Caldwell Cassady Curry) and a plaintiff-friendly procedural track record in E.D. Texas signals that any company with quantum dot-integrated products should model E.D. Texas litigation exposure as a baseline risk scenario.
Nanoco v LG — key questions answered
The Court’s operative order in Case No. 2:25-cv-00431 dismissed all claims without prejudice, despite the parties’ stipulation referencing dismissal ‘with prejudice.’ The Court’s order is the controlling instrument. A without-prejudice dismissal means Nanoco retains the right to refile the same patent claims against LG, subject to applicable statutes of limitations.
Nanoco asserted four U.S. patents: US7867557B2, US7803423B2, US8524365B2, and US7588828B2. All relate to quantum dot nanoparticle compositions and methods. The accused products were LG and LGEUS consumer electronics incorporating quantum dots, including TVs, monitors, laptops, tablets, and mobile phones.
Rule 41(a)(1)(A)(ii) allows parties to dismiss a case by filing a signed stipulation after all parties who have appeared agree. It requires no court approval for dismissal itself, though the court acknowledges it. No merits ruling is issued. If without prejudice, the plaintiff may refile; if with prejudice, claims are extinguished. In this case the Court’s order specifies without prejudice.
Nanoco was represented by Caldwell Cassady Curry PC, Miller Fair Henry PLLC, and The McCarty Firm PC. LG Electronics was represented by Latham & Watkins LLP (with teams in multiple offices) and Gillam & Smith, LLP. Caldwell Cassady Curry is a prominent plaintiff-side patent litigation boutique with significant E.D. Texas experience.
Based on publicly available records, Nanoco Technologies has previously asserted quantum dot-related patents against other major consumer electronics manufacturers, including Samsung. Nanoco’s litigation history suggests a consistent strategy of enforcing its cadmium-free quantum dot IP portfolio against OEMs whose display products incorporate quantum dot materials. This case against LG is consistent with that broader enforcement pattern.
PatSnap Eureka searches patents and litigation data to answer instantly.