May 20, 2025
Signify Shifts Patent Enforcement Strategy
Plus, attorney David Radulescu shares four other trends impacting patent litigation
In the war rooms of LED lighting technology patent litigation, predictability has long been a quiet comfort — at least for defendants. Companies sued by Signify, the Dutch lighting giant behind the EnabLED licensing program, once relied on familiar blueprints: a recycled lineup of frequently-asserted patents, repeated legal theories, and enough precedent to construct a reasonable defense. But according to veteran patent litigator David Radulescu, that era may be over.
In a May 15 webinar attended by scores of lighting executives and counsel, Radulescu laid out a stark shift in Signify’s IP litigation strategy: the company is now asserting never-before-litigated patents — many of them tailored to individual defendants. “If you look at the last five to eight cases,” Radulescu said, “what you see is a single patent case having unique patents being asserted.” That, he added, is new.
One Giant, Many Arrows
The numbers speak volumes. In the Atomi case, four of eight asserted patents had never been used by Signify in previous litigation. In the Keystone case, it was four of nine. ETI Lighting faced five unique patents; Nanoleaf, three; and Liton — one of the more recent targets — encountered two entirely new ones.
This isn’t just procedural nuance — it’s strategic shift. In the past, cornerstone patents like the infamous ‘604 patent were rolled out again and again across multiple cases. “If a single patent is asserted in six cases, there is a long history,” Radulescu said. “You can look back, and defenses have been developed... But it looks like there’s a new strategy to assert a subset of patents only in very specific cases.”
And the implications are profound. With each new case charting unfamiliar legal terrain, defense costs go up — and so does pressure to settle. “There may be a need to sign up more licensees,” Radulescu suggested, framing the tactic as a practical response to stalled licensing velocity in North America.
Disrupting the Defense Industrial Complex
By asserting unique patents in each case, Signify effectively cuts the connective tissue between defendants, disrupting coordinated legal defenses. Shared strategies become less viable when every target faces a different intellectual landmine.
It also minimizes risk across the broader portfolio. If one patent gets invalidated in court, others remain untouched — legal damage is compartmentalized. At the same time, the unpredictability refreshes legal pressure, keeping potential infringers off balance and reminding the industry of the depth of Signify’s IP war chest.
Signify seems to be sending a message: The ammo isn’t running low. It’s just being repackaged.
Four More Takeaways: Patent Pressure Across the Board
The Signify pivot may have stolen the spotlight, but Radulescu also highlighted four broader IP trends that lighting professionals should be watching closely.
- U.S. Patent Office Denial Rates Are Rising: The era of reflexively filing Inter Partes Review (IPR) petitions to invalidate patents is losing steam. In Q1 2025, the USPTO denied 32% of IPR requests — a sharp uptick from years of sub-20% denial rates. This shift follows policy changes at the Patent Trial and Appeal Board and signals a retreat from the playbook many large defendants used to reliably pause litigation. The result: patent holders, including smaller companies and NPEs, are gaining stronger footing, and litigation is becoming harder to stall.
- Design Patents Are Back — and Broader : Radulescu observed that design patent litigation is on the rise, with the Northern District of Illinois alone responsible for half of all U.S. design patent cases filed in 2024. Within the lighting industry, decorative fixture makers are asserting rights more aggressively — particularly in the hospitality sector. Plaintiffs aren’t just targeting manufacturers; they're also suing architects, sourcing firms, and building owners involved in allegedly infringing installs.
- China’s Patent Surge: Chinese companies now control 23% of all U.S. LED patents, up from just 16% one year earlier. That dramatic rise is driven by both aggressive filings and acquisitions, suggesting Chinese firms are positioning themselves for more active enforcement roles in global IP battles. Whether this leads to NPE-style tactics or direct litigation, it marks a growing shift in the power dynamics of LED intellectual property — particularly for cost-sensitive North American suppliers relying on private-label imports.
- The NPE Resurgence: Radulescu noted that these lawsuits tend to rely on older, foundational patents and often aim for fast settlements against retailers and distributors. New non-practicing entities (NPE) like BX LED, Edison LED, and SemiLED Innovations are acquiring once-dormant chip and packaging patents from OEMs such as Bridgelux and Epistar. They're using these assets to sue in patent-friendly districts, most often Texas. With a steady stream of filings and a pattern of quick resolutions, these entities are quietly redrawing the litigation map in LED IP enforcement.
A Smarter, Sharper IP Battlefield
As Signify evolves from a repeat-player into a precision-striker, it is forcing its targets to adapt in kind. Gone are the days of fighting off the same patent in court after court. The company is signaling it has the resources, the portfolio, and the intent to keep adversaries guessing.
This is more than a change in tactics. It’s a recalibration of pressure, timing, and perception — a reminder to the lighting industry that the threat landscape is shifting, and yesterday’s defenses may not hold tomorrow. It’s also a moment when those facing — or anticipating — litigation may find value in listening to attorneys like David Radulescu, who’s been in the thick of it long enough to see the patterns shift before the industry does.
