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Shedding Light on LED Patent Litigation: Insights from David Radulescu’s Webinar


by Randy Reid May 8, 2023

David Radulescu, Ph.D., Founder and Partner of Radulescu LLP, an elite patent litigation boutique firm based in New York City, delivered a comprehensive webinar on the state of the playing field for solid-state lighting and patent litigation on April 26, 2023.  
David Radulescu has for many years spoken on patent issues facing the LED lighting industry during LightFair.  These privately hosted meetings have been well-attended by LED lighting companies interested in learning more about the increasing threat of patent litigation to their businesses.  Because of the postponement of LightFair 2020 and other industry conferences due to COVID-19, Dr. Radulescu and his firm have moved the annual talk online for the third year in a row.
The webinar was neatly packaged into 6 segments:

•    Recent Trends in U.S. Patent Litigation in the LED Industry
•    The LED Patent Litigation Landscape
•    Update on the Signify EnabLED Licensing Program
•    Status of other LED Licensing programs
•    Non-Practicing Entity Update
•    Common Pitfalls in LED Patent Enforcement/Defense

Dr. Radulescu first reviewed trends in LED patents and patent litigation in the United States.

After hitting another 10-year high in 2020, in 2022, U.S. patent grants were still, but increased 9.5% from 2021.  2022 saw a decrease in grants from U.S. and Japanese inventors for the second year in a row, an increase in grants to Chinese and South Korean inventors, and for the first time, China surpassed South Korea in patent grants.  LED patent grants are up after two years of decreases, but still down from an all-time high in 2019.   

Most of the LED patent assignees in 2022 rest in the display/mobile device realm including top-of-the-heap Samsung with 378 patents.

While most of the patents were assigned to firms more closely aligned to displays, tablets, and smartphones, the top 30 lighting companies in 2022 continued to include LumiLeds, Seoul Semi, Signify, Lutron, Shezan China Star, Xiamen Eco Lighting, Xiamen Leedarson Lighting, and Cree, in that order, with IBM, Hubbell, and LEDVANCE dropping out of the top 30.  Notably, the 2022 U.S. Patent Overall Crown went to Samsung, ending IBM’s 30-year reign of the top grantee.

Overall, U.S. patent litigation activity was down 5% from 2021, with 3555 cases filed in 2022 compared to 3716 cases in 2021.  2022 saw no change in the most popular district court venues, with the Western District of Texas, the District of Delaware, and the Eastern District of Texas comprising the top 3 once again.  At the PTAB, IPR institution rates jumped significantly to 67% in 2022, compared to 59% in 2021.


An IPR (inter partes review) is a procedure for challenging the validity of a U.S. patent before the United States Patent and Trademark Office.  They have a general life cycle, which Dr. Radulescu reviewed.  14% of the IPRs are settled out of court within 6 months.  By 6 months, 33% are denied and 67% are instituted and move on to trial.  Most are resolved by 18 months, with 13% being settled between the parties.


Dr. Radulescu then provided a deep dive into patent lawsuits currently still active and those settled in one way or another over the last 5 years.  Of the 67 LED patent infringement suits initiated in 2018,  2 are still active. In 2019, the numbers are 76/3; in 2020 92/12; from 2021 81/23; and for 2022, 52 of the 69 filed suits are still active.  Notable suits in 2022 include suits brought by Philips/Signify, BX LED LLC, and Lexington Luminance, and a number of suits brought by companies looking to license their portfolios, and non-practicing entities.

Over the past five years, Signify/Philips’ EnabLED Campaign has continued with the company bringing five suits in 2019, three in 2021, three in 2022, and one in 2023.  Of note, Signify lost four cases in a row to EGLO in Germany, and responded by filing suit in the U.S., which is ongoing. Dr. Radulescu also analyzed the patents that Signify is asserting in its more recent suits and reviewed the recent statistics on the EnabLED licensing program.

Dr. Radulescu reviewed other notable licensing program campaigns, including Lynk Labs, CAO Lighting, and UC Santa Barbara.  After bringing suit against Samsung and Home Depot in district court, Lynk Labs saw most of its patents invalidated by the PTAB, as together, Home Depot and Samsung filed 23 IPRs.  In the last year, CAO Lighting won $2 million from GE Lighting/Current after a jury trial in Delaware, had 5 IPRs filed against its patents, and is heading towards trial against Osram. Dr. Radulescu also reviewed UC Santa Barbara’s recent ITC investigations, which concluded in a finding of no violation by the full ITC, and which is now on appeal, with argument scheduled at the Federal Circuit this month.  Dr. Radulescu further provided a review of current non-practicing entity campaigns brought by Bench Walk, Heavy Duty Lighting, LedComm, Lexington Luminance, BX LED, and Ferruiz.


Finally, Dr. Radulescu discussed common pitfalls in LED patent enforcement and defense, going over several hypothetical situations that LED lighting companies often find themselves facing.

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