June 5, 2024   

Keystone Accused of Violating Numerous Signify Patents

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Asserted patents involve certain downlights, lamps, driver circuits and area lights


Signify, the worldwide leader in lighting, filed a lawsuit against Pennsylvania-based Keystone Technologies in the United States District Court for the Northern District of Georgia on May 31, 2024. The complaint alleges that Keystone infringed upon eight of Signify's patents related to LED technology.

The patents in question cover various aspects of LED lighting systems, such as driver circuits, downlights, and configurable lighting systems. Signify claims that Keystone's products, including the XFIT Area Light, Advanta Downlight, HID Replacement LED Lamps, Aviva Retrofit Downlights, SmartDrive LED Lamps, and Circa LED Slim Wafer Downlights, infringe upon these patents.


Above:  Excerpt from complaint; Keystone XFIT area light is alleged to infringe on Signify patent 8,063,577

In response to our inquiry on this legal action, a Signify spokesperson responded in part, “The eight asserted patents are part of the Signify EnabLED licensing program, under which licenses are available to companies offering products that practice these patented technologies. Signify believes that our patents are infringed and valid. We respect other companies’ or individuals’ intellectual property and expect others to respect our intellectual property.”

Keystone Technologies is not listed among the 1,336 licensees currently cited as participating in Signify's EnabLED licensing program.

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Above:  Excerpt from complaint; Keystone LED lamp accused of patent infringement

The lawsuit filed by Signify also includes a copy of a $182 invoice for a single 63-watt color-selectable HID Replacement LED Bulb with a mogul screw base, often described as a corncob lamp. The order was placed through Grainger’s Marietta, Georgia location seemingly by an attorney from Alston & Bird, the law firm representing Signify in this case.


Signify is seeking damages and a permanent injunction against Keystone to prevent further alleged infringement. The company claims that Keystone has been aware of its infringement since receiving notice as early as February 14, 2020, for some of the patents, and continued to infringe despite this knowledge.




According to the complaint, Signify made several attempts to communicate with Keystone Technologies regarding the alleged patent infringement. The lawsuit states that Signify sent letters to Keystone on multiple occasions between February 2020 and May 2024, informing them of the alleged infringement of various patents. Despite these communication attempts, Signify claims that Keystone continued its infringing activities, leading to the filing of the lawsuit. The complaint also includes exhibit emails that Signify repeatedly sent to Keystone, but seemingly received no response.

In the complaint, Signify highlights its position as a market leader in LED lighting and its significant investments in research and development. The company also establishes justification for selecting the court venue emphasizing its strong presence in the Northern District of Georgia, with its wholly-owned subsidiary, Cooper Lighting, headquartered in Peachtree City and Sanford Stadium, home of the University of Georgia Bulldogs, pictured as one of its many projects.  Three of the asserted patents were originally assigned to Cooper Lighting.

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Above: Signify supports the North Georgia District Court venue by citing the University of Georgia's "Stanford [sic] Stadium" as a project that utilizes Signify LED lighting products

Signify alleges that Keystone's infringement has caused damage to the company and is seeking compensation for lost profits and/or reasonable royalties. Additionally, Signify claims that Keystone's continued infringement after receiving notice is willful and deliberate, entitling Signify to increased damages and attorneys' fees.

The lawsuit demands a jury trial and seeks a judgment that Keystone has infringed and continues to infringe upon the patents in question, a permanent injunction against Keystone and its affiliates, and monetary relief for damages, costs, and fees.


As of publication, Keystone Technologies has not responded to Inside Lighting's multiple requests for comment, the first of which was sent on Tuesday afternoon. According to court records, the lawsuit has not yet been officially served to Keystone's registered agent in Lawrenceville, Georgia. Once served, Keystone will have 21 days to respond to the complaint.