On June 5, 2025, Samsung Display SDI filed a lawsuit in the U.S. District Court for the Northern District of Texas against China Star Optoelectronics Technology (CSOT), TCL China Star Optoelectronics Technology, Ultimate Eshop (operating under the name “Parts4Repair”), and eTech Parts Plus, alleging infringement of three OLED patents.
This comes just a week after Samsung’s fourth lawsuit in the U.S. against BOE Technology Group on May 28, 2025, further escalating what was initially a patent dispute between the leading display panel companies of South Korea and China. The new case broadens the scope of the conflict, signaling Samsung's intent to challenge the entire display panel industry in China.
In fact, CSOT had already been indirectly involved in a U.S. Section 337 investigation initiated by Samsung in 2023, which targeted certain U.S. retailers and repair companies that sold or used Chinese-made display products. According to court filings, Samsung had issued CSOT an infringement notice as early as July 2022.
Subsequently, Samsung launched a Section 337 investigation with the U.S. International Trade Commission, targeting 18 U.S. retailers and repair firms that utilized Chinese-made displays, one of which was eTech Parts Plus. Evidence suggests that the panels used by eTech Parts Plus are highly likely to have been supplied by CSOT. This connection prompted CSOT to challenge the validity of Samsung’s patents in 2023.
The allegedly infringing products listed in Samsung's latest lawsuit include components such as the "TCL 20 Pro 5G LCD screen digitizer assembly" and "Platinum Soft OLED screen assembly." Some of these products were integrated into TCL smartphones sold in the U.S., which included models like the TCL 10 Pro, TCL 20 Pro 5G, TCL 30, TCL 30 5G, and TCL 30+.
The patents involved in the case are:
US Patent No. 11,594,578, titled “Pixel Arrangement Structure of an Organic Light Emitting Display Device.”
US Patent No. 7,414,599, titled “Organic Light Emitting Device Pixel Circuit and Driving Method Therefor.”
US Patent No. 9,330,593, titled “Stage Circuit and Organic Light Emitting Display Using the Same.”
Notably, the ‘599 and ‘593 patents were also part of the Samsung lawsuit against BOE Technology from the previous week. However, the ‘578 patent had not been included in any of Samsung’s earlier lawsuits against BOE Technology. This suggests that the ‘578 patent is being specifically asserted against CSOT in the current case.
