Seoul Semiconductor has announced that companies manufacturing or packaging blue, green, white or ultraviolet (UV) LEDs made from the semiconductor material indium gallium nitride (InGaN) may be subject to patents owned by Seoul (see press release). These patents include US patent no. 5,075,742, which was granted in December 1991 and is (according to the USPTO site) assigned to the French State represented by the Minister of the Post, Telecommunications and Space.
The patent relates to semiconductor material structures containing multiple layers, where some of the layers contain three-dimensional inclusions. These inclusions have a narrower forbidden bandgap than the forbidden band of the material in the surrounding layer. InGaN-based light-emitting layers are believed to have this type of material structure.
This patent was the subject of a recent ruling issued by the United States District Court for the Eastern District of Texas. The lawsuit was filed by Seoul against Nichia and Daktronics, the leading LED display manufacturer. A copy of the ruling, which clarifies the patent’s claims, may be downloaded from Seoul’s website.
The Korean company says that the ruling supports its view that the patent is fundamental to InGaN-based LED technology.
Seoul says that the patent, including its family of patents in Japan, Germany, UK, and France, are available for licensing to appropriate business partners. Already, says Seoul, three companies have received a license to use its patents.
Seoul says that it will take “necessary steps” to protect its intellectual property rights and that “infringement of Seoul's patents may subject a company to injunctive relief.”
Nichia distances itself from Seoul
In early February, Nichia and Seoul Semiconductor (SSC) announced that their long-running and extensive series of patent lawsuits had come to an end with the announcement that the companies would enter a cross-licensing agreement (see News).
However, on February 18 Nichia felt compelled to release a clarification statement, distancing itself from its Korean competitor. The press release said that “Nichia is by no means a ‘comrade’ of SSC in any sense in any market and will continue to be a law-abiding competitor of SSC.”
The clarification statement referenced various news articles that had reported or implied the existence of cooperative arrangements between Nichia and SS, in respect to the global LED market. “In order to avoid any misunderstanding, Nichia would like to make it very clear that there is no agreement, understanding, or arrangement whatsoever, whether express or implied, between Nichia and SSC relating to the LED market, let alone cooperative marketing arrangements of any kind for the LED,” said Nichia’s statement.
SemiLEDs and Nichia settle patent dispute
Nichia and Semi-Photonics Co., Ltd. have settled the patent case (Case No. Hei 19 (wa) 10399) before the Osaka District Court.
Semi-Photonics Co., Ltd., a wholly owned subsidiary of SemiLEDs Corporation (Boise, Idaho, USA), has withdrawn the above case as a result of the settlement.
SemiLEDs became entangled in the one of lawsuits between Nichia and Seoul Semiconductor, because Seoul had used chips supplied by SemiLEDs. See News for more details.