Mitsubishi Chemical Corporation has filed a patent-infringement lawsuit in Korea against Intematix and a distributor, over red phosphors.

Mitsubishi Chemical Corporation (MCC), the Tokyo, Japan-based phosphor, LED and lamp manufacturer, has filed a patent-infringement lawsuit in Korea against US-based Intematix Corporation and a Korean distributor, GVP.

Filed in Seoul Central District Court, the infringement lawsuit seeks to prohibit the two companies from importing and selling certain red-emitting phosphor products in Korea.

Mitsubishi Chemical claims that the products in question infringe a patent in Korea (no. 816693) that covers red-emitting phosphors. The patent is owned by MCC and National Institute of Material Science.

Red-emitting phosphors are commonly used in warm-white LEDs, in combination with other phosphors, to provide the desired emission spectrum.

The Korean patent no. 816693 relates to a nitride-type red phosphor commonly known as CASN and SCASN. Such phosphors have the general formula of CaAlSiN3:Eu. The patent also covers LEDs, lighting equipment, displays and other products in which such a phosphor is used.

MCC says that it owns many other patents that are also relevant to CASN and SCASN phosphors, adding: “Should a party infringe any of MCC’s patents, we will take every appropriate measure without overlooking it.”

About the Author 

Tim Whitaker is the Editor of LEDs Magazine.