Samsung Electronics Co. has replied to a patent-infringement lawsuit filed against it by Sharp Corp. by lodging complaints of its own with the U.S. International Trade Commission and the Tokyo District Court on Dec. 21.

Samsung's U.S. complaint alleges Osaka-based Sharp's LCD products infringe upon four of its U.S. patents. The patents were not detailed in Samsung's statement.

Samsung asked that Sharp be blocked from importing into the U.S. products that contain the LCDs in question. Such products could include TVs, laptop PCs and cell phones.

On Dec. 12 Sharp filed a patent-infringement lawsuit against Seoul, Korea-based Samsung in the Seoul Central District Court. The lawsuit alleges the LCD modules and televisions manufactured and/or sold by Samsung in South Korea infringe on three Sharp patents.

The Korean patents concern technology that allows high brightness and high-speed response as well as a wide viewing angle, Sharp said in a statement.

The lawsuit was the second filed by Sharp against Samsung. On Aug. 6, Sharp filed a suit in the U.S. District Court for the Eastern District of Texas alleging LCD modules manufactured by Samsung and LCD TVs, computer monitors and mobile phones that incorporate the modules infringed on certain of its U.S. patents.