Samsung Display, an affiliate of Samsung Electronics, asked a Seoul patents court last week to annul seven patents related to organic light-emitting diode (OLED) panel technologies held by LG, a company spokesman said Monday.
Samsung argued that the technologies lacked the originality and innovation to warrant a patent.
"These are typical legal steps to defend a company's stance in a patent infringement suit," the Samsung spokesman told AFP.
The move came after LG Display -- one of the world's top flat-screen TV makers -- filed a patents suit in September against the two Samsung units for allegedly infringing seven of its OLED-related technologies.
LG said that five of Samsung's products, including its global hit Galaxy S-series smartphones and tablet computer Galaxy Tab, infringed its patents.
Later in the same month, Samsung filed a court complaint accusing LG of luring away senior Samsung OLED researchers even though they had signed contracts preventing them working for a rival.