Matsushita has gone to court to stop LG Electronics selling plasma display panels in Japan or importing them into the country.
Better known in the UK for its Panasonic brand, Matsushita has acted after more than a year of fruitless talks with the South Korean company over its failure to recognise two Matsushita heat dissipation patents.
"Unfortunately, there was no agreement," said Panasonic spokesman Yoshihiro Kitadeya. "In fact, it's more like a breakdown, and we decided LG's time was up."
Calling Matsushita's move regrettable and unjust, LG said it also held patents for plasma display and computer technologies and would fight any injunction and import ban.
This is the second major legal tussle between Japanese and Korean electronics companies over plasma display patents, as Japanese companies attempt to assert their intellectual property rights in the hotly contested and rapidly growing plasma display and TV market.
Earlier this year, Fujitsu also tried to ban Japanese imports of panels from Samsung, alleging patent infringement. The dispute was settled in June.
Plasma technology is increasing popular for displays and TVs with screen sizes of 37in across the diagonal and bigger. Worldwide sales of 40in+ plasma TVs should double this year and hit 11 million units in 2008, according to market research company iSuppli.
Panasonic claims to be the world's number one maker of plasma panels with a 23% share of the market in the second quarter of this year. Samsung SDI was second biggest with 22.5% and LG Electronics third with 20.5%, according to Panasonic data.
"It's not a matter of damage to our business, it's more an intellectual property issue," said Kitadeya. "We are asking LG to play by the global rules."
Paul Kallender writes for IDG News Service