As display panel makers of South Korea and China are vying to win greater global market share, the rivalry appears to be expanding into a patent war.

Chinese top display panel manufacturer BOE Technology and two of its subsidiaries recently filed six lawsuits against Samsung Display and its five Chinese entities concerning patent infringement at Chongqing No. 1 Intermediate People’s Court in southwestern China, according to the court.

The Beijing-based firm also took two legal proceedings against Chongqing Jingdong Jiapin Trading, a subsidiary of ecommerce giant JD.com selling electronic products.

According to company records tracked by business data provider Qichacha, all cases filed by BOE are over "infringement of patent rights of inventions." While details on the technology claimed to be stolen by Samsung is not revealed, industry officials say it is related to organic light-emitting diode panels.

The trial is expected to kick off on May 18.

Industry watchers here say the series of legal proceedings by the Chinese display panel supplier could be a "retaliatory" response to Samsung, which had filed a complaint against 17 smartphone repair shops in the US.

In December last year, the Korean display panel maker filed the complaint to the US International Trade Commission, claiming that the repair shops are using “illegal” panels that infringe on its highly sophisticated OLED patents.

The patents include Diamond Pixel, one of the key strengths of Samsung OLEDs. The display-making unit of Samsung Electronics is a market leader making almost 70 percent of OLED panels used in high-end mobile devices, including Samsung Galaxy and Apple iPhone smartphones.

While Samsung avoided targeting the display producers and took action against the US repair shops, it was largely seen as an attempt to deter the Chinese panel makers that supply the panels to the repair shops at cheaper prices.

Samsung has requested the US trade watchdog ban the repair shops from importing the panels using its technologies without permission.

As the ITC kicked off the probe into the case earlier this year, BOE "volunteered" to be investigated by the ITC, an industry source explained.

"Samsung has not mentioned BOE related to the ITC case, but the Chinese company must have felt guilt over (its usage of) the Diamond Pixel technology," an industry official said under the condition of anonymity.

Industry watchers say the legal action by BOE is an attempt to deter the Korean display maker's expansion in China.

Samsung has acknowledged that it found products sold in the markets were using panels infringing on its Diamond Pixel technology, and has expressed strong determination to offer no leniency for frequent patent infringements.

"We are actively looking into ways to better protect our intellectual property rights, an outcome of the hard work of all company officials,” said Choi Kwon-young, executive vice president at Samsung Display, during an earnings call in January.