Legal experts yesterday urged Chinese technology companies to file more and better patents in the US, after the US International Trade Commission (ITC) started another patent infringement investigation into Chinese technology giants Huawei and ZTE on Monday.

The ITC voted to institute an investigation of certain electronic imaging devices produced by Shenzhen-based Huawei Technologies Co and ZTE Corp and their US subsidiaries, the agency said in a statement on its website.

New Hampshire, US-based FlashPoint Technology filed a complaint to the ITC on May 23, alleging that these companies had violated Section 337 of the US Tariff Act of 1930 in the importation into the US and sale of certain mobile phones, tablet computers and other devices that have imaging capabilities, because they allegedly infringed FlashPoint's patents, according to the statement.

It was not the first time that Huawei has faced such intellectual property (IP) accusations this year. On May 18, the ITC began probing electronic devices with a retractable USB connector made by 45 global companies, including Huawei.

"Some foreign firms simply use the lawsuits to squeeze their competitors out of the market," said Ma Xiushan, deputy secretary-general of the China Intellectual Property Society.

If a violation of Section 337 is found, the ITC may issue orders barring the import of certain products into the US, and FlashPoint has requested that the agency issue an exclusion order and cease and desist orders.

As Chinese IP applications in the US have increased in recent years, the number of IP cases in which Chinese companies are being sued is stablizing, Ding Liang, a lawyer at King & Wood, a Beijing-based law firm, told the Global Times.

But there is still room for Chinese firms to increase their patents filed in the US and improve the patents' quality, he said.

China's State Intellectual Property Office Commissioner Tian Lipu said in September last year that the office had accepted 10,701 international patent applications filed by Chinese firms from January to August 2011, up 38.1 percent year-on-year.