US technology giant Apple on Thursday asked a Beijing court to strike down a patent ruling by state authorities, as it fights an intellectual property battle with a Chinese firm.
Apple representatives had asked China's patent review board, which operates under the State Intellectual Property Office, to declare Zhizhen's original patent invalid.
The body rejected the request, and Apple went to Beijing's Number One Intermediate People's Court seeking a judicial review.
"Our side firmly believe that the ruling by the defendant was based on incorrect facts and laws that were inappropriately referred to," Apple said in its presentation to the court.
"We appeal to the court to revoke the defendant's ruling No. 21307," it said.
Its lawyers told the hearing that Zhizhen's technology was not original enough or innovative enough to deserve a patent.
The proceedings ended Thursday afternoon and the chief of the five-judge panel said the court would send the parties its decision at a later date.
Outside court, Zhizhen's president said there was "nothing new" in Apple's arguments, adding he was not afraid of taking on the US giant.
"Those whose feet are bare do not fear those who wear shoes," Zhu Pinpin said, using a Chinese saying meaning that those who own little have nothing to lose.
Siri, which responds to a user's commands through voice recognition software, made its formal debut with the release of the iPhone 4S in 2011.
Zhizhen says its earlier "Xiao i Robot" product works in a similar way and has wide applications.
Zhizhen's lawyer Yuan Yang complained about the US firm's legal tactics. "It is a consistent strategy of Apple to tirelessly try to make your patent invalid and protract cases as long as possible to pressure you to give in," he told AFP.
Zhizhen appeared only as a third party at the proceedings, which were between Apple and the patent review board, he added.
Lawyers for Apple and the patent review board declined to comment to AFP.
The case is the latest dispute to involve Apple in China, where its products are popular but where it has sometimes been embroiled in controversy.
Apple chief executive officer Tim Cook said in January last year that he expected China to become his company's largest market.
Apple in 2012 paid $60 million to settle a separate legal dispute with a Chinese firm over the iPad trademark.Last year, Apple was subjected to a barrage of criticism from state-run media over warranty policies that only ended after it published a Chinese-language letter of apology from Cook on its website.