QIPC said QuadTech's latest claim, filed last week in the Northern District of California, was the same as one already filed in Pennsylvania's Federal District Court.
The company said it has repeatedly stated in its court papers that the QI register control products sold in the US do not infringe QuadTech's US patent 5,412,577. It also insisted that its Intelligent Density System (IDS) does not infringe the patent.
In April, QIPC defeated QuadTech's request for a preliminary injunction in the US District Court for the Eastern District of Pennsylvania.
According to QIPC, it also defeated QuadTech's attempt to include new claims of infringement against its IDS in the same month.
In a statement, QIPC said: "Now, QuadTech has filed a new case in a different federal court, the Federal District Court for the Northern District of California.
"It has made the allegations of infringement by the IDS [that] Judge Robreno would not permit in the Eastern District of Pennsylvania. QI will address QuadTech's latest tactic in court."
It added: "QI believes that Judge Robreno's decisions are the first step toward its total vindication in QuadTech's legal assault in the United States."
QuadTech's latest claim, seeking damages and injunctive relief, was filed in the Northern District of California and alleges that QIPC's IDS infringes US patent 5,412,577. According to the company, the founders and owners of QIPC are former QuadTech employees.
QuadTech president Karl Fritchen said: "We have a large worldwide patent portfolio. QuadTech invests a lot of time and money in developing our industry-leading technology and we will continue to vigourously protect our intellectual property wherever and whenever our patents are infringed."
The legal action in California is the third such action against QIPC by QuadTech.
In June 2008, a German court in Düsseldorf ruled in QuadTech's favour in a similar infringement case and granted an injunction to prevent QIPC selling its markless register control MRC system.
The Court of Appeals in Germany later upheld the injunction granted against QIPC.
A year later, QuadTech filed a legal action in the US District Court alleging that QIPC's MRC, sold in both mark and markless mode, infringed US patent 5,412,577. The trial date for the case in Pennsylvania has not yet been set.
QuadTech produces press control technology and sells its automated auxiliary control systems to the web offset newspaper and commercial, packaging and publication gravure markets. QIPC supplies closed-loop colour and register control equipment for web offset printing presses.
