Eastman Kodak has won another round in its digital imaging patent battle with Ampex Corp.

Reuters is reporting that the US Court of Appeals for the Federal Circuit affirmed without comment a lower court's ruling that granted Kodak summary judgment.

The case has been rumbling on since October 2004 when Ampex accused Kodak of infringing its copyright for digital cameras.

After ten months of litigation before the International Trade Commission (ITC), and after the submission of initial trial testimony, Ampex dropped its ITC complaint.

It, however, continued it action filed at the same time in the District of Delaware, which also asserted patent infringement.

In May 2006, Kodak filed a motion asking the court for a ruling that it had not infringed Ampex's patent.

The District Court granted the motion in November 2006, finding that Kodak was entitled to a favorable judgment as a matter of law, and that none of the asserted claims of Ampex's patent were infringed.

However, Ampex appealed this decision and has now lost again.