Copyright Infringement ExpertsMicrosoft has asked a judge to dismiss an infringement suit targeting their Cortana digital assistant products, capitalizing on an earlier ruling that invalidated three patents at the center of the case.

Microsoft’s attorneys argued that the March 31st ruling from U.S. District Judge Richard G. Andrews of the District of Delaware destroyed the case from IPA Technologies Inc., as the American subsidiary of WiLAN tries to use the personal digital assistant technology underpinning Apple Inc.’s Siri.

Microsoft’s argument in its motion to dismiss was that the Andrews’ opinion extinguished all of IPA’s claims on the same three patents of which it accused Microsoft of infringing. In addition, the company claimed that a second set of patents were also invalid because of the Delaware judge’s ruling.

This action is in the middle of IPA’s overall battle to protect technology that it acquired from SRI International Inc.. That company had been developing personal digital assistants with a grant from the Defense Advanced Research Projects Agency. SRI spun off Siri Inc. in 2007 and granted the new IPA a non-exclusive license to the patent portfolio, according to IPA.

The personal digital assistant technology was released as an iPhone 3GS app in 2010. In the spring of that year, Apple acquired Siri Inc. and released the Siri personal digital assistant as an integrated feature of the iPhone 4s later in 2011. IPA argues that they own the patents by assignment.

IPA has brought suits against a host of tech heavyweights in the past year. They allege that the major American companies of improperly incorporating the patented technology into a variety of mobile devices and tablets.

However, in March 2018, Judge Andrews held that the ’021, ’061 and ’718 patents were “replete” with references to already-existing technology and outlined no inventive concepts to support a finding of validity under U.S. patent law. The judge’s ruling only applied to the first claim asserted in each patent, but IPA stated those were representative of all the remaining claims.

Microsoft argued in its brief that the rest of the patents’ claims were directed at the same abstract idea and used similar “generic, functional language” to reference well-known and conventional technology. Microsoft argued that IPA’s complaint lacked specific allegations of infringement and failed to plead a cause of action under Federal Rule of Civil Procedure 12(b)(6).

“The [three patents] contain a total of 186 unasserted claims, and the complaint provides no allegations suggesting that even IPA believes that any Microsoft product infringes any of them,” they said. They argued that other allegations in the Second Amended Complaint “fail to plausibly suggest that IPA’s claims are patent-eligible.”