Motorola has had 13 claims in its patent infringement case against Microsoft dismissed by a US judge.
The patents in question deal with the encoding and decoding of video. For Motorola and Microsoft the case stems back to 2010 when the original patent infringement allegations were filed in a western district court of Washington State.
Microsoft had asked judge James Robart to dismiss the claims on Motorola patents 7310374, 7310375, 7310376. Microsoft alleged that the sloppy language in those patents meant Motorola's claims were invalid.
Judge Robart's has agreed with Microsoft's allegations. According to the judge's summary on the ruling, Motorola was unable to prove the patents in question's properly outline an infringement.
"The 'means for decoding' limitations claim[s] all corresponding structure under the sun by expansively defining the function in the specification as anything that decodes digital data," wrote judge Robart in his summary for the case.
"This definition renders the 'means for decoding' limitation invalid for indefiniteness."
The ruling adds to the lengthy Motorola v. Microsoft patent infringement case. Motorola brought the case to court in 2010.
Google-subsidiary Motorola Mobility had claimed that it deserves to be awarded as much as $4bn dollars for the use of its patents. Meanwhile, Microsoft argued the firm is only entitled to about $1m for the patents.
Prior to this ruling judge Robart shot down Motorola's attempts to get a sales ban on certain Microsoft devices that it alleges are infringing.