Santa Clara-based Rovi has brought cases against several rival companies over its on-screen TV guides and has already made settlements with the likes of TV maker LG Electronics and Mitsubishi.
The firm is seeking hundreds of millions of dollars in damages.
But a judge at United States International Trade Commission found Netflix and streaming video-box maker Roku had not violated the patents.
A final decision is expected in October.
Set-top box maker Roku was also cleared of an infringement, though Rovi noted that three out of four of its patents were found to be valid.
“While we are disappointed in the initial determination of no infringement and expect to exercise our right to petition the full Commission of the ITC for a review of this decision, we are pleased that the majority of the patents involved were confirmed valid,” Samir Armaly, executive VP, worldwide intellectual property and licensing for Rovi, said in a statement.