Whenever collateral estoppel comes up in a patent case, it usually generates some interesting discussion. Yesterday's decision from Judge Andrews in TQ Delta v. 2Wire is no different.
After the Federal Circuit reversed a PTAB determination of unpatentability on an unasserted claim, the plaintiff moved to estop the defendant from challenging the validity of two related claims in the district court litigation.
Judge Andrews concluded that summary judgment was inappropriate because the defendant adequately "explained how the differences between the [asserted claims] and [the adjudicated claim] alter the invalidity analysis[,]" but he also addressed an interesting question: Is a petitioner "fully represented" in an IPR when another petitioner is taking the laboring oar before the PTAB?
The defendant …