Collateral Estoppel Causes PTAB To Reverse Course And Institute IPR

The Patent Trial and Appeal Board granted a request for rehearing and instituted inter partes review of a web browsing patent in order to reconcile an inconsistency with a final judgment of un-patentability in the IPR of a related patent. The ultimate decision to institute review rested on a finding that patent owner was collaterally estopped from arguing against a factual finding about a prior art reference relevant to both IPRs.

After the PTAB denied institution of the present IPR, petitioner filed a request for rehearing. In their briefing, the parties discussed the final written decision in an earlier IPR finding unpatentable the claims of a related patent. In that decision, the PTAB found, and patent owner did not argue to the contrary, that a prior art reference disclosed a certain limitation related to ranking multiple websites. In the present IPR, petitioner argued that the PTAB overlooked this disclosure in the prior art reference. Both parties and the PTAB