Generally speaking, inter partes patent reexamination was pursued relatively infrequently by foreign based entities. Unlike their U.S. based counterparts, foreign based companies rarely employed patent reexamination as a tool to resolve patent disputes in a more cost effective manner, and/or to pressure opponents in a parallel litigation. This phenomena was especially odd for Japanese innovators. This is because many of the top ten patent filers are Japanese companies. Clearly these companies were familiar with USPTO proceedings, but remained uncomfortable with the USPTO as a source of potential resolution for patent validity disputes.
Since the passage of the new patentability challenges of the America Invents Act (AIA), the public has overwhelmingly embraced Inter Partes Review (IPR) and Covered Business Method (CBM) proceedings as a viable option to traditional patent limitation—and, unlike inter partes patent reexamination, Japanese innovators are not far behind. The chart below identifies the Japanese companies actively involved in IPR proceedings. (Click to Enlarge)
As shown in the chart, Toyota Motor and Sony lead the pack in aggressively utilizing IPR as a patent challenge mechanism. Perhaps of more interest is the participation of a healthy dose of smaller, Japanese organizations. This trend, which was never the case in reexamination, appears to suggest a widespread adoption of IPR by Japanese companies as an effective patent litigation defense.