Japan’s First Injunction Ruling on SEP Infringement - Pantech v. Google Tokyo District Court Decision

On June 23, the Tokyo District Court in Japan issued a ruling in a lawsuit filed by South Korean mobile manufacturer Pantech against Google’s Japanese subsidiary for alleged infringement of wireless communication patents.

The case involved a dispute over a Standard Essential Patent (SEP) related to LTE (4G), with Pantech as the SEP holder. The court recognized the infringement of the SEP and ruled that Google was not a willing licensee. It further determined that Pantech’s request for an injunction did not constitute an abuse of rights, thereby granting the injunction. This marks the first injunction ruling in Japan based on SEP infringement.

Google’s uncooperative stance during the court-led settlement process was a key factor in the decision.

In Japan, a SEP holder’s FRAND declaration to a Standard Setting Organization (SSO) is not interpreted as a contract made for the benefit of third parties (implementers). Instead, under the principle of good faith in civil law, SEP holders are understood to bear a duty to negotiate in good faith with third parties (implementers). If this duty is not fulfilled, the exercise of the right to seek an injunction may be restricted as an abuse of rights (as seen in Apple v. Samsung, Japan IP High Court, 2014). Therefore, injunctions for SEP infringement are generally considered harder to obtain than for ordinary patents. The fact that an injunction was granted in this case is seen as “extremely rare.”

As the importance of SEPs in high-speed communications such as 5G continues to grow, this ruling is expected to influence future patent negotiations.

– Tokyo District Court
– Case Number: 2023 (Wa) No. 70501
– Ruling Date: June 23, 2025