Keisen wins against Infringement Suit before Tokyo District Court

Taro Yaguchi, Senior Partner at Keisen Associates, successfully defended the Japanese distributor of a US GPS navigation products producer before the Tokyo District Court, against claims of patent infringement asserted by a Japanese competitor. The Tokyo District Court dismissed the claims of the litigant, affirming the defendant’s claims, in August 2016.

The Japanese litigant alleged in 2013 that the US products sold in Japan violated its GPS patents. When Keisen Associates and the litigant’s representatives were unable to reach an agreement, the litgant claimed infringement and sought damages from the Japanese distributor of the products in the Tokyo District Court. In August 2016, the District Court found that the defendant’s position was valid: the products did not infringe the litigant’s patents and its interpretation of the patent claims were improper.

This case involves prosecution history (“file wrapper”) estoppel, in that the litigant was claiming rights it had stopped claiming during prosecution. In addition, Keisen Associates and the District Court noted that under the doctrine of equivalents, the litigant’s claims (for recalculating driving routes if a turn is missed, by means of deriving directly from two points the necessary change) had been illegitimately expanded in the litigation to cover, possibly, the method (used in Garmin instruments) of calculating routes by indirect calculation of routes.

More Information

  • Tokyo District Court’s decision (in Japanese)


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