Kim & Chang’s Intellectual Property Practice successfully defended its client, Tencent Korea (the “Defendant”) in a recent patent infringement lawsuit involving WeChat, a messenger application serviced by Tencent, the Chinese multinational company.

The case involved patents relating to providing translations of texts on websites (the “Subject Patents”).  Specifically, according to the Subject Patents, both the original text and the translated text are pre-stored and, when the user requests to view the translated text, the original text is replaced by the pre-stored translated text.  During such process, other media such as image, video or audio components featured on the website remain unchanged.

The patentee of the Subject Patents (the “Plaintiff”) is a non-practicing entity that does not actually provide any translation service utilizing the Subject Patents, but is engaged in patent lawsuits against various multinational companies including Tencent.

The Plaintiff filed a lawsuit against Tencent Korea arguing that WeChat infringes the Subject Patents due to WeChat’s function of translating messages into the language that had been pre-set as the user’s default language and displaying such translated messages on the messenger screen.  In response, Kim & Chang first highlighted that the Plaintiff’s assertion of infringement against Tencent Korea, the Defendant, is unreasonable, as the Defendant was never involved in development and/or distribution of WeChat.  Further, to prevent the Plaintiff from filing a separate lawsuit against Tencent Headquarters in China, we reinforced to the courts that WeChat does not infringe the Subject Patents.  In particular, we focused on the fact that the translation mechanism of the Subject Patents differ from that of WeChat.  Specifically, we argued that the translation of messages in WeChat is carried out after the original text is entered into the application and the user makes a request for its translation, whereas the Subject Patents require both the original text and the translated text to be pre-stored before the user makes a request for translation.  In this regard, we indicated that this difference could be verified through screenshots of using the translation functions of the WeChat application and that review or analysis of WeChat’s source codes is unnecessary.

As a result, despite the Plaintiff’s effort in attempting to prove otherwise by presenting results of analysis produced by its software engineer, we were able to persuade both the Seoul Central District Court and the Patent Court that the Defendant did not infringe the Subject Patents.  This finding was ultimately affirmed by the Supreme Court of Korea.

Through this meaningful decision, Tencent Korea was not only able to successfully defend itself against the assertion made by a non-practicing entity without having to disclose any of its technical or business trade secrets, but could also eliminate the risk of having a patent infringement assertion alleged against Tencent Headquarters in China.