SK Magic has filed a lawsuit against Cuckoo Homesys, claiming that they infringed upon their ice water purifier patent. Despite sending two cease and desist letters last month, SK Magic reports that Cuckoo Homesys has shown no intention of resolving the matter, leading SK Magic to proceed with a position of seeking a patent infringement injunction and indemnification for damages. Following the ongoing 8-year patent dispute between Coway and Chung Ho Nais Co., Ltd., the legal dispute between SK Magic and Cuckoo Homesys has entangled major water purifier rental and sales companies in Korea, with all of them being drawn into lawsuits.

According to SK Magic, the technology infringed upon by Cuckoo Homesys is SK Magic’s patent registered under the number “10-2464193,” which was filed in February 2018. The company explains that this technology applies a 4-way valve to the ice water purifier, allowing for miniaturization and maximizing energy efficiency.

Cuckoo Homesys refutes SK Magic’s claims as untrue. They argue that while SK Magic’s patent for the 4-way valve is registered specifically for using a liquid refrigerant for defrosting, their own technology uses a different method involving a gaseous refrigerant. Moreover, Cuckoo Homesys’s position is that there is prior art that has been publicly disclosed in Japan and Korea regarding the 4-way valve patent itself. In other words, they assert that the situation falls under the category of technology freely usable in the presence of relevant prior art.

This is not the first time that a patent dispute concerning ice water purifiers has arisen. In 2014, ChungHo Nais Co., Ltd. filed a lawsuit against Coway, accusing them of infringing upon their ice water purifier patent technology. The dispute has gone on for over 8 years, with the Court of First Instance ruling that Coway should “dispose of relevant product equipment and compensate ChungHo Nais Co., Ltd. with 10 billion KRW.” However, the appellate court overturned this decision, determining that Coway had not infringed upon the patent. Both parties are currently awaiting the schedule for the Supreme Court’s ruling.