‘Patent Validity’ Overturned Invalidity Ruling... Jipyong Secures 11 Billion Won in Damages in Secondary Battery Patent Case [Design of Victory]

Jipyong LLC

M Plus Achieves Final Victory in Patent Infringement Case After Eight Years

Logically Challenging "Hindsight Bias" in the Court's Reasoning

Thoroughly Proving Damages with Rigorous Data Analysis

"After a technology emerges, anyone can think it is simple. However, the value of a patent must be evaluated based on whether such an idea could have been easily conceived at the time when the technology did not exist."

On September 9, Sung Changik, an attorney at Jipyong LLC, explained in an interview with The Asia Business Daily how he led the patent infringement litigation for battery equipment maker M Plus to a final victory after eight years.

Min Jihong, Sung Changik, and Huh Jong, lawyers (from left), pose before an interview with The Asia Business Daily at Jipyung Office on Sejong-daero, Jung-gu, Seoul. Photo by Jo Yongjun

M Plus filed a lawsuit against Sungwon Enertec, claiming infringement of its patented stacking device for secondary battery plates. In the first trial, the related invalidation litigation resulted in a ruling that the patent was invalid, so the claim was dismissed. Later, the Supreme Court overturned the invalidation judgment. In the appellate review of the infringement suit, the court recognized patent infringement and ordered damages of about 11 billion won, including delay interest, in addition to prohibiting the manufacture, sale, and requiring disposal of the infringing products. In July, the Supreme Court rejected the opposing side's final appeal, confirming the judgment.

The turning point was defending the validity of the patent. The opposing party argued that applying similar technology from another industry to secondary battery equipment was not difficult and thus lacked inventive step. Jipyong countered with the argument that one must beware of “hindsight bias,” whereby one believes that, having seen the finished technology, it would have been obvious in the past as well.

Attorney Sung compared this to Columbus’s egg. He said, "Once you see how to stand the egg by breaking its base, anyone thinks they can do it, but conceiving of the method beforehand is a different matter. The key question was whether it was truly simple, at that time, to apply technologies from other fields to secondary battery manufacturing." While the invalidation litigation involved a separate legal representative, Jipyong shared information so that arguments would not conflict and coordinated their defense strategies between the cases.

There were additional variables in determining infringement. In the first trial, the opposing party stated that their equipment operated in essentially the same way as M Plus’s patent, but reversed this claim during the appeal. Jipyong defended its position by citing the legal principle that confessions made in trial cannot be easily withdrawn once established.

The main issue in the latter part of the litigation was the amount of damages. Attorney Heo Jong explained, "In patent infringement cases, the plaintiff must prove how many units the other party sold and what the profit margin was, but most of the relevant documents are actually held by the defendant, which is a major challenge."

Jipyong worked with an accounting firm to analyze M Plus's cost of goods sold and sales amount to determine the profit margin. They made use of not only court orders for document production but also customs and tax office records to uncover evidence of approximately 100 more sales than what the defendant had declared. Through staff interviews and an analysis of the manpower and labor required, they also proved that M Plus had the capacity to actually produce these additional units. As a result, and unusually for a domestic patent infringement case, the court awarded damages of about 11 billion won, including delay interest.

This ruling not only awarded monetary compensation for past infringements but also recognized bans on future production, sales, and required disposal. Attorney Min Jihong stated, "This decision sends a message that the liability for patent infringement is not insignificant compared to any benefit gained," and added, "It demonstrates the importance of actively enforcing rights to protect technology."

This content was produced with the assistance of AI translation services.