The Korean Supreme Court recently rendered an en banc decision that a Trial Board decision that allows amendment of patent claims, but is rendered after the de novo legal proceedings (i.e., the Trial Board and the Patent Court proceedings where facts are found and tried de novo) in a parallel patent invalidation action have been concluded, does not qualify as a basis for demanding a retrial of the patent invalidation action based on the amended claims (Supreme Court Decision 2016 Hu 2522 decided on January 22, 2020). 

▶Background of the Case 

A challenger filed a petition to invalidate a patent, alleging that the patented invention lacked inventiveness over the prior art.  The Board of Trials upheld the validity of the patent and the challenger brought an appeal against the Trial Board decision before the Patent Court.   

The Patent Court revoked the trial decision, ruling that the claims in the patent were invalid for lack of inventiveness.  

The patentee appealed to the Supreme Court against the Patent Court’s decision; thereafter, lodged a petition before the Board of Trials to have the claims in the patent amended.  

While the appeal before the Supreme Court was still pending, the Board of Trials rendered a decision granting the amendment of the challenged claims; and the Trial Board decision statutorily became conclusive and irrevocable when a certified copy of the decision was served on the patentee. 

Further, under the Korean Patent Act, the Trial Board’s decision allowing the claim amendment has the retroactive effect as if the patent had been issued with the amended claims ab initio. 

▶Main Issues Presented Before the Supreme Court 

On appeal, the patentee first argued that the Patent Court’s decision of invalidating the patent, made based on the pre-amendment claims, should be set aside and the challenger’s patent invalidity claim should be retried based on the amended claims, these being retroactively effective, citing the relevant Supreme Court decisions. 

Secondly, the patentee asked for the reversal of the Patent Court decision, contending that the invention defined in the pre-amended claims was still inventive over the cited prior art. 

▶Relevant Precedents 

With respect to the first issue on appeal, there are in fact a series of Supreme Court decisions in support of the patentee’s request for retrial (see, e.g., Supreme Court Case No. 99 Hu 598 decided on October 12, 2001). 

However, criticisms against the above Supreme Court decisions have been raised as the Highest Court’s leniency tends to create or harbor the effect of encouraging the patentees to abuse the judicial proceedings by way of delaying the filing of the correction trial until the final appeal is brought to the Supreme Court, thereby effectively frustrating a third party’s challenge against the validity of the patent. 

▶The Supreme Court Decision 

Recognizing the legal significance and ramifications present in the first ground of appeal demanding a retrial based on amended patent claims, the Supreme Court convened the en banc panel and held that the Trial Board decision allowing the claim amendment, which was procured after the exhaustion of the de novo fact finding proceedings before the Trial Board and, subsequently, before the Patent Court, does not qualify as a statutory ground for demanding a retrial of the patent invalidation action based on the amended claims, while reversing its own earlier precedents discussed above. 

Although not explicitly articulated, the Supreme Court’s recent decision was made apparently in response to the concerns raised with respect to the patentee’s tactic of delaying or frustrating a third party’s challenge against the validity of a patent. 

Over the dictum, the Highest Court further enunciated that the holding of this decision would equally apply with respect to:  

i) patent infringement action; and 

ii) scope confirmation trial. 

As for the second ground of appeal, however, the Supreme Court sided with the patentee, ruling that the original claims are valid, and remanded the case to the lower court. 

▶Impact of the Decision 

In accordance with the above Supreme Court decision, therefore, patentees will have to bring a correction trial to have patent claims amended before lodging a final appeal before the Supreme Court against adverse decisions rendered in patent infringement actions, invalidation petitions or scope confirmation trials. 

In more specific practical terms, this decision in effect mandates the patentees to bring a correction trial, at the latest, within a time frame capable of enabling the Patent Court to render its decision based on amended claims, if allowed.