The Korean Intellectual Property Office (KIPO) recently updated its examination guidelines (effective as of December 14, 2020) to provide specific examples and instructions regarding description requirements for parameter inventions. The updated guidelines reflect the holdings of a recent Patent Court decision (2018Heo9152 rendered on February 6, 2020) which invalidated a parameter patent for failing to satisfy the description requirement.

In Korea, parameter inventions are defined as inventions including, as a part of the elements of the invention, a parameter which an applicant has created that covers certain physical/chemical properties and which is not generally used in the pertinent art. Alternatively, a parameter invention can be a new combination of physical and/or chemical parameters.

Historically, the Korean courts have applied very strict standards for determining the patentability of parameter inventions. However, during prosecution, it is generally difficult to assess the patentability of a parameter invention since the most relevant prior art is not always clear. Moreover, it is sometimes difficult to fully understand the technical significance of a parameter at the time of prosecution. This resulted in parameter inventions being granted with a somewhat broader scope of protection, which then resulted in most parameter patents being invalidated if challenged in post-grant proceedings.

The revised KIPO examination guidelines regarding description requirements for parameter inventions state that in order for a parameter invention to satisfy description requirements for the specification, it must enable one skilled in the art to properly understand and practice all of the claimed elements, including the parameter, over the entire numerical range specified in the claims based on the descriptions in the specification without special knowledge or excessive experimentations based on the level of technology at the time of the filing date. Moreover, the working effects caused from the elements must be shown over the entire numerical ranges through specific experiments or examples provided in the specification or should be easily derived by one skilled in the art in view of the level of the technology at the time of the filing date. 

The revised KIPO examination guidelines also provide several specific examples where the description requirements for a parameter invention were deemed insufficient: 

• where the definition and technical significance of the parameter are not clearly described; 
• where the manufacturing method for the product defined by the parameter is not described;
• where the working and comparative examples confirming the working effects attributable to the parameter over the entire numerical range are not provided; and
• where explanations on the procedures, conditions and instruments for properly measuring the parameter are not provided. 

Under the revised guidelines, we expect it will become difficult to obtain allowance of parameter inventions. Thus, we recommend taking extra care when drafting applications for parameter inventions to ensure compliance with the new guidelines, especially since many of the description requirements cannot be corrected by amendments. For instance, if an amendment was attempted to add descriptions providing the definition or technical significance of a claimed parameter, this would likely be rejected as adding new matter.