Under the Korean patent law, it is not allowed to file a continuation application. Furthermore, after a notice of grant has been issued, it is not available to amend claims, and an applicant is only able to correct typo errors or to narrow claim scope. Any extension of the scope of protection by amendment after grant is not allowed.
The scope of a claim must be narrow enough to be novel and non-obvious over the prior arts. On the other hand, however, claims should be infringed by the competitor’s products, services or processes and thus the scope of claims must be broad enough to cover competitor’s product or process. Even after grant, an applicant may want to have a chance to change the scope of protection.
A divisional application can play a key role for this purpose because an applicant may prepare a new set of claims having broader scope of protection than those of original application. A divisional application can be tricky. It must be differentiated from the original application in the scope of claims. But the same specification can be used for a divisional application. And more than one divisional application can be filed based on an original application.
Substantive examination of a divisional application must be requested with fee for further prosecution. Request for the examination of divisional application may be filed within five years from a filing date of an original application.
In conclusion, therefore, through filing divisional applications, applicants can strategically obtain additional patents for broader scope of protection than those of a parent patent application; or build a patent portfolio, which means more proper and various forms of claims that can be designed to cover competitors’ products, services, or processes after monitoring them for 5 years at maximum.