Patent Act Article 23

Deemed as lack of noveltyA person shall not be entitled to a patent if the claimed invention was described in the specification, claim(s) or drawing(s) of a patent issued or an application for invention or utility model patent published, in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention. However, this shall not apply where the applicant of the later-filed patent application is also the applicant of the earlier-filed patent application for invention or utility model.