Evidence adopted to interpret claims includes intrinsic evidence and extrinsic evidence, wherein the intrinsic evidence includes words of the claim, description of the invention (utility model), drawings and file wrapper of the filing history, and the file wrapper is a file with documents in addition to the original specification upon filing during the process from the filing of the patent application until the maintenance of the patent, such as supplement, amendment, correction, response, answer, reply brief or other relevant documents during the stages of examination, invalidation or administrative remedies. Further, Article 28 of the former Patent Act before October 24, 2001 stipulated that “An applicant or patentee can file a follow-on patent application when there is a reinvention; however, the term thereof is to be ended along with the termination of the original patent term. Said reinvention is an invention completed by utilizing the major technical content of the original invention.” That is, such follow-on institution is one that provides protection upon any follow-on improved invention or expanded invention pursuant to the original invention, so as to attain the protection upon the improved invention through the adoption of the follow-on patent institution. Nevertheless, the patent term of a follow-on patent is the same as the parent patent, that is, to be ended along with the termination of the original patent term, and therefore, there is no need to pay any annuity for the follow-on patent, and while the major technical content of the follow-on patent is the same as that of the parent patent, it is needless to say that the intrinsic evidence adopted to interpret the claims shall include the relevant documentary file of the parent patent.