Legal analysis: the patent right has a time limit, and the validity period cannot be extended. The term of the invention patent is 20 years, and the term of the utility model patent and the design patent is 10 years, both of which are counted from the date of application. The patentee shall pay the annual fee from the year when the patent right is granted.
Legal basis: Article 42 of the Patent Law of People's Republic of China (PRC) has a term of 20 years, and the term of utility model patent and design patent is 10 years, counting from the date of filing.