Legal analysis: When the patent protection period expires, the patent right terminates. After the expiration of the patent period, it cannot be extended. The patent enters the public domain and belongs to all mankind, and anyone can use it. Legal basis: Article 42 of the Patent Law of the People's Republic of China, the term of patent for invention is 2 years, the term of patent for utility model is 1 years, and the term of patent for design is 15 years, all of which are counted from the date of application.
if a patent for invention is granted after four years from the date of application and three years from the date of substantive examination request, the patent administration department of the State Council shall, at the request of the patentee, compensate for the unreasonable delay of the invention patent in the process of authorization, except for the unreasonable delay caused by the applicant.
in order to compensate for the time occupied by the examination and approval of the new drug listing, the patent administration department of the State Council shall compensate the patentee for the patent period of the invention patent related to the new drug that has obtained the listing license in China. The compensation period shall not exceed five years, and the total effective patent right period after the new drug is approved for listing shall not exceed fourteen years.
article 43 the patentee shall pay the annual fee from the year when the patent right is granted.
Article 44 In any of the following circumstances, the patent right shall be terminated before the expiration of the time limit:
(1) Failing to pay the annual fee as required;
(2) the patentee renounces his patent right in writing.
if the patent right is terminated before the expiration of the time limit, it shall be registered and announced by the patent administration department of the State Council.