Legal analysis: because the invention patent is protected for 20 years and the utility model is protected for 10 years, this period is dead. For various reasons, the application process of each patent is different from acceptance to authorization. If it is counted from the date of authorization, the guarantee time will be different.
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.