The approval procedures and cycles for invention patents are different from those for utility models and designs. The approval cycle for invention patents generally takes 3-5 years, and the review and approval cycles for utility models and designs generally take half a year to one year. Invention patents must go through the stages of acceptance, preliminary examination, early disclosure, substantive examination, and authorization announcement. Utility models and designs only go through three stages: acceptance, preliminary examination and authorization announcement. Article 35 of the Patent Law stipulates that within three years from the date of filing of an invention patent application, the patent administration department of the State Council may conduct a substantive examination of the application upon request made by the applicant at any time; if the applicant fails to request a substantive examination beyond the time limit without justifiable reasons, The application is deemed to have been withdrawn. When the patent administration department of the State Council deems it necessary, it may conduct a substantive examination of an invention patent application on its own.