How long is the examination cycle of patent substance?

1. The time for examining the substance of a patent is uncertain, usually 6- 18 months, which depends on the content of the invention, the examiner's understanding of the invention, the examiner's work arrangement and the time for the documents to travel to and from the applicant or his agent. 2. The patent examination process * * * service does not charge any fees at present. 3. The applicant for a patent for invention may take the initiative to modify the application for a patent for invention within three months from the date of receiving the notice from the Patent Office that the application for a patent for invention has entered the substantive examination stage. According to the Patent Law, the examination and approval procedure of an application for a patent for invention includes five stages: acceptance, preliminary examination, publication, actual examination and authorization. The application for a patent for utility model or design does not undergo early publication and substantive examination in the examination and approval, and there are only three stages: acceptance, preliminary examination and authorization.