Legal analysis: There is no regulation on the maximum number of times that examination action notices can be sent during the substantive examination stage of an invention patent. When the examiner discovers during the substantive examination stage that the patent application is inconsistent with the provisions of the Patent Law and its Implementing Rules, he or she will issue a notice of examination opinion. If the applicant lodges a complaint with the examiner within the specified time after receiving the notice of examination opinion, If the examiner has answered the questions and made a statement of opinions and obtained the examiner's approval, and the examiner finds no new problems during the follow-up examination, an authorization notice will be issued; but if the examiner finds new problems during the follow-up examination, an authorization notice will be issued. An examination opinion notice will be issued again.
Legal basis: "Patent Law of the People's Republic of China" Article 31 An application for a patent for an invention or utility model shall be limited to one invention or utility model. Two or more inventions or utility models belonging to one general inventive concept can be filed as one application. A design patent application shall be limited to one design. Two or more similar designs for the same product, or two or more designs for products of the same category that are sold or used in sets, can be submitted as one application.