1) the invention patent must have a substantive examination stage, because the invention has the longest protection period, so the examination is the most stringent; That is, during the review process, all open technologies (including documents, patents, public meetings, etc.). ) to search, to review the novelty, creativity and practicality of technical content.
2) In principle, there is no substantive examination stage for utility model patents, but in recent years, China National Intellectual Property Administration has strengthened its examination, so it will take out some cases for substantive examination.
3) There is no substantive examination stage for the design patent. If accepted, it will be authorized after the preliminary examination time.