It is recommended that you apply for invention and utility model patents at the same time, because the publication of an invention patent takes about 18 months, and the authorization of a utility model takes about 8 months. If your utility model patent is authorized, you You can find some factories to see if you can discuss cooperation. Then you will have a real product, and then apply for substantive review on the invention patent. The possibility of authorization will increase, and it will also facilitate the manufacturing and sales of your products. In the absence of any doubt, the latest authorization for an invention patent is the third year after application. You have enough time to prepare.