Subordinate patent

You should be talking about applying for a patent on the basis of other people's patent improvement. The subordinate patent is also a patent right, but you can't produce your own patent without the permission of the prior patentee, because when you produce your own patent, you must also adopt the patent of others, which is infringement. Of course, if the prior patentee uses your innovation to produce a product, it is unacceptable and also an infringement.

When you notice that the patent is written, there is a preface and a characteristic part in the claim. The preface describes the existing technology, and the characteristic part is innovation. In fact, the preface and the characteristic part are used to protect the whole. Since the preface is someone else's patented technology, it is of course a subordinate patent, unless you don't need to take advantage of other people's creative labor achievements in the front.