Patent classification of patents

Patents are divided into valid patents and invalid patents according to the ownership of the owner. After an application for a patent is authorized, it is called an invalid patent because it exceeds the statutory protection period, or because the patentee fails to pay the annual patent fee in time, or any individual or unit requests to declare the patent invalid, and it is determined by the Patent Reexamination Board and declared invalid. Invalid patents are no longer binding on the use of the technology involved.