How did invalid patents come into being? What is an invalid patent?

Simple explanation of invalid patent: invalid patent generally refers to a patent that has not been approved or authorized but has been declared invalid or lost its patent right and is no longer protected by patent law for various reasons stipulated by law. Invalidated patents become a kind of free social public resources, and naturally become "well-known public resources" because of their expiration. Invalid patented products are no longer protected. Since the invalid patent has been patented and made public, the re-submitted patent application is not novel. However, an improved invention-creation based on the original patent can be granted a patent right after applying for a patent. 1. What is an invalid patent? Invalid patent generally refers to an invention or patent that has not been authorized or lost due to various reasons stipulated by law and is no longer protected by patent law. Second, how did invalid patents come into being? (a) the patent application documents do not meet the requirements of preliminary examination. After accepting an application for a patent, China National Intellectual Property Administration shall make a preliminary examination on whether the application procedures are complete, whether the documents are complete, whether the instructions conform to the provisions of the patent law, whether the identity of the applicant conforms to the requirements of the patent law, whether the invention theme belongs to the protection scope of the patent law, and whether the application fee is paid. If the above matters do not meet the requirements, the applicant shall be required to make corrections within a specified time limit. If the applicant fails to make corrections within the time limit, his application shall be deemed to have been withdrawn. If it still does not meet the requirements of the patent law after correction, it shall be rejected. Whether it is deemed to be withdrawn or rejected, the patent in the application is invalid. (2) The patent applicant withdraws it after the publication of the application. After preliminary examination, China National Intellectual Property Administration believed that the application for a patent for invention was in conformity with the provisions of the Patent Law, and immediately announced the applicant's invention. The applicant shall request substantive examination within the statutory time limit. Where the applicant fails to request substantive examination, the application shall be deemed to have been withdrawn and become an invalid patent. (3) The patent applicant fails to reply within the time limit without justifiable reasons. If China National Intellectual Property Administration considers that the invention patent does not conform to the provisions of the Patent Law after substantive examination, it shall notify the applicant and ask him to state his opinions or amend his application within a specified time limit. If the applicant fails to reply within the time limit without justifiable reasons, it shall be deemed to have been withdrawn and become an invalid patent.