Expired patents generally refer to inventions or patents that have not been authorized or have lost patent rights due to various reasons stipulated by law, and are no longer protected by patent laws. So what are the causes of expired patents? Next, Bajie Intellectual Property will take you to understand the relevant knowledge. What are the causes of expired patents? (1) Patent application documents do not meet the preliminary examination requirements. After accepting a patent application, the State Intellectual Property Office must check whether the application procedures are complete, whether the documents are complete, whether the description complies with the provisions of the patent law, whether the identity of the applicant meets the requirements of the patent law, whether the subject matter of the invention falls within the scope of protection of the patent law, and whether The application fee has been paid for preliminary review. (2) The patent applicant withdraws the application after it is published. After preliminary examination, the State Intellectual Property Office determines that the invention patent application complies with the provisions of the Patent Law and will announce the applicant's invention immediately. The applicant should request substantive examination within the statutory period. If the applicant does not request substantive examination, the application will be deemed to have been withdrawn and become an invalid patent. (3) The patent applicant fails to respond within the time limit without justifiable reasons. If the State Intellectual Property Office determines that the invention patent does not comply with the provisions of the Patent Law after conducting a substantive examination, it will notify the applicant and require it to state its opinions within a specified time limit or make modifications to its application. If the applicant fails to respond within the time limit without justifiable reasons, it will be deemed to have been withdrawn and the patent will become invalid. (4) It has not applied for patent protection in my country. Patent rights are territorial, and patent rights granted by a country can only be supported and protected within the areas governed by the laws of that country. If a foreign patent does not apply for patent protection in China within one year, it will not be protected by China's patent law, and the patent will become an invalid patent in China. (5) The patentee fails to pay fees on time. The patentee must fulfill the obligation to pay the patent maintenance fee. If the patentee fails to pay the patent maintenance fee on time without justifiable reasons, the patentee will be deemed to have automatically given up the patent right and the patent will become invalid. (6) The invention patent application was rejected. The national patent administration department believed that the patent applicant's statements and modifications still did not comply with the provisions of the patent law and rejected the patent application. (7) The application is withdrawn before the patent is granted or the patent right is declared invalid. If the applicant withdraws the patent application before the patent right is granted, or after the patent right is granted, other units or individuals discover that the grant of the patent right does not comply with the relevant provisions of the Patent Law, the applicant may request the Patent Reexamination Board to declare the patent right invalid. (8) The patentee voluntarily gives up the patent right. Although some patented technologies are still within the protection period, the patentee has deemed it to be of no use value and is unwilling to continue to assume various obligations for it, so he voluntarily declares his abandonment in writing. (9) The protection period expires. After the authorized patent protection period expires, the patentee no longer enjoys exclusive rights. The patent protection period in my country is 20 years from the date of application.