legal ground
Article 18 of the Measures for the Registration of Patent Pledge
Under any of the following circumstances, the parties concerned shall go through the formalities for cancellation of pledge registration in China National Intellectual Property Administration with the Notice of Registration of Patent Pledge and relevant supporting documents: (1) The debtor performs the debt on schedule or the pledger pays off the guaranteed debt in advance; (2) The pledge right has been realized; (3) The pledgee waives the pledge. (4) The pledge contract is invalid or revoked because the main contract is invalid or revoked; (five) other circumstances in which the pledge is extinguished according to law. After receiving the application for cancellation of registration, China National Intellectual Property Administration issued the Notice of Cancellation of Patent Pledge Registration to the parties after examination. The validity of patent pledge registration shall be terminated from the date of cancellation.